Accessibility

This skill reviews and fixes semantics, keyboard and focus behavior, accessible names, forms, announcements, motion and zoom. It reports each failure against the WCAG criterion it breaks and writes the fix in the project's styling system.

Reviewing means two walks. Keyboard-only, where every flow completes without a mouse. Then screen-reader, where every control announces a name, a role and its state. When unsure, take the platform default over a custom rebuild, and remove ARIA rather than add it.

Contrast measurement and color fixes belong to better-colors. Text sizing, iOS input zoom and language metadata belong to better-typography. Spacing between targets and spatial RTL belong to better-layout. Label, error and alt-text wording belong to better-writing. Animation recipes, hover styling and scroll containment belong to better-ui.

Criteria, not conventions

A finding cites a WCAG 2.2 Level A or AA criterion by number, or a concrete task an assistive-technology user cannot complete. Everything else is a recommendation and never HIGH. That covers AAA criteria, APG conventions, the one-<h1> and no-skipped-levels outline and the 44px and 40px targets. The criterion thresholds below are exact. The larger targets are heuristics, so keep an established, usable density.

Native elements first

The first rule of ARIA: don't use ARIA when a native element exists. <button> for actions, <a href> for navigation, never <div onClick>. A real link must support Cmd/Ctrl/middle-click. See semantics-and-aria.md for landmarks and button-vs-link.

Disabled means unavailable

Use native disabled when a control is genuinely unavailable. Reach for aria-disabled="true" only when it should stay focusable, then block pointer, keyboard and form behavior in code and style the state explicitly. The rules are in semantics-and-aria.md.

Visible focus rings

Style :focus-visible, not bare :focus. Keyboard users get a ring and mouse users usually don't. Prefer the browser's unmodified indicator.

A custom ring needs a project focus token or another explicit color. It must reach 3:1 against every adjacent color it crosses, currentColor included, under 1.4.11. A 2px solid perimeter with a 3:1 change of contrast is the 2.4.13 AAA target. Never use outline: none without a verified replacement, and preserve system colors in forced-colors mode.

A focused element must never sit fully hidden behind a sticky header, footer or banner (2.4.11). Give the scroller scroll-padding-top equal to the sticky header's height. Recipes are in focus-and-keyboard.md.

Full keyboard support

Every pointer interaction needs a keyboard path. Follow the ARIA APG patterns: Escape closes overlays, arrow keys move within composite widgets, Tab moves between widgets, Enter and Space activate buttons.

Use only tabindex="0" to join the natural tab order and tabindex="-1" for programmatic focus. Positive values break that order. Composite widgets use roving tabindex, where the active item is 0 and every other is -1. Where focus must stay in an input, as in a combobox, use aria-activedescendant instead. Key maps per widget are in focus-and-keyboard.md.

Trap and restore focus

Prefer <dialog> opened with showModal(), which makes the background inert and handles Escape. A custom overlay sets inert on the background, role="dialog" and aria-modal="true" on itself. Either way, move focus inside on open and return it to the trigger on close.

Client-side route changes reset nothing. Update document.title and move focus to the new view's <h1> or <main>. Both recipes are in focus-and-keyboard.md.

Minimum hit area

WCAG 2.5.8's Level AA baseline is a 24×24 CSS-pixel target, or one of its exceptions. Aim for 44×44px on touch and 40×40px on desktop where density permits. Extend with a pseudo-element when the visible element should stay smaller.

Never let extended hit areas overlap. Give decorative layers pointer-events: none, so a glow never swallows the clicks meant for the control beneath it.

Every drag interaction needs a single-pointer alternative, such as buttons or a menu that reorder or move the same item (2.5.7). Sizes, exceptions and collision rules are in hit-areas.md.

Label and type every control

Every input gets a <label for> or a wrapping <label>. A placeholder is never a label. Label and control share one hit target, with no dead zone between a checkbox and its text.

Add a valid autocomplete token and a descriptive name attribute, plus the type and inputmode that summon the right keyboard. Never block paste; users paste passwords and one-time codes. See forms.md.

Errors that announce

Validate on submit, never by disabling submit until the form is valid. Mark failing fields aria-invalid="true", point aria-describedby at the inline error text and focus the first invalid field. Submit behavior while the request runs is in forms.md.

Accessible names everywhere

Icon-only buttons need a descriptive aria-label. Visible label text must appear in the accessible name. Decorative elements get aria-hidden="true", never on a focusable element.

Don't rely on color alone

Status needs a redundant cue: an icon, text or an underline alongside the color (1.4.1).

This skill decides which contrast requirement applies:

Inactive controls and logos are exempt. Use better-colors to measure the rendered pair. When it fails, report the pair and the criterion it misses, and leave the colors alone unless asked.

Honor prefers-reduced-motion

Wrap motion in @media (prefers-reduced-motion: no-preference) so it is opt-in. Under reduced motion, replace slides and scales with opacity crossfades, and kill parallax and autoplay entirely. See motion-and-zoom.md.

Nothing the user needs runs on a timer

Anything moving, blinking or updating on its own for more than 5 seconds needs a visible pause control (2.2.2). Toasts carrying an action or an error stay until dismissed. The rules are in motion-and-zoom.md.

Announce dynamic content

Three mechanisms, three jobs. aria-describedby carries field-specific validation. A polite live region (role="status") carries non-urgent updates not tied to a control, such as toasts and result counts. role="alert" carries urgent untied errors and nothing else.

Repeated polite announcements need a stable empty region rendered before its text updates. Dynamically inserted alerts vary in support, so test them on the screen readers you target. See screen-readers.md.

Alt text by purpose

Decorative images get alt="". Informative images describe the meaning. Functional images describe the action, never the picture. The full table is in screen-readers.md.

Structure is navigation

Use headings that describe their sections and form a coherent outline. Expose one visible primary <main> landmark. When repeated navigation or chrome precedes it, make a "Skip to content" link the first focusable element. Anchored headings get scroll-margin-top.

Survive zoom and text resize

Text must survive 200% resize (1.4.4), and the page must reflow at 320px width without horizontal scrolling (1.4.10). Text containers take min-height, not height, and better-layout owns the rest of that fix. Never set maximum-scale=1 or user-scalable=no in the viewport meta. iOS input zoom is fixed with better-typography's 16px rule instead.

Before you finish

Reporting

Severity. HIGH prevents a task, hides content from assistive technology or creates a systemic failure. MEDIUM makes an interaction meaningfully harder. LOW is isolated polish. This domain's share of better-interface's escalation triggers is HIGH on sight. That is a missing accessible name, a missing focus indicator and a pointer path with no keyboard path. It is also motion ignoring reduced motion, loss at 320px or 200% and meaning carried by color alone.

Verification. Without a browser: accessible names on every interactive element, keyboard handlers on non-native controls, focus styles, prefers-reduced-motion guards and form labels bound to their inputs. With one: tab the flow in order, read computed names and roles from the accessibility tree, confirm a visible focus indicator at every stop and run an automated audit. Report every check you could not run as Not verified.

Format. Group findings under the principle each violates, ordered by severity, one row per root cause listing every location it appears in:

Location is path/to/file:line. Why names the WCAG criterion or principle and the user impact.

End with Block when any HIGH remains, Approve otherwise, leaving the rest in the table as work to do. Never Approve coverage you did not inspect. With nothing to report, state "No actionable accessibility findings" and report verification.