diff --git a/.changeset/fix-frozen-dashboard-animations.md b/.changeset/fix-frozen-dashboard-animations.md
new file mode 100644
index 0000000000..8f75f4bdd2
--- /dev/null
+++ b/.changeset/fix-frozen-dashboard-animations.md
@@ -0,0 +1,11 @@
+---
+"@fusion/dashboard": patch
+---
+
+Unfreeze dashboard spinners and pulse/enter animations. Transition tokens
+(`--transition-slow: 0.3s ease`) bundle a duration and an easing; 15 animation
+declarations reused them as bare durations, which made the whole `animation`
+declaration invalid at computed-value time and silently resolved it to
+`animation: none`. Animation rules now use new duration-only tokens
+(`--duration-instant/fast/normal/slow`), with the transition tokens derived
+from them, and a repo-wide CSS regression test forbids the pattern.
diff --git a/docs/dashboard-guide.md b/docs/dashboard-guide.md
index bac1ef0fb4..a3335bb409 100644
--- a/docs/dashboard-guide.md
+++ b/docs/dashboard-guide.md
@@ -1072,7 +1072,7 @@ The `index.html` shell is templated server-side: the server injects a per-user `
 
 ### Design tokens
 
-`styles.css` is the source of truth for tokens (`--space-*`, `--radius-*`, `--shadow-*`, `--transition-*`, `--font-*`, `--header-height`, `--mobile-nav-height`, `--standalone-bottom-gap`, `--overlay-padding-top`) and color variables (`--bg`, `--surface`, `--card`, `--text`, `--text-muted`, status colors `--triage`/`--todo`/`--in-progress`/`--in-review`/`--done`, semantic `--color-success`/`--color-error`/`--color-warning`/`--color-info`, status backgrounds `--status-*-bg`).
+`styles.css` is the source of truth for tokens (`--space-*`, `--radius-*`, `--shadow-*`, `--duration-*`, `--transition-*`, `--font-*`, `--header-height`, `--mobile-nav-height`, `--standalone-bottom-gap`, `--overlay-padding-top`) and color variables (`--bg`, `--surface`, `--card`, `--text`, `--text-muted`, status colors `--triage`/`--todo`/`--in-progress`/`--in-review`/`--done`, semantic `--color-success`/`--color-error`/`--color-warning`/`--color-info`, status backgrounds `--status-*-bg`).
 
 **Always reference tokens. Never hardcode pixels, hex, or `rgba()` in component CSS** — the only exception is inside `:root`/theme blocks where tokens are *defined*. For translucent backgrounds use `color-mix(in srgb, var(--color) X%, transparent)`, not `rgba()`.
 
@@ -1168,6 +1168,7 @@ Reuse `packages/dashboard/app/utils/filePathLinkify.tsx` and `FileBrowserContext
 - **Mobile board scroll-snap (FN-001)** — `scroll-snap-type: x mandatory` on mobile `.board` causes iOS Safari to compress the viewport when switching from ListView. Use `x proximity` + `overflow-anchor: none`.
 - **`lucide-react` icon adds** — update `vi.mock("lucide-react")` test mocks immediately; missing exports cascade.
 - **`.spin` is global** — don't redefine the generic spin keyframes in component CSS.
+- **Animation durations use `--duration-*`, never `--transition-*`** — transition tokens carry a `duration easing` pair; substituting one into an `animation` shorthand that names its own easing (or into `calc()`) is invalid at computed-value time and silently resolves the whole declaration to `animation: none`. Enforced by `animation-duration-tokens.css.test.ts`; see `docs/solutions/ui-bugs/css-animation-frozen-by-transition-token-shape-mismatch.md`.
 
 ## Integration Branch Push to Origin
 
diff --git a/docs/solutions/ui-bugs/css-animation-frozen-by-transition-token-shape-mismatch.md b/docs/solutions/ui-bugs/css-animation-frozen-by-transition-token-shape-mismatch.md
new file mode 100644
index 0000000000..62d174d7b8
--- /dev/null
+++ b/docs/solutions/ui-bugs/css-animation-frozen-by-transition-token-shape-mismatch.md
@@ -0,0 +1,106 @@
+---
+title: CSS animations silently frozen by transition tokens used as durations (IACVT)
+date: 2026-06-03
+category: ui-bugs
+module: dashboard
+problem_type: ui_bug
+component: frontend_stimulus
+symptoms:
+  - "Spinners, status-dot pulses, and entrance animations render but never move"
+  - "No console errors, no DevTools strikethrough, no @keyframes parse errors"
+  - "getComputedStyle(el).animationName returns \"none\" on affected elements; el.getAnimations() is empty"
+  - "Other animations on the same page work fine, making the bug look intermittent"
+root_cause: wrong_api
+resolution_type: code_fix
+severity: high
+related_components:
+  - tooling
+tags: [css-custom-properties, iacvt, animation, design-tokens, transition-tokens, regression-test, dashboard-css]
+---
+
+# CSS animations silently frozen by transition tokens used as durations (IACVT)
+
+## Problem
+
+Dashboard spinners, status-dot pulses, and entrance animations rendered but never moved. The `--transition-*` design tokens carry a duration+easing **pair** (`--transition-slow: 0.3s ease`), and 15 `animation` declarations across 14 CSS files reused them as bare durations — which silently invalidated each whole declaration.
+
+## Symptoms
+
+- Spinners/loaders/pulses visible in the DOM but completely frozen
+- Zero diagnostics: no console error, no DevTools strikethrough, the declaration looks healthy in the Styles panel
+- `getComputedStyle(el).animationName === "none"` and `el.getAnimations().length === 0` on affected elements
+- Some animations on the same page kept working (see Why This Works), so the bug appeared intermittent
+- Invisible to static CSS reading and to jsdom-based tests
+
+## What Didn't Work
+
+- **Prior partial fixes (FN-5855, FN-5913)** addressed only the `.animate-spin` utility, which uses a literal `1s` duration — a separate code path. The token-misuse pattern survived both fixes.
+- Checking for `prefers-reduced-motion` overrides or `animation-play-state` rules — none existed.
+- Suspecting duplicate `@keyframes spin` definitions across component CSS files — all were valid `rotate(360deg)` definitions; identical re-definitions are harmless.
+- Dev-server repro without a backend (Vite's `/api` proxy prefix-matches the app's own `/api.ts` module requests, blanking the page). Repro that worked: **production build served statically**, injected test elements, measured via `getComputedStyle`/`getAnimations()`.
+
+## Solution
+
+Fix PR: Runfusion/Fusion#1386 (commit `2d2024fb0`).
+
+Split the tokens: bare durations become the source of truth, transition pairs are derived so the two can never drift (`packages/dashboard/app/styles.css`):
+
+```css
+/* Before — token encodes BOTH duration and easing */
+--transition-slow: 0.3s ease;
+
+/* After — duration is the source of truth; transition pair is derived
+   (same pattern for instant/fast/normal/slow) */
+--duration-slow: 0.3s;
+--transition-slow: var(--duration-slow) ease;
+```
+
+All 15 animation declarations switched to the duration tokens:
+
+```css
+/* Before — IACVT: substitutes to two <easing-function> values */
+animation: spin var(--transition-slow) linear infinite;
+/* Before — IACVT: calc() cannot multiply "0.3s ease" */
+animation: spin calc(var(--transition-slow) * 4) linear infinite;
+
+/* After */
+animation: spin var(--duration-slow) linear infinite;
+animation: spin calc(var(--duration-slow) * 4) linear infinite;
+```
+
+`transition:` consumers of `--transition-*` were always valid and stay unchanged.
+
+## Why This Works
+
+This is the **invalid-at-computed-value-time (IACVT)** mechanism from CSS Custom Properties Level 1. `var()` substitution happens *after* parsing, as opaque tokens — the parser cannot type-check. When the substituted value is invalid for the property, the browser does not ignore just the bad token; **the entire declaration is discarded** and the property falls back to inherited/initial. For `animation`, initial is `none`. No error is reported anywhere.
+
+```
+animation: spin var(--transition-slow) linear infinite
+              ↓ substitution
+animation: spin 0.3s ease linear infinite
+                 ↑    ↑      ↑
+             <time> <easing> <easing>   ← second easing keyword = invalid
+              ↓ IACVT
+animation: none                        ← whole declaration silently dropped
+```
+
+Why some animations kept working: `animation: spin var(--transition-slow) infinite` (no second easing) is *valid* — `0.3s ease` parses as `<time> <easing-function>`. Only declarations adding their own easing keyword, or wrapping the token in `calc()`, broke. That inconsistency is what made the bug look intermittent.
+
+## Prevention
+
+- **The failure mode generalizes:** IACVT applies to *any* property consuming a custom property — the same silent whole-declaration drop can disable `transition`, `grid-template-columns`, `transform`, etc. Treat token value *shape* as part of its contract.
+- **Token design rule:** never bundle multiple value types in one token if any consumer needs just one of them. Keep duration-only tokens (`--duration-*`) as the source of truth and derive combined tokens (`--transition-*: var(--duration-*) ease`) from them.
+- **Regression test:** `packages/dashboard/app/__tests__/animation-duration-tokens.css.test.ts` sweeps every CSS file under `app/` and fails on the three invalid shapes:
+  1. `animation:` shorthand combining `var(--transition-*)` with an explicit easing keyword
+  2. `calc(var(--transition-*)` anywhere
+  3. `animation-duration: var(--transition-*)`
+
+  It also asserts the duration tokens exist and that `--transition-*` stay derived. It enumerated all 15 broken sites red before the fix.
+- **Verification rule:** IACVT cannot be caught by linters (the CSS is syntactically valid) or jsdom (no computed-value validation). Definitive check is in a real browser engine: `getComputedStyle(el).animationName !== "none"` and `el.getAnimations().length > 0`.
+
+## Related Issues
+
+- Runfusion/Fusion#1386 — fix PR for this bug
+- Runfusion/Fusion#39 / PR #40 — earlier frozen-spinner incident with a *different* root cause (`.animate-spin`/`@keyframes spin` not globally scoped); useful contrast case at the same symptom layer
+- `docs/dashboard-guide.md` §Design tokens / §Common pitfalls — token family documentation (update candidates)
+- The token misuse spread widely because dashboard CSS was previously extracted from a 40k-line monolith into ~56 component files (auto memory [claude])
diff --git a/packages/dashboard/app/__tests__/animation-duration-tokens.css.test.ts b/packages/dashboard/app/__tests__/animation-duration-tokens.css.test.ts
new file mode 100644
index 0000000000..2d8b307c1a
--- /dev/null
+++ b/packages/dashboard/app/__tests__/animation-duration-tokens.css.test.ts
@@ -0,0 +1,113 @@
+import { describe, expect, it } from "vitest";
+import { readFileSync, readdirSync, statSync } from "fs";
+import { join, relative, resolve } from "path";
+
+/**
+ * Transition tokens (--transition-fast/normal/slow/instant) bundle a duration
+ * AND an easing keyword (e.g. "0.3s ease"). They are only valid where the
+ * `transition` shorthand expects that pair.
+ *
+ * Reusing them as bare durations inside `animation` shorthands silently kills
+ * the animation: substituting "0.3s ease" next to an explicit easing keyword
+ * (`linear`, `ease-in-out`, ...) produces two <easing-function> values, which
+ * makes the whole declaration invalid at computed-value time — the browser
+ * resolves it to `animation: none` with no console error. Wrapping the token
+ * in `calc()` fails the same way (you cannot multiply "0.3s ease").
+ *
+ * This froze 14 dashboard spinners/pulses (FN-5855/FN-5913 follow-up).
+ * Animation durations must use the duration-only tokens (--duration-*).
+ */
+
+const APP_DIR = resolve(__dirname, "..");
+
+function collectCssFiles(dir: string): string[] {
+  const out: string[] = [];
+  for (const entry of readdirSync(dir)) {
+    if (entry === "node_modules" || entry.startsWith(".")) continue;
+    const full = join(dir, entry);
+    const info = statSync(full);
+    if (info.isDirectory()) out.push(...collectCssFiles(full));
+    else if (entry.endsWith(".css")) out.push(full);
+  }
+  return out;
+}
+
+const EASING_KEYWORD =
+  /\b(?:linear|ease(?:-in|-out|-in-out)?|cubic-bezier\(|steps\()/;
+
+function findViolations(css: string): string[] {
+  const violations: string[] = [];
+  const lines = css.split("\n");
+
+  lines.forEach((line, index) => {
+    const lineNo = index + 1;
+
+    // calc() over a duration+easing pair is always invalid.
+    if (/calc\(\s*var\(--transition-/.test(line)) {
+      violations.push(`line ${lineNo}: calc() over a transition token — ${line.trim()}`);
+      return;
+    }
+
+    // animation shorthand: a transition token plus an explicit easing keyword
+    // substitutes to two easing functions and invalidates the declaration.
+    const animationMatch = line.match(/animation\s*:\s*([^;}]*)/);
+    if (animationMatch && /var\(--transition-/.test(animationMatch[1])) {
+      const valueWithoutToken = animationMatch[1].replace(/var\(--transition-[a-z]+\)/g, "");
+      if (EASING_KEYWORD.test(valueWithoutToken)) {
+        violations.push(
+          `line ${lineNo}: transition token + explicit easing in animation shorthand — ${line.trim()}`,
+        );
+      }
+    }
+
+    // animation-duration longhand cannot hold "0.3s ease" either.
+    if (/animation-duration\s*:\s*[^;}]*var\(--transition-/.test(line)) {
+      violations.push(`line ${lineNo}: transition token as animation-duration — ${line.trim()}`);
+    }
+  });
+
+  return violations;
+}
+
+describe("animation duration tokens", () => {
+  const cssFiles = collectCssFiles(APP_DIR);
+
+  it("finds the app stylesheets", () => {
+    expect(cssFiles.length).toBeGreaterThan(10);
+  });
+
+  it("defines duration-only tokens alongside the transition tokens", () => {
+    const styles = readFileSync(resolve(APP_DIR, "styles.css"), "utf8");
+    for (const speed of ["instant", "fast", "normal", "slow"]) {
+      expect(styles).toMatch(new RegExp(`--duration-${speed}:\\s*[\\d.]+m?s\\s*;`));
+      // Transition tokens must stay derived from the duration tokens so the
+      // two cannot drift apart.
+      expect(styles).toMatch(
+        new RegExp(`--transition-${speed}:\\s*var\\(--duration-${speed}\\)\\s+ease\\s*;`),
+      );
+    }
+  });
+
+  it("never uses duration+easing transition tokens where a bare duration is required", () => {
+    const allViolations: string[] = [];
+
+    for (const file of cssFiles) {
+      const css = readFileSync(file, "utf8");
+      const violations = findViolations(css);
+      for (const violation of violations) {
+        allViolations.push(`${relative(APP_DIR, file)} ${violation}`);
+      }
+    }
+
+    expect(allViolations).toEqual([]);
+  });
+
+  it("flags the frozen-spinner pattern if it is reintroduced", () => {
+    expect(findViolations(".x { animation: spin var(--transition-slow) linear infinite; }")).toHaveLength(1);
+    expect(findViolations(".x { animation: spin calc(var(--transition-slow) * 4) linear infinite; }")).toHaveLength(1);
+    expect(findViolations(".x { animation-duration: var(--transition-slow); }")).toHaveLength(1);
+    // Valid: token used in transition shorthand, or animation without a second easing.
+    expect(findViolations(".x { transition: color var(--transition-fast); }")).toHaveLength(0);
+    expect(findViolations(".x { animation: fadeIn var(--duration-fast) ease-out; }")).toHaveLength(0);
+  });
+});
diff --git a/packages/dashboard/app/components/CustomProvidersSection.css b/packages/dashboard/app/components/CustomProvidersSection.css
index 6c954cba22..b291e549e7 100644
--- a/packages/dashboard/app/components/CustomProvidersSection.css
+++ b/packages/dashboard/app/components/CustomProvidersSection.css
@@ -113,7 +113,7 @@
 }
 
 .spin {
-  animation: custom-provider-spin calc(var(--transition-slow) * 4) linear infinite;
+  animation: custom-provider-spin calc(var(--duration-slow) * 4) linear infinite;
 }
 
 @media (max-width: 768px) {
diff --git a/packages/dashboard/app/components/DbCorruptionBanner.css b/packages/dashboard/app/components/DbCorruptionBanner.css
index 76f07035ae..bbdf321de8 100644
--- a/packages/dashboard/app/components/DbCorruptionBanner.css
+++ b/packages/dashboard/app/components/DbCorruptionBanner.css
@@ -73,7 +73,7 @@
 }
 
 .db-corruption-banner__refresh-icon--spinning {
-  animation: status-dot-pulse var(--transition-slow) ease-in-out infinite;
+  animation: status-dot-pulse var(--duration-slow) ease-in-out infinite;
 }
 
 .db-corruption-banner__link {
diff --git a/packages/dashboard/app/components/DockerProvisioningStatus.css b/packages/dashboard/app/components/DockerProvisioningStatus.css
index 6c6a2f3a19..0a488ae74f 100644
--- a/packages/dashboard/app/components/DockerProvisioningStatus.css
+++ b/packages/dashboard/app/components/DockerProvisioningStatus.css
@@ -20,7 +20,7 @@
   height: var(--space-sm);
   border-radius: 50%;
   background-color: var(--todo);
-  animation: provisioning-pulse var(--transition-normal) ease-in-out infinite;
+  animation: provisioning-pulse var(--duration-normal) ease-in-out infinite;
 }
 
 .provisioning-status__dot:nth-child(2) {
diff --git a/packages/dashboard/app/components/FileMentionPopup.css b/packages/dashboard/app/components/FileMentionPopup.css
index 4906a223b7..ac3af26905 100644
--- a/packages/dashboard/app/components/FileMentionPopup.css
+++ b/packages/dashboard/app/components/FileMentionPopup.css
@@ -170,7 +170,7 @@
   border: calc(var(--space-xs) / 2) solid var(--border);
   border-top-color: var(--text-muted);
   border-radius: 50%;
-  animation: spin var(--transition-slow) linear infinite;
+  animation: spin var(--duration-slow) linear infinite;
 }
 
 @media (max-width: 768px) {
diff --git a/packages/dashboard/app/components/IssueMentionPopup.css b/packages/dashboard/app/components/IssueMentionPopup.css
index 660614bc3c..f335dd4259 100644
--- a/packages/dashboard/app/components/IssueMentionPopup.css
+++ b/packages/dashboard/app/components/IssueMentionPopup.css
@@ -81,7 +81,7 @@
   border: calc(var(--space-xs) / 2) solid var(--border);
   border-top-color: var(--text-muted);
   border-radius: 50%;
-  animation: spin var(--transition-slow) linear infinite;
+  animation: spin var(--duration-slow) linear infinite;
 }
 
 @media (max-width: 768px) {
diff --git a/packages/dashboard/app/components/ListView.css b/packages/dashboard/app/components/ListView.css
index 1c24679382..6a3e2fb1b1 100644
--- a/packages/dashboard/app/components/ListView.css
+++ b/packages/dashboard/app/components/ListView.css
@@ -815,7 +815,7 @@
 }
 
 .list-section-header ~ tr {
-  animation: section-expand var(--transition-normal) ease-out;
+  animation: section-expand var(--duration-normal) ease-out;
 }
 
 /* Empty section row */
diff --git a/packages/dashboard/app/components/NodesView.css b/packages/dashboard/app/components/NodesView.css
index 2d54303184..d9f1f221e1 100644
--- a/packages/dashboard/app/components/NodesView.css
+++ b/packages/dashboard/app/components/NodesView.css
@@ -14,8 +14,8 @@
 }
 
 .nodes-view {
-  --nodes-view-spin-duration: calc(var(--transition-slow) * 4);
-  --nodes-view-pulse-duration: calc(var(--transition-slow) * 5);
+  --nodes-view-spin-duration: calc(var(--duration-slow) * 4);
+  --nodes-view-pulse-duration: calc(var(--duration-slow) * 5);
   display: flex;
   flex-direction: column;
   gap: var(--space-md);
diff --git a/packages/dashboard/app/components/OnboardingDisclosure.css b/packages/dashboard/app/components/OnboardingDisclosure.css
index c8fff61b1a..0a6f64f2c2 100644
--- a/packages/dashboard/app/components/OnboardingDisclosure.css
+++ b/packages/dashboard/app/components/OnboardingDisclosure.css
@@ -45,7 +45,7 @@
   color: var(--text-muted);
   font-size: var(--font-size-sm, 12px);
   line-height: 1.5;
-  animation: onboarding-disclosure-enter var(--transition-fast) ease-out;
+  animation: onboarding-disclosure-enter var(--duration-fast) ease-out;
 }
 
 @keyframes onboarding-disclosure-enter {
diff --git a/packages/dashboard/app/components/OnboardingResumeCard.css b/packages/dashboard/app/components/OnboardingResumeCard.css
index 5779b8abf6..9dc56f285b 100644
--- a/packages/dashboard/app/components/OnboardingResumeCard.css
+++ b/packages/dashboard/app/components/OnboardingResumeCard.css
@@ -8,7 +8,7 @@
   padding: var(--space-sm) var(--space-lg);
   border-bottom: var(--btn-border-width) solid var(--border);
   background: var(--surface);
-  animation: onboarding-resume-card-enter var(--transition-normal) ease-out;
+  animation: onboarding-resume-card-enter var(--duration-normal) ease-out;
 }
 
 @keyframes onboarding-resume-card-enter {
diff --git a/packages/dashboard/app/components/SetupWizardModal.css b/packages/dashboard/app/components/SetupWizardModal.css
index 77c75ff9af..41d622d807 100644
--- a/packages/dashboard/app/components/SetupWizardModal.css
+++ b/packages/dashboard/app/components/SetupWizardModal.css
@@ -39,7 +39,7 @@
   /* vh fallback first for browsers without dvh support; dvh upgrade follows. */
   max-height: min(720px, calc(100vh - var(--overlay-padding-top, 10vh) - var(--space-lg)));
   max-height: min(720px, calc(100dvh - var(--overlay-padding-top, 10vh) - var(--space-lg)));
-  animation: slideUp var(--transition-normal) ease-out;
+  animation: slideUp var(--duration-normal) ease-out;
   overflow: hidden;
   /* Prevent flex parents from squeezing this below its content's needs. */
   flex-shrink: 0;
diff --git a/packages/dashboard/app/components/SystemStatsModal.css b/packages/dashboard/app/components/SystemStatsModal.css
index d40319ea48..803932d0eb 100644
--- a/packages/dashboard/app/components/SystemStatsModal.css
+++ b/packages/dashboard/app/components/SystemStatsModal.css
@@ -48,7 +48,7 @@
 }
 
 .system-stats-modal__refresh--spinning {
-  animation: system-stats-modal-refresh-spin var(--transition-slow) linear infinite;
+  animation: system-stats-modal-refresh-spin var(--duration-slow) linear infinite;
 }
 
 @keyframes system-stats-modal-refresh-spin {
diff --git a/packages/dashboard/app/components/TaskIdIntegrityBanner.css b/packages/dashboard/app/components/TaskIdIntegrityBanner.css
index 1f67bb6f60..7f6f9d2f2a 100644
--- a/packages/dashboard/app/components/TaskIdIntegrityBanner.css
+++ b/packages/dashboard/app/components/TaskIdIntegrityBanner.css
@@ -74,7 +74,7 @@
 }
 
 .task-id-integrity-banner__refresh-icon--spinning {
-  animation: status-dot-pulse var(--transition-slow) ease-in-out infinite;
+  animation: status-dot-pulse var(--duration-slow) ease-in-out infinite;
 }
 
 .task-id-integrity-banner__error {
diff --git a/packages/dashboard/app/components/TodoView.css b/packages/dashboard/app/components/TodoView.css
index 4934750071..a70ead3d8a 100644
--- a/packages/dashboard/app/components/TodoView.css
+++ b/packages/dashboard/app/components/TodoView.css
@@ -353,7 +353,7 @@
 }
 
 .todo-loading-icon {
-  animation: spin calc(var(--transition-slow) * 4) linear infinite;
+  animation: spin calc(var(--duration-slow) * 4) linear infinite;
 }
 
 @keyframes spin {
diff --git a/packages/dashboard/app/styles.css b/packages/dashboard/app/styles.css
index 6d79a8e50d..14cd285bbe 100644
--- a/packages/dashboard/app/styles.css
+++ b/packages/dashboard/app/styles.css
@@ -89,7 +89,7 @@ html {
 
 .status-dot--connecting {
   background: var(--color-warning);
-  animation: status-dot-pulse var(--transition-slow) ease-in-out infinite;
+  animation: status-dot-pulse var(--duration-slow) ease-in-out infinite;
 }
 
 .status-dot--pending {
@@ -160,11 +160,21 @@ html {
   --focus-ring: 0 0 0 2px rgba(88, 166, 255, 0.15);
   --focus-ring-strong: 0 0 0 2px rgba(88, 166, 255, 0.3);
 
-  /* Animation tokens */
-  --transition-instant: 0.1s ease;
-  --transition-fast: 0.15s ease;
-  --transition-normal: 0.2s ease;
-  --transition-slow: 0.3s ease;
+  /* Animation tokens.
+     --duration-* are bare durations, safe anywhere (animation shorthands,
+     animation-duration, calc()). --transition-* bundle duration + easing and
+     are ONLY valid in `transition` shorthands: substituting "0.3s ease" into
+     an `animation` shorthand that names its own easing (or into calc())
+     invalidates the whole declaration at computed-value time, silently
+     freezing the animation. Enforced by animation-duration-tokens.css.test.ts. */
+  --duration-instant: 0.1s;
+  --duration-fast: 0.15s;
+  --duration-normal: 0.2s;
+  --duration-slow: 0.3s;
+  --transition-instant: var(--duration-instant) ease;
+  --transition-fast: var(--duration-fast) ease;
+  --transition-normal: var(--duration-normal) ease;
+  --transition-slow: var(--duration-slow) ease;
 
   /* Backward-compatible aliases */
   --radius: var(--radius-md);
diff --git a/packages/dashboard/vitest.config.ts b/packages/dashboard/vitest.config.ts
index bf5e608710..44b08d92f7 100644
--- a/packages/dashboard/vitest.config.ts
+++ b/packages/dashboard/vitest.config.ts
@@ -24,6 +24,7 @@ const qualityAppFoundationUiTests = [
   "app/__tests__/activity-log-mobile-layout.test.ts",
   "app/__tests__/agent-css-classes.test.ts",
   "app/__tests__/agent-runs-ui.test.ts",
+  "app/__tests__/animation-duration-tokens.css.test.ts",
   "app/__tests__/auth.test.ts",
   "app/__tests__/board-mobile-corner-rendering.test.ts",
   "app/__tests__/board-tablet-overflow.test.ts",