Accessibility Fix Patterns

Contents: Fix-then-verify loop; color-contrast; label; label-title-only; image-alt; button-name; link-name; region / landmark-one-main; heading-order; aria-allowed-attr; aria-required-attr; aria-required-children / aria-required-parent; aria-valid-attr-value; focus-trap (focus management); tabindex; html-has-lang; document-title; duplicate-id; listitem; definition-list; Upstream shadcn and Base UI findings.

Violations come from addon-a11y, which axe-checks every story under Vitest (configured in .storybook/a11y.ts), .playwright/a11y.ts (Playwright), or the code-audit-frontend agent's a11y bucket. General a11y guidance lives in frontend/.claude/rules/accessibility.md.

Fix-then-verify loop

1. Fix one violation with the pattern below; for a rule id not listed here, use the violation's help and failureSummary from the axe output.
2. Re-run the reporter that flagged it: Vitest pnpm test --run --project storybook <story-file>, Playwright pnpm pw <spec-file>.
3. Some rules are not checked by the story run. addon-a11y runs the WCAG 2.0/2.1 A and AA tags and disables region (a story renders a fragment outside the page landmarks), so landmark-one-main and page-has-heading-one never fire there: assert the page landmark and heading in the page story's play instead (exactly one main, one level-1 heading). Verify color-contrast with pnpm pw when a story run is ambiguous, since the Playwright scan renders the same stories in the full page.
4. Repeat until the reporter shows no violations.

color-contrast

WCAG AA requires 4.5:1 for normal text, 3:1 for large text. Use the theme role tokens (see frontend/.claude/rules/tailwind.md) instead of raw palette colors: each token carries a light and a dark value that pass in both themes. Pair a surface token with its foreground (bg-primary with text-primary-foreground).

// BAD, fails contrast in dark mode, raw colors
<p className="text-gray-400 bg-white">Status</p>

// GOOD, role tokens, contrast-safe in both themes
<p className="bg-background text-foreground">Status</p>

If a token itself fails (the placeholder values are a neutral default), fix the value in app/styles/theme.css and keep it an accessibility fix, per frontend/.claude/rules/design-baseline.md.

label

Form inputs need an associated label. Compose the ui Field parts around the control rather than a bare <label>: FieldLabel htmlFor names it, and FieldError carries the error. See frontend/.claude/skills/react-code/references/conform-forms.md for the full wiring.

// BAD, bare input with no label association
<input type="text" name="email" />

// GOOD, Field and FieldLabel wire the label to the ui control
<Field>
  <FieldLabel htmlFor="email">{t('email')}</FieldLabel>
  <Input id="email" name="email" />
</Field>

label-title-only

title attributes are not labels, screen readers and mobile devices ignore them. Use aria-label or a real <label>.

// BAD, title is not an accessible name
<input type="text" title="Search" />

// GOOD, aria-label provides the accessible name
<input type="text" aria-label={t('search')} />

image-alt

Every <img> needs alt. Content images describe the image; decorative images use alt="". See frontend/.claude/rules/accessibility.md.

// BAD, no alt attribute
<img src="/logo.png" />

// GOOD, content image
<img src="/logo.png" alt={t('companyLogo')} />

// GOOD, decorative image, hidden from AT
<img src="/divider.svg" alt="" />

button-name

Buttons need an accessible name. Visible text is fine; icon-only buttons need aria-label.

// BAD, icon-only button with no name
<button onClick={onClose}>
  <CloseIcon />
</button>

// GOOD, aria-label supplies the name
<button aria-label={t('close')} onClick={onClose}>
  <CloseIcon />
</button>

// GOOD, visible text, no aria-label needed
<button onClick={onSave}>{t('save')}</button>

link-name

Same pattern as button-name, anchors need an accessible name.

// BAD, icon-only link
<Link to="/settings"><GearIcon /></Link>

// GOOD, aria-label on the link
<Link to="/settings" aria-label={t('settings')}>
  <GearIcon />
</Link>

region / landmark-one-main

Page content must live inside a landmark, and there must be exactly one <main>. The Layout component owns the <main> landmark, page components render inside it and should not add their own.

// BAD, page component wraps itself in <main>, duplicating Layout's
const Page = () => (
  <main>
    <h1>{t('title')}</h1>
  </main>
);

// GOOD, page renders into Layout's <main>
const Page = () => (
  <>
    <h1>{t('title')}</h1>
  </>
);

heading-order

One <h1> per page. Levels do not skip, h2 → h4 is a violation.

// BAD, skips h3
<h2>{t('section')}</h2>
<h4>{t('subsection')}</h4>

// GOOD, sequential levels
<h2>{t('section')}</h2>
<h3>{t('subsection')}</h3>

aria-allowed-attr

ARIA attributes are role-scoped. Look up the role; only attrs in its allowed list are valid. Common case: aria-checked only on role="checkbox", role="radio", role="menuitemcheckbox", role="menuitemradio", role="switch", role="treeitem".

// BAD, aria-checked is not allowed on a button
<button aria-checked={selected}>{t('toggle')}</button>

// GOOD, aria-pressed for buttons, aria-checked for checkbox role
<button aria-pressed={selected}>{t('toggle')}</button>

aria-required-attr

Some roles require companion attrs. role="combobox" requires aria-expanded and aria-controls. On a disclosure button axe does not require aria-controls, but pointing it at the controlled element's id is still good practice.

// Passes axe, but aria-expanded with no aria-controls leaves the panel unnamed
<button aria-expanded={open}>{t('menu')}</button>

// Better, aria-controls names the panel
<button aria-expanded={open} aria-controls="menu-panel">
  {t('menu')}
</button>
<div id="menu-panel" hidden={!open}>...</div>

aria-required-children / aria-required-parent

Composite roles need their child roles, and child roles need the right parent. Prefer semantic HTML (<ul><li>, <select><option>) over recreating these structures with ARIA.

// BAD, role="listbox" with no role="option" children
<div role="listbox">
  <div>{t('one')}</div>
  <div>{t('two')}</div>
</div>

// GOOD, semantic <select> with <option> children
<select aria-label={t('choose')}>
  <option value="1">{t('one')}</option>
  <option value="2">{t('two')}</option>
</select>

aria-valid-attr-value

aria-* attrs that take id refs must point at existing ids; boolean attrs take true/false, not arbitrary strings.

// BAD, aria-labelledby points at id that does not exist
<input aria-labelledby="missing-id" />

// GOOD, id exists in the DOM
<>
  <span id="email-label">{t('email')}</span>
  <input aria-labelledby="email-label" />
</>

focus-trap (focus management)

Modals must trap focus while open and return focus to the trigger on close (see frontend/.claude/rules/accessibility.md). Use the native <dialog> opened with showModal(): the browser makes the rest of the page inert, closes it on Escape, and restores focus to the opener on close. Reach for a dialog library only if the project already has one installed.

// BAD, open modal leaves focus on body, close drops focus
{
  open && (
    <div role="dialog">
      <button onClick={() => setOpen(false)}>{t('close')}</button>
    </div>
  );
}

// GOOD, native modal dialog handles inert background, Escape, and focus restore
const dialogRef = useRef<HTMLDialogElement>(null);
const handleClickOpen = () => dialogRef.current?.showModal();
const handleClickClose = () => dialogRef.current?.close();

<>
  <button onClick={handleClickOpen} type="button">
    {t('open')}
  </button>
  <dialog ref={dialogRef}>
    <button onClick={handleClickClose} type="button">
      {t('close')}
    </button>
  </dialog>
</>;

tabindex

Positive tabindex (tabindex={1}, tabindex={2}, ...) reorders the tab sequence and is always a violation. Use tabIndex={0} to insert into natural order, tabIndex={-1} for programmatic-only focus.

// BAD, positive tabindex skews tab order
<div tabIndex={1}>{t('first')}</div>
<div tabIndex={2}>{t('second')}</div>

// GOOD, natural DOM order, programmatic focus on the panel
<div tabIndex={0}>{t('first')}</div>
<div tabIndex={0}>{t('second')}</div>
<section tabIndex={-1} ref={panelRef}>...</section>

html-has-lang

<html> must have a lang attribute. The React Router root sets it from the i18n locale; if a violation appears, the root loader is not threading locale through. Verify the root layout reads locale from the request context and renders <html lang={locale}>.

// BAD, hardcoded or missing lang
<html>...</html>

// GOOD, locale from the loader / i18n
<html lang={locale}>...</html>

document-title

Every page needs a <title>. Resolve the string in the route loader with getInstance(context) (see frontend/.claude/rules/i18n.md) and render <title> (and <meta name="description">) as JSX, either in the route component (as app/routes/_public._index.tsx does) or in the page it renders; React 19 hoists it into <head>. Do not add a route meta export: next to a JSX <title> it produces duplicate tags (react-code skill, Gate 4).

// BAD, no <title> rendered
const DashboardRoute = () => <DashboardPage />;

// GOOD, i18n-resolved title in the loader, rendered as JSX
export const loader = async ({context}: Route.LoaderArgs) => {
  const i18next = getInstance(context);

  return {title: i18next.t('dashboard.meta.title', {ns: 'pages'})};
};

const DashboardRoute = () => {
  const {title} = useLoaderData<typeof loader>();

  return (
    <>
      <title>{title}</title>
      <DashboardPage />
    </>
  );
};

duplicate-id

Every id in the rendered DOM must be unique. Common Conform pitfall: rendering the same field name twice in a fieldset produces duplicate ids. Pass an explicit unique id.

// BAD, same field rendered twice, ids collide
<Input name="email" />
<Input name="email" />

// GOOD, unique ids
<Input id="email-primary" name="emailPrimary" />
<Input id="email-secondary" name="emailSecondary" />

listitem

<li> must be a direct child of <ul> or <ol>. A standalone <li> is a violation.

// BAD, <li> with no list parent
<div>
  <li>{t('one')}</li>
</div>

// GOOD, wrapped in <ul>
<ul>
  <li>{t('one')}</li>
</ul>

definition-list

<dt> and <dd> must live inside <dl>. Group related term/description pairs in one <dl>.

// BAD, dt/dd outside <dl>
<div>
  <dt>{t('term')}</dt>
  <dd>{t('definition')}</dd>
</div>

// GOOD, wrapped in <dl>
<dl>
  <dt>{t('term')}</dt>
  <dd>{t('definition')}</dd>
</dl>

Upstream shadcn and Base UI findings

The vendored components/ui/ files are byte-identical to shadcn add output and are never edited silently. The policy lives in wiki/decisions/shadcn Component Layer.md (never hand-edit a ui file). For a violation from a vendored file, report it upstream and work around it on the consuming side: the GAIA component or story that renders the ui control. Radix Select aria-hidden sibling findings (shadcn-ui/ui#10074, shadcn-ui/ui#8707) are informational: they describe the Radix Select, which does not apply because GAIA's base-nova style uses Base UI.