Keyboard & Focus

What Airframe provides

Airframe applies visible focus indicators to all interactive elements automatically. No setup required.

:where(a, button, input, select, textarea, summary, [tabindex]):focus-visible {
  outline: var(--af-focus-ring-width) solid var(--af-focus-ring-color);
  outline-offset: var(--af-focus-ring-offset);
}

Focus tokens

Token	Purpose
`--af-focus-ring-width`	Ring thickness
`--af-focus-ring-color`	Ring color
`--af-focus-ring-offset`	Gap between element and ring

Override these tokens in your theme to change focus appearance globally.

Focus trapping

Native <dialog> with showModal() marks the rest of the page as inert, which prevents tab from leaving the dialog. This covers most use cases but has known gaps:

Some browsers (notably Safari) can leak focus outside the dialog
Screen reader virtual cursors can navigate past the dialog boundary
Focus restoration to the trigger on close is inconsistent across browsers

For production apps, supplement native behavior with a focus trap library (e.g. focus-trap). Airframe does not ship that JS.

<dialog class="af-dialog">
  <div class="af-dialog-header">
    <h2 class="af-dialog-title">Title</h2>
    <button class="af-btn" onclick="this.closest('dialog').close()">Close</button>
  </div>
  <div class="af-dialog-body">
    <p>Content here.</p>
  </div>
</dialog>

Skip links

Use af-skip. Hidden until focused; then a control at the start of the viewport.

<a href="#main" class="af-skip">Skip to content</a>

<nav class="af-navbar">...</nav>

<main id="main" tabindex="-1">...</main>

Rules to follow

Never remove focus outlines. Airframe enforces this in base styles.

/* ❌ Never do this */
*:focus { outline: none; }

/* ✅ Airframe handles focus automatically */

Use semantic elements. A <button> is keyboard accessible by default. A <div> is not.

<!-- ❌ Not keyboard accessible -->
<div onclick="doSomething()">Click me</div>

<!-- ✅ Keyboard accessible by default -->

<button onclick="doSomething()">Click me</button>

Avoid positive tabindex. It breaks the natural DOM tab order.

<!-- ❌ Breaks tab order -->
<button tabindex="2">Second</button>
<button tabindex="1">First</button>

<!-- ✅ Let DOM order determine tab order -->

<button>First</button>
<button>Second</button>