diff --git a/apps/web/src/features/trackReplay/layers/replayLayers.ts b/apps/web/src/features/trackReplay/layers/replayLayers.ts
index 013c4ba..c297e3e 100644
--- a/apps/web/src/features/trackReplay/layers/replayLayers.ts
+++ b/apps/web/src/features/trackReplay/layers/replayLayers.ts
@@ -3,7 +3,7 @@ import type { Layer } from '@deck.gl/core';
 import type { ProcessedTrack } from '../model/track.types';
 import { getShipKindColor } from '../lib/adapters';
 import { TRACK_REPLAY_LAYER_IDS } from './trackLayers';
-import { DEPTH_DISABLED_PARAMS } from '../../../widgets/map3d/constants';
+import { DEPTH_DISABLED_PARAMS } from '../../../shared/lib/map/mapConstants';
 
 interface ReplayTrip {
   vesselId: string;
diff --git a/apps/web/src/features/trackReplay/layers/trackLayers.ts b/apps/web/src/features/trackReplay/layers/trackLayers.ts
index 206e3d0..640d4ea 100644
--- a/apps/web/src/features/trackReplay/layers/trackLayers.ts
+++ b/apps/web/src/features/trackReplay/layers/trackLayers.ts
@@ -1,6 +1,6 @@
 import { IconLayer, PathLayer, ScatterplotLayer, TextLayer } from '@deck.gl/layers';
 import type { Layer, PickingInfo } from '@deck.gl/core';
-import { DEPTH_DISABLED_PARAMS, SHIP_ICON_MAPPING } from '../../../widgets/map3d/constants';
+import { DEPTH_DISABLED_PARAMS, SHIP_ICON_MAPPING } from '../../../shared/lib/map/mapConstants';
 import { getCachedShipIcon } from '../../../widgets/map3d/lib/shipIconCache';
 import { getShipKindColor } from '../lib/adapters';
 import type { CurrentVesselPosition, ProcessedTrack } from '../model/track.types';
diff --git a/apps/web/src/features/weatherOverlay/useWeatherOverlay.ts b/apps/web/src/features/weatherOverlay/useWeatherOverlay.ts
index 2262708..ea95aea 100644
--- a/apps/web/src/features/weatherOverlay/useWeatherOverlay.ts
+++ b/apps/web/src/features/weatherOverlay/useWeatherOverlay.ts
@@ -9,7 +9,7 @@ import {
   RadarLayer,
   ColorRamp,
 } from '@maptiler/weather';
-import { getMapTilerKey } from '../../widgets/map3d/lib/mapCore';
+import { getMapTilerKey } from '../../shared/lib/map/mapTilerKey';
 
 /** 6종 기상 레이어 ID */
 export type WeatherLayerId =
diff --git a/apps/web/src/shared/lib/map/mapConstants.ts b/apps/web/src/shared/lib/map/mapConstants.ts
new file mode 100644
index 0000000..f17991a
--- /dev/null
+++ b/apps/web/src/shared/lib/map/mapConstants.ts
@@ -0,0 +1,20 @@
+// ── Shared map constants ──
+// Moved from widgets/map3d/constants.ts to resolve FSD layer violation
+// (features/ must not import from widgets/).
+
+export const SHIP_ICON_MAPPING = {
+  ship: {
+    x: 0,
+    y: 0,
+    width: 128,
+    height: 128,
+    anchorX: 64,
+    anchorY: 64,
+    mask: true,
+  },
+} as const;
+
+export const DEPTH_DISABLED_PARAMS = {
+  depthCompare: 'always',
+  depthWriteEnabled: false,
+} as const;
diff --git a/apps/web/src/shared/lib/map/mapTilerKey.ts b/apps/web/src/shared/lib/map/mapTilerKey.ts
new file mode 100644
index 0000000..16e6af9
--- /dev/null
+++ b/apps/web/src/shared/lib/map/mapTilerKey.ts
@@ -0,0 +1,9 @@
+// Moved from widgets/map3d/lib/mapCore.ts to resolve FSD layer violation
+// (features/ must not import from widgets/).
+
+export function getMapTilerKey(): string | null {
+  const k = import.meta.env.VITE_MAPTILER_KEY;
+  if (typeof k !== 'string') return null;
+  const v = k.trim();
+  return v ? v : null;
+}
diff --git a/apps/web/src/widgets/map3d/constants.ts b/apps/web/src/widgets/map3d/constants.ts
index 3da1d96..c29a7bc 100644
--- a/apps/web/src/widgets/map3d/constants.ts
+++ b/apps/web/src/widgets/map3d/constants.ts
@@ -15,18 +15,9 @@ const OVERLAY_FLEET_RANGE_RGB = OVERLAY_RGB.fleetRange;
 const OVERLAY_SUSPICIOUS_RGB = OVERLAY_RGB.suspicious;
 
 // ── Ship icon mapping (Deck.gl IconLayer) ──
+// Canonical source: shared/lib/map/mapConstants.ts (re-exported for local usage)
 
-export const SHIP_ICON_MAPPING = {
-  ship: {
-    x: 0,
-    y: 0,
-    width: 128,
-    height: 128,
-    anchorX: 64,
-    anchorY: 64,
-    mask: true,
-  },
-} as const;
+export { SHIP_ICON_MAPPING } from '../../shared/lib/map/mapConstants';
 
 // ── Ship constants ──
 
@@ -70,10 +61,8 @@ export const DECK_VIEW_ID = 'mapbox';
 
 // ── Depth params ──
 
-export const DEPTH_DISABLED_PARAMS = {
-  depthCompare: 'always',
-  depthWriteEnabled: false,
-} as const;
+// Canonical source: shared/lib/map/mapConstants.ts (re-exported for local usage)
+export { DEPTH_DISABLED_PARAMS } from '../../shared/lib/map/mapConstants';
 
 export const GLOBE_OVERLAY_PARAMS = {
   depthCompare: 'less-equal',
diff --git a/apps/web/src/widgets/map3d/lib/mapCore.ts b/apps/web/src/widgets/map3d/lib/mapCore.ts
index 1a35be3..e95616e 100644
--- a/apps/web/src/widgets/map3d/lib/mapCore.ts
+++ b/apps/web/src/widgets/map3d/lib/mapCore.ts
@@ -83,12 +83,8 @@ export function extractProjectionType(map: maplibregl.Map): MapProjectionId | un
   return undefined;
 }
 
-export function getMapTilerKey(): string | null {
-  const k = import.meta.env.VITE_MAPTILER_KEY;
-  if (typeof k !== 'string') return null;
-  const v = k.trim();
-  return v ? v : null;
-}
+// Canonical source: shared/lib/map/mapTilerKey.ts (re-exported for local usage)
+export { getMapTilerKey } from '../../../shared/lib/map/mapTilerKey';
 
 export function getLayerId(value: unknown): string | null {
   if (!value || typeof value !== 'object') return null;