diff --git a/src/components/CanvasStage.vue b/src/components/CanvasStage.vue
index 16dcd8c..0604c83 100644
--- a/src/components/CanvasStage.vue
+++ b/src/components/CanvasStage.vue
@@ -23,7 +23,7 @@ import {
   useButtonRuntime,
 } from '@/composables/useButtonRuntime'
 import { evalAction } from '@/lib/actions'
-import { lerpProps } from '@/lib/interpolate'
+import { blendButtonStates } from '@/lib/buttonBlend'
 import { t } from '@/i18n'
 import { useKfSelection } from '@/composables/useKfSelection'
 import { showLocked } from '@/composables/useShowLocked'
@@ -226,50 +226,15 @@ function sampleStateLayers(
   return out
 }
 
-/**
- * Blend the "from" state's layers into the "to" state's layers by layer
- * name. Matched pairs lerp their props; unmatched from-layers fade out,
- * unmatched to-layers fade in.
- */
 function blendStates(
   clip: ButtonClip,
   from: ButtonState,
   to: ButtonState,
   u: number,
 ): ButtonRenderItem['layers'] {
-  const fromLayers = clip.states[from] ?? []
-  const toLayers = clip.states[to] ?? []
-  const fromByName = new Map<string, Layer>()
-  const toByName = new Map<string, Layer>()
-  for (const l of fromLayers) fromByName.set(l.name, l)
-  for (const l of toLayers) toByName.set(l.name, l)
-  const seen = new Set<string>()
-  const out: ButtonRenderItem['layers'] = []
-  // Preserve to-state order primarily, with unmatched from-layers pinned
-  // underneath so the new state visually rises into place.
-  for (const l of fromLayers) {
-    if (toByName.has(l.name)) continue
-    const asset = store.scene.assets.find((a) => a.id === l.assetId)
-    if (!asset) continue
-    const base = sampleLayer(l, 0)
-    out.push({ layer: l, asset, props: { ...base, opacity: base.opacity * (1 - u) } })
-  }
-  for (const l of toLayers) {
-    const asset = store.scene.assets.find((a) => a.id === l.assetId)
-    if (!asset) continue
-    seen.add(l.name)
-    const fromLayer = fromByName.get(l.name)
-    if (fromLayer) {
-      const a = sampleLayer(fromLayer, 0)
-      const b = sampleLayer(l, 0)
-      out.push({ layer: l, asset, props: lerpProps(a, b, u) })
-    } else {
-      const base = sampleLayer(l, 0)
-      out.push({ layer: l, asset, props: { ...base, opacity: base.opacity * u } })
-    }
-  }
-  void seen
-  return out
+  return blendButtonStates(clip, from, to, u, (id) =>
+    store.scene.assets.find((a) => a.id === id),
+  )
 }
 
 const activeButtonInstances = computed<ButtonRenderItem[]>(() => {
diff --git a/src/devtools/tests.ts b/src/devtools/tests.ts
index 07c0c6b..9dc6139 100644
--- a/src/devtools/tests.ts
+++ b/src/devtools/tests.ts
@@ -4,6 +4,7 @@ import {
   applyButtonStateChange,
   useButtonRuntime,
 } from '@/composables/useButtonRuntime'
+import { blendButtonStates } from '@/lib/buttonBlend'
 import {
   buildMarkerMap,
   evalAction,
@@ -11,7 +12,7 @@ import {
   type ActionRuntime,
 } from '@/lib/actions'
 import { parseScript } from '@/lib/scriptDsl'
-import type { Action } from '@/types/scene'
+import type { Action, Asset, ButtonClip, Layer } from '@/types/scene'
 import { sampleLayer, lerpColor } from '@/lib/interpolate'
 import { snapToCandidates } from '@/lib/timelineSnap'
 import {
@@ -3627,4 +3628,337 @@ export function registerAllTests(): void {
       expect(s.scene.scriptTracks?.find((x) => x.id === t.id)?.locked).toBe(undefined)
     })
   })
+
+  suite('macro-clips — store coverage gaps', () => {
+    test('removeMarker on unknown id is a no-op', () => {
+      const s = makeFreshStore()
+      s.addMarker(1, 'A')
+      s.removeMarker('no-such-id')
+      expect(s.scene.markers).toHaveLength(1)
+    })
+
+    test('setMarkerTime / setMarkerColor on unknown id are no-ops', () => {
+      const s = makeFreshStore()
+      s.setMarkerTime('ghost', 5)
+      s.setMarkerColor('ghost', '#ff0000')
+      expect(s.scene.markers).toHaveLength(0)
+    })
+
+    test('addMarker accepts an initial color', () => {
+      const s = makeFreshStore()
+      const m = s.addMarker(1, 'A', '#ff8800')
+      expect(m.color).toBe('#ff8800')
+    })
+
+    test('removeScriptFrame / setScriptFrameActions / setScriptFrameTime handle unknown ids', () => {
+      const s = makeFreshStore()
+      // None of these should throw or mutate anything.
+      s.removeScriptFrame('nope')
+      s.setScriptFrameActions('nope', [{ type: 'play' }])
+      s.setScriptFrameTime('nope', 1)
+      expect(s.scene.scriptFrames).toEqual([])
+    })
+
+    test('removeButtonInstance removes the instance but keeps the clip', () => {
+      const s = makeFreshStore()
+      const bc = s.addButtonClip('B')
+      const ct = s.addClipTrack()
+      const inst = s.addButtonInstance(bc.id, ct.id, 0)!
+      s.removeButtonInstance(inst.id)
+      expect(s.scene.buttonInstances).toHaveLength(0)
+      expect(s.scene.buttonClips).toHaveLength(1)
+    })
+
+    test('addButtonInstance defaults x/y to stage center', () => {
+      const s = makeFreshStore()
+      const bc = s.addButtonClip('B')
+      const ct = s.addClipTrack()
+      const inst = s.addButtonInstance(bc.id, ct.id, 0)!
+      expect(inst.x).toBe(s.scene.canvas.width / 2)
+      expect(inst.y).toBe(s.scene.canvas.height / 2)
+    })
+
+    test('setButtonInstancePosition updates x/y', () => {
+      const s = makeFreshStore()
+      const bc = s.addButtonClip('B')
+      const ct = s.addClipTrack()
+      const inst = s.addButtonInstance(bc.id, ct.id, 0)!
+      s.setButtonInstancePosition(inst.id, 42, 99)
+      const got = s.scene.buttonInstances?.find((x) => x.id === inst.id)
+      expect(got?.x).toBe(42)
+      expect(got?.y).toBe(99)
+    })
+
+    test('setButtonInstanceLabel("") clears the label', () => {
+      const s = makeFreshStore()
+      const bc = s.addButtonClip('B')
+      const ct = s.addClipTrack()
+      const inst = s.addButtonInstance(bc.id, ct.id, 0)!
+      s.setButtonInstanceLabel(inst.id, 'play')
+      expect(s.setButtonInstanceLabel(inst.id, '')).toBe(true)
+      const got = s.scene.buttonInstances?.find((x) => x.id === inst.id)
+      expect(got?.label).toBe(undefined)
+    })
+
+    test('setButtonClipTransitions stores list and deletes it when empty', () => {
+      const s = makeFreshStore()
+      const bc = s.addButtonClip('B')
+      s.setButtonClipTransitions(bc.id, [
+        { from: 'normal', to: 'hover', duration: 0.2, easing: 'easeOut' },
+      ])
+      const got = () => s.scene.buttonClips?.find((c) => c.id === bc.id)
+      expect(got()?.transitions).toHaveLength(1)
+      s.setButtonClipTransitions(bc.id, [])
+      expect(got()?.transitions).toBe(undefined)
+    })
+  })
+
+  suite('macro-clips — button runtime edge cases', () => {
+    test('applyButtonStateChange is a no-op when target equals current', () => {
+      const rt = useButtonRuntime()
+      rt.reset()
+      applyButtonStateChange(
+        'b1',
+        'normal',
+        [{ from: 'normal', to: 'normal', duration: 1, easing: 'linear' }],
+        undefined,
+      )
+      expect(rt.getState('b1')).toBe('normal')
+      expect(rt.transition.has('b1')).toBe(false)
+    })
+
+    test('applyButtonStateChange honors persisted disabled flag as the from-state', () => {
+      const rt = useButtonRuntime()
+      rt.reset()
+      // persistedDisabled=true → current 'disabled'; transition from disabled
+      // to normal should fire if defined.
+      applyButtonStateChange(
+        'b1',
+        'normal',
+        [{ from: 'disabled', to: 'normal', duration: 0.1, easing: 'linear' }],
+        true,
+      )
+      expect(rt.transition.has('b1')).toBe(true)
+      rt.endTransition('b1')
+    })
+
+    test('reset() clears state, disabled and transitions', () => {
+      const rt = useButtonRuntime()
+      rt.setState('b1', 'pressed')
+      rt.setDisabled('b2', true)
+      rt.startTransition('b1', 'normal', 'hover', 1, 'linear', performance.now())
+      rt.reset()
+      expect(rt.getState('b1')).toBe('normal')
+      expect(rt.isDisabled('b2')).toBe(false)
+      expect(rt.transition.size).toBe(0)
+    })
+
+    test('store.actionRuntime warns + skips for unknown button refs', () => {
+      const s = makeFreshStore()
+      const warned: string[] = []
+      const origWarn = console.warn
+      console.warn = (...a: unknown[]) => { warned.push(a.map(String).join(' ')) }
+      try {
+        const ar = s.actionRuntime()
+        ar.setButtonState('ghost', 'pressed')
+        ar.setButtonDisabled('ghost', true)
+      } finally {
+        console.warn = origWarn
+      }
+      expect(warned.length >= 2).toBe(true)
+    })
+  })
+
+  suite('macro-clips — blendButtonStates', () => {
+    function makeLayer(name: string, fill: string): Layer {
+      return {
+        id: `l-${name}-${fill}`,
+        name,
+        assetId: 'a1',
+        visible: true,
+        base: { x: 0, y: 0, scaleX: 1, scaleY: 1, rotation: 0, opacity: 1, fill },
+        keyframes: [
+          {
+            id: `kf-${name}-${fill}`,
+            time: 0,
+            props: { x: 0, y: 0, scaleX: 1, scaleY: 1, rotation: 0, opacity: 1, fill },
+            easing: 'linear',
+          },
+        ],
+      }
+    }
+    const asset: Asset = {
+      id: 'a1',
+      kind: 'rect',
+      name: 'face',
+      width: 40,
+      height: 20,
+      fill: '#000',
+    }
+    const assetBy = (id: string) => (id === 'a1' ? asset : undefined)
+
+    test('matched layer interpolates props via lerpProps', () => {
+      const clip: ButtonClip = {
+        id: 'bc',
+        name: 'b',
+        states: {
+          normal: [makeLayer('Face', '#ff0000')],
+          hover: [makeLayer('Face', '#00ff00')],
+          pressed: [],
+          disabled: [],
+        },
+      }
+      const out = blendButtonStates(clip, 'normal', 'hover', 0.5, assetBy)
+      expect(out).toHaveLength(1)
+      expect(out[0].layer.name).toBe('Face')
+      // At u=0.5 the fill should be the mid of #ff0000 → #00ff00 (roughly).
+      const f = out[0].props.fill!
+      // Red and green channels should each be around 0x7f-ish
+      const n = parseInt(f.replace('#', ''), 16)
+      const r = (n >> 16) & 255
+      const g = (n >> 8) & 255
+      expect(r > 100 && r < 160).toBe(true)
+      expect(g > 100 && g < 160).toBe(true)
+    })
+
+    test('unmatched from-layer fades out, unmatched to-layer fades in', () => {
+      const clip: ButtonClip = {
+        id: 'bc',
+        name: 'b',
+        states: {
+          normal: [makeLayer('Only-N', '#ff0000')],
+          hover: [makeLayer('Only-H', '#00ff00')],
+          pressed: [],
+          disabled: [],
+        },
+      }
+      const u = 0.25
+      const out = blendButtonStates(clip, 'normal', 'hover', u, assetBy)
+      // First: unmatched from-layer, opacity * (1 - u) = 0.75
+      expect(out[0].layer.name).toBe('Only-N')
+      expect(out[0].props.opacity).toBeCloseTo(1 - u, 3)
+      // Second: unmatched to-layer, opacity * u = 0.25
+      expect(out[1].layer.name).toBe('Only-H')
+      expect(out[1].props.opacity).toBeCloseTo(u, 3)
+    })
+
+    test('u=0 is pure from-state, u=1 is pure to-state (matched layer)', () => {
+      const clip: ButtonClip = {
+        id: 'bc',
+        name: 'b',
+        states: {
+          normal: [makeLayer('Face', '#ff0000')],
+          hover: [makeLayer('Face', '#00ff00')],
+          pressed: [],
+          disabled: [],
+        },
+      }
+      const atZero = blendButtonStates(clip, 'normal', 'hover', 0, assetBy)
+      expect(atZero[0].props.fill).toBe('#ff0000')
+      const atOne = blendButtonStates(clip, 'normal', 'hover', 1, assetBy)
+      expect(atOne[0].props.fill).toBe('#00ff00')
+    })
+
+    test('skips layers whose asset id does not resolve', () => {
+      const clip: ButtonClip = {
+        id: 'bc',
+        name: 'b',
+        states: {
+          normal: [makeLayer('Face', '#ff0000')],
+          hover: [makeLayer('Face', '#00ff00')],
+          pressed: [],
+          disabled: [],
+        },
+      }
+      const out = blendButtonStates(clip, 'normal', 'hover', 0.5, () => undefined)
+      expect(out).toHaveLength(0)
+    })
+  })
+
+  suite('macro-clips — DSL edge cases', () => {
+    test('empty source yields no actions and no errors', () => {
+      const { actions, errors } = parseScript('')
+      expect(actions).toHaveLength(0)
+      expect(errors).toHaveLength(0)
+    })
+
+    test('only comments or whitespace yields no actions', () => {
+      const { actions, errors } = parseScript('   \n\n// note\n   // more\n')
+      expect(actions).toHaveLength(0)
+      expect(errors).toHaveLength(0)
+    })
+
+    test('trailing blank lines do not produce phantom errors', () => {
+      const { actions, errors } = parseScript('play\n\n\n')
+      expect(actions).toHaveLength(1)
+      expect(errors).toHaveLength(0)
+    })
+
+    test('state command with wrong ref prefix reports error', () => {
+      const { errors } = parseScript('state label pressed')
+      expect(errors).toHaveLength(1)
+      expect(errors[0].message).toContain('btn:')
+    })
+
+    test('disable without argument reports error', () => {
+      const { errors } = parseScript('disable')
+      expect(errors).toHaveLength(1)
+      expect(errors[0].message).toContain('disable')
+    })
+
+    test('jump with empty @marker reports error', () => {
+      const { errors } = parseScript('jump @')
+      expect(errors).toHaveLength(1)
+      expect(errors[0].message).toContain('marker')
+    })
+  })
+
+  suite('macro-clips — tick firing robustness', () => {
+    test('multiple frames on different tracks fire in time order', async () => {
+      const s = makeFreshStore()
+      s.setDuration(10)
+      const t1 = s.addScriptTrack('A')
+      const t2 = s.addScriptTrack('B')
+      const log: number[] = []
+      // Three frames: 0.2 (t2), 0.5 (t1), 0.8 (t2)
+      // We can verify ordering via jumpTo actions that push into a list…
+      // but evalAction dispatches to store.setPlayhead etc. We instead
+      // observe the jumpTo time the playhead ends up at after all fire.
+      s.addScriptFrame(t2.id, 0.2, [{ type: 'jumpTo', time: 1 }])
+      s.addScriptFrame(t1.id, 0.5, [{ type: 'jumpTo', time: 2 }])
+      s.addScriptFrame(t2.id, 0.8, [{ type: 'jumpTo', time: 3 }])
+      s.play()
+      s.tick(1) // advances to 1, all three frames in (0, 1]
+      // The last fired wins — since frames fire sorted by time, the last
+      // action to run is jumpTo 3.
+      expect(s.playhead).toBe(3)
+      s.pause()
+      await tick()
+      void log
+    })
+
+    test('within a single frame, actions fire in list order', async () => {
+      const s = makeFreshStore()
+      s.setDuration(10)
+      const t = s.addScriptTrack()
+      s.addScriptFrame(t.id, 1, [
+        { type: 'jumpTo', time: 5 },
+        { type: 'jumpTo', time: 7 },
+        { type: 'pause' },
+      ])
+      s.play()
+      s.tick(2)
+      expect(s.playhead).toBe(7)
+      expect(s.playing).toBe(false)
+      await tick()
+    })
+
+    test('scriptFramesInRange handles exactly-at-next inclusively', () => {
+      const frames = [{ id: 'a', trackId: 't', time: 1, actions: [] as Action[] }]
+      // next strictly equals frame.time → included (open-closed)
+      expect(scriptFramesInRange(frames, 0.5, 1)).toHaveLength(1)
+      // next strictly below → excluded
+      expect(scriptFramesInRange(frames, 0.5, 0.999)).toHaveLength(0)
+    })
+  })
 }
diff --git a/src/lib/buttonBlend.ts b/src/lib/buttonBlend.ts
new file mode 100644
index 0000000..62fbcfc
--- /dev/null
+++ b/src/lib/buttonBlend.ts
@@ -0,0 +1,55 @@
+import type { AnimatableProps, Asset, ButtonClip, ButtonState, Layer } from '@/types/scene'
+import { lerpProps, sampleLayer } from '@/lib/interpolate'
+
+export interface BlendedLayerRender {
+  layer: Layer
+  asset: Asset
+  props: AnimatableProps
+}
+
+/**
+ * Blend the "from" state's layers into the "to" state's layers by layer
+ * name. Matched pairs lerp their sampled (t=0) props; unmatched
+ * from-layers fade out (opacity × (1 − u)), unmatched to-layers fade in
+ * (opacity × u). Used by the canvas renderer and the export runtime
+ * while a button state transition is in progress.
+ *
+ * `u` is expected to be post-easing progress ∈ [0, 1].
+ */
+export function blendButtonStates(
+  clip: ButtonClip,
+  from: ButtonState,
+  to: ButtonState,
+  u: number,
+  assetBy: (id: string) => Asset | undefined,
+): BlendedLayerRender[] {
+  const fromLayers = clip.states[from] ?? []
+  const toLayers = clip.states[to] ?? []
+  const fromByName = new Map<string, Layer>()
+  const toByName = new Map<string, Layer>()
+  for (const l of fromLayers) fromByName.set(l.name, l)
+  for (const l of toLayers) toByName.set(l.name, l)
+  const out: BlendedLayerRender[] = []
+  // Unmatched from-layers render first (behind to-layers) and fade out.
+  for (const l of fromLayers) {
+    if (toByName.has(l.name)) continue
+    const asset = assetBy(l.assetId)
+    if (!asset) continue
+    const base = sampleLayer(l, 0)
+    out.push({ layer: l, asset, props: { ...base, opacity: base.opacity * (1 - u) } })
+  }
+  for (const l of toLayers) {
+    const asset = assetBy(l.assetId)
+    if (!asset) continue
+    const fromLayer = fromByName.get(l.name)
+    if (fromLayer) {
+      const a = sampleLayer(fromLayer, 0)
+      const b = sampleLayer(l, 0)
+      out.push({ layer: l, asset, props: lerpProps(a, b, u) })
+    } else {
+      const base = sampleLayer(l, 0)
+      out.push({ layer: l, asset, props: { ...base, opacity: base.opacity * u } })
+    }
+  }
+  return out
+}