From bd9ec023eefc4b5d26fa8b66c4338e97104f0f96 Mon Sep 17 00:00:00 2001
From: Maze Winther <mazewinther@gmail.com>
Date: Wed, 1 Apr 2026 19:27:49 +0200
Subject: [PATCH] refactor: split constants by domain and isolate timeline
 panel from core

---
 .../editor/panels/assets/views/assets.tsx     |   4 +-
 .../assets/views/settings/background.tsx      |  14 +-
 .../panels/assets/views/settings/index.tsx    |   2 +-
 .../panels/preview/preview-viewport.tsx       |   2 +-
 .../editor/panels/preview/toolbar.tsx         |   2 +-
 .../panels/properties/tabs/speed-tab.tsx      |   2 +-
 .../panels/properties/tabs/text-tab.tsx       |   6 +-
 .../editor/panels/timeline/bookmarks.tsx      |  24 +-
 .../editor/panels/timeline/drag-line.tsx      |   4 +-
 .../editor/panels/timeline/drop-target.ts}    | 508 +++++++++---------
 .../editor/panels/timeline/index.tsx          |  50 +-
 .../editor/panels/timeline/interaction.ts     |   4 +
 .../editor/panels/timeline/layers.ts          |   6 +
 .../editor/panels/timeline/layout.ts          |  16 +
 .../panels}/timeline/selection-hit-testing.ts | 269 +++++-----
 .../editor/panels/timeline/snap-indicator.tsx |   2 +-
 .../editor/panels/timeline/theme.ts           |  29 +
 .../panels/timeline/timeline-element.tsx      |  12 +-
 .../panels/timeline/timeline-playhead.tsx     |   4 +-
 .../editor/panels/timeline/timeline-ruler.tsx |  14 +-
 .../panels/timeline/timeline-toolbar.tsx      |  11 +-
 .../editor/panels/timeline/timeline-track.tsx |   5 +-
 .../editor/panels/timeline/track-layout.ts    |  37 ++
 apps/web/src/core/managers/audio-manager.ts   |   2 +-
 apps/web/src/core/managers/project-manager.ts |  12 +-
 .../element/use-element-interaction.ts        |  27 +-
 .../timeline/element/use-element-resize.ts    |   4 +-
 .../timeline/element/use-keyframe-drag.ts     |  13 +-
 .../src/hooks/timeline/use-bookmark-drag.ts   |   7 +-
 .../timeline/use-snap-indicator-position.ts   |   5 +-
 .../hooks/timeline/use-timeline-drag-drop.ts  |  19 +-
 .../hooks/timeline/use-timeline-playhead.ts   |  10 +-
 .../src/hooks/timeline/use-timeline-seek.ts   |   4 +-
 .../src/hooks/timeline/use-timeline-zoom.ts   |  33 +-
 apps/web/src/hooks/use-paste-media.ts         |   4 +-
 apps/web/src/lib/background/constants.ts      |  11 +
 apps/web/src/lib/canvas/constants.ts          |  10 +
 .../src/lib/commands/media/add-media-asset.ts |   2 +-
 .../timeline/element/insert-element.ts        |   4 +-
 .../element/retime/update-element-retime.ts   |   2 +-
 .../timeline/track/toggle-track-mute.ts       |   4 +-
 .../{project => fps}/__tests__/fps.test.ts    | 130 ++---
 apps/web/src/lib/fps/constants.ts             |   9 +
 .../src/lib/{project/fps.ts => fps/utils.ts}  |  78 +--
 apps/web/src/lib/media/audio.ts               |  12 +-
 apps/web/src/lib/panels/constants.ts          |   9 +
 apps/web/src/lib/preview/constants.ts         |   7 +
 apps/web/src/lib/retime/audio-stretch.ts      |   2 +-
 apps/web/src/lib/retime/index.ts              |   1 +
 apps/web/src/lib/retime/presets.ts            |   2 +-
 .../retime/rate.ts}                           |  55 +-
 apps/web/src/lib/retime/resolve.ts            |   2 +-
 apps/web/src/lib/text/constants.ts            |  12 +
 apps/web/src/lib/timeline/creation.ts         |   1 +
 apps/web/src/lib/timeline/defaults.ts         |   4 +-
 apps/web/src/lib/timeline/drag-utils.ts       |   4 +-
 apps/web/src/lib/timeline/element-utils.ts    |  10 +-
 apps/web/src/lib/timeline/index.ts            |   2 +-
 apps/web/src/lib/timeline/pixel-utils.ts      |   4 +-
 .../lib/timeline/placement/track-factory.ts   |   4 +-
 apps/web/src/lib/timeline/ruler-utils.ts      |   4 +-
 apps/web/src/lib/timeline/scale.ts            |   3 +
 apps/web/src/lib/timeline/snap-utils.ts       |   4 +-
 .../src/lib/timeline/track-capabilities.ts    |  20 +
 apps/web/src/lib/timeline/track-utils.ts      |  62 ---
 apps/web/src/lib/timeline/tracks.ts           |   9 +
 apps/web/src/lib/timeline/zoom-utils.ts       |  15 +-
 .../src/services/renderer/scene-builder.ts    |   5 +-
 .../migrations/__tests__/v1-to-v2.test.ts     |  16 +-
 .../migrations/transformers/v1-to-v2.ts       |  24 +-
 apps/web/src/stores/editor-store.ts           |   2 +-
 apps/web/src/stores/panel-store.ts            |   2 +-
 72 files changed, 939 insertions(+), 775 deletions(-)
 rename apps/web/src/{lib/timeline/drop-utils.ts => components/editor/panels/timeline/drop-target.ts} (87%)
 create mode 100644 apps/web/src/components/editor/panels/timeline/interaction.ts
 create mode 100644 apps/web/src/components/editor/panels/timeline/layers.ts
 create mode 100644 apps/web/src/components/editor/panels/timeline/layout.ts
 rename apps/web/src/{lib => components/editor/panels}/timeline/selection-hit-testing.ts (88%)
 create mode 100644 apps/web/src/components/editor/panels/timeline/theme.ts
 create mode 100644 apps/web/src/components/editor/panels/timeline/track-layout.ts
 create mode 100644 apps/web/src/lib/background/constants.ts
 create mode 100644 apps/web/src/lib/canvas/constants.ts
 rename apps/web/src/lib/{project => fps}/__tests__/fps.test.ts (94%)
 create mode 100644 apps/web/src/lib/fps/constants.ts
 rename apps/web/src/lib/{project/fps.ts => fps/utils.ts} (96%)
 create mode 100644 apps/web/src/lib/panels/constants.ts
 create mode 100644 apps/web/src/lib/preview/constants.ts
 rename apps/web/src/{constants/retime-constants.ts => lib/retime/rate.ts} (74%)
 create mode 100644 apps/web/src/lib/text/constants.ts
 create mode 100644 apps/web/src/lib/timeline/creation.ts
 create mode 100644 apps/web/src/lib/timeline/scale.ts
 create mode 100644 apps/web/src/lib/timeline/track-capabilities.ts
 delete mode 100644 apps/web/src/lib/timeline/track-utils.ts
 create mode 100644 apps/web/src/lib/timeline/tracks.ts

diff --git a/apps/web/src/components/editor/panels/assets/views/assets.tsx b/apps/web/src/components/editor/panels/assets/views/assets.tsx
index e17e4d4a..031d2e6a 100644
--- a/apps/web/src/components/editor/panels/assets/views/assets.tsx
+++ b/apps/web/src/components/editor/panels/assets/views/assets.tsx
@@ -25,7 +25,7 @@ import {
 	TooltipProvider,
 	TooltipTrigger,
 } from "@/components/ui/tooltip";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
 import { useEditor } from "@/hooks/use-editor";
 import { useFileUpload } from "@/hooks/use-file-upload";
 import { invokeAction } from "@/lib/actions";
@@ -257,7 +257,7 @@ function MediaAssetDraggable({
 		startTime: number;
 	}) => {
 		const duration =
-			asset.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+			asset.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 		const element = buildElementFromMedia({
 			mediaId: asset.id,
 			mediaType: asset.type,
diff --git a/apps/web/src/components/editor/panels/assets/views/settings/background.tsx b/apps/web/src/components/editor/panels/assets/views/settings/background.tsx
index 7a81188f..bbceac7d 100644
--- a/apps/web/src/components/editor/panels/assets/views/settings/background.tsx
+++ b/apps/web/src/components/editor/panels/assets/views/settings/background.tsx
@@ -8,10 +8,10 @@ import {
 	SectionTitle,
 } from "@/components/section";
 import {
-	BLUR_INTENSITY_PRESETS,
-	DEFAULT_BLUR_INTENSITY,
-	DEFAULT_COLOR,
-} from "@/constants/project-constants";
+	BACKGROUND_BLUR_INTENSITY_PRESETS,
+	DEFAULT_BACKGROUND_BLUR_INTENSITY,
+	DEFAULT_BACKGROUND_COLOR,
+} from "@/lib/background/constants";
 import { patternCraftGradients } from "@/data/colors/pattern-craft";
 import { colors } from "@/data/colors/solid";
 import { syntaxUIGradients } from "@/data/colors/syntax-ui";
@@ -164,16 +164,16 @@ export function BackgroundContent() {
 	const currentBlurIntensity = isBlurBackground
 		? (activeProject.settings.background as { blurIntensity: number })
 				.blurIntensity
-		: DEFAULT_BLUR_INTENSITY;
+		: DEFAULT_BACKGROUND_BLUR_INTENSITY;
 
 	const currentBackgroundColor = isColorBackground
 		? (activeProject.settings.background as { color: string }).color
-		: DEFAULT_COLOR;
+		: DEFAULT_BACKGROUND_COLOR;
 	const canvasSize = activeProject.settings.canvasSize;
 
 	const blurPreviews = useMemo(
 		() =>
-			BLUR_INTENSITY_PRESETS.map((blur) => (
+			BACKGROUND_BLUR_INTENSITY_PRESETS.map((blur) => (
 				<BlurPreview
 					key={blur.value}
 					blur={blur}
diff --git a/apps/web/src/components/editor/panels/assets/views/settings/index.tsx b/apps/web/src/components/editor/panels/assets/views/settings/index.tsx
index 1526a842..6c819a36 100644
--- a/apps/web/src/components/editor/panels/assets/views/settings/index.tsx
+++ b/apps/web/src/components/editor/panels/assets/views/settings/index.tsx
@@ -9,7 +9,7 @@ import {
 	SelectTrigger,
 	SelectValue,
 } from "@/components/ui/select";
-import { FPS_PRESETS } from "@/constants/project-constants";
+import { FPS_PRESETS } from "@/lib/fps/constants";
 import { useEditor } from "@/hooks/use-editor";
 import {
 	Section,
diff --git a/apps/web/src/components/editor/panels/preview/preview-viewport.tsx b/apps/web/src/components/editor/panels/preview/preview-viewport.tsx
index 8fd38768..51e5d2d0 100644
--- a/apps/web/src/components/editor/panels/preview/preview-viewport.tsx
+++ b/apps/web/src/components/editor/panels/preview/preview-viewport.tsx
@@ -17,7 +17,7 @@ import {
 	screenToCanvas,
 } from "@/lib/preview/preview-coords";
 import { clamp, isNearlyEqual } from "@/utils/math";
-import { PREVIEW_ZOOM } from "@/constants/editor-constants";
+import { PREVIEW_ZOOM } from "@/lib/preview/constants";
 
 const MIDDLE_MOUSE_BUTTON = 1;
 const IS_AT_FIT_EPSILON = 0.001;
diff --git a/apps/web/src/components/editor/panels/preview/toolbar.tsx b/apps/web/src/components/editor/panels/preview/toolbar.tsx
index 340058d0..0be1ec46 100644
--- a/apps/web/src/components/editor/panels/preview/toolbar.tsx
+++ b/apps/web/src/components/editor/panels/preview/toolbar.tsx
@@ -22,7 +22,7 @@ import {
 	SelectItem,
 	SelectSeparator,
 } from "@/components/ui/select";
-import { PREVIEW_ZOOM_PRESETS } from "@/constants/editor-constants";
+import { PREVIEW_ZOOM_PRESETS } from "@/lib/preview/constants";
 import { usePreviewViewport } from "./preview-viewport";
 import { GridPopover } from "./guide-popover";
 import { usePreviewStore } from "@/stores/preview-store";
diff --git a/apps/web/src/components/editor/panels/properties/tabs/speed-tab.tsx b/apps/web/src/components/editor/panels/properties/tabs/speed-tab.tsx
index da86c626..cb10aac3 100644
--- a/apps/web/src/components/editor/panels/properties/tabs/speed-tab.tsx
+++ b/apps/web/src/components/editor/panels/properties/tabs/speed-tab.tsx
@@ -11,7 +11,7 @@ import {
 	MAX_RETIME_RATE,
 	clampRetimeRate,
 	canMaintainPitch,
-} from "@/constants/retime-constants";
+} from "@/lib/retime/rate";
 import type { AudioElement, VideoElement } from "@/lib/timeline";
 import {
 	Section,
diff --git a/apps/web/src/components/editor/panels/properties/tabs/text-tab.tsx b/apps/web/src/components/editor/panels/properties/tabs/text-tab.tsx
index 4c58023b..11412c04 100644
--- a/apps/web/src/components/editor/panels/properties/tabs/text-tab.tsx
+++ b/apps/web/src/components/editor/panels/properties/tabs/text-tab.tsx
@@ -18,13 +18,13 @@ import { Button } from "@/components/ui/button";
 import { uppercase } from "@/utils/string";
 import { clamp, formatNumberForDisplay } from "@/utils/math";
 import { useEditor } from "@/hooks/use-editor";
-import { DEFAULT_COLOR } from "@/constants/project-constants";
 import {
 	CORNER_RADIUS_MAX,
+	DEFAULT_TEXT_COLOR,
 	CORNER_RADIUS_MIN,
 	MAX_FONT_SIZE,
 	MIN_FONT_SIZE,
-} from "@/constants/text-constants";
+} from "@/lib/text/constants";
 import { usePropertyDraft } from "../hooks/use-property-draft";
 import { useKeyframedColorProperty } from "../hooks/use-keyframed-color-property";
 import { useKeyframedNumberProperty } from "../hooks/use-keyframed-number-property";
@@ -343,7 +343,7 @@ function BackgroundSection({
 	trackId: string;
 }) {
 	const editor = useEditor();
-	const lastSelectedColor = useRef(DEFAULT_COLOR);
+	const lastSelectedColor = useRef(DEFAULT_TEXT_COLOR);
 	const { localTime, isPlayheadWithinElementRange } = useElementPlayhead({
 		startTime: element.startTime,
 		duration: element.duration,
diff --git a/apps/web/src/components/editor/panels/timeline/bookmarks.tsx b/apps/web/src/components/editor/panels/timeline/bookmarks.tsx
index e2dc09f1..d4b1657e 100644
--- a/apps/web/src/components/editor/panels/timeline/bookmarks.tsx
+++ b/apps/web/src/components/editor/panels/timeline/bookmarks.tsx
@@ -6,10 +6,10 @@ import { useEditor } from "@/hooks/use-editor";
 import type { BookmarkDragState } from "@/hooks/timeline/use-bookmark-drag";
 import { BOOKMARK_TIME_EPSILON } from "@/lib/timeline/bookmarks";
 import {
-	DEFAULT_BOOKMARK_COLOR,
-	TIMELINE_BOOKMARK_ROW_HEIGHT,
-} from "@/constants/timeline-constants";
-import { DEFAULT_FPS } from "@/constants/project-constants";
+	DEFAULT_TIMELINE_BOOKMARK_COLOR,
+} from "./theme";
+import { TIMELINE_BOOKMARK_ROW_HEIGHT_PX } from "./layout";
+import { DEFAULT_FPS } from "@/lib/fps/constants";
 import { getSnappedSeekTime } from "opencut-wasm";
 import {
 	ArrowTurnBackwardIcon,
@@ -83,12 +83,12 @@ export function TimelineBookmarksRow({
 	return (
 		<div
 			className="relative flex-1 overflow-hidden"
-			style={{ height: TIMELINE_BOOKMARK_ROW_HEIGHT }}
+			style={{ height: TIMELINE_BOOKMARK_ROW_HEIGHT_PX }}
 		>
 			<button
 				className="relative w-full cursor-default select-none border-0 bg-transparent p-0"
 				style={{
-					height: TIMELINE_BOOKMARK_ROW_HEIGHT,
+					height: TIMELINE_BOOKMARK_ROW_HEIGHT_PX,
 					width: `${dynamicTimelineWidth}px`,
 				}}
 				aria-label="Timeline ruler"
@@ -153,7 +153,7 @@ function TimelineBookmark({
 	const left = timelineTimeToSnappedPixels({ time: displayTime, zoomLevel });
 	const bookmarkLeft = left - BOOKMARK_HALF_WIDTH_PX;
 	const rightHalfLeft = BOOKMARK_HALF_WIDTH_PX + Math.max(durationWidth, 0);
-	const iconColor = bookmark.color ?? DEFAULT_BOOKMARK_COLOR;
+	const iconColor = bookmark.color ?? DEFAULT_TIMELINE_BOOKMARK_COLOR;
 
 	const handleSeek = () => seekToBookmarkTime({ editor, time });
 
@@ -298,12 +298,16 @@ function BookmarkPopoverContent({
 }) {
 	const editor = useEditor();
 	const [draftColorHex, setDraftColorHex] = useState(
-		(bookmark.color ?? DEFAULT_BOOKMARK_COLOR).replace("#", "").toUpperCase(),
+		(bookmark.color ?? DEFAULT_TIMELINE_BOOKMARK_COLOR)
+			.replace("#", "")
+			.toUpperCase(),
 	);
 
 	useEffect(() => {
 		setDraftColorHex(
-			(bookmark.color ?? DEFAULT_BOOKMARK_COLOR).replace("#", "").toUpperCase(),
+			(bookmark.color ?? DEFAULT_TIMELINE_BOOKMARK_COLOR)
+				.replace("#", "")
+				.toUpperCase(),
 		);
 	}, [bookmark.color]);
 
@@ -357,7 +361,7 @@ function BookmarkPopoverContent({
 					/>
 					{bookmark.color &&
 						bookmark.color.replace(/^#/, "").toUpperCase() !==
-							DEFAULT_BOOKMARK_COLOR.replace(/^#/, "").toUpperCase() && (
+							DEFAULT_TIMELINE_BOOKMARK_COLOR.replace(/^#/, "").toUpperCase() && (
 							<Button
 								type="button"
 								variant="text"
diff --git a/apps/web/src/components/editor/panels/timeline/drag-line.tsx b/apps/web/src/components/editor/panels/timeline/drag-line.tsx
index a5a145b4..89a4c93f 100644
--- a/apps/web/src/components/editor/panels/timeline/drag-line.tsx
+++ b/apps/web/src/components/editor/panels/timeline/drag-line.tsx
@@ -1,6 +1,6 @@
-import { getDropLineY } from "@/lib/timeline/drop-utils";
+import { getDropLineY } from "./drop-target";
 import type { TimelineTrack, DropTarget } from "@/lib/timeline";
-import { TIMELINE_LAYERS } from "@/constants/timeline-constants";
+import { TIMELINE_LAYERS } from "./layers";
 
 interface DragLineProps {
 	dropTarget: DropTarget | null;
diff --git a/apps/web/src/lib/timeline/drop-utils.ts b/apps/web/src/components/editor/panels/timeline/drop-target.ts
similarity index 87%
rename from apps/web/src/lib/timeline/drop-utils.ts
rename to apps/web/src/components/editor/panels/timeline/drop-target.ts
index 161d2714..dbd4efaf 100644
--- a/apps/web/src/lib/timeline/drop-utils.ts
+++ b/apps/web/src/components/editor/panels/timeline/drop-target.ts
@@ -1,257 +1,251 @@
-import type {
-	TimelineTrack,
-	TimelineElement,
-} from "@/lib/timeline";
-import { TRACK_CONFIG, TRACK_GAP } from "@/constants/timeline-constants";
-import type { ComputeDropTargetParams, DropTarget } from "@/lib/timeline";
-import { resolveTrackPlacement } from "@/lib/timeline/placement";
-
-function findElementAtPosition({
-	mouseX,
-	tracks,
-	trackIndex,
-	targetElementTypes,
-	pixelsPerSecond,
-	zoomLevel,
-}: {
-	mouseX: number;
-	tracks: TimelineTrack[];
-	trackIndex: number;
-	targetElementTypes: string[];
-	pixelsPerSecond: number;
-	zoomLevel: number;
-}): { elementId: string; trackId: string } | null {
-	const time = mouseX / (pixelsPerSecond * zoomLevel);
-	const track = tracks[trackIndex];
-	if (!track || !("elements" in track)) return null;
-
-	const hit = track.elements.find(
-		(element: TimelineElement) =>
-			targetElementTypes.includes(element.type) &&
-			element.startTime <= time &&
-			time < element.startTime + element.duration,
-	);
-	if (!hit) return null;
-	return { elementId: hit.id, trackId: track.id };
-}
-
-function getTrackAtY({
-	mouseY,
-	tracks,
-	verticalDragDirection,
-}: {
-	mouseY: number;
-	tracks: TimelineTrack[];
-	verticalDragDirection?: "up" | "down" | null;
-}): { trackIndex: number; relativeY: number } | null {
-	let cumulativeHeight = 0;
-
-	for (let i = 0; i < tracks.length; i++) {
-		const trackHeight = TRACK_CONFIG[tracks[i].type].height;
-		const trackTop = cumulativeHeight;
-		const trackBottom = trackTop + trackHeight;
-
-		if (mouseY >= trackTop && mouseY < trackBottom) {
-			return {
-				trackIndex: i,
-				relativeY: mouseY - trackTop,
-			};
-		}
-
-		if (i < tracks.length - 1 && verticalDragDirection) {
-			const gapTop = trackBottom;
-			const gapBottom = gapTop + TRACK_GAP;
-			if (mouseY >= gapTop && mouseY < gapBottom) {
-				const isDraggingUp = verticalDragDirection === "up";
-				return {
-					trackIndex: isDraggingUp ? i : i + 1,
-					relativeY: isDraggingUp ? trackHeight - 1 : 0,
-				};
-			}
-		}
-
-		cumulativeHeight += trackHeight + TRACK_GAP;
-	}
-
-	return null;
-}
-
-const EMPTY_TARGET_ELEMENT = null;
-
-function fallbackNewTrackDropTarget({
-	xPosition,
-}: {
-	xPosition: number;
-}): DropTarget {
-	return {
-		trackIndex: 0,
-		isNewTrack: true,
-		insertPosition: null,
-		xPosition,
-		targetElement: EMPTY_TARGET_ELEMENT,
-	};
-}
-
-export function computeDropTarget({
-	elementType,
-	mouseX,
-	mouseY,
-	tracks,
-	playheadTime,
-	isExternalDrop,
-	elementDuration,
-	pixelsPerSecond,
-	zoomLevel,
-	verticalDragDirection,
-	startTimeOverride,
-	excludeElementId,
-	targetElementTypes,
-}: ComputeDropTargetParams): DropTarget {
-	const xPosition =
-		typeof startTimeOverride === "number"
-			? startTimeOverride
-			: isExternalDrop
-				? playheadTime
-				: Math.max(0, mouseX / (pixelsPerSecond * zoomLevel));
-
-	if (tracks.length === 0) {
-		const placementResult = resolveTrackPlacement({
-			tracks,
-			elementType,
-			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
-			strategy: {
-				type: "preferIndex",
-				trackIndex: 0,
-				hoverDirection: "below",
-				createNewTrackOnly: true,
-			},
-		});
-		const emptyTimelineResult =
-			placementResult?.kind === "newTrack" ? placementResult : null;
-		if (!emptyTimelineResult) {
-			return fallbackNewTrackDropTarget({ xPosition });
-		}
-
-		return {
-			trackIndex: emptyTimelineResult.insertIndex,
-			isNewTrack: true,
-			insertPosition: emptyTimelineResult.insertPosition,
-			xPosition,
-			targetElement: EMPTY_TARGET_ELEMENT,
-		};
-	}
-
-	const trackAtMouse = getTrackAtY({ mouseY, tracks, verticalDragDirection });
-
-	if (!trackAtMouse) {
-		const isAboveAllTracks = mouseY < 0;
-
-		const placementResult = resolveTrackPlacement({
-			tracks,
-			elementType,
-			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
-			strategy: {
-				type: "preferIndex",
-				trackIndex: isAboveAllTracks ? 0 : tracks.length - 1,
-				hoverDirection: isAboveAllTracks ? "above" : "below",
-				createNewTrackOnly: true,
-			},
-		});
-		const outOfBoundsResult =
-			placementResult?.kind === "newTrack" ? placementResult : null;
-		if (!outOfBoundsResult) {
-			return fallbackNewTrackDropTarget({ xPosition });
-		}
-
-		return {
-			trackIndex: outOfBoundsResult.insertIndex,
-			isNewTrack: true,
-			insertPosition: outOfBoundsResult.insertPosition,
-			xPosition,
-			targetElement: EMPTY_TARGET_ELEMENT,
-		};
-	}
-
-	const { trackIndex, relativeY } = trackAtMouse;
-	const track = tracks[trackIndex];
-
-	if (
-		targetElementTypes &&
-		targetElementTypes.length > 0
-	) {
-		const targetElement = findElementAtPosition({
-			mouseX,
-			tracks,
-			trackIndex,
-			targetElementTypes,
-			pixelsPerSecond,
-			zoomLevel,
-		});
-		if (targetElement) {
-			return {
-				trackIndex,
-				isNewTrack: false,
-				insertPosition: null,
-				xPosition,
-				targetElement,
-			};
-		}
-	}
-
-	const trackHeight = TRACK_CONFIG[track.type].height;
-	const placementResult = resolveTrackPlacement({
-		tracks,
-		elementType,
-		timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
-		strategy: {
-			type: "preferIndex",
-			trackIndex,
-			hoverDirection: relativeY < trackHeight / 2 ? "above" : "below",
-			verticalDragDirection,
-		},
-	});
-	if (!placementResult) {
-		return fallbackNewTrackDropTarget({ xPosition });
-	}
-
-	if (placementResult.kind === "existingTrack") {
-		const adjustedXPosition =
-			placementResult.adjustedStartTime ?? xPosition;
-
-		return {
-			trackIndex: placementResult.trackIndex,
-			isNewTrack: false,
-			insertPosition: null,
-			xPosition: adjustedXPosition,
-			targetElement: EMPTY_TARGET_ELEMENT,
-		};
-	}
-
-	return {
-		trackIndex: placementResult.insertIndex,
-		isNewTrack: true,
-		insertPosition: placementResult.insertPosition,
-		xPosition,
-		targetElement: EMPTY_TARGET_ELEMENT,
-	};
-}
-
-export function getDropLineY({
-	dropTarget,
-	tracks,
-}: {
-	dropTarget: DropTarget;
-	tracks: TimelineTrack[];
-}): number {
-	const safeTrackIndex = Math.min(
-		Math.max(dropTarget.trackIndex, 0),
-		tracks.length,
-	);
-	let y = 0;
-
-	for (let i = 0; i < safeTrackIndex; i++) {
-		y += TRACK_CONFIG[tracks[i].type].height + TRACK_GAP;
-	}
-
-	return y;
-}
+import type { TimelineTrack, TimelineElement } from "@/lib/timeline";
+import type { ComputeDropTargetParams, DropTarget } from "@/lib/timeline";
+import { resolveTrackPlacement } from "@/lib/timeline/placement";
+import { TIMELINE_TRACK_GAP_PX } from "./layout";
+import { getTrackHeight } from "./track-layout";
+
+function findElementAtPosition({
+	mouseX,
+	tracks,
+	trackIndex,
+	targetElementTypes,
+	pixelsPerSecond,
+	zoomLevel,
+}: {
+	mouseX: number;
+	tracks: TimelineTrack[];
+	trackIndex: number;
+	targetElementTypes: string[];
+	pixelsPerSecond: number;
+	zoomLevel: number;
+}): { elementId: string; trackId: string } | null {
+	const time = mouseX / (pixelsPerSecond * zoomLevel);
+	const track = tracks[trackIndex];
+	if (!track || !("elements" in track)) return null;
+
+	const hit = track.elements.find(
+		(element: TimelineElement) =>
+			targetElementTypes.includes(element.type) &&
+			element.startTime <= time &&
+			time < element.startTime + element.duration,
+	);
+	if (!hit) return null;
+	return { elementId: hit.id, trackId: track.id };
+}
+
+function getTrackAtY({
+	mouseY,
+	tracks,
+	verticalDragDirection,
+}: {
+	mouseY: number;
+	tracks: TimelineTrack[];
+	verticalDragDirection?: "up" | "down" | null;
+}): { trackIndex: number; relativeY: number } | null {
+	let cumulativeHeight = 0;
+
+	for (let i = 0; i < tracks.length; i++) {
+		const trackHeight = getTrackHeight({ type: tracks[i].type });
+		const trackTop = cumulativeHeight;
+		const trackBottom = trackTop + trackHeight;
+
+		if (mouseY >= trackTop && mouseY < trackBottom) {
+			return {
+				trackIndex: i,
+				relativeY: mouseY - trackTop,
+			};
+		}
+
+		if (i < tracks.length - 1 && verticalDragDirection) {
+			const gapTop = trackBottom;
+			const gapBottom = gapTop + TIMELINE_TRACK_GAP_PX;
+			if (mouseY >= gapTop && mouseY < gapBottom) {
+				const isDraggingUp = verticalDragDirection === "up";
+				return {
+					trackIndex: isDraggingUp ? i : i + 1,
+					relativeY: isDraggingUp ? trackHeight - 1 : 0,
+				};
+			}
+		}
+
+		cumulativeHeight += trackHeight + TIMELINE_TRACK_GAP_PX;
+	}
+
+	return null;
+}
+
+const EMPTY_TARGET_ELEMENT = null;
+
+function fallbackNewTrackDropTarget({
+	xPosition,
+}: {
+	xPosition: number;
+}): DropTarget {
+	return {
+		trackIndex: 0,
+		isNewTrack: true,
+		insertPosition: null,
+		xPosition,
+		targetElement: EMPTY_TARGET_ELEMENT,
+	};
+}
+
+export function computeDropTarget({
+	elementType,
+	mouseX,
+	mouseY,
+	tracks,
+	playheadTime,
+	isExternalDrop,
+	elementDuration,
+	pixelsPerSecond,
+	zoomLevel,
+	verticalDragDirection,
+	startTimeOverride,
+	excludeElementId,
+	targetElementTypes,
+}: ComputeDropTargetParams): DropTarget {
+	const xPosition =
+		typeof startTimeOverride === "number"
+			? startTimeOverride
+			: isExternalDrop
+				? playheadTime
+				: Math.max(0, mouseX / (pixelsPerSecond * zoomLevel));
+
+	if (tracks.length === 0) {
+		const placementResult = resolveTrackPlacement({
+			tracks,
+			elementType,
+			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+			strategy: {
+				type: "preferIndex",
+				trackIndex: 0,
+				hoverDirection: "below",
+				createNewTrackOnly: true,
+			},
+		});
+		const emptyTimelineResult =
+			placementResult?.kind === "newTrack" ? placementResult : null;
+		if (!emptyTimelineResult) {
+			return fallbackNewTrackDropTarget({ xPosition });
+		}
+
+		return {
+			trackIndex: emptyTimelineResult.insertIndex,
+			isNewTrack: true,
+			insertPosition: emptyTimelineResult.insertPosition,
+			xPosition,
+			targetElement: EMPTY_TARGET_ELEMENT,
+		};
+	}
+
+	const trackAtMouse = getTrackAtY({ mouseY, tracks, verticalDragDirection });
+
+	if (!trackAtMouse) {
+		const isAboveAllTracks = mouseY < 0;
+
+		const placementResult = resolveTrackPlacement({
+			tracks,
+			elementType,
+			timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+			strategy: {
+				type: "preferIndex",
+				trackIndex: isAboveAllTracks ? 0 : tracks.length - 1,
+				hoverDirection: isAboveAllTracks ? "above" : "below",
+				createNewTrackOnly: true,
+			},
+		});
+		const outOfBoundsResult =
+			placementResult?.kind === "newTrack" ? placementResult : null;
+		if (!outOfBoundsResult) {
+			return fallbackNewTrackDropTarget({ xPosition });
+		}
+
+		return {
+			trackIndex: outOfBoundsResult.insertIndex,
+			isNewTrack: true,
+			insertPosition: outOfBoundsResult.insertPosition,
+			xPosition,
+			targetElement: EMPTY_TARGET_ELEMENT,
+		};
+	}
+
+	const { trackIndex, relativeY } = trackAtMouse;
+	const track = tracks[trackIndex];
+
+	if (targetElementTypes && targetElementTypes.length > 0) {
+		const targetElement = findElementAtPosition({
+			mouseX,
+			tracks,
+			trackIndex,
+			targetElementTypes,
+			pixelsPerSecond,
+			zoomLevel,
+		});
+		if (targetElement) {
+			return {
+				trackIndex,
+				isNewTrack: false,
+				insertPosition: null,
+				xPosition,
+				targetElement,
+			};
+		}
+	}
+
+	const trackHeight = getTrackHeight({ type: track.type });
+	const placementResult = resolveTrackPlacement({
+		tracks,
+		elementType,
+		timeSpans: [{ startTime: xPosition, duration: elementDuration, excludeElementId }],
+		strategy: {
+			type: "preferIndex",
+			trackIndex,
+			hoverDirection: relativeY < trackHeight / 2 ? "above" : "below",
+			verticalDragDirection,
+		},
+	});
+	if (!placementResult) {
+		return fallbackNewTrackDropTarget({ xPosition });
+	}
+
+	if (placementResult.kind === "existingTrack") {
+		const adjustedXPosition = placementResult.adjustedStartTime ?? xPosition;
+
+		return {
+			trackIndex: placementResult.trackIndex,
+			isNewTrack: false,
+			insertPosition: null,
+			xPosition: adjustedXPosition,
+			targetElement: EMPTY_TARGET_ELEMENT,
+		};
+	}
+
+	return {
+		trackIndex: placementResult.insertIndex,
+		isNewTrack: true,
+		insertPosition: placementResult.insertPosition,
+		xPosition,
+		targetElement: EMPTY_TARGET_ELEMENT,
+	};
+}
+
+export function getDropLineY({
+	dropTarget,
+	tracks,
+}: {
+	dropTarget: DropTarget;
+	tracks: TimelineTrack[];
+}): number {
+	const safeTrackIndex = Math.min(
+		Math.max(dropTarget.trackIndex, 0),
+		tracks.length,
+	);
+	let y = 0;
+
+	for (let i = 0; i < safeTrackIndex; i++) {
+		y += getTrackHeight({ type: tracks[i].type }) + TIMELINE_TRACK_GAP_PX;
+	}
+
+	return y;
+}
diff --git a/apps/web/src/components/editor/panels/timeline/index.tsx b/apps/web/src/components/editor/panels/timeline/index.tsx
index 819413e6..4114ae2c 100644
--- a/apps/web/src/components/editor/panels/timeline/index.tsx
+++ b/apps/web/src/components/editor/panels/timeline/index.tsx
@@ -38,20 +38,26 @@ import { SnapIndicator } from "./snap-indicator";
 import type { SnapPoint } from "@/lib/timeline/snap-utils";
 import type { TimelineTrack } from "@/lib/timeline";
 import {
-	TIMELINE_CONSTANTS,
-	TRACK_GAP,
 	TIMELINE_SCROLLBAR_SIZE_PX,
-} from "@/constants/timeline-constants";
+	TIMELINE_CONTENT_TOP_PADDING_PX,
+	TIMELINE_TRACK_GAP_PX,
+	TIMELINE_TRACK_LABELS_COLUMN_WIDTH_PX,
+} from "./layout";
 import { useElementInteraction } from "@/hooks/timeline/element/use-element-interaction";
 import {
-	getTrackHeight,
-	getCumulativeHeightBefore,
-	getTotalTracksHeight,
-	canTracktHaveAudio,
+	canTrackHaveAudio,
 	canTrackBeHidden,
 	getTimelineZoomMin,
 	getTimelinePaddingPx,
 } from "@/lib/timeline";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
+import {
+	getTrackHeight,
+	getCumulativeHeightBefore,
+	getTotalTracksHeight,
+} from "./track-layout";
+import { SELECTED_TRACK_ROW_CLASS } from "./theme";
+import { TIMELINE_HORIZONTAL_WHEEL_STEP_PX } from "./interaction";
 import { isMainTrack } from "@/lib/timeline/placement";
 import { TimelineToolbar } from "./timeline-toolbar";
 import { useElementSelection } from "@/hooks/timeline/element/use-element-selection";
@@ -67,7 +73,7 @@ import { useEditor } from "@/hooks/use-editor";
 import { useTimelinePlayhead } from "@/hooks/timeline/use-timeline-playhead";
 import { DragLine } from "./drag-line";
 import { invokeAction } from "@/lib/actions";
-import { resolveTimelineElementIntersections } from "@/lib/timeline/selection-hit-testing";
+import { resolveTimelineElementIntersections } from "./selection-hit-testing";
 import { cn } from "@/utils/ui";
 
 const TRACKS_CONTAINER_MAX_HEIGHT = 800;
@@ -230,7 +236,7 @@ export function Timeline() {
 					Math.abs(e.deltaX) > Math.abs(e.deltaY) ? e.deltaX : e.deltaY;
 				const clamped =
 					Math.sign(raw) *
-					Math.min(Math.abs(raw), TIMELINE_CONSTANTS.HORIZONTAL_WHEEL_STEP_PX);
+					Math.min(Math.abs(raw), TIMELINE_HORIZONTAL_WHEEL_STEP_PX);
 				tracks.scrollLeft = Math.max(0, tracks.scrollLeft + clamped);
 			} else {
 				tracks.scrollTop = Math.max(0, tracks.scrollTop + e.deltaY);
@@ -335,7 +341,7 @@ export function Timeline() {
 	const containerWidth =
 		tracksContainerRef.current?.clientWidth || FALLBACK_CONTAINER_WIDTH;
 	const contentWidth =
-		timelineDuration * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+		timelineDuration * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 	const paddingPx = getTimelinePaddingPx({
 		containerWidth,
 		zoomLevel,
@@ -383,7 +389,7 @@ export function Timeline() {
 
 	const timelineHeaderHeight =
 		(timelineHeaderRef.current?.getBoundingClientRect().height ?? 0) +
-			TIMELINE_CONSTANTS.PADDING_TOP_PX || 0;
+			TIMELINE_CONTENT_TOP_PADDING_PX || 0;
 
 	return (
 		<section
@@ -483,7 +489,7 @@ export function Timeline() {
 												TRACKS_CONTAINER_HEIGHT.max,
 												getTotalTracksHeight({ tracks }),
 											),
-										) + TIMELINE_CONSTANTS.PADDING_TOP_PX
+										) + TIMELINE_CONTENT_TOP_PADDING_PX
 									}px`,
 								}}
 								onMouseDown={(event) => {
@@ -577,7 +583,10 @@ function TrackLabelsPanel({
 	);
 
 	return (
-		<div className="flex w-28 shrink-0 flex-col border-r">
+		<div
+			className="flex shrink-0 flex-col border-r"
+			style={{ width: `${TIMELINE_TRACK_LABELS_COLUMN_WIDTH_PX}px` }}
+		>
 			<div
 				className="shrink-0"
 				style={{ height: timelineHeaderHeight || 48 }}
@@ -585,21 +594,24 @@ function TrackLabelsPanel({
 			<div ref={trackLabelsRef} className="flex-1 overflow-hidden">
 				<div ref={trackLabelsScrollRef} className="size-full overflow-hidden">
 					{tracks.length > 0 && (
-						<div className="flex flex-col" style={{ gap: `${TRACK_GAP}px` }}>
+						<div
+							className="flex flex-col"
+							style={{ gap: `${TIMELINE_TRACK_GAP_PX}px` }}
+						>
 							{tracks.map((track) => (
 								<div
 									key={track.id}
 									className={cn(
 										"group flex items-center px-3",
 										tracksWithSelection.has(track.id) &&
-											TIMELINE_CONSTANTS.TRACK_SELECTED_BG,
+											SELECTED_TRACK_ROW_CLASS,
 									)}
 									style={{
 										height: `${getTrackHeight({ type: track.type })}px`,
 									}}
 								>
 									<div className="flex min-w-0 flex-1 items-center justify-end gap-2">
-										{canTracktHaveAudio(track) && (
+										{canTrackHaveAudio(track) && (
 											<TrackToggleIcon
 												isOff={track.muted}
 												icons={{ on: VolumeHighIcon, off: VolumeOffIcon }}
@@ -707,10 +719,10 @@ function TimelineTrackRows({
 							className={cn(
 								"absolute right-0 left-0 transition-colors",
 								tracksWithSelection.has(track.id) &&
-									TIMELINE_CONSTANTS.TRACK_SELECTED_BG,
+									SELECTED_TRACK_ROW_CLASS,
 							)}
 							style={{
-								top: `${TIMELINE_CONSTANTS.PADDING_TOP_PX + getCumulativeHeightBefore({ tracks, trackIndex: index })}px`,
+								top: `${TIMELINE_CONTENT_TOP_PADDING_PX + getCumulativeHeightBefore({ tracks, trackIndex: index })}px`,
 								height: `${getTrackHeight({ type: track.type })}px`,
 							}}
 						>
@@ -753,7 +765,7 @@ function TimelineTrackRows({
 								timeline.toggleTrackMute({ trackId: track.id });
 							}}
 						>
-							{canTracktHaveAudio(track) && track.muted
+							{canTrackHaveAudio(track) && track.muted
 								? "Unmute track"
 								: "Mute track"}
 						</ContextMenuItem>
diff --git a/apps/web/src/components/editor/panels/timeline/interaction.ts b/apps/web/src/components/editor/panels/timeline/interaction.ts
new file mode 100644
index 00000000..fe0210a4
--- /dev/null
+++ b/apps/web/src/components/editor/panels/timeline/interaction.ts
@@ -0,0 +1,4 @@
+export const TIMELINE_DRAG_THRESHOLD_PX = 5;
+export const TIMELINE_HORIZONTAL_WHEEL_STEP_PX = 40;
+export const TIMELINE_ZOOM_BUTTON_FACTOR = 1.7;
+export const TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD = 0.15;
diff --git a/apps/web/src/components/editor/panels/timeline/layers.ts b/apps/web/src/components/editor/panels/timeline/layers.ts
new file mode 100644
index 00000000..d59db412
--- /dev/null
+++ b/apps/web/src/components/editor/panels/timeline/layers.ts
@@ -0,0 +1,6 @@
+export const TIMELINE_LAYERS = {
+	trackContent: 10,
+	dragLine: 20,
+	playhead: 30,
+	snapIndicator: 40,
+} as const;
diff --git a/apps/web/src/components/editor/panels/timeline/layout.ts b/apps/web/src/components/editor/panels/timeline/layout.ts
new file mode 100644
index 00000000..88443797
--- /dev/null
+++ b/apps/web/src/components/editor/panels/timeline/layout.ts
@@ -0,0 +1,16 @@
+import type { TrackType } from "@/lib/timeline";
+
+export const TIMELINE_TRACK_HEIGHTS_PX: Record<TrackType, number> = {
+	video: 65,
+	text: 25,
+	audio: 50,
+	graphic: 25,
+	effect: 25,
+} as const;
+
+export const TIMELINE_TRACK_GAP_PX = 6;
+export const TIMELINE_TRACK_LABELS_COLUMN_WIDTH_PX = 112;
+export const TIMELINE_RULER_HEIGHT_PX = 22;
+export const TIMELINE_BOOKMARK_ROW_HEIGHT_PX = 16;
+export const TIMELINE_SCROLLBAR_SIZE_PX = 12;
+export const TIMELINE_CONTENT_TOP_PADDING_PX = 2;
diff --git a/apps/web/src/lib/timeline/selection-hit-testing.ts b/apps/web/src/components/editor/panels/timeline/selection-hit-testing.ts
similarity index 88%
rename from apps/web/src/lib/timeline/selection-hit-testing.ts
rename to apps/web/src/components/editor/panels/timeline/selection-hit-testing.ts
index 3c0f597e..6488e29a 100644
--- a/apps/web/src/lib/timeline/selection-hit-testing.ts
+++ b/apps/web/src/components/editor/panels/timeline/selection-hit-testing.ts
@@ -1,133 +1,136 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
-import { getCumulativeHeightBefore, getTrackHeight } from "@/lib/timeline";
-import type { TimelineTrack } from "@/lib/timeline";
-
-type TimelineElementRef = { trackId: string; elementId: string };
-
-interface SelectionRectangle {
-	left: number;
-	top: number;
-	right: number;
-	bottom: number;
-}
-
-function getNormalizedRectangle({
-	startPos,
-	endPos,
-}: {
-	startPos: { x: number; y: number };
-	endPos: { x: number; y: number };
-}): SelectionRectangle {
-	return {
-		left: Math.min(startPos.x, endPos.x),
-		top: Math.min(startPos.y, endPos.y),
-		right: Math.max(startPos.x, endPos.x),
-		bottom: Math.max(startPos.y, endPos.y),
-	};
-}
-
-function getSelectionRectangleInContent({
-	container,
-	scrollContainer,
-	startPos,
-	endPos,
-}: {
-	container: HTMLElement;
-	scrollContainer: HTMLDivElement | null;
-	startPos: { x: number; y: number };
-	endPos: { x: number; y: number };
-}): SelectionRectangle {
-	const containerRect = container.getBoundingClientRect();
-	const scrollRect = scrollContainer?.getBoundingClientRect() ?? containerRect;
-	const scrollLeft = scrollContainer?.scrollLeft ?? 0;
-	const scrollTop = scrollContainer?.scrollTop ?? 0;
-
-	const adjustedStart = {
-		x: startPos.x - containerRect.left + scrollLeft,
-		y: startPos.y - scrollRect.top + scrollTop,
-	};
-	const adjustedEnd = {
-		x: endPos.x - containerRect.left + scrollLeft,
-		y: endPos.y - scrollRect.top + scrollTop,
-	};
-
-	return getNormalizedRectangle({
-		startPos: adjustedStart,
-		endPos: adjustedEnd,
-	});
-}
-
-function isRectangleIntersecting({
-	elementRectangle,
-	selectionRectangle,
-}: {
-	elementRectangle: SelectionRectangle;
-	selectionRectangle: SelectionRectangle;
-}): boolean {
-	return !(
-		elementRectangle.right < selectionRectangle.left ||
-		elementRectangle.left > selectionRectangle.right ||
-		elementRectangle.bottom < selectionRectangle.top ||
-		elementRectangle.top > selectionRectangle.bottom
-	);
-}
-
-export function resolveTimelineElementIntersections({
-	container,
-	scrollContainer,
-	tracks,
-	zoomLevel,
-	startPos,
-	currentPos,
-}: {
-	container: HTMLElement;
-	scrollContainer: HTMLDivElement | null;
-	tracks: TimelineTrack[];
-	zoomLevel: number;
-	startPos: { x: number; y: number };
-	currentPos: { x: number; y: number };
-}): TimelineElementRef[] {
-	const selectionRectangle = getSelectionRectangleInContent({
-		container,
-		scrollContainer,
-		startPos,
-		endPos: currentPos,
-	});
-	const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
-	const selectedElements: TimelineElementRef[] = [];
-
-	for (const [trackIndex, track] of tracks.entries()) {
-		const trackTop = getCumulativeHeightBefore({
-			tracks,
-			trackIndex,
-		});
-		const trackHeight = getTrackHeight({ type: track.type });
-		const elementTop = TIMELINE_CONSTANTS.PADDING_TOP_PX + trackTop;
-		const elementBottom = elementTop + trackHeight;
-
-		for (const element of track.elements) {
-			const elementLeft = element.startTime * pixelsPerSecond;
-			const elementRight = elementLeft + element.duration * pixelsPerSecond;
-			const elementRectangle = {
-				left: elementLeft,
-				top: elementTop,
-				right: elementRight,
-				bottom: elementBottom,
-			};
-
-			if (
-				isRectangleIntersecting({
-					elementRectangle,
-					selectionRectangle,
-				})
-			) {
-				selectedElements.push({
-					trackId: track.id,
-					elementId: element.id,
-				});
-			}
-		}
-	}
-
-	return selectedElements;
-}
+import type { TimelineTrack } from "@/lib/timeline";
+import { getTimelinePixelsPerSecond } from "@/lib/timeline/pixel-utils";
+import {
+	TIMELINE_CONTENT_TOP_PADDING_PX,
+} from "./layout";
+import { getCumulativeHeightBefore, getTrackHeight } from "./track-layout";
+
+type TimelineElementRef = { trackId: string; elementId: string };
+
+interface SelectionRectangle {
+	left: number;
+	top: number;
+	right: number;
+	bottom: number;
+}
+
+function getNormalizedRectangle({
+	startPos,
+	endPos,
+}: {
+	startPos: { x: number; y: number };
+	endPos: { x: number; y: number };
+}): SelectionRectangle {
+	return {
+		left: Math.min(startPos.x, endPos.x),
+		top: Math.min(startPos.y, endPos.y),
+		right: Math.max(startPos.x, endPos.x),
+		bottom: Math.max(startPos.y, endPos.y),
+	};
+}
+
+function getSelectionRectangleInContent({
+	container,
+	scrollContainer,
+	startPos,
+	endPos,
+}: {
+	container: HTMLElement;
+	scrollContainer: HTMLDivElement | null;
+	startPos: { x: number; y: number };
+	endPos: { x: number; y: number };
+}): SelectionRectangle {
+	const containerRect = container.getBoundingClientRect();
+	const scrollRect = scrollContainer?.getBoundingClientRect() ?? containerRect;
+	const scrollLeft = scrollContainer?.scrollLeft ?? 0;
+	const scrollTop = scrollContainer?.scrollTop ?? 0;
+
+	const adjustedStart = {
+		x: startPos.x - containerRect.left + scrollLeft,
+		y: startPos.y - scrollRect.top + scrollTop,
+	};
+	const adjustedEnd = {
+		x: endPos.x - containerRect.left + scrollLeft,
+		y: endPos.y - scrollRect.top + scrollTop,
+	};
+
+	return getNormalizedRectangle({
+		startPos: adjustedStart,
+		endPos: adjustedEnd,
+	});
+}
+
+function isRectangleIntersecting({
+	elementRectangle,
+	selectionRectangle,
+}: {
+	elementRectangle: SelectionRectangle;
+	selectionRectangle: SelectionRectangle;
+}): boolean {
+	return !(
+		elementRectangle.right < selectionRectangle.left ||
+		elementRectangle.left > selectionRectangle.right ||
+		elementRectangle.bottom < selectionRectangle.top ||
+		elementRectangle.top > selectionRectangle.bottom
+	);
+}
+
+export function resolveTimelineElementIntersections({
+	container,
+	scrollContainer,
+	tracks,
+	zoomLevel,
+	startPos,
+	currentPos,
+}: {
+	container: HTMLElement;
+	scrollContainer: HTMLDivElement | null;
+	tracks: TimelineTrack[];
+	zoomLevel: number;
+	startPos: { x: number; y: number };
+	currentPos: { x: number; y: number };
+}): TimelineElementRef[] {
+	const selectionRectangle = getSelectionRectangleInContent({
+		container,
+		scrollContainer,
+		startPos,
+		endPos: currentPos,
+	});
+	const pixelsPerSecond = getTimelinePixelsPerSecond({ zoomLevel });
+	const selectedElements: TimelineElementRef[] = [];
+
+	for (const [trackIndex, track] of tracks.entries()) {
+		const trackTop = getCumulativeHeightBefore({
+			tracks,
+			trackIndex,
+		});
+		const trackHeight = getTrackHeight({ type: track.type });
+		const elementTop = TIMELINE_CONTENT_TOP_PADDING_PX + trackTop;
+		const elementBottom = elementTop + trackHeight;
+
+		for (const element of track.elements) {
+			const elementLeft = element.startTime * pixelsPerSecond;
+			const elementRight = elementLeft + element.duration * pixelsPerSecond;
+			const elementRectangle = {
+				left: elementLeft,
+				top: elementTop,
+				right: elementRight,
+				bottom: elementBottom,
+			};
+
+			if (
+				isRectangleIntersecting({
+					elementRectangle,
+					selectionRectangle,
+				})
+			) {
+				selectedElements.push({
+					trackId: track.id,
+					elementId: element.id,
+				});
+			}
+		}
+	}
+
+	return selectedElements;
+}
diff --git a/apps/web/src/components/editor/panels/timeline/snap-indicator.tsx b/apps/web/src/components/editor/panels/timeline/snap-indicator.tsx
index 766d0843..a86e2a5e 100644
--- a/apps/web/src/components/editor/panels/timeline/snap-indicator.tsx
+++ b/apps/web/src/components/editor/panels/timeline/snap-indicator.tsx
@@ -6,7 +6,7 @@ import {
 	getCenteredLineLeft,
 	TIMELINE_INDICATOR_LINE_WIDTH_PX,
 } from "@/lib/timeline";
-import { TIMELINE_LAYERS } from "@/constants/timeline-constants";
+import { TIMELINE_LAYERS } from "./layers";
 interface SnapIndicatorProps {
 	snapPoint: SnapPoint | null;
 	zoomLevel: number;
diff --git a/apps/web/src/components/editor/panels/timeline/theme.ts b/apps/web/src/components/editor/panels/timeline/theme.ts
new file mode 100644
index 00000000..e7fc1f11
--- /dev/null
+++ b/apps/web/src/components/editor/panels/timeline/theme.ts
@@ -0,0 +1,29 @@
+import type { TrackType } from "@/lib/timeline";
+
+export const TIMELINE_TRACK_THEME: Record<
+	TrackType,
+	{
+		elementClassName: string;
+		waveformColor?: string;
+	}
+> = {
+	video: { elementClassName: "transparent" },
+	text: { elementClassName: "bg-[#5DBAA0]" },
+	audio: {
+		elementClassName: "bg-[#8F5DBA]",
+		waveformColor: "rgba(255, 255, 255, 0.5)",
+	},
+	graphic: { elementClassName: "bg-[#BA5D7A]" },
+	effect: { elementClassName: "bg-[#5d93ba]" },
+} as const;
+
+export const SELECTED_TRACK_ROW_CLASS = "bg-accent/50";
+export const DEFAULT_TIMELINE_BOOKMARK_COLOR = "#009dff";
+
+export function getTimelineElementClassName({
+	type,
+}: {
+	type: TrackType;
+}): string {
+	return TIMELINE_TRACK_THEME[type].elementClassName.trim();
+}
diff --git a/apps/web/src/components/editor/panels/timeline/timeline-element.tsx b/apps/web/src/components/editor/panels/timeline/timeline-element.tsx
index bb30b0b0..25218d78 100644
--- a/apps/web/src/components/editor/panels/timeline/timeline-element.tsx
+++ b/apps/web/src/components/editor/panels/timeline/timeline-element.tsx
@@ -12,8 +12,6 @@ import { useKeyframeSelection } from "@/hooks/timeline/element/use-keyframe-sele
 import type { SnapPoint } from "@/lib/timeline/snap-utils";
 import { getElementKeyframes } from "@/lib/animation";
 import {
-	getElementClasses,
-	getTrackHeight,
 	canElementHaveAudio,
 	canElementBeHidden,
 	hasElementEffects,
@@ -21,7 +19,11 @@ import {
 	timelineTimeToPixels,
 	timelineTimeToSnappedPixels,
 } from "@/lib/timeline";
-import { ELEMENT_TYPE_CONFIG } from "@/constants/timeline-constants";
+import { getTrackHeight } from "./track-layout";
+import {
+	getTimelineElementClassName,
+	TIMELINE_TRACK_THEME,
+} from "./theme";
 import {
 	ContextMenu,
 	ContextMenuContent,
@@ -464,7 +466,7 @@ function ElementInner({
 				<div
 					className={cn(
 						"absolute inset-0 overflow-hidden rounded-sm",
-						getElementClasses({ type: track.type }),
+						getTimelineElementClassName({ type: track.type }),
 						isReducedOpacity && "opacity-50",
 					)}
 				>
@@ -710,7 +712,7 @@ function AudioElementContent({ element }: { element: AudioElement }) {
 				<AudioWaveform
 					audioBuffer={audioBuffer}
 					audioUrl={audioUrl}
-					color={ELEMENT_TYPE_CONFIG.audio.waveformColor}
+					color={TIMELINE_TRACK_THEME.audio.waveformColor}
 				/>
 				<MediaElementHeader name={mediaLabel} hasFade={false} />
 			</div>
diff --git a/apps/web/src/components/editor/panels/timeline/timeline-playhead.tsx b/apps/web/src/components/editor/panels/timeline/timeline-playhead.tsx
index 1abe65bd..361f1398 100644
--- a/apps/web/src/components/editor/panels/timeline/timeline-playhead.tsx
+++ b/apps/web/src/components/editor/panels/timeline/timeline-playhead.tsx
@@ -9,9 +9,9 @@ import {
 import { useTimelinePlayhead } from "@/hooks/timeline/use-timeline-playhead";
 import { useEditor } from "@/hooks/use-editor";
 import {
-	TIMELINE_LAYERS,
 	TIMELINE_SCROLLBAR_SIZE_PX,
-} from "@/constants/timeline-constants";
+} from "./layout";
+import { TIMELINE_LAYERS } from "./layers";
 
 interface TimelinePlayheadProps {
 	zoomLevel: number;
diff --git a/apps/web/src/components/editor/panels/timeline/timeline-ruler.tsx b/apps/web/src/components/editor/panels/timeline/timeline-ruler.tsx
index 09562f23..9e49bf6c 100644
--- a/apps/web/src/components/editor/panels/timeline/timeline-ruler.tsx
+++ b/apps/web/src/components/editor/panels/timeline/timeline-ruler.tsx
@@ -1,9 +1,9 @@
 import { type JSX, useLayoutEffect, useRef } from "react";
 import {
-	TIMELINE_CONSTANTS,
-	TIMELINE_RULER_HEIGHT,
-} from "@/constants/timeline-constants";
-import { DEFAULT_FPS } from "@/constants/project-constants";
+	BASE_TIMELINE_PIXELS_PER_SECOND,
+} from "@/lib/timeline/scale";
+import { TIMELINE_RULER_HEIGHT_PX } from "./layout";
+import { DEFAULT_FPS } from "@/lib/fps/constants";
 import { useEditor } from "@/hooks/use-editor";
 import { getRulerConfig, shouldShowLabel } from "@/lib/timeline/ruler-utils";
 import { useScrollPosition } from "@/hooks/timeline/use-scroll-position";
@@ -31,7 +31,7 @@ export function TimelineRuler({
 	handleRulerMouseDown,
 }: TimelineRulerProps) {
 	const duration = useEditor((e) => e.timeline.getTotalDuration());
-	const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+	const pixelsPerSecond = BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 	const visibleDuration = dynamicTimelineWidth / pixelsPerSecond;
 	const effectiveDuration = Math.max(duration, visibleDuration);
 	const fps =
@@ -107,7 +107,7 @@ export function TimelineRuler({
 			aria-valuemax={effectiveDuration}
 			aria-valuenow={0}
 			className="relative flex-1 overflow-x-visible"
-			style={{ height: TIMELINE_RULER_HEIGHT }}
+			style={{ height: TIMELINE_RULER_HEIGHT_PX }}
 			onWheel={handleWheel}
 			onClick={(event) => {
 				// Ruler seek already happens on mousedown via playhead scrubbing.
@@ -124,7 +124,7 @@ export function TimelineRuler({
 				ref={rulerRef}
 				className="relative cursor-default select-none"
 				style={{
-					height: TIMELINE_RULER_HEIGHT,
+					height: TIMELINE_RULER_HEIGHT_PX,
 					width: `${dynamicTimelineWidth}px`,
 				}}
 				onMouseDown={handleRulerMouseDown}
diff --git a/apps/web/src/components/editor/panels/timeline/timeline-toolbar.tsx b/apps/web/src/components/editor/panels/timeline/timeline-toolbar.tsx
index ff43e00a..ecaf37e2 100644
--- a/apps/web/src/components/editor/panels/timeline/timeline-toolbar.tsx
+++ b/apps/web/src/components/editor/panels/timeline/timeline-toolbar.tsx
@@ -14,7 +14,10 @@ import {
 	SplitButtonSeparator,
 } from "@/components/ui/split-button";
 import { Slider } from "@/components/ui/slider";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import {
+	TIMELINE_ZOOM_BUTTON_FACTOR,
+} from "./interaction";
+import { TIMELINE_ZOOM_MAX } from "@/lib/timeline/scale";
 import { sliderToZoom, zoomToSlider } from "@/lib/timeline/zoom-utils";
 import { ScenesView } from "@/components/editor/scenes-view";
 import { type TActionWithOptionalArgs, invokeAction } from "@/lib/actions";
@@ -60,10 +63,10 @@ export function TimelineToolbar({
 		const newZoomLevel =
 			direction === "in"
 				? Math.min(
-						TIMELINE_CONSTANTS.ZOOM_MAX,
-						zoomLevel * TIMELINE_CONSTANTS.ZOOM_BUTTON_FACTOR,
+						TIMELINE_ZOOM_MAX,
+						zoomLevel * TIMELINE_ZOOM_BUTTON_FACTOR,
 					)
-				: Math.max(minZoom, zoomLevel / TIMELINE_CONSTANTS.ZOOM_BUTTON_FACTOR);
+				: Math.max(minZoom, zoomLevel / TIMELINE_ZOOM_BUTTON_FACTOR);
 		setZoomLevel({ zoom: newZoomLevel });
 	};
 
diff --git a/apps/web/src/components/editor/panels/timeline/timeline-track.tsx b/apps/web/src/components/editor/panels/timeline/timeline-track.tsx
index ffc2007b..888e1496 100644
--- a/apps/web/src/components/editor/panels/timeline/timeline-track.tsx
+++ b/apps/web/src/components/editor/panels/timeline/timeline-track.tsx
@@ -5,7 +5,8 @@ import { TimelineElement } from "./timeline-element";
 import type { TimelineTrack } from "@/lib/timeline";
 import type { TimelineElement as TimelineElementType } from "@/lib/timeline";
 import type { SnapPoint } from "@/lib/timeline/snap-utils";
-import { TIMELINE_CONSTANTS, TIMELINE_LAYERS } from "@/constants/timeline-constants";
+import { TIMELINE_LAYERS } from "./layers";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 import { useEdgeAutoScroll } from "@/hooks/timeline/use-edge-auto-scroll";
 import type { ElementDragState } from "@/lib/timeline";
 import { useEditor } from "@/hooks/use-editor";
@@ -59,7 +60,7 @@ export function TimelineTrackContent({
 		getMouseClientX: () => lastMouseXRef.current ?? 0,
 		rulerScrollRef,
 		tracksScrollRef,
-		contentWidth: duration * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel,
+		contentWidth: duration * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel,
 	});
 
 	return (
diff --git a/apps/web/src/components/editor/panels/timeline/track-layout.ts b/apps/web/src/components/editor/panels/timeline/track-layout.ts
new file mode 100644
index 00000000..89cc4d05
--- /dev/null
+++ b/apps/web/src/components/editor/panels/timeline/track-layout.ts
@@ -0,0 +1,37 @@
+import type { TrackType } from "@/lib/timeline";
+import {
+	TIMELINE_TRACK_GAP_PX,
+	TIMELINE_TRACK_HEIGHTS_PX,
+} from "./layout";
+
+export function getTrackHeight({ type }: { type: TrackType }): number {
+	return TIMELINE_TRACK_HEIGHTS_PX[type];
+}
+
+export function getCumulativeHeightBefore({
+	tracks,
+	trackIndex,
+}: {
+	tracks: Array<{ type: TrackType }>;
+	trackIndex: number;
+}): number {
+	return tracks
+		.slice(0, trackIndex)
+		.reduce(
+			(sum, track) => sum + getTrackHeight({ type: track.type }) + TIMELINE_TRACK_GAP_PX,
+			0,
+		);
+}
+
+export function getTotalTracksHeight({
+	tracks,
+}: {
+	tracks: Array<{ type: TrackType }>;
+}): number {
+	const tracksHeight = tracks.reduce(
+		(sum, track) => sum + getTrackHeight({ type: track.type }),
+		0,
+	);
+	const gapsHeight = Math.max(0, tracks.length - 1) * TIMELINE_TRACK_GAP_PX;
+	return tracksHeight + gapsHeight;
+}
diff --git a/apps/web/src/core/managers/audio-manager.ts b/apps/web/src/core/managers/audio-manager.ts
index 9e6be22c..0f642b1f 100644
--- a/apps/web/src/core/managers/audio-manager.ts
+++ b/apps/web/src/core/managers/audio-manager.ts
@@ -2,7 +2,7 @@ import type { EditorCore } from "@/core";
 import {
 	clampRetimeRate,
 	shouldMaintainPitch,
-} from "@/constants/retime-constants";
+} from "@/lib/retime/rate";
 import type { AudioClipSource } from "@/lib/media/audio";
 import { createAudioContext, collectAudioClips } from "@/lib/media/audio";
 import {
diff --git a/apps/web/src/core/managers/project-manager.ts b/apps/web/src/core/managers/project-manager.ts
index 916ab328..10a9229d 100644
--- a/apps/web/src/core/managers/project-manager.ts
+++ b/apps/web/src/core/managers/project-manager.ts
@@ -12,11 +12,9 @@ import { storageService } from "@/services/storage/service";
 import { toast } from "sonner";
 import { generateUUID } from "@/utils/id";
 import { UpdateProjectSettingsCommand } from "@/lib/commands/project";
-import {
-	DEFAULT_FPS,
-	DEFAULT_CANVAS_SIZE,
-	DEFAULT_COLOR,
-} from "@/constants/project-constants";
+import { DEFAULT_BACKGROUND_COLOR } from "@/lib/background/constants";
+import { DEFAULT_CANVAS_SIZE } from "@/lib/canvas/constants";
+import { DEFAULT_FPS } from "@/lib/fps/constants";
 import { buildDefaultScene, getProjectDurationFromScenes } from "@/lib/scenes";
 import { buildScene } from "@/services/renderer/scene-builder";
 import { CanvasRenderer } from "@/services/renderer/canvas-renderer";
@@ -29,7 +27,7 @@ import {
 import { loadFonts } from "@/lib/fonts/google-fonts";
 import { DEFAULTS } from "@/lib/timeline/defaults";
 import { getElementFontFamilies } from "@/lib/timeline/element-utils";
-import { getRaisedProjectFpsForImportedMedia } from "@/lib/project/fps";
+import { getRaisedProjectFpsForImportedMedia } from "@/lib/fps/utils";
 import type { MediaAsset } from "@/lib/media/types";
 
 export interface MigrationState {
@@ -101,7 +99,7 @@ export class ProjectManager {
 				originalCanvasSize: null,
 				background: {
 					type: "color",
-					color: DEFAULT_COLOR,
+					color: DEFAULT_BACKGROUND_COLOR,
 				},
 			},
 			version: CURRENT_PROJECT_VERSION,
diff --git a/apps/web/src/hooks/timeline/element/use-element-interaction.ts b/apps/web/src/hooks/timeline/element/use-element-interaction.ts
index 3e0a6997..193379ed 100644
--- a/apps/web/src/hooks/timeline/element/use-element-interaction.ts
+++ b/apps/web/src/hooks/timeline/element/use-element-interaction.ts
@@ -10,12 +10,10 @@ import { useEditor } from "@/hooks/use-editor";
 import { useShiftKey } from "@/hooks/use-shift-key";
 import { useTimelineStore } from "@/stores/timeline-store";
 import { useElementSelection } from "@/hooks/timeline/element/use-element-selection";
-import {
-	DRAG_THRESHOLD_PX,
-	TIMELINE_CONSTANTS,
-} from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
+import { TIMELINE_DRAG_THRESHOLD_PX } from "@/components/editor/panels/timeline/interaction";
 import { snapTimeToFrame } from "opencut-wasm";
-import { computeDropTarget } from "@/lib/timeline/drop-utils";
+import { computeDropTarget } from "@/components/editor/panels/timeline/drop-target";
 import { getMouseTimeFromClientX } from "@/lib/timeline/drag-utils";
 import { generateUUID } from "@/utils/id";
 import { snapElementEdge, type SnapPoint } from "@/lib/timeline/snap-utils";
@@ -70,7 +68,7 @@ function getClickOffsetTime({
 	zoomLevel: number;
 }): number {
 	const clickOffsetX = clientX - elementRect.left;
-	return clickOffsetX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel);
+	return clickOffsetX / (BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel);
 }
 
 function getVerticalDragDirection({
@@ -136,7 +134,7 @@ function getDragDropTarget({
 		playheadTime: snappedTime,
 		isExternalDrop: false,
 		elementDuration,
-		pixelsPerSecond: TIMELINE_CONSTANTS.PIXELS_PER_SECOND,
+		pixelsPerSecond: BASE_TIMELINE_PIXELS_PER_SECOND,
 		zoomLevel,
 		startTimeOverride: snappedTime,
 		excludeElementId: movingElement.id,
@@ -288,7 +286,10 @@ export function useElementInteraction({
 			if (isPendingDrag && pendingDragRef.current) {
 				const deltaX = Math.abs(clientX - pendingDragRef.current.startMouseX);
 				const deltaY = Math.abs(clientY - pendingDragRef.current.startMouseY);
-				if (deltaX > DRAG_THRESHOLD_PX || deltaY > DRAG_THRESHOLD_PX) {
+				if (
+					deltaX > TIMELINE_DRAG_THRESHOLD_PX ||
+					deltaY > TIMELINE_DRAG_THRESHOLD_PX
+				) {
 					const activeProject = editor.project.getActive();
 					if (!activeProject) return;
 					const scrollLeft = scrollContainer.scrollLeft;
@@ -416,7 +417,10 @@ export function useElementInteraction({
 			if (mouseDownLocationRef.current) {
 				const deltaX = Math.abs(clientX - mouseDownLocationRef.current.x);
 				const deltaY = Math.abs(clientY - mouseDownLocationRef.current.y);
-				if (deltaX <= DRAG_THRESHOLD_PX && deltaY <= DRAG_THRESHOLD_PX) {
+				if (
+					deltaX <= TIMELINE_DRAG_THRESHOLD_PX &&
+					deltaY <= TIMELINE_DRAG_THRESHOLD_PX
+				) {
 					mouseDownLocationRef.current = null;
 					endDrag();
 					onSnapPointChange?.(null);
@@ -596,7 +600,10 @@ export function useElementInteraction({
 			if (mouseDownLocationRef.current) {
 				const deltaX = Math.abs(event.clientX - mouseDownLocationRef.current.x);
 				const deltaY = Math.abs(event.clientY - mouseDownLocationRef.current.y);
-				if (deltaX > DRAG_THRESHOLD_PX || deltaY > DRAG_THRESHOLD_PX) {
+				if (
+					deltaX > TIMELINE_DRAG_THRESHOLD_PX ||
+					deltaY > TIMELINE_DRAG_THRESHOLD_PX
+				) {
 					mouseDownLocationRef.current = null;
 					return;
 				}
diff --git a/apps/web/src/hooks/timeline/element/use-element-resize.ts b/apps/web/src/hooks/timeline/element/use-element-resize.ts
index 26bd8ef9..890820d7 100644
--- a/apps/web/src/hooks/timeline/element/use-element-resize.ts
+++ b/apps/web/src/hooks/timeline/element/use-element-resize.ts
@@ -1,5 +1,5 @@
 import { useState, useEffect, useRef, useCallback } from "react";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 import { snapTimeToFrame } from "opencut-wasm";
 import type { TimelineElement, TimelineTrack } from "@/lib/timeline";
 import { useEditor } from "@/hooks/use-editor";
@@ -190,7 +190,7 @@ export function useTimelineElementResize({
 
 			const deltaX = clientX - resizing.startX;
 			let deltaTime =
-				deltaX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel);
+				deltaX / (BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel);
 			let resizeSnapPoint: SnapPoint | null = null;
 
 			const projectFps = editor.project.getActive().settings.fps;
diff --git a/apps/web/src/hooks/timeline/element/use-keyframe-drag.ts b/apps/web/src/hooks/timeline/element/use-keyframe-drag.ts
index e0bf8084..bbe843f2 100644
--- a/apps/web/src/hooks/timeline/element/use-keyframe-drag.ts
+++ b/apps/web/src/hooks/timeline/element/use-keyframe-drag.ts
@@ -9,10 +9,8 @@ import { useEditor } from "@/hooks/use-editor";
 import { useKeyframeSelection } from "./use-keyframe-selection";
 import { snapTimeToFrame, getSnappedSeekTime } from "opencut-wasm";
 import { timelineTimeToSnappedPixels } from "@/lib/timeline";
-import {
-	DRAG_THRESHOLD_PX,
-	TIMELINE_CONSTANTS,
-} from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
+import { TIMELINE_DRAG_THRESHOLD_PX } from "@/components/editor/panels/timeline/interaction";
 import { RetimeKeyframeCommand } from "@/lib/commands/timeline/element/keyframes/retime-keyframe";
 import { BatchCommand } from "@/lib/commands";
 import type { SelectedKeyframeRef } from "@/lib/animation/types";
@@ -64,7 +62,7 @@ export function useKeyframeDrag({
 	const activeProject = editor.project.getActive();
 	const fps = activeProject.settings.fps;
 
-	const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+	const pixelsPerSecond = BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 
 	const endDrag = useCallback(() => {
 		setDragState(initialDragState);
@@ -127,7 +125,7 @@ export function useKeyframeDrag({
 		const handleMouseMove = ({ clientX }: MouseEvent) => {
 			if (isPendingDrag && pendingDragRef.current) {
 				const deltaX = Math.abs(clientX - pendingDragRef.current.startMouseX);
-				if (deltaX <= DRAG_THRESHOLD_PX) return;
+				if (deltaX <= TIMELINE_DRAG_THRESHOLD_PX) return;
 
 				const pending = pendingDragRef.current;
 				pendingDragRef.current = null;
@@ -248,7 +246,8 @@ export function useKeyframeDrag({
 
 			const wasDrag =
 				mouseDownXRef.current !== null &&
-				Math.abs(event.clientX - mouseDownXRef.current) > DRAG_THRESHOLD_PX;
+				Math.abs(event.clientX - mouseDownXRef.current) >
+				TIMELINE_DRAG_THRESHOLD_PX;
 			mouseDownXRef.current = null;
 
 			if (wasDrag) return;
diff --git a/apps/web/src/hooks/timeline/use-bookmark-drag.ts b/apps/web/src/hooks/timeline/use-bookmark-drag.ts
index 4a1185bd..14d58d9a 100644
--- a/apps/web/src/hooks/timeline/use-bookmark-drag.ts
+++ b/apps/web/src/hooks/timeline/use-bookmark-drag.ts
@@ -7,7 +7,7 @@ import {
 } from "react";
 import { useEditor } from "@/hooks/use-editor";
 import { useShiftKey } from "@/hooks/use-shift-key";
-import { DRAG_THRESHOLD_PX } from "@/constants/timeline-constants";
+import { TIMELINE_DRAG_THRESHOLD_PX } from "@/components/editor/panels/timeline/interaction";
 import { snapTimeToFrame } from "opencut-wasm";
 import { getMouseTimeFromClientX } from "@/lib/timeline/drag-utils";
 import {
@@ -131,7 +131,10 @@ export function useBookmarkDrag({
 				const deltaX = Math.abs(event.clientX - startMouseX);
 				const deltaY = Math.abs(event.clientY - startMouseY);
 
-				if (deltaX <= DRAG_THRESHOLD_PX && deltaY <= DRAG_THRESHOLD_PX) {
+				if (
+					deltaX <= TIMELINE_DRAG_THRESHOLD_PX &&
+					deltaY <= TIMELINE_DRAG_THRESHOLD_PX
+				) {
 					return;
 				}
 
diff --git a/apps/web/src/hooks/timeline/use-snap-indicator-position.ts b/apps/web/src/hooks/timeline/use-snap-indicator-position.ts
index 3dc34b7f..b941dcb5 100644
--- a/apps/web/src/hooks/timeline/use-snap-indicator-position.ts
+++ b/apps/web/src/hooks/timeline/use-snap-indicator-position.ts
@@ -1,6 +1,6 @@
 import { useEffect, useState } from "react";
 import { timelineTimeToSnappedPixels } from "@/lib/timeline";
-import { TRACK_LABELS_WIDTH_PX } from "@/constants/timeline-constants";
+import { TIMELINE_TRACK_LABELS_COLUMN_WIDTH_PX } from "@/components/editor/panels/timeline/layout";
 interface UseSnapIndicatorPositionParams {
 	snapPoint: { time: number } | null;
 	zoomLevel: number;
@@ -44,7 +44,8 @@ export function useSnapIndicatorPosition({
 		time: snapPoint?.time ?? 0,
 		zoomLevel,
 	});
-	const leftPosition = TRACK_LABELS_WIDTH_PX + timelinePosition - scrollLeft;
+	const leftPosition =
+		TIMELINE_TRACK_LABELS_COLUMN_WIDTH_PX + timelinePosition - scrollLeft;
 
 	return {
 		leftPosition,
diff --git a/apps/web/src/hooks/timeline/use-timeline-drag-drop.ts b/apps/web/src/hooks/timeline/use-timeline-drag-drop.ts
index ce6f1341..8e87510c 100644
--- a/apps/web/src/hooks/timeline/use-timeline-drag-drop.ts
+++ b/apps/web/src/hooks/timeline/use-timeline-drag-drop.ts
@@ -3,7 +3,8 @@ import { useEditor } from "@/hooks/use-editor";
 import { processMediaAssets } from "@/lib/media/processing";
 import { toast } from "sonner";
 import { showMediaUploadToast } from "@/lib/media/upload-toast";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 import { snapTimeToFrame } from "opencut-wasm";
 import {
 	buildTextElement,
@@ -14,7 +15,7 @@ import {
 } from "@/lib/timeline/element-utils";
 import { AddTrackCommand, InsertElementCommand } from "@/lib/commands/timeline";
 import { BatchCommand } from "@/lib/commands";
-import { computeDropTarget } from "@/lib/timeline/drop-utils";
+import { computeDropTarget } from "@/components/editor/panels/timeline/drop-target";
 import { getDragData, hasDragData } from "@/lib/drag-data";
 import { isMainTrack } from "@/lib/timeline/placement";
 import type { TrackType, DropTarget, ElementType } from "@/lib/timeline";
@@ -82,14 +83,14 @@ export function useTimelineDragDrop({
 				elementType === "sticker" ||
 				elementType === "effect"
 			) {
-				return TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+				return DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 			}
 			if (mediaId) {
 				const mediaAssets = editor.media.getAssets();
 				const media = mediaAssets.find((m) => m.id === mediaId);
-				return media?.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+				return media?.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 			}
-			return TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+			return DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 		},
 		[editor],
 	);
@@ -158,7 +159,7 @@ export function useTimelineDragDrop({
 				playheadTime: currentTime,
 				isExternalDrop: isExternal,
 				elementDuration: duration,
-				pixelsPerSecond: TIMELINE_CONSTANTS.PIXELS_PER_SECOND,
+				pixelsPerSecond: BASE_TIMELINE_PIXELS_PER_SECOND,
 				zoomLevel,
 				targetElementTypes,
 			});
@@ -330,7 +331,7 @@ export function useTimelineDragDrop({
 				dragData.mediaType === "audio" ? "audio" : "video";
 
 			const duration =
-				mediaAsset.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+				mediaAsset.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 			const element = buildElementFromMedia({
 				mediaId: mediaAsset.id,
 				mediaType: mediaAsset.type,
@@ -445,7 +446,7 @@ export function useTimelineDragDrop({
 
 						const duration =
 							createdAsset.duration ??
-							TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+							DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 						const currentTracks = editor.timeline.getTracks();
 						const currentTime = editor.playback.getCurrentTime();
 						const onlyTrack = currentTracks[0];
@@ -467,7 +468,7 @@ export function useTimelineDragDrop({
 									playheadTime: currentTime,
 									isExternalDrop: true,
 									elementDuration: duration,
-									pixelsPerSecond: TIMELINE_CONSTANTS.PIXELS_PER_SECOND,
+									pixelsPerSecond: BASE_TIMELINE_PIXELS_PER_SECOND,
 									zoomLevel,
 								});
 
diff --git a/apps/web/src/hooks/timeline/use-timeline-playhead.ts b/apps/web/src/hooks/timeline/use-timeline-playhead.ts
index d4cfcc06..fce84135 100644
--- a/apps/web/src/hooks/timeline/use-timeline-playhead.ts
+++ b/apps/web/src/hooks/timeline/use-timeline-playhead.ts
@@ -8,7 +8,7 @@ import {
 	getCenteredLineLeft,
 	timelineTimeToSnappedPixels,
 } from "@/lib/timeline";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 
 interface UseTimelinePlayheadProps {
 	zoomLevel: number;
@@ -67,7 +67,7 @@ export function useTimelinePlayhead({
 			const relativeMouseX = event.clientX - rulerRect.left;
 
 			const timelineContentWidth =
-				duration * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+				duration * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 
 			const clampedMouseX = Math.max(
 				0,
@@ -78,7 +78,7 @@ export function useTimelinePlayhead({
 				0,
 				Math.min(
 					duration,
-					clampedMouseX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel),
+					clampedMouseX / (BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel),
 				),
 			);
 
@@ -161,7 +161,7 @@ export function useTimelinePlayhead({
 		getMouseClientX: () => lastMouseXRef.current,
 		rulerScrollRef,
 		tracksScrollRef,
-		contentWidth: duration * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel,
+		contentWidth: duration * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel,
 	});
 
 	useEffect(() => {
@@ -248,7 +248,7 @@ export function useTimelinePlayhead({
 			if (!rulerViewport || !tracksViewport) return;
 
 			const playheadPixels =
-				time * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevelRef.current;
+				time * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevelRef.current;
 			const viewportWidth = rulerViewport.clientWidth;
 			const scrollMinimum = 0;
 			const scrollMaximum = rulerViewport.scrollWidth - viewportWidth;
diff --git a/apps/web/src/hooks/timeline/use-timeline-seek.ts b/apps/web/src/hooks/timeline/use-timeline-seek.ts
index 2672062f..1690153e 100644
--- a/apps/web/src/hooks/timeline/use-timeline-seek.ts
+++ b/apps/web/src/hooks/timeline/use-timeline-seek.ts
@@ -1,6 +1,6 @@
 import { useCallback, useRef } from "react";
 import type { MutableRefObject, RefObject } from "react";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 import { getSnappedSeekTime } from "opencut-wasm";
 import { useEditor } from "../use-editor";
 
@@ -132,7 +132,7 @@ export function useTimelineSeek({
 				Math.min(
 					duration,
 					(mouseX + scrollLeft) /
-						(TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel),
+						(BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel),
 				),
 			);
 
diff --git a/apps/web/src/hooks/timeline/use-timeline-zoom.ts b/apps/web/src/hooks/timeline/use-timeline-zoom.ts
index 64a0fb58..a1740384 100644
--- a/apps/web/src/hooks/timeline/use-timeline-zoom.ts
+++ b/apps/web/src/hooks/timeline/use-timeline-zoom.ts
@@ -7,7 +7,14 @@ import {
 	useRef,
 	useState,
 } from "react";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import {
+	TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD,
+} from "@/components/editor/panels/timeline/interaction";
+import {
+	TIMELINE_ZOOM_MAX,
+	TIMELINE_ZOOM_MIN,
+	BASE_TIMELINE_PIXELS_PER_SECOND,
+} from "@/lib/timeline/scale";
 import { useEditor } from "@/hooks/use-editor";
 import { zoomToSlider } from "@/lib/timeline/zoom-utils";
 
@@ -30,7 +37,7 @@ interface UseTimelineZoomReturn {
 
 export function useTimelineZoom({
 	containerRef,
-	minZoom = TIMELINE_CONSTANTS.ZOOM_MIN,
+	minZoom = TIMELINE_ZOOM_MIN,
 	initialZoom,
 	initialScrollLeft,
 	initialPlayheadTime,
@@ -49,7 +56,7 @@ export function useTimelineZoom({
 			hasInitializedRef.current = true;
 			return Math.max(
 				minZoom,
-				Math.min(TIMELINE_CONSTANTS.ZOOM_MAX, initialZoom),
+					Math.min(TIMELINE_ZOOM_MAX, initialZoom),
 			);
 		}
 		return minZoom;
@@ -91,7 +98,7 @@ export function useTimelineZoom({
 			setZoomLevel((prev) => {
 				const nextZoom = Math.max(
 					minZoom,
-					Math.min(TIMELINE_CONSTANTS.ZOOM_MAX, prev * zoomFactor),
+					Math.min(TIMELINE_ZOOM_MAX, prev * zoomFactor),
 				);
 				return nextZoom;
 			});
@@ -105,7 +112,7 @@ export function useTimelineZoom({
 		if (initialZoom !== undefined && !hasInitializedRef.current) {
 			hasInitializedRef.current = true;
 			setZoomLevel(
-				Math.max(minZoom, Math.min(TIMELINE_CONSTANTS.ZOOM_MAX, initialZoom)),
+				Math.max(minZoom, Math.min(TIMELINE_ZOOM_MAX, initialZoom)),
 			);
 			return;
 		}
@@ -126,7 +133,7 @@ export function useTimelineZoom({
 						: zoomLevelOrUpdater;
 				const clampedZoom = Math.max(
 					minZoom,
-					Math.min(TIMELINE_CONSTANTS.ZOOM_MAX, nextZoom),
+					Math.min(TIMELINE_ZOOM_MAX, nextZoom),
 				);
 				return clampedZoom;
 			});
@@ -153,12 +160,12 @@ export function useTimelineZoom({
 		});
 		const isCrossingThresholdUp =
 			previousSliderPercent <
-				TIMELINE_CONSTANTS.ZOOM_ANCHOR_PLAYHEAD_THRESHOLD &&
-			sliderPercent >= TIMELINE_CONSTANTS.ZOOM_ANCHOR_PLAYHEAD_THRESHOLD;
+				TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD &&
+			sliderPercent >= TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD;
 		const isCrossingThresholdDown =
 			previousSliderPercent >=
-				TIMELINE_CONSTANTS.ZOOM_ANCHOR_PLAYHEAD_THRESHOLD &&
-			sliderPercent < TIMELINE_CONSTANTS.ZOOM_ANCHOR_PLAYHEAD_THRESHOLD;
+				TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD &&
+			sliderPercent < TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD;
 
 		const syncScroll = (scrollLeft: number) => {
 			scrollElement.scrollLeft = scrollLeft;
@@ -178,11 +185,11 @@ export function useTimelineZoom({
 			isInPlayheadAnchorModeRef.current = true;
 		}
 
-		if (sliderPercent >= TIMELINE_CONSTANTS.ZOOM_ANCHOR_PLAYHEAD_THRESHOLD) {
+		if (sliderPercent >= TIMELINE_ZOOM_ANCHOR_PLAYHEAD_THRESHOLD) {
 			const playheadPixelsBefore =
-				playheadTime * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * previousZoom;
+				playheadTime * BASE_TIMELINE_PIXELS_PER_SECOND * previousZoom;
 			const playheadPixelsAfter =
-				playheadTime * TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+				playheadTime * BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 
 			const viewportOffset = playheadPixelsBefore - currentScrollLeft;
 			const newScrollLeft = playheadPixelsAfter - viewportOffset;
diff --git a/apps/web/src/hooks/use-paste-media.ts b/apps/web/src/hooks/use-paste-media.ts
index 2c9c43ea..1cba34c0 100644
--- a/apps/web/src/hooks/use-paste-media.ts
+++ b/apps/web/src/hooks/use-paste-media.ts
@@ -7,7 +7,7 @@ import { buildElementFromMedia } from "@/lib/timeline/element-utils";
 import { AddMediaAssetCommand } from "@/lib/commands/media";
 import { InsertElementCommand } from "@/lib/commands/timeline";
 import { BatchCommand } from "@/lib/commands";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
 import { isTypableDOMElement } from "@/utils/browser";
 import type { MediaType } from "@/lib/media/types";
 
@@ -74,7 +74,7 @@ export function usePasteMedia() {
 							);
 							const assetId = addMediaCmd.getAssetId();
 							const duration =
-								asset.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION;
+								asset.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS;
 							const trackType = asset.type === "audio" ? "audio" : "video";
 
 							const element = buildElementFromMedia({
diff --git a/apps/web/src/lib/background/constants.ts b/apps/web/src/lib/background/constants.ts
new file mode 100644
index 00000000..654154a5
--- /dev/null
+++ b/apps/web/src/lib/background/constants.ts
@@ -0,0 +1,11 @@
+export const BACKGROUND_BLUR_INTENSITY_PRESETS: Array<{
+	label: string;
+	value: number;
+}> = [
+	{ label: "Light", value: 10 },
+	{ label: "Medium", value: 50 },
+	{ label: "Heavy", value: 100 },
+] as const;
+
+export const DEFAULT_BACKGROUND_BLUR_INTENSITY = 10;
+export const DEFAULT_BACKGROUND_COLOR = "#000000";
diff --git a/apps/web/src/lib/canvas/constants.ts b/apps/web/src/lib/canvas/constants.ts
new file mode 100644
index 00000000..dce75bcb
--- /dev/null
+++ b/apps/web/src/lib/canvas/constants.ts
@@ -0,0 +1,10 @@
+import type { TCanvasSize } from "@/lib/project/types";
+
+export const DEFAULT_CANVAS_PRESETS: TCanvasSize[] = [
+	{ width: 1920, height: 1080 },
+	{ width: 1080, height: 1920 },
+	{ width: 1080, height: 1080 },
+	{ width: 1440, height: 1080 },
+];
+
+export const DEFAULT_CANVAS_SIZE: TCanvasSize = { width: 1920, height: 1080 };
diff --git a/apps/web/src/lib/commands/media/add-media-asset.ts b/apps/web/src/lib/commands/media/add-media-asset.ts
index 86fa3e35..6f54ee72 100644
--- a/apps/web/src/lib/commands/media/add-media-asset.ts
+++ b/apps/web/src/lib/commands/media/add-media-asset.ts
@@ -5,7 +5,7 @@ import type { MediaAsset } from "@/lib/media/types";
 import { generateUUID } from "@/utils/id";
 import { storageService } from "@/services/storage/service";
 import { hasMediaId } from "@/lib/timeline/element-utils";
-import { getHighestImportedVideoFps } from "@/lib/project/fps";
+import { getHighestImportedVideoFps } from "@/lib/fps/utils";
 import { UpdateProjectSettingsCommand } from "@/lib/commands/project";
 
 export class AddMediaAssetCommand extends Command {
diff --git a/apps/web/src/lib/commands/timeline/element/insert-element.ts b/apps/web/src/lib/commands/timeline/element/insert-element.ts
index cdff3565..2119d219 100644
--- a/apps/web/src/lib/commands/timeline/element/insert-element.ts
+++ b/apps/web/src/lib/commands/timeline/element/insert-element.ts
@@ -9,7 +9,7 @@ import type {
 import { generateUUID } from "@/utils/id";
 import { requiresMediaId } from "@/lib/timeline/element-utils";
 import type { MediaAsset } from "@/lib/media/types";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
 import { graphicsRegistry, registerDefaultGraphics } from "@/lib/graphics";
 import {
 	applyPlacement,
@@ -136,7 +136,7 @@ export class InsertElementCommand extends Command {
 			startTime: element.startTime,
 			trimStart: element.trimStart ?? 0,
 			trimEnd: element.trimEnd ?? 0,
-			duration: element.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+			duration: element.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 		} as TimelineElement;
 	}
 
diff --git a/apps/web/src/lib/commands/timeline/element/retime/update-element-retime.ts b/apps/web/src/lib/commands/timeline/element/retime/update-element-retime.ts
index 4057ec41..f0574ce7 100644
--- a/apps/web/src/lib/commands/timeline/element/retime/update-element-retime.ts
+++ b/apps/web/src/lib/commands/timeline/element/retime/update-element-retime.ts
@@ -1,5 +1,5 @@
 import { EditorCore } from "@/core";
-import { clampRetimeRate } from "@/constants/retime-constants";
+import { clampRetimeRate } from "@/lib/retime/rate";
 import { clampAnimationsToDuration } from "@/lib/animation";
 import { Command } from "@/lib/commands/base-command";
 import { getTimelineDurationForSourceSpan, getSourceSpanAtClipTime } from "@/lib/retime";
diff --git a/apps/web/src/lib/commands/timeline/track/toggle-track-mute.ts b/apps/web/src/lib/commands/timeline/track/toggle-track-mute.ts
index 120220fe..0094f1de 100644
--- a/apps/web/src/lib/commands/timeline/track/toggle-track-mute.ts
+++ b/apps/web/src/lib/commands/timeline/track/toggle-track-mute.ts
@@ -1,7 +1,7 @@
 import { Command } from "@/lib/commands/base-command";
 import type { TimelineTrack } from "@/lib/timeline";
 import { EditorCore } from "@/core";
-import { canTracktHaveAudio } from "@/lib/timeline";
+import { canTrackHaveAudio } from "@/lib/timeline";
 
 export class ToggleTrackMuteCommand extends Command {
 	private savedState: TimelineTrack[] | null = null;
@@ -22,7 +22,7 @@ export class ToggleTrackMuteCommand extends Command {
 		}
 
 		const updatedTracks = this.savedState.map((track) =>
-			track.id === this.trackId && canTracktHaveAudio(track)
+			track.id === this.trackId && canTrackHaveAudio(track)
 				? { ...track, muted: !track.muted }
 				: track,
 		);
diff --git a/apps/web/src/lib/project/__tests__/fps.test.ts b/apps/web/src/lib/fps/__tests__/fps.test.ts
similarity index 94%
rename from apps/web/src/lib/project/__tests__/fps.test.ts
rename to apps/web/src/lib/fps/__tests__/fps.test.ts
index b30408ef..fd082bb2 100644
--- a/apps/web/src/lib/project/__tests__/fps.test.ts
+++ b/apps/web/src/lib/fps/__tests__/fps.test.ts
@@ -1,65 +1,65 @@
-import { describe, expect, test } from "bun:test";
-import {
-	getHighestImportedVideoFps,
-	getRaisedProjectFpsForImportedMedia,
-} from "@/lib/project/fps";
-
-describe("getHighestImportedVideoFps", () => {
-	test("returns the highest valid video fps", () => {
-		expect(
-			getHighestImportedVideoFps({
-				mediaAssets: [
-					{ type: "audio" },
-					{ type: "video", fps: 30 },
-					{ type: "image", fps: 120 },
-					{ type: "video", fps: 60 },
-				],
-			}),
-		).toBe(60);
-	});
-
-	test("ignores missing and invalid fps values", () => {
-		expect(
-			getHighestImportedVideoFps({
-				mediaAssets: [
-					{ type: "video" },
-					{ type: "video", fps: 0 },
-					{ type: "video", fps: -10 },
-					{ type: "audio", fps: 120 },
-				],
-			}),
-		).toBeNull();
-	});
-});
-
-describe("getRaisedProjectFpsForImportedMedia", () => {
-	test("raises the project fps to match a higher-fps import", () => {
-		expect(
-			getRaisedProjectFpsForImportedMedia({
-				currentFps: 30,
-				importedAssets: [{ type: "video", fps: 60 }],
-			}),
-		).toBe(60);
-	});
-
-	test("does not lower the project fps for lower-fps imports", () => {
-		expect(
-			getRaisedProjectFpsForImportedMedia({
-				currentFps: 60,
-				importedAssets: [{ type: "video", fps: 10 }],
-			}),
-		).toBeNull();
-	});
-
-	test("ignores non-video imports", () => {
-		expect(
-			getRaisedProjectFpsForImportedMedia({
-				currentFps: 30,
-				importedAssets: [
-					{ type: "image", fps: 60 },
-					{ type: "audio", fps: 120 },
-				],
-			}),
-		).toBeNull();
-	});
-});
+import { describe, expect, test } from "bun:test";
+import {
+	getHighestImportedVideoFps,
+	getRaisedProjectFpsForImportedMedia,
+} from "@/lib/fps/utils";
+
+describe("getHighestImportedVideoFps", () => {
+	test("returns the highest valid video fps", () => {
+		expect(
+			getHighestImportedVideoFps({
+				mediaAssets: [
+					{ type: "audio" },
+					{ type: "video", fps: 30 },
+					{ type: "image", fps: 120 },
+					{ type: "video", fps: 60 },
+				],
+			}),
+		).toBe(60);
+	});
+
+	test("ignores missing and invalid fps values", () => {
+		expect(
+			getHighestImportedVideoFps({
+				mediaAssets: [
+					{ type: "video" },
+					{ type: "video", fps: 0 },
+					{ type: "video", fps: -10 },
+					{ type: "audio", fps: 120 },
+				],
+			}),
+		).toBeNull();
+	});
+});
+
+describe("getRaisedProjectFpsForImportedMedia", () => {
+	test("raises the project fps to match a higher-fps import", () => {
+		expect(
+			getRaisedProjectFpsForImportedMedia({
+				currentFps: 30,
+				importedAssets: [{ type: "video", fps: 60 }],
+			}),
+		).toBe(60);
+	});
+
+	test("does not lower the project fps for lower-fps imports", () => {
+		expect(
+			getRaisedProjectFpsForImportedMedia({
+				currentFps: 60,
+				importedAssets: [{ type: "video", fps: 10 }],
+			}),
+		).toBeNull();
+	});
+
+	test("ignores non-video imports", () => {
+		expect(
+			getRaisedProjectFpsForImportedMedia({
+				currentFps: 30,
+				importedAssets: [
+					{ type: "image", fps: 60 },
+					{ type: "audio", fps: 120 },
+				],
+			}),
+		).toBeNull();
+	});
+});
diff --git a/apps/web/src/lib/fps/constants.ts b/apps/web/src/lib/fps/constants.ts
new file mode 100644
index 00000000..100c043a
--- /dev/null
+++ b/apps/web/src/lib/fps/constants.ts
@@ -0,0 +1,9 @@
+export const FPS_PRESETS = [
+	{ value: "24", label: "24 fps" },
+	{ value: "25", label: "25 fps" },
+	{ value: "30", label: "30 fps" },
+	{ value: "60", label: "60 fps" },
+	{ value: "120", label: "120 fps" },
+] as const;
+
+export const DEFAULT_FPS = 30;
diff --git a/apps/web/src/lib/project/fps.ts b/apps/web/src/lib/fps/utils.ts
similarity index 96%
rename from apps/web/src/lib/project/fps.ts
rename to apps/web/src/lib/fps/utils.ts
index f031d348..8e3221a1 100644
--- a/apps/web/src/lib/project/fps.ts
+++ b/apps/web/src/lib/fps/utils.ts
@@ -1,39 +1,39 @@
-import type { MediaAsset } from "@/lib/media/types";
-
-type MediaAssetFpsInput = Pick<MediaAsset, "type" | "fps">;
-
-export function getHighestImportedVideoFps({
-	mediaAssets,
-}: {
-	mediaAssets: MediaAssetFpsInput[];
-}): number | null {
-	let highestFps: number | null = null;
-
-	for (const asset of mediaAssets) {
-		const fps = asset.fps ?? Number.NaN;
-		if (asset.type !== "video") continue;
-		if (!Number.isFinite(fps) || fps <= 0) continue;
-
-		highestFps = highestFps === null ? fps : Math.max(highestFps, fps);
-	}
-
-	return highestFps;
-}
-
-export function getRaisedProjectFpsForImportedMedia({
-	currentFps,
-	importedAssets,
-}: {
-	currentFps: number;
-	importedAssets: MediaAssetFpsInput[];
-}): number | null {
-	const highestImportedVideoFps = getHighestImportedVideoFps({
-		mediaAssets: importedAssets,
-	});
-
-	if (highestImportedVideoFps === null || highestImportedVideoFps <= currentFps) {
-		return null;
-	}
-
-	return highestImportedVideoFps;
-}
+import type { MediaAsset } from "@/lib/media/types";
+
+type MediaAssetFpsInput = Pick<MediaAsset, "type" | "fps">;
+
+export function getHighestImportedVideoFps({
+	mediaAssets,
+}: {
+	mediaAssets: MediaAssetFpsInput[];
+}): number | null {
+	let highestFps: number | null = null;
+
+	for (const asset of mediaAssets) {
+		const fps = asset.fps ?? Number.NaN;
+		if (asset.type !== "video") continue;
+		if (!Number.isFinite(fps) || fps <= 0) continue;
+
+		highestFps = highestFps === null ? fps : Math.max(highestFps, fps);
+	}
+
+	return highestFps;
+}
+
+export function getRaisedProjectFpsForImportedMedia({
+	currentFps,
+	importedAssets,
+}: {
+	currentFps: number;
+	importedAssets: MediaAssetFpsInput[];
+}): number | null {
+	const highestImportedVideoFps = getHighestImportedVideoFps({
+		mediaAssets: importedAssets,
+	});
+
+	if (highestImportedVideoFps === null || highestImportedVideoFps <= currentFps) {
+		return null;
+	}
+
+	return highestImportedVideoFps;
+}
diff --git a/apps/web/src/lib/media/audio.ts b/apps/web/src/lib/media/audio.ts
index 0afc42fb..d1025aa9 100644
--- a/apps/web/src/lib/media/audio.ts
+++ b/apps/web/src/lib/media/audio.ts
@@ -4,7 +4,7 @@ import type {
 	RetimeConfig,
 	TimelineTrack,
 } from "@/lib/timeline";
-import { shouldMaintainPitch } from "@/constants/retime-constants";
+import { shouldMaintainPitch } from "@/lib/retime/rate";
 import type { MediaAsset } from "@/lib/media/types";
 import { applyAudioMasteringToBuffer } from "@/lib/media/audio-mastering";
 import type { AudioCapableElement } from "@/lib/timeline/audio-state";
@@ -16,7 +16,7 @@ import {
 	doesElementHaveEnabledAudio,
 } from "@/lib/timeline/audio-separation";
 import { canElementHaveAudio, hasMediaId } from "@/lib/timeline/element-utils";
-import { canTracktHaveAudio } from "@/lib/timeline";
+import { canTrackHaveAudio } from "@/lib/timeline";
 import { mediaSupportsAudio } from "@/lib/media/media-utils";
 import { getSourceTimeAtClipTime, renderRetimedBuffer } from "@/lib/retime";
 import { Input, ALL_FORMATS, BlobSource, AudioBufferSink } from "mediabunny";
@@ -97,7 +97,7 @@ export async function collectAudioElements({
 	const pendingElements: Array<Promise<CollectedAudioElement | null>> = [];
 
 	for (const track of tracks) {
-		if (canTracktHaveAudio(track) && track.muted) continue;
+		if (canTrackHaveAudio(track) && track.muted) continue;
 
 		for (const element of track.elements) {
 			if (!canElementHaveAudio(element)) continue;
@@ -108,7 +108,7 @@ export async function collectAudioElements({
 				: null;
 			if (!doesElementHaveEnabledAudio({ element, mediaAsset })) continue;
 
-			const isTrackMuted = canTracktHaveAudio(track) && track.muted;
+			const isTrackMuted = canTrackHaveAudio(track) && track.muted;
 
 			if (element.type === "audio") {
 				pendingElements.push(
@@ -453,7 +453,7 @@ export async function collectAudioMixSources({
 	const pendingLibrarySources: Array<Promise<AudioMixSource | null>> = [];
 
 	for (const track of tracks) {
-		if (canTracktHaveAudio(track) && track.muted) continue;
+		if (canTrackHaveAudio(track) && track.muted) continue;
 
 		for (const element of track.elements) {
 			if (!canElementHaveAudio(element)) continue;
@@ -515,7 +515,7 @@ export async function collectAudioClips({
 	const pendingLibraryClips: Array<Promise<AudioClipSource | null>> = [];
 
 	for (const track of tracks) {
-		const isTrackMuted = canTracktHaveAudio(track) && track.muted;
+		const isTrackMuted = canTrackHaveAudio(track) && track.muted;
 
 		for (const element of track.elements) {
 			if (!canElementHaveAudio(element)) continue;
diff --git a/apps/web/src/lib/panels/constants.ts b/apps/web/src/lib/panels/constants.ts
new file mode 100644
index 00000000..5a570469
--- /dev/null
+++ b/apps/web/src/lib/panels/constants.ts
@@ -0,0 +1,9 @@
+export const PANEL_CONFIG = {
+	panels: {
+		tools: 25,
+		preview: 50,
+		properties: 25,
+		mainContent: 50,
+		timeline: 50,
+	},
+} as const;
diff --git a/apps/web/src/lib/preview/constants.ts b/apps/web/src/lib/preview/constants.ts
new file mode 100644
index 00000000..9e6f5905
--- /dev/null
+++ b/apps/web/src/lib/preview/constants.ts
@@ -0,0 +1,7 @@
+export const PREVIEW_ZOOM_PRESETS = [25, 50, 75, 100, 150, 200];
+
+export const PREVIEW_ZOOM = {
+	min: 0.25,
+	max: 16,
+	step: 1.25,
+} as const;
diff --git a/apps/web/src/lib/retime/audio-stretch.ts b/apps/web/src/lib/retime/audio-stretch.ts
index f8dd297c..92902dff 100644
--- a/apps/web/src/lib/retime/audio-stretch.ts
+++ b/apps/web/src/lib/retime/audio-stretch.ts
@@ -1,5 +1,5 @@
 import { PitchShifter } from "soundtouchjs";
-import { clampRetimeRate, shouldMaintainPitch } from "@/constants/retime-constants";
+import { clampRetimeRate, shouldMaintainPitch } from "@/lib/retime/rate";
 import type { RetimeConfig } from "@/lib/timeline";
 import { getSourceTimeAtClipTime } from "./resolve";
 
diff --git a/apps/web/src/lib/retime/index.ts b/apps/web/src/lib/retime/index.ts
index ca6725dd..2ab1d10f 100644
--- a/apps/web/src/lib/retime/index.ts
+++ b/apps/web/src/lib/retime/index.ts
@@ -1,3 +1,4 @@
+export * from "./rate";
 export * from "./audio-stretch";
 export * from "./presets";
 export * from "./resolve";
diff --git a/apps/web/src/lib/retime/presets.ts b/apps/web/src/lib/retime/presets.ts
index 777c0219..fbd391ff 100644
--- a/apps/web/src/lib/retime/presets.ts
+++ b/apps/web/src/lib/retime/presets.ts
@@ -1,5 +1,5 @@
 import type { RetimeConfig } from "@/lib/timeline";
-import { clampRetimeRate } from "@/constants/retime-constants";
+import { clampRetimeRate } from "@/lib/retime/rate";
 
 export function buildConstantRetime({
 	rate,
diff --git a/apps/web/src/constants/retime-constants.ts b/apps/web/src/lib/retime/rate.ts
similarity index 74%
rename from apps/web/src/constants/retime-constants.ts
rename to apps/web/src/lib/retime/rate.ts
index c9949583..75ea530b 100644
--- a/apps/web/src/constants/retime-constants.ts
+++ b/apps/web/src/lib/retime/rate.ts
@@ -1,30 +1,25 @@
-export const DEFAULT_RETIME_RATE = 1;
-export const MIN_RETIME_RATE = 0.01;
-export const MAX_RETIME_RATE = 5;
-export const MAX_PITCH_PRESERVE_RATE = 10;
-
-export function clampRetimeRate({ rate }: { rate: number }): number {
-	if (!Number.isFinite(rate) || rate <= 0) {
-		return DEFAULT_RETIME_RATE;
-	}
-
-	return Math.min(Math.max(rate, MIN_RETIME_RATE), MAX_RETIME_RATE);
-}
-
-export function canMaintainPitch({ rate }: { rate: number }): boolean {
-	if (!Number.isFinite(rate) || rate <= 0) {
-		return false;
-	}
-
-	return clampRetimeRate({ rate }) <= MAX_PITCH_PRESERVE_RATE;
-}
-
-export function shouldMaintainPitch({
-	rate,
-	maintainPitch,
-}: {
-	rate: number;
-	maintainPitch?: boolean;
-}): boolean {
-	return maintainPitch === true && canMaintainPitch({ rate });
-}
+export const DEFAULT_RETIME_RATE = 1;
+export const MIN_RETIME_RATE = 0.01;
+export const MAX_RETIME_RATE = 5;
+
+export function clampRetimeRate({ rate }: { rate: number }): number {
+	if (!Number.isFinite(rate) || rate <= 0) {
+		return DEFAULT_RETIME_RATE;
+	}
+
+	return Math.min(Math.max(rate, MIN_RETIME_RATE), MAX_RETIME_RATE);
+}
+
+export function canMaintainPitch({ rate }: { rate: number }): boolean {
+	return Number.isFinite(rate) && rate > 0;
+}
+
+export function shouldMaintainPitch({
+	rate,
+	maintainPitch,
+}: {
+	rate: number;
+	maintainPitch?: boolean;
+}): boolean {
+	return maintainPitch === true && canMaintainPitch({ rate });
+}
diff --git a/apps/web/src/lib/retime/resolve.ts b/apps/web/src/lib/retime/resolve.ts
index 31a562be..5e7236d5 100644
--- a/apps/web/src/lib/retime/resolve.ts
+++ b/apps/web/src/lib/retime/resolve.ts
@@ -1,5 +1,5 @@
 import type { RetimeConfig } from "@/lib/timeline";
-import { clampRetimeRate } from "@/constants/retime-constants";
+import { clampRetimeRate } from "@/lib/retime/rate";
 
 function getSafeRate({ rate }: { rate: number }): number {
 	return clampRetimeRate({ rate });
diff --git a/apps/web/src/lib/text/constants.ts b/apps/web/src/lib/text/constants.ts
new file mode 100644
index 00000000..a101f209
--- /dev/null
+++ b/apps/web/src/lib/text/constants.ts
@@ -0,0 +1,12 @@
+export const MIN_FONT_SIZE = 5;
+export const MAX_FONT_SIZE = 300;
+export const DEFAULT_TEXT_COLOR = "#000000";
+
+/**
+ * higher value: smaller font size
+ * lower value: larger font size
+ */
+export const FONT_SIZE_SCALE_REFERENCE = 90;
+
+export const CORNER_RADIUS_MIN = 0;
+export const CORNER_RADIUS_MAX = 100;
diff --git a/apps/web/src/lib/timeline/creation.ts b/apps/web/src/lib/timeline/creation.ts
new file mode 100644
index 00000000..335ab912
--- /dev/null
+++ b/apps/web/src/lib/timeline/creation.ts
@@ -0,0 +1 @@
+export const DEFAULT_NEW_ELEMENT_DURATION_SECONDS = 5;
diff --git a/apps/web/src/lib/timeline/defaults.ts b/apps/web/src/lib/timeline/defaults.ts
index 01dbe912..bc968a3c 100644
--- a/apps/web/src/lib/timeline/defaults.ts
+++ b/apps/web/src/lib/timeline/defaults.ts
@@ -1,4 +1,4 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
 import type { TTimelineViewState } from "@/lib/project/types";
 import type { BlendMode, Transform } from "@/lib/rendering";
 import type { TextElement } from "./types";
@@ -41,7 +41,7 @@ const defaultTextElement: Omit<TextElement, "id"> = {
 	textDecoration: "none",
 	letterSpacing: defaultTextLetterSpacing,
 	lineHeight: defaultTextLineHeight,
-	duration: TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+	duration: DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 	startTime: 0,
 	trimStart: 0,
 	trimEnd: 0,
diff --git a/apps/web/src/lib/timeline/drag-utils.ts b/apps/web/src/lib/timeline/drag-utils.ts
index cf59a20d..8efeab79 100644
--- a/apps/web/src/lib/timeline/drag-utils.ts
+++ b/apps/web/src/lib/timeline/drag-utils.ts
@@ -1,4 +1,4 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 
 export function getMouseTimeFromClientX({
 	clientX,
@@ -14,6 +14,6 @@ export function getMouseTimeFromClientX({
 	const mouseX = clientX - containerRect.left + scrollLeft;
 	return Math.max(
 		0,
-		mouseX / (TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel),
+		mouseX / (BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel),
 	);
 }
diff --git a/apps/web/src/lib/timeline/element-utils.ts b/apps/web/src/lib/timeline/element-utils.ts
index 5820b96d..96588903 100644
--- a/apps/web/src/lib/timeline/element-utils.ts
+++ b/apps/web/src/lib/timeline/element-utils.ts
@@ -1,4 +1,4 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { DEFAULT_NEW_ELEMENT_DURATION_SECONDS } from "@/lib/timeline/creation";
 import {
 	MASKABLE_ELEMENT_TYPES,
 	RETIMABLE_ELEMENT_TYPES,
@@ -115,7 +115,7 @@ export function buildTextElement({
 		type: "text",
 		name: t.name ?? DEFAULTS.text.element.name,
 		content: t.content ?? DEFAULTS.text.element.content,
-		duration: t.duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		duration: t.duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 		startTime,
 		trimStart: 0,
 		trimEnd: 0,
@@ -150,7 +150,7 @@ export function buildEffectElement({
 		name: capitalizeFirstLetter({ string: instance.type }),
 		effectType,
 		params: instance.params,
-		duration: duration ?? TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		duration: duration ?? DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 		startTime,
 		trimStart: 0,
 		trimEnd: 0,
@@ -178,7 +178,7 @@ export function buildStickerElement({
 		stickerId,
 		intrinsicWidth,
 		intrinsicHeight,
-		duration: TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		duration: DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 		startTime,
 		trimStart: 0,
 		trimEnd: 0,
@@ -208,7 +208,7 @@ export function buildGraphicElement({
 		name: name ?? capitalizeFirstLetter({ string: instance.definitionId }),
 		definitionId: instance.definitionId,
 		params: { ...instance.params, ...(params ?? {}) } as ParamValues,
-		duration: TIMELINE_CONSTANTS.DEFAULT_ELEMENT_DURATION,
+		duration: DEFAULT_NEW_ELEMENT_DURATION_SECONDS,
 		startTime,
 		trimStart: 0,
 		trimEnd: 0,
diff --git a/apps/web/src/lib/timeline/index.ts b/apps/web/src/lib/timeline/index.ts
index 83a6a0f0..469b916e 100644
--- a/apps/web/src/lib/timeline/index.ts
+++ b/apps/web/src/lib/timeline/index.ts
@@ -2,7 +2,7 @@ import type { TimelineTrack } from "./types";
 
 export * from "./types";
 export * from "./drag";
-export * from "./track-utils";
+export * from "./track-capabilities";
 export * from "./track-element-update";
 export * from "./element-utils";
 export * from "./audio-separation";
diff --git a/apps/web/src/lib/timeline/pixel-utils.ts b/apps/web/src/lib/timeline/pixel-utils.ts
index c4635e52..e93b5ab5 100644
--- a/apps/web/src/lib/timeline/pixel-utils.ts
+++ b/apps/web/src/lib/timeline/pixel-utils.ts
@@ -1,4 +1,4 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 
 export const TIMELINE_INDICATOR_LINE_WIDTH_PX = 2;
 
@@ -31,7 +31,7 @@ export function getTimelinePixelsPerSecond({
 }: {
 	zoomLevel: number;
 }): number {
-	return TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+	return BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 }
 
 export function timelineTimeToPixels({
diff --git a/apps/web/src/lib/timeline/placement/track-factory.ts b/apps/web/src/lib/timeline/placement/track-factory.ts
index e77a8a96..ee056261 100644
--- a/apps/web/src/lib/timeline/placement/track-factory.ts
+++ b/apps/web/src/lib/timeline/placement/track-factory.ts
@@ -1,4 +1,4 @@
-import { TRACK_CONFIG } from "@/constants/timeline-constants";
+import { DEFAULT_TRACK_NAMES } from "@/lib/timeline/tracks";
 import type { TrackType, TimelineTrack } from "@/lib/timeline";
 
 export function buildEmptyTrack({
@@ -10,7 +10,7 @@ export function buildEmptyTrack({
 	type: TrackType;
 	name?: string;
 }): TimelineTrack {
-	const trackName = name ?? TRACK_CONFIG[type].defaultName;
+	const trackName = name ?? DEFAULT_TRACK_NAMES[type];
 
 	switch (type) {
 		case "video":
diff --git a/apps/web/src/lib/timeline/ruler-utils.ts b/apps/web/src/lib/timeline/ruler-utils.ts
index 94ef416a..732d9ea4 100644
--- a/apps/web/src/lib/timeline/ruler-utils.ts
+++ b/apps/web/src/lib/timeline/ruler-utils.ts
@@ -1,4 +1,4 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 
 /**
  * frame intervals for labels - starts at 2 so there's always at least
@@ -56,7 +56,7 @@ export function getRulerConfig({
 	zoomLevel: number;
 	fps: number;
 }): RulerConfig {
-	const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+	const pixelsPerSecond = BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 	const pixelsPerFrame = pixelsPerSecond / fps;
 
 	const labelIntervalSeconds = findOptimalInterval({
diff --git a/apps/web/src/lib/timeline/scale.ts b/apps/web/src/lib/timeline/scale.ts
new file mode 100644
index 00000000..7770f59f
--- /dev/null
+++ b/apps/web/src/lib/timeline/scale.ts
@@ -0,0 +1,3 @@
+export const BASE_TIMELINE_PIXELS_PER_SECOND = 50;
+export const TIMELINE_ZOOM_MIN = 0.1;
+export const TIMELINE_ZOOM_MAX = 100;
diff --git a/apps/web/src/lib/timeline/snap-utils.ts b/apps/web/src/lib/timeline/snap-utils.ts
index 2efe24e4..ef5d6e11 100644
--- a/apps/web/src/lib/timeline/snap-utils.ts
+++ b/apps/web/src/lib/timeline/snap-utils.ts
@@ -1,5 +1,5 @@
 import type { Bookmark, TimelineTrack } from "@/lib/timeline";
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import { BASE_TIMELINE_PIXELS_PER_SECOND } from "@/lib/timeline/scale";
 import { BOOKMARK_TIME_EPSILON } from "@/lib/timeline/bookmarks";
 import { getElementKeyframes } from "@/lib/animation";
 
@@ -107,7 +107,7 @@ export function snapToNearestPoint({
 	zoomLevel: number;
 	snapThreshold?: number;
 }): SnapResult {
-	const pixelsPerSecond = TIMELINE_CONSTANTS.PIXELS_PER_SECOND * zoomLevel;
+	const pixelsPerSecond = BASE_TIMELINE_PIXELS_PER_SECOND * zoomLevel;
 	const thresholdInSeconds = snapThreshold / pixelsPerSecond;
 
 	let closestSnapPoint: SnapPoint | null = null;
diff --git a/apps/web/src/lib/timeline/track-capabilities.ts b/apps/web/src/lib/timeline/track-capabilities.ts
new file mode 100644
index 00000000..08ee841c
--- /dev/null
+++ b/apps/web/src/lib/timeline/track-capabilities.ts
@@ -0,0 +1,20 @@
+import type {
+	TimelineTrack,
+	VideoTrack,
+	AudioTrack,
+	GraphicTrack,
+	TextTrack,
+	EffectTrack,
+} from "@/lib/timeline";
+
+export function canTrackHaveAudio(
+	track: TimelineTrack,
+): track is VideoTrack | AudioTrack {
+	return track.type === "audio" || track.type === "video";
+}
+
+export function canTrackBeHidden(
+	track: TimelineTrack,
+): track is VideoTrack | TextTrack | GraphicTrack | EffectTrack {
+	return track.type !== "audio";
+}
diff --git a/apps/web/src/lib/timeline/track-utils.ts b/apps/web/src/lib/timeline/track-utils.ts
deleted file mode 100644
index cc9e67c4..00000000
--- a/apps/web/src/lib/timeline/track-utils.ts
+++ /dev/null
@@ -1,62 +0,0 @@
-import type {
-	TrackType,
-	TimelineTrack,
-	VideoTrack,
-	AudioTrack,
-	GraphicTrack,
-	TextTrack,
-	EffectTrack,
-} from "@/lib/timeline";
-import {
-	TRACK_CONFIG,
-	ELEMENT_TYPE_CONFIG,
-	TRACK_GAP,
-} from "@/constants/timeline-constants";
-
-export function canTracktHaveAudio(
-	track: TimelineTrack,
-): track is VideoTrack | AudioTrack {
-	return track.type === "audio" || track.type === "video";
-}
-
-export function canTrackBeHidden(
-	track: TimelineTrack,
-): track is VideoTrack | TextTrack | GraphicTrack | EffectTrack {
-	return track.type !== "audio";
-}
-
-export function getElementClasses({ type }: { type: TrackType }) {
-	return ELEMENT_TYPE_CONFIG[type].background.trim();
-}
-
-export function getTrackHeight({ type }: { type: TrackType }): number {
-	return TRACK_CONFIG[type].height;
-}
-
-export function getCumulativeHeightBefore({
-	tracks,
-	trackIndex,
-}: {
-	tracks: Array<{ type: TrackType }>;
-	trackIndex: number;
-}): number {
-	return tracks
-		.slice(0, trackIndex)
-		.reduce(
-			(sum, track) => sum + getTrackHeight({ type: track.type }) + TRACK_GAP,
-			0,
-		);
-}
-
-export function getTotalTracksHeight({
-	tracks,
-}: {
-	tracks: Array<{ type: TrackType }>;
-}): number {
-	const tracksHeight = tracks.reduce(
-		(sum, track) => sum + getTrackHeight({ type: track.type }),
-		0,
-	);
-	const gapsHeight = Math.max(0, tracks.length - 1) * TRACK_GAP;
-	return tracksHeight + gapsHeight;
-}
diff --git a/apps/web/src/lib/timeline/tracks.ts b/apps/web/src/lib/timeline/tracks.ts
new file mode 100644
index 00000000..181b9fcf
--- /dev/null
+++ b/apps/web/src/lib/timeline/tracks.ts
@@ -0,0 +1,9 @@
+import type { TrackType } from "@/lib/timeline";
+
+export const DEFAULT_TRACK_NAMES: Record<TrackType, string> = {
+	video: "Video track",
+	text: "Text track",
+	audio: "Audio track",
+	graphic: "Graphic track",
+	effect: "Effect track",
+} as const;
diff --git a/apps/web/src/lib/timeline/zoom-utils.ts b/apps/web/src/lib/timeline/zoom-utils.ts
index bbc0b6ae..c06957d0 100644
--- a/apps/web/src/lib/timeline/zoom-utils.ts
+++ b/apps/web/src/lib/timeline/zoom-utils.ts
@@ -1,4 +1,7 @@
-import { TIMELINE_CONSTANTS } from "@/constants/timeline-constants";
+import {
+	BASE_TIMELINE_PIXELS_PER_SECOND,
+	TIMELINE_ZOOM_MAX,
+} from "@/lib/timeline/scale";
 
 const PADDING_MAX_RATIO = 0.75;
 const PADDING_MIN_RATIO = 0.15;
@@ -16,9 +19,9 @@ export function getTimelineZoomMin({
 	const contentRatioAtMinZoom = 1 - PADDING_MAX_RATIO;
 	const availableWidth = safeContainerWidth * contentRatioAtMinZoom;
 	const zoomToFit =
-		availableWidth / (safeDuration * TIMELINE_CONSTANTS.PIXELS_PER_SECOND);
+		availableWidth / (safeDuration * BASE_TIMELINE_PIXELS_PER_SECOND);
 
-	return Math.min(TIMELINE_CONSTANTS.ZOOM_MAX, zoomToFit);
+	return Math.min(TIMELINE_ZOOM_MAX, zoomToFit);
 }
 
 export function getTimelinePaddingPx({
@@ -49,7 +52,7 @@ export function getZoomPercent({
 	zoomLevel: number;
 	minZoom: number;
 }): number {
-	return (zoomLevel - minZoom) / (TIMELINE_CONSTANTS.ZOOM_MAX - minZoom);
+	return (zoomLevel - minZoom) / (TIMELINE_ZOOM_MAX - minZoom);
 }
 
 /**
@@ -59,7 +62,7 @@ export function getZoomPercent({
 export function sliderToZoom({
 	sliderPosition,
 	minZoom,
-	maxZoom = TIMELINE_CONSTANTS.ZOOM_MAX,
+	maxZoom = TIMELINE_ZOOM_MAX,
 }: {
 	sliderPosition: number;
 	minZoom: number;
@@ -75,7 +78,7 @@ export function sliderToZoom({
 export function zoomToSlider({
 	zoomLevel,
 	minZoom,
-	maxZoom = TIMELINE_CONSTANTS.ZOOM_MAX,
+	maxZoom = TIMELINE_ZOOM_MAX,
 }: {
 	zoomLevel: number;
 	minZoom: number;
diff --git a/apps/web/src/services/renderer/scene-builder.ts b/apps/web/src/services/renderer/scene-builder.ts
index 8fd8631b..76b97021 100644
--- a/apps/web/src/services/renderer/scene-builder.ts
+++ b/apps/web/src/services/renderer/scene-builder.ts
@@ -11,7 +11,7 @@ import { BlurBackgroundNode } from "./nodes/blur-background-node";
 import { EffectLayerNode } from "./nodes/effect-layer-node";
 import type { BaseNode } from "./nodes/base-node";
 import type { TBackground, TCanvasSize } from "@/lib/project/types";
-import { DEFAULT_BLUR_INTENSITY } from "@/constants/project-constants";
+import { DEFAULT_BACKGROUND_BLUR_INTENSITY } from "@/lib/background/constants";
 import { isMainTrack } from "@/lib/timeline/placement";
 
 const PREVIEW_MAX_IMAGE_SIZE = 2048;
@@ -252,7 +252,8 @@ export function buildScene({
 		const blurNodes = buildBlurBackgroundNodes({
 			track: mainTrack,
 			mediaMap,
-			blurIntensity: background.blurIntensity ?? DEFAULT_BLUR_INTENSITY,
+			blurIntensity:
+				background.blurIntensity ?? DEFAULT_BACKGROUND_BLUR_INTENSITY,
 		});
 		for (const node of blurNodes) {
 			rootNode.add(node);
diff --git a/apps/web/src/services/storage/migrations/__tests__/v1-to-v2.test.ts b/apps/web/src/services/storage/migrations/__tests__/v1-to-v2.test.ts
index 31f7dae8..7a4dd641 100644
--- a/apps/web/src/services/storage/migrations/__tests__/v1-to-v2.test.ts
+++ b/apps/web/src/services/storage/migrations/__tests__/v1-to-v2.test.ts
@@ -1,10 +1,10 @@
 import { describe, expect, test } from "bun:test";
 import {
-	DEFAULT_BLUR_INTENSITY,
-	DEFAULT_CANVAS_SIZE,
-	DEFAULT_COLOR,
-	DEFAULT_FPS,
-} from "@/constants/project-constants";
+	DEFAULT_BACKGROUND_BLUR_INTENSITY,
+	DEFAULT_BACKGROUND_COLOR,
+} from "@/lib/background/constants";
+import { DEFAULT_CANVAS_SIZE } from "@/lib/canvas/constants";
+import { DEFAULT_FPS } from "@/lib/fps/constants";
 import type { MediaAssetData } from "@/services/storage/types";
 import { getProjectId, transformProjectV1ToV2 } from "../transformers/v1-to-v2";
 import {
@@ -119,7 +119,7 @@ describe("V1 to V2 Migration", () => {
 
 			const background = settings.background as Record<string, unknown>;
 			expect(background.type).toBe("color");
-			expect(background.color).toBe(DEFAULT_COLOR);
+			expect(background.color).toBe(DEFAULT_BACKGROUND_COLOR);
 		});
 
 		test("uses default blur intensity when missing", async () => {
@@ -135,7 +135,9 @@ describe("V1 to V2 Migration", () => {
 
 			const settings = result.project.settings as Record<string, unknown>;
 			const background = settings.background as Record<string, unknown>;
-			expect(background.blurIntensity).toBe(DEFAULT_BLUR_INTENSITY);
+			expect(background.blurIntensity).toBe(
+				DEFAULT_BACKGROUND_BLUR_INTENSITY,
+			);
 		});
 
 		test("preserves currentSceneId", async () => {
diff --git a/apps/web/src/services/storage/migrations/transformers/v1-to-v2.ts b/apps/web/src/services/storage/migrations/transformers/v1-to-v2.ts
index 52701cd5..a2c72478 100644
--- a/apps/web/src/services/storage/migrations/transformers/v1-to-v2.ts
+++ b/apps/web/src/services/storage/migrations/transformers/v1-to-v2.ts
@@ -1,9 +1,9 @@
 import {
-	DEFAULT_BLUR_INTENSITY,
-	DEFAULT_CANVAS_SIZE,
-	DEFAULT_COLOR,
-	DEFAULT_FPS,
-} from "@/constants/project-constants";
+	DEFAULT_BACKGROUND_BLUR_INTENSITY,
+	DEFAULT_BACKGROUND_COLOR,
+} from "@/lib/background/constants";
+import { DEFAULT_CANVAS_SIZE } from "@/lib/canvas/constants";
+import { DEFAULT_FPS } from "@/lib/fps/constants";
 import { IndexedDBAdapter } from "@/services/storage/indexeddb-adapter";
 import type { MediaAssetData } from "@/services/storage/types";
 import type { MigrationResult, ProjectRecord } from "./types";
@@ -739,14 +739,17 @@ function getBackgroundValue({
 				type: "blur",
 				blurIntensity: getNumberValue({
 					value: value.blurIntensity,
-					fallback: DEFAULT_BLUR_INTENSITY,
+					fallback: DEFAULT_BACKGROUND_BLUR_INTENSITY,
 				}),
 			};
 		}
 
 		return {
 			type: "color",
-			color: getStringValue({ value: value.color, fallback: DEFAULT_COLOR }),
+			color: getStringValue({
+				value: value.color,
+				fallback: DEFAULT_BACKGROUND_COLOR,
+			}),
 		};
 	}
 
@@ -755,14 +758,17 @@ function getBackgroundValue({
 			type: "blur",
 			blurIntensity: getNumberValue({
 				value: blurIntensity,
-				fallback: DEFAULT_BLUR_INTENSITY,
+				fallback: DEFAULT_BACKGROUND_BLUR_INTENSITY,
 			}),
 		};
 	}
 
 	return {
 		type: "color",
-		color: getStringValue({ value: backgroundColor, fallback: DEFAULT_COLOR }),
+		color: getStringValue({
+			value: backgroundColor,
+			fallback: DEFAULT_BACKGROUND_COLOR,
+		}),
 	};
 }
 
diff --git a/apps/web/src/stores/editor-store.ts b/apps/web/src/stores/editor-store.ts
index 0eb3c93e..50aa1b08 100644
--- a/apps/web/src/stores/editor-store.ts
+++ b/apps/web/src/stores/editor-store.ts
@@ -1,5 +1,5 @@
 import { create } from "zustand";
-import { DEFAULT_CANVAS_PRESETS } from "@/constants/project-constants";
+import { DEFAULT_CANVAS_PRESETS } from "@/lib/canvas/constants";
 import type { TCanvasSize } from "@/lib/project/types";
 
 interface EditorState {
diff --git a/apps/web/src/stores/panel-store.ts b/apps/web/src/stores/panel-store.ts
index 6f22b6b4..72f4e9bc 100644
--- a/apps/web/src/stores/panel-store.ts
+++ b/apps/web/src/stores/panel-store.ts
@@ -1,6 +1,6 @@
 import { create } from "zustand";
 import { persist } from "zustand/middleware";
-import { PANEL_CONFIG } from "@/constants/editor-constants";
+import { PANEL_CONFIG } from "@/lib/panels/constants";
 
 export interface PanelSizes {
 	tools: number;