diff --git a/apps/web/app/detections/[detectionId]/page.tsx b/apps/web/app/detections/[detectionId]/page.tsx
index c8f171d..e767375 100644
--- a/apps/web/app/detections/[detectionId]/page.tsx
+++ b/apps/web/app/detections/[detectionId]/page.tsx
@@ -216,8 +216,11 @@ function EvidenceTimeline({ evidenceItems }: { evidenceItems: EvidenceItem[] })
           title="No evidence available"
         />
       ) : (
-        <ol className="timeline-list">
-          {evidenceItems.map((item) => (
+        <ol
+          aria-label="Evidence timeline ordered oldest to newest"
+          className="timeline-list"
+        >
+          {evidenceItems.map((item, index) => (
             <li
               className={`timeline-item ${evidenceTypeClass(item.evidence_type)}`}
               key={item.evidence_id}
@@ -231,6 +234,10 @@ function EvidenceTimeline({ evidenceItems }: { evidenceItems: EvidenceItem[] })
                   </div>
                   <time dateTime={item.timestamp}>{formatTimestamp(item.timestamp)}</time>
                 </div>
+                <p className="sr-only">
+                  Evidence item {index + 1} of {evidenceItems.length}, ordered
+                  by timestamp.
+                </p>
                 <p>{item.description}</p>
                 <dl className="evidence-meta">
                   <div>
diff --git a/apps/web/app/globals.css b/apps/web/app/globals.css
index f32a0f0..01c3dfb 100644
--- a/apps/web/app/globals.css
+++ b/apps/web/app/globals.css
@@ -41,6 +41,25 @@ a {
   min-height: 100vh;
 }
 
+.skip-link {
+  position: absolute;
+  z-index: 20;
+  top: 10px;
+  left: 10px;
+  transform: translateY(-140%);
+  border: 2px solid var(--accent-strong);
+  border-radius: 7px;
+  background: var(--surface);
+  color: var(--accent-strong);
+  font-weight: 760;
+  padding: 10px 12px;
+}
+
+.skip-link:focus-visible {
+  transform: translateY(0);
+  outline: 3px solid #cfe7db;
+}
+
 .site-header {
   border-bottom: 1px solid var(--border);
   background: rgb(255 255 255 / 92%);
@@ -59,6 +78,12 @@ a {
 .brand {
   display: grid;
   gap: 2px;
+  border-radius: 7px;
+}
+
+.brand:focus-visible {
+  outline: 3px solid #cfe7db;
+  outline-offset: 4px;
 }
 
 .brand-name {
@@ -93,7 +118,8 @@ a {
 .nav-link:focus-visible {
   border-color: var(--border);
   background: var(--surface-muted);
-  outline: none;
+  outline: 3px solid #cfe7db;
+  outline-offset: 2px;
 }
 
 .page-shell {
@@ -102,6 +128,23 @@ a {
   padding: 28px 0 48px;
 }
 
+.page-shell:focus-visible {
+  outline: 3px solid #cfe7db;
+  outline-offset: 6px;
+}
+
+.sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+  padding: 0;
+}
+
 .hero {
   display: grid;
   grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
@@ -339,7 +382,8 @@ h3 {
 .primary-action:hover,
 .primary-action:focus-visible {
   background: var(--accent-strong);
-  outline: none;
+  outline: 3px solid #cfe7db;
+  outline-offset: 2px;
 }
 
 .secondary-action {
@@ -350,7 +394,8 @@ h3 {
 .secondary-action:hover,
 .secondary-action:focus-visible {
   background: #edf6f1;
-  outline: none;
+  outline: 3px solid #cfe7db;
+  outline-offset: 2px;
 }
 
 .overview-grid {
@@ -547,7 +592,8 @@ h3 {
 .back-link:hover,
 .back-link:focus-visible {
   color: var(--accent-strong);
-  outline: none;
+  outline: 3px solid #cfe7db;
+  outline-offset: 3px;
 }
 
 .content-panel {
@@ -899,6 +945,13 @@ h3 {
   gap: 14px;
 }
 
+.form-help {
+  margin-bottom: 0;
+  color: var(--muted);
+  font-size: 0.9rem;
+  line-height: 1.5;
+}
+
 .review-form div {
   display: grid;
   gap: 7px;
@@ -926,7 +979,8 @@ h3 {
 .review-form input:focus,
 .review-form textarea:focus {
   border-color: var(--accent);
-  outline: 3px solid #dceee6;
+  outline: 3px solid #cfe7db;
+  outline-offset: 1px;
 }
 
 .review-actions {
@@ -963,7 +1017,22 @@ h3 {
 }
 
 .review-actions button:focus-visible {
-  outline: 3px solid #dceee6;
+  outline: 3px solid #cfe7db;
+  outline-offset: 2px;
+}
+
+.submit-status {
+  min-height: 1.25em;
+  color: var(--muted);
+  font-size: 0.9rem;
+  font-weight: 650;
+  line-height: 1.4;
+}
+
+.draft-copy button:focus-visible,
+.review-actions button:focus-visible {
+  outline: 3px solid #cfe7db;
+  outline-offset: 2px;
 }
 
 .decision-result {
diff --git a/apps/web/app/layout.tsx b/apps/web/app/layout.tsx
index 4252727..653cb5e 100644
--- a/apps/web/app/layout.tsx
+++ b/apps/web/app/layout.tsx
@@ -22,6 +22,9 @@ export default function RootLayout({ children }: { children: ReactNode }) {
     <html lang="en">
       <body>
         <div className="shell">
+          <a className="skip-link" href="#main-content">
+            Skip to main content
+          </a>
           <header className="site-header">
             <div className="header-inner">
               <Link className="brand" href="/">
@@ -38,7 +41,9 @@ export default function RootLayout({ children }: { children: ReactNode }) {
               <DemoDataBadge />
             </div>
           </header>
-          <main className="page-shell">{children}</main>
+          <main className="page-shell" id="main-content" tabIndex={-1}>
+            {children}
+          </main>
         </div>
       </body>
     </html>
diff --git a/apps/web/app/recommendations/recommendation-review-panel.tsx b/apps/web/app/recommendations/recommendation-review-panel.tsx
index ae84b74..c84d229 100644
--- a/apps/web/app/recommendations/recommendation-review-panel.tsx
+++ b/apps/web/app/recommendations/recommendation-review-panel.tsx
@@ -33,6 +33,7 @@ export function RecommendationReviewPanel({
 
   const canSubmit =
     reviewer.trim().length > 0 && reason.trim().length > 0 && submittingAction === null;
+  const isSubmitting = submittingAction !== null;
 
   async function submitDecision(action: DecisionAction) {
     setSubmittingAction(action);
@@ -96,10 +97,20 @@ export function RecommendationReviewPanel({
           <dd>{formatEvidenceIds(recommendation.evidence_ids)}</dd>
         </div>
       </dl>
-      <form className="review-form" onSubmit={handleSubmit}>
+      <form
+        aria-busy={isSubmitting}
+        aria-describedby="decision-form-help decision-submit-status"
+        className="review-form"
+        onSubmit={handleSubmit}
+      >
+        <p className="form-help" id="decision-form-help">
+          Enter a reviewer and decision reason before approving, rejecting, or
+          deferring this simulator-backed recommendation.
+        </p>
         <div>
           <label htmlFor="reviewer">Reviewer name</label>
           <input
+            aria-describedby="decision-form-help"
             id="reviewer"
             name="reviewer"
             onChange={(event) => setReviewer(event.target.value)}
@@ -111,6 +122,7 @@ export function RecommendationReviewPanel({
         <div>
           <label htmlFor="reason">Decision reason</label>
           <textarea
+            aria-describedby="decision-form-help"
             id="reason"
             name="reason"
             onChange={(event) => setReason(event.target.value)}
@@ -121,6 +133,7 @@ export function RecommendationReviewPanel({
         </div>
         <div className="review-actions" aria-label="Recommendation decision actions">
           <button
+            aria-describedby="decision-submit-status"
             disabled={!canSubmit}
             onClick={() => submitDecision("approve")}
             type="button"
@@ -128,6 +141,7 @@ export function RecommendationReviewPanel({
             {submittingAction === "approve" ? "Approving..." : "Approve"}
           </button>
           <button
+            aria-describedby="decision-submit-status"
             disabled={!canSubmit}
             onClick={() => submitDecision("reject")}
             type="button"
@@ -135,6 +149,7 @@ export function RecommendationReviewPanel({
             {submittingAction === "reject" ? "Rejecting..." : "Reject"}
           </button>
           <button
+            aria-describedby="decision-submit-status"
             disabled={!canSubmit}
             onClick={() => submitDecision("defer")}
             type="button"
@@ -142,6 +157,17 @@ export function RecommendationReviewPanel({
             {submittingAction === "defer" ? "Deferring..." : "Defer"}
           </button>
         </div>
+        <div
+          className="submit-status"
+          id="decision-submit-status"
+          role="status"
+        >
+          {isSubmitting
+            ? `Recording ${submittingAction} decision...`
+            : canSubmit
+              ? "Decision actions are available."
+              : "Decision actions are disabled until reviewer and reason are entered."}
+        </div>
       </form>
       {errorMessage !== null ? (
         <div className="state-panel error-panel" role="alert">
diff --git a/apps/web/e2e/operations-workbench-demo.spec.ts b/apps/web/e2e/operations-workbench-demo.spec.ts
index 010e49c..4478410 100644
--- a/apps/web/e2e/operations-workbench-demo.spec.ts
+++ b/apps/web/e2e/operations-workbench-demo.spec.ts
@@ -10,6 +10,10 @@ test("walks the simulator-backed Operations Workbench demo path", async ({ page
   resetDemoState();
 
   await page.goto("/");
+  await page.keyboard.press("Tab");
+  await expect(page.getByRole("link", { name: "Skip to main content" })).toBeFocused();
+  await page.keyboard.press("Enter");
+  await expect(page.locator("#main-content")).toBeFocused();
   await expect(page.getByText("Simulator-backed demo data").first()).toBeVisible();
   await expect(page.getByText("Synthetic local scenario; not real plant data.").first()).toBeVisible();
   await expect(page.getByRole("region", { name: "Local API connection state" })).toBeVisible();
@@ -76,13 +80,19 @@ async function recordDecision(
   action: "Approve" | "Reject" | "Defer",
   expectedDecision: "approved" | "rejected" | "deferred",
 ) {
+  await expect(page.getByRole("button", { name: action })).toBeDisabled();
   await page.getByLabel("Reviewer name").fill(`quality_engineer_${expectedDecision}`);
   await page
     .getByLabel("Decision reason")
     .fill(`Playwright smoke test recorded a ${expectedDecision} demo decision.`);
-  await page.getByRole("button", { name: action }).click();
+  await expect(page.getByRole("button", { name: action })).toBeEnabled();
+  await expect(page.locator("#decision-submit-status")).toContainText(
+    "Decision actions are available.",
+  );
+  await page.getByRole("button", { name: action }).focus();
+  await page.keyboard.press("Enter");
 
-  const feedback = page.getByRole("status");
+  const feedback = page.locator(".decision-result");
   await expect(feedback).toContainText(`Demo audit feedback: ${expectedDecision}`);
   await expect(feedback).toContainText(`Reviewer: quality_engineer_${expectedDecision}`);
   await expect(feedback).toContainText(`Updated status: ${expectedDecision}`);
diff --git a/apps/web/tests/app-shell.test.mjs b/apps/web/tests/app-shell.test.mjs
index 0989b81..12d30da 100644
--- a/apps/web/tests/app-shell.test.mjs
+++ b/apps/web/tests/app-shell.test.mjs
@@ -22,6 +22,8 @@ test("workbench placeholder routes exist", async () => {
 test("navigation includes the required demo routes", () => {
   const layout = readFileSync(join(root, "app/layout.tsx"), "utf8");
 
+  assert.match(layout, /Skip to main content/);
+  assert.match(layout, /id="main-content"/);
   assert.match(layout, /Overview/);
   assert.match(layout, /Detections/);
   assert.match(layout, /Recommendations/);
@@ -219,6 +221,52 @@ test("workbench state panels distinguish local demo data gaps from API failures"
   assert.match(styles, /min-height: 260px/);
 });
 
+test("accessibility baseline covers landmarks, focus, forms, badges, and timeline order", () => {
+  const layout = readFileSync(join(root, "app/layout.tsx"), "utf8");
+  const demoState = readFileSync(join(root, "app/components/demo-state.tsx"), "utf8");
+  const detail = readFileSync(join(root, "app/detections/[detectionId]/page.tsx"), "utf8");
+  const panel = readFileSync(
+    join(root, "app/recommendations/recommendation-review-panel.tsx"),
+    "utf8",
+  );
+  const styles = readFileSync(join(root, "app/globals.css"), "utf8");
+
+  assert.match(layout, /className="skip-link"/);
+  assert.match(layout, /<main className="page-shell" id="main-content"/);
+  assert.match(layout, /nav aria-label="Primary navigation"/);
+  assert.match(demoState, /status-badge-label/);
+  assert.match(detail, /aria-label="Evidence timeline ordered oldest to newest"/);
+  assert.match(detail, /<ol/);
+  assert.match(detail, /<time dateTime=/);
+  assert.match(detail, /className="sr-only"/);
+  assert.match(panel, /aria-busy=\{isSubmitting\}/);
+  assert.match(panel, /aria-describedby="decision-form-help decision-submit-status"/);
+  assert.match(panel, /id="decision-form-help"/);
+  assert.match(panel, /id="decision-submit-status"/);
+  assert.match(panel, /Decision actions are disabled until reviewer and reason are entered/);
+  assert.match(styles, /\.skip-link/);
+  assert.match(styles, /:focus-visible/);
+  assert.match(styles, /\.sr-only/);
+  assert.match(styles, /outline: 3px solid #cfe7db/);
+
+  const contrastPairs = [
+    ["#18201c", "#ffffff", "body text on cards"],
+    ["#607066", "#ffffff", "muted text on cards"],
+    ["#0f4d3b", "#e8f5ee", "success badge"],
+    ["#8b5a10", "#fff8e7", "warning badge"],
+    ["#9f2d35", "#fff0f1", "danger badge"],
+    ["#315f9f", "#eef4ff", "info badge"],
+    ["#ffffff", "#176b52", "primary action"],
+  ];
+
+  for (const [foreground, background, label] of contrastPairs) {
+    assert.ok(
+      contrastRatio(foreground, background) >= 4.5,
+      `${label} contrast should be at least 4.5:1`,
+    );
+  }
+});
+
 test("operations workbench docs link to the demo runbook", async () => {
   const rootReadme = readFileSync(join(root, "..", "..", "README.md"), "utf8");
   const appReadme = readFileSync(join(root, "README.md"), "utf8");
@@ -266,3 +314,28 @@ test("demo polish keeps pages readable without raw JSON panels", () => {
   assert.match(styles, /max-width: 1240px/);
   assert.match(styles, /metric-grid/);
 });
+
+function contrastRatio(foreground, background) {
+  const fg = relativeLuminance(hexToRgb(foreground));
+  const bg = relativeLuminance(hexToRgb(background));
+  const lighter = Math.max(fg, bg);
+  const darker = Math.min(fg, bg);
+  return (lighter + 0.05) / (darker + 0.05);
+}
+
+function hexToRgb(value) {
+  const normalized = value.replace("#", "");
+  return [0, 2, 4].map((offset) =>
+    Number.parseInt(normalized.slice(offset, offset + 2), 16),
+  );
+}
+
+function relativeLuminance(rgb) {
+  const [red, green, blue] = rgb.map((channel) => {
+    const normalized = channel / 255;
+    return normalized <= 0.03928
+      ? normalized / 12.92
+      : ((normalized + 0.055) / 1.055) ** 2.4;
+  });
+  return 0.2126 * red + 0.7152 * green + 0.0722 * blue;
+}
diff --git a/docs/LEARNING_LOG.md b/docs/LEARNING_LOG.md
index 222665b..67a88fa 100644
--- a/docs/LEARNING_LOG.md
+++ b/docs/LEARNING_LOG.md
@@ -3418,3 +3418,50 @@ make test-e2e
 
 During rehearsal, intentionally visit a stale detection URL and confirm the
 presenter can recover from the visible `Next step:` text without opening docs.
+
+## 2026-05-22 - Workbench accessibility baseline
+
+### What changed
+
+Added a focused accessibility baseline for issue #179. The Workbench now has a
+skip link, a named main content target, stronger visible focus styling, form
+helper/status text for governed recommendation decisions, and clearer semantic
+ordering for the evidence timeline.
+
+### Why it was built that way
+
+The issue asks for a practical demo baseline, not a full design system or WCAG
+certification effort. The change stays in the existing Workbench shell,
+components, styles, smoke test, and runbook so the manufacturer demo remains
+small, keyboard navigable, and understandable.
+
+### How data flows through it
+
+The data flow is unchanged. Process Sentinel detections, evidence,
+recommendations, and RCA/CAPA draft data still come from the local FastAPI demo
+API. The accessibility changes improve how existing states and controls are
+announced and reached.
+
+### How to run it
+
+```bash
+make demo
+make api
+cd apps/web
+npm run dev
+```
+
+### How to test it
+
+```bash
+cd apps/web
+npm test
+npm run lint
+npm run typecheck
+make test-e2e
+```
+
+### What to learn next
+
+Before the external demo, walk the route flow with only the keyboard and record
+any remaining non-blocking accessibility debt in the runbook.
diff --git a/docs/demo/OPERATIONS_WORKBENCH_DEMO_RUNBOOK.md b/docs/demo/OPERATIONS_WORKBENCH_DEMO_RUNBOOK.md
index e6f9671..bbd38b8 100644
--- a/docs/demo/OPERATIONS_WORKBENCH_DEMO_RUNBOOK.md
+++ b/docs/demo/OPERATIONS_WORKBENCH_DEMO_RUNBOOK.md
@@ -64,6 +64,24 @@ http://127.0.0.1:3000
     evidence summary, recommended containment, CAPA placeholder, and human
     review requirement are visible.
 
+## Accessibility Baseline
+
+During rehearsal, do a quick keyboard and screen-reader semantics check:
+
+1. Press Tab on the overview page and confirm `Skip to main content` appears.
+2. Use Tab to reach primary navigation, `Open detection`, evidence workflow
+   links, recommendation decision controls, and RCA/CAPA draft actions.
+3. Confirm the recommendation decision buttons remain disabled until reviewer
+   and reason fields are filled, then can be triggered from the keyboard.
+4. Confirm status, severity, and risk badges include visible text and are not
+   explained by color alone.
+5. Confirm the evidence timeline reads oldest to newest and each item exposes a
+   timestamp, title, description, and related IDs.
+
+Remaining non-blocking accessibility debt: this MVP does not claim WCAG
+certification, does not include a full automated accessibility suite, and has
+not gone through formal assistive-technology testing across browsers.
+
 ## API Recovery Check
 
 If the API is stopped or `NEXT_PUBLIC_API_BASE_URL` points at the wrong port,