Accessibility that comes with the craft

Accessibility is not a compliance checkbox bolted on at the end; it is the floor for interface craft. Most of it is free if you use the platform: native elements ship with keyboard support, real labels announce themselves, and a visible focus ring is one CSS rule. Apply these principles when building or reviewing UI code, and match the project's existing styling system (Tailwind vs. plain CSS vs. CSS-in-JS) when applying fixes.

When reviewing, walk the interface as a keyboard-only user first (every flow must complete without a mouse), then as a screen-reader user: does each control announce a name, a role, and its state? When unsure, prefer the platform default over a custom rebuild, and remove ARIA rather than add it.

Rendered-pair contrast measurement and color remediation are covered by the colors skill; visual text sizing and iOS input zoom by typography; spatial RTL layout by layout. Voice, labels and empty states are writing. Radius, shadow and motion are ui. This skill does not own those domains.

Quick Reference

Core Principles

1. Native Elements First

The first rule of ARIA: don't use ARIA when a native element exists. <button> for actions, <a href> for navigation (it must support Cmd/Ctrl/middle-click), never <div onClick>. No ARIA is better than bad ARIA.

2. Visible Focus Rings

Style :focus-visible, not bare :focus, so keyboard users get a ring and mouse users usually don't. Prefer the browser's unmodified focus indicator. If the design needs a custom ring, use a project focus token or another explicit color and verify the complete indicator against every adjacent color it crosses; currentColor is acceptable only after the same check. Use at least a 2px solid perimeter or an equivalent visible area. Never use outline: none without a verified replacement, and preserve system colors in forced-colors mode.

3. Full Keyboard Support

Every pointer interaction needs a keyboard path, following the ARIA APG patterns: Escape closes overlays, arrow keys move within composite widgets (tabs, menus, listboxes), Tab moves between widgets, Enter and Space activate. Only tabindex="0" (join the natural tab order) and tabindex="-1" (programmatic focus), never positive values, which break the natural order. Composite widgets use roving tabindex: the active item is 0, all others -1.

4. Trap and Restore Focus

Modals set inert on the background content, move focus inside on open, and return focus to the trigger on close. Add overscroll-behavior: contain so background content doesn't scroll.

5. Minimum Hit Area

WCAG 2.5.8's Level AA baseline is a 24×24 CSS-pixel target or one of its defined spacing, equivalent-control, inline, user-agent, or essential exceptions. For easier activation, aim for 44×44px in touch contexts and 40×40px in desktop interfaces when density permits. Extend with a pseudo-element if the visible element should stay smaller. Never let extended hit areas overlap.

6. Label and Type Every Control

Every input gets a <label for> or wrapping <label>; a placeholder is never a label, and label and control share one hit target: no dead zones between a checkbox and its text. Add autocomplete with a meaningful name, and the correct type and inputmode for the keyboard. Never block paste; users paste passwords and one-time codes.

7. Errors That Announce

Keep submit enabled until the request starts, then disable with a spinner while keeping the original label. Validate on submit: mark failing fields with aria-invalid="true", point aria-describedby at the inline error text, and focus the first invalid field. Use native disabled when a native control is genuinely unavailable. Use aria-disabled="true" only when retaining focusability or discoverability is intentional; then block pointer, keyboard, and form behavior in code and style the state explicitly.

8. 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.

9. Don't Rely on Color Alone

Status needs a redundant cue: icon, text, or underline alongside the color. Determine which WCAG contrast requirement applies from the content and state, then use colors to measure the rendered foreground/background pair. When contrast fails, report the pair and requirement it misses; do not change the project's colors unless asked.

10. 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; kill parallax and autoplay entirely. Independent of the preference: autoplaying media needs a visible pause control, and toasts carrying actions or errors stay until dismissed.

11. Announce Dynamic Content

Use aria-describedby for field-specific validation, a polite live region (role="status") for non-urgent updates not tied to a control such as toasts or result counts, and role="alert" only for urgent errors not tied to a control. For reliable repeated polite announcements, render a stable empty region before updating its text; dynamically inserted alerts have different support and must be tested with the target screen readers.

12. Alt Text by Purpose

Decorative images get alt="", informative images describe the meaning, functional images describe the action: a search icon button is alt="Search", not alt="magnifying glass".

13. Structure Is Navigation

Use headings that describe their sections and form a coherent outline; one page-level <h1> and properly nested levels are the recommended default, not standalone WCAG pass/fail rules. 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.

14. Survive Zoom and Text Resize

The page must work at 200% zoom and reflow at 320px width without horizontal scrolling. Use min-height instead of fixed height on text containers, prefer rem breakpoints where they fit the codebase's conventions, and never use user-scalable=no or maximum-scale=1.

Common Mistakes

Review Output Format

Use this format only when the user asks for a standalone accessibility review. When interface orchestrates the review, provide domain evidence and findings to that skill and let its output format, severity scale, consolidation rules, cap, and verdict take precedence.

Present the standalone review in two parts.

Findings

Group all confirmed findings by principle. Use a markdown table with Severity, Location, Before, After, and Why columns. Never use separate "Before:" / "After:" lines.

• Severity: HIGH prevents a task, hides content from assistive technology, or creates a systemic accessibility failure; MEDIUM makes an interaction meaningfully harder; LOW is isolated polish.
• Location: cite path/to/file:line. If the artifact has no source files, cite the exact screen and component instead.
• Before / After: show the current implementation and an actionable replacement.
• Why: name the violated principle and its user impact.

Consolidate a repeated systemic issue into one row and list every affected location. Omit principles with no findings.

Example

Accessible names everywhere

Visible focus rings

Errors that announce

Minimum hit area

Verification and Verdict

After the findings:

1. Verification: list the exact checks run and their observed results, including keyboard traversal, accessible-name inspection, and screen-reader or automated checks when applicable. If a check was not run, state what still needs verification.
2. Verdict: Block if any HIGH finding remains, Needs changes if only MEDIUM or LOW findings remain, and Approve only when no actionable findings remain.

When there are no findings, omit the tables, state "No actionable accessibility findings", report verification, and end with Approve.