better-accessibility
GitHub专注于前端界面无障碍工程,涵盖键盘导航、ARIA语义、表单及屏幕阅读器支持。用于构建或审查UI组件时确保符合WCAG标准,解决键盘和读屏问题。
触发场景
安装
npx skills add jakubkrehel/skills --skill better-accessibility -g -y
SKILL.md
Frontmatter
{
"name": "better-accessibility",
"description": "Accessibility engineering for product interfaces, from focus states and keyboard support to ARIA, forms, and screen readers. Use when building or reviewing UI components, modals, menus, forms, custom widgets, or when the user says \"make this accessible\" or reports keyboard or screen-reader issues. Triggers on accessibility, a11y, WCAG, aria, focus ring, focus-visible, focus trap, keyboard navigation, tab order, tabindex, screen reader, sr-only, aria-live, alt text, hit area, touch target, prefers-reduced-motion, autoplay, toast duration, skip link, semantic HTML, aria-label, form errors, disabled buttons, \"not keyboard accessible\"."
}
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 better-colors skill; visual text sizing and iOS input zoom by better-typography; spatial RTL layout by better-layout.
Quick Reference
| Category | When to Use |
|---|---|
| Focus & Keyboard | Focus rings, skip links, tabindex, focus trapping, APG keyboard patterns |
| Semantics & ARIA | Native elements first, button vs link, landmarks, accessible names, disabled states |
| Forms | Labels, autocomplete, error messaging, input types |
| Screen Readers | Visually hidden content, live regions, toasts, alt text, SVG |
| Hit Areas | Target sizes, expanding hit areas, collision rules |
| Motion & Zoom | prefers-reduced-motion, autoplay and timed UI, 200% zoom, reflow, rem vs px |
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 better-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
| Mistake | Fix |
|---|---|
outline: none to remove the focus ring |
Style :focus-visible instead; mouse clicks won't show it |
| Custom focus color assumed to work everywhere | Verify the full indicator against every adjacent color and in forced-colors mode |
<div onClick> for a button or link |
<button> for actions, <a href> for navigation |
| Placeholder used as the only label | Add a visible <label for>; placeholders disappear on input |
Positive tabindex to fix focus order |
Fix the DOM order; only use 0 and -1 |
| Repeated polite update inconsistently announced | Keep a stable empty status region and update its text; test the target screen readers |
assertive live region for a routine toast |
Use polite; reserve assertive for errors |
aria-hidden="true" on a focusable element |
Remove it or make the element non-focusable |
| Functional icon alt describes the picture | Describe the action: alt="Search", not alt="magnifying glass" |
maximum-scale=1 to stop iOS input zoom |
16px input font on mobile (see better-typography); never block zoom |
| Submit disabled until the form is valid | Keep it enabled; validate on submit and focus the first error |
Review Output Format
Use this format only when the user asks for a standalone accessibility review. When better-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:
HIGHprevents a task, hides content from assistive technology, or creates a systemic accessibility failure;MEDIUMmakes an interaction meaningfully harder;LOWis 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
| Severity | Location | Before | After | Why |
|---|---|---|---|---|
| HIGH | src/Dialog.tsx:42 |
<button><XIcon /></button> |
Add aria-label="Close"; mark the icon aria-hidden="true" |
The icon-only control has no accessible name |
| HIGH | src/Nav.tsx:18 |
<a href="/settings"><GearIcon /></a> |
Add aria-label="Settings" |
The link destination is unavailable to screen readers |
Visible focus rings
| Severity | Location | Before | After | Why |
|---|---|---|---|---|
| HIGH | src/button.css:12 |
button:focus { outline: none; } |
button:focus-visible { outline: 2px solid; outline-offset: 2px; } |
Keyboard users cannot see focus |
| HIGH | src/Menu.tsx:31 |
focus:outline-none |
focus-visible:outline-2 focus-visible:outline-offset-2 |
Menu navigation has no visible focus indicator |
Errors that announce
| Severity | Location | Before | After | Why |
|---|---|---|---|---|
| HIGH | src/EmailField.tsx:27 |
Error shown only as border-red-500 |
Add aria-invalid="true" + aria-describedby="email-error" with inline error text |
Color alone neither explains nor announces the error |
| MEDIUM | src/SignupForm.tsx:64 |
Submit disabled until the form is valid | Keep submit enabled; on failure, focus the first invalid field | A disabled action hides what must be fixed |
Minimum hit area
| Severity | Location | Before | After | Why |
|---|---|---|---|---|
| MEDIUM | src/Toolbar.tsx:22 |
size-4 icon-only button |
Extend the hit area to 44×44px with after:absolute after:size-11 |
The target is too small for reliable touch input |
Verification and Verdict
After the findings:
- 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.
- Verdict:
Blockif anyHIGHfinding remains,Needs changesif onlyMEDIUMorLOWfindings remain, andApproveonly when no actionable findings remain.
When there are no findings, omit the tables, state "No actionable accessibility findings", report verification, and end with Approve.
版本历史
- a673333 当前 2026-07-30 20:27


