ARIA Tabs Pattern

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  background: #0a0a0a;
  color: #e4e4e7;
  line-height: 1.6;
  min-height: 100vh;
}

.demo {
  max-width: 720px;
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

.demo-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: #fafafa;
  letter-spacing: -0.02em;
}

.demo-sub {
  color: #a1a1aa;
  margin-top: 0.25rem;
  font-size: 0.95rem;
}

/* Tabs Wrapper */
.tabs-wrapper {
  margin-top: 2rem;
  background: #111113;
  border: 1px solid #27272a;
  border-radius: 12px;
  overflow: hidden;
}

/* Tablist */
.tablist {
  display: flex;
  border-bottom: 1px solid #27272a;
  background: #0e0e10;
  overflow-x: auto;
}

.tab {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.85rem 1.25rem;
  font-size: 0.85rem;
  font-weight: 500;
  font-family: inherit;
  color: #71717a;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.tab:hover {
  color: #d4d4d8;
  background: rgba(255, 255, 255, 0.03);
}

.tab--active {
  color: #fafafa;
  border-bottom-color: #3b82f6;
}

.tab:focus-visible {
  outline: 2px solid #3b82f6;
  outline-offset: -2px;
  border-radius: 4px;
}

.tab-icon {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

/* Tab Panels */
.tabpanel {
  padding: 1.5rem;
  display: none;
  animation: fadeIn 0.2s ease-out;
}

.tabpanel--active,
.tabpanel:not([hidden]) {
  display: block;
}

.tabpanel:focus-visible {
  outline: 2px solid #3b82f6;
  outline-offset: -2px;
}

.panel-heading {
  font-size: 1.1rem;
  font-weight: 600;
  color: #fafafa;
  margin-bottom: 1.25rem;
}

/* Form */
.form-group {
  margin-bottom: 1rem;
}

.form-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: #a1a1aa;
  margin-bottom: 0.35rem;
}

.form-input {
  width: 100%;
  padding: 0.6rem 0.85rem;
  background: #09090b;
  border: 1px solid #27272a;
  border-radius: 8px;
  color: #e4e4e7;
  font-size: 0.875rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s;
}

.form-input:focus {
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-textarea {
  resize: vertical;
  min-height: 80px;
}

.radio-group {
  display: flex;
  gap: 1.25rem;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.875rem;
  color: #d4d4d8;
  cursor: pointer;
}

/* Members */
.member-list {
  list-style: none;
}

.member-item {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 0.75rem 0;
}

.member-item + .member-item {
  border-top: 1px solid #1e1e22;
}

.member-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: #fff;
  flex-shrink: 0;
}

.member-info {
  display: flex;
  flex-direction: column;
}

.member-name {
  font-size: 0.875rem;
  font-weight: 500;
  color: #fafafa;
}

.member-role {
  font-size: 0.75rem;
  color: #71717a;
}

/* Toggles */
.toggle-list {
  display: flex;
  flex-direction: column;
}

.toggle-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  cursor: pointer;
}

.toggle-item + .toggle-item {
  border-top: 1px solid #1e1e22;
}

.toggle-text {
  display: flex;
  flex-direction: column;
}

.toggle-text strong {
  font-size: 0.875rem;
  font-weight: 500;
  color: #e4e4e7;
}

.toggle-desc {
  font-size: 0.78rem;
  color: #71717a;
  margin-top: 0.1rem;
}

.toggle-input {
  width: 40px;
  height: 22px;
  appearance: none;
  background: #27272a;
  border-radius: 100px;
  position: relative;
  cursor: pointer;
  flex-shrink: 0;
  transition: background 0.2s;
}

.toggle-input::before {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #71717a;
  transition: transform 0.2s, background 0.2s;
}

.toggle-input:checked {
  background: #3b82f6;
}

.toggle-input:checked::before {
  transform: translateX(18px);
  background: #fff;
}

.toggle-input:focus-visible {
  outline: 2px solid #3b82f6;
  outline-offset: 2px;
}

/* Billing */
.billing-card {
  background: #09090b;
  border: 1px solid #27272a;
  border-radius: 10px;
  padding: 1.25rem;
}

.billing-plan {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.billing-plan-name {
  font-size: 1rem;
  font-weight: 600;
  color: #3b82f6;
}

.billing-plan-price {
  font-size: 1.5rem;
  font-weight: 700;
  color: #fafafa;
}

.billing-plan-period {
  font-size: 0.8rem;
  font-weight: 400;
  color: #71717a;
}

.billing-plan-desc {
  font-size: 0.85rem;
  color: #a1a1aa;
  margin-bottom: 1rem;
}

.billing-meta {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  font-size: 0.8rem;
  color: #71717a;
}

.billing-meta strong {
  color: #d4d4d8;
}

/* Info Panel */
.info-panel {
  margin-top: 2rem;
  background: #111113;
  border: 1px solid #27272a;
  border-radius: 12px;
  padding: 1.5rem;
}

.info-title {
  font-size: 1rem;
  font-weight: 600;
  color: #fafafa;
  margin-bottom: 0.75rem;
}

.info-subtitle {
  font-size: 0.9rem;
  font-weight: 600;
  color: #fafafa;
  margin-top: 1.25rem;
  margin-bottom: 0.5rem;
}

.info-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.info-list li {
  font-size: 0.825rem;
  color: #a1a1aa;
}

.info-list code {
  background: #1e1e22;
  padding: 0.12rem 0.4rem;
  border-radius: 4px;
  font-size: 0.78rem;
  color: #60a5fa;
  font-family: "SF Mono", "Fira Code", monospace;
}

.kbd-list {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.kbd-item {
  font-size: 0.825rem;
  color: #a1a1aa;
}

kbd {
  display: inline-block;
  padding: 0.1rem 0.45rem;
  background: #1e1e22;
  border: 1px solid #3f3f46;
  border-radius: 4px;
  font-size: 0.75rem;
  font-family: "SF Mono", "Fira Code", monospace;
  color: #d4d4d8;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

(() => {
  const tablist = document.querySelector('[role="tablist"]');
  const tabs = Array.from(tablist.querySelectorAll('[role="tab"]'));
  const panels = tabs.map((tab) => document.getElementById(tab.getAttribute("aria-controls")));

  function activateTab(tab) {
    // Deactivate all tabs
    tabs.forEach((t) => {
      t.setAttribute("aria-selected", "false");
      t.setAttribute("tabindex", "-1");
      t.classList.remove("tab--active");
    });

    // Hide all panels
    panels.forEach((p) => {
      p.hidden = true;
      p.classList.remove("tabpanel--active");
    });

    // Activate selected tab
    tab.setAttribute("aria-selected", "true");
    tab.setAttribute("tabindex", "0");
    tab.classList.add("tab--active");
    tab.focus();

    // Show associated panel
    const panel = document.getElementById(tab.getAttribute("aria-controls"));
    panel.hidden = false;
    panel.classList.add("tabpanel--active");
  }

  // Click handler
  tabs.forEach((tab) => {
    tab.addEventListener("click", () => activateTab(tab));
  });

  // Keyboard handler
  tablist.addEventListener("keydown", (e) => {
    const currentIndex = tabs.indexOf(document.activeElement);
    if (currentIndex === -1) return;

    let newIndex;

    switch (e.key) {
      case "ArrowRight":
        e.preventDefault();
        newIndex = (currentIndex + 1) % tabs.length;
        activateTab(tabs[newIndex]);
        break;

      case "ArrowLeft":
        e.preventDefault();
        newIndex = (currentIndex - 1 + tabs.length) % tabs.length;
        activateTab(tabs[newIndex]);
        break;

      case "Home":
        e.preventDefault();
        activateTab(tabs[0]);
        break;

      case "End":
        e.preventDefault();
        activateTab(tabs[tabs.length - 1]);
        break;
    }
  });
})();

<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>ARIA Tabs Pattern</title>
  <link rel="stylesheet" href="style.css" />
</head>
<body>
  <div class="demo">
    <h1 class="demo-title">ARIA Tabs Pattern</h1>
    <p class="demo-sub">WAI-ARIA compliant tabs with keyboard navigation and proper role attributes.</p>

    <div class="tabs-wrapper">
      <div role="tablist" aria-label="Project settings" class="tablist">
        <button role="tab"
                id="tab-general"
                aria-selected="true"
                aria-controls="panel-general"
                tabindex="0"
                class="tab tab--active">
          <svg class="tab-icon" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="3"/><path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1-2.83 2.83l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-4 0v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1 0-4h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 2.83-2.83l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 4 0v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 2.83l-.06.06A1.65 1.65 0 0 0 19.4 9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 0 4h-.09a1.65 1.65 0 0 0-1.51 1z"/></svg>
          General
        </button>
        <button role="tab"
                id="tab-members"
                aria-selected="false"
                aria-controls="panel-members"
                tabindex="-1"
                class="tab">
          <svg class="tab-icon" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M17 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2"/><circle cx="9" cy="7" r="4"/><path d="M23 21v-2a4 4 0 0 0-3-3.87"/><path d="M16 3.13a4 4 0 0 1 0 7.75"/></svg>
          Members
        </button>
        <button role="tab"
                id="tab-notifications"
                aria-selected="false"
                aria-controls="panel-notifications"
                tabindex="-1"
                class="tab">
          <svg class="tab-icon" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M18 8A6 6 0 0 0 6 8c0 7-3 9-3 9h18s-3-2-3-9"/><path d="M13.73 21a2 2 0 0 1-3.46 0"/></svg>
          Notifications
        </button>
        <button role="tab"
                id="tab-billing"
                aria-selected="false"
                aria-controls="panel-billing"
                tabindex="-1"
                class="tab">
          <svg class="tab-icon" xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="1" y="4" width="22" height="16" rx="2" ry="2"/><line x1="1" y1="10" x2="23" y2="10"/></svg>
          Billing
        </button>
      </div>

      <!-- General Panel -->
      <div role="tabpanel"
           id="panel-general"
           aria-labelledby="tab-general"
           tabindex="0"
           class="tabpanel tabpanel--active">
        <h3 class="panel-heading">General Settings</h3>
        <div class="form-group">
          <label class="form-label" for="project-name">Project Name</label>
          <input type="text" id="project-name" class="form-input" value="ARIA Components" />
        </div>
        <div class="form-group">
          <label class="form-label" for="project-desc">Description</label>
          <textarea id="project-desc" class="form-input form-textarea" rows="3">A collection of accessible UI components implementing WAI-ARIA design patterns.</textarea>
        </div>
        <div class="form-group">
          <label class="form-label">Visibility</label>
          <div class="radio-group">
            <label class="radio-label"><input type="radio" name="visibility" checked /> Public</label>
            <label class="radio-label"><input type="radio" name="visibility" /> Private</label>
          </div>
        </div>
      </div>

      <!-- Members Panel -->
      <div role="tabpanel"
           id="panel-members"
           aria-labelledby="tab-members"
           tabindex="0"
           class="tabpanel"
           hidden>
        <h3 class="panel-heading">Team Members</h3>
        <ul class="member-list">
          <li class="member-item">
            <div class="member-avatar" style="background:#3b82f6;">AL</div>
            <div class="member-info"><span class="member-name">Alice Lin</span><span class="member-role">Owner</span></div>
          </li>
          <li class="member-item">
            <div class="member-avatar" style="background:#8b5cf6;">BK</div>
            <div class="member-info"><span class="member-name">Bob Kim</span><span class="member-role">Admin</span></div>
          </li>
          <li class="member-item">
            <div class="member-avatar" style="background:#ec4899;">CR</div>
            <div class="member-info"><span class="member-name">Carol Rivera</span><span class="member-role">Member</span></div>
          </li>
          <li class="member-item">
            <div class="member-avatar" style="background:#f59e0b;">DT</div>
            <div class="member-info"><span class="member-name">Dan Torres</span><span class="member-role">Member</span></div>
          </li>
        </ul>
      </div>

      <!-- Notifications Panel -->
      <div role="tabpanel"
           id="panel-notifications"
           aria-labelledby="tab-notifications"
           tabindex="0"
           class="tabpanel"
           hidden>
        <h3 class="panel-heading">Notification Preferences</h3>
        <div class="toggle-list">
          <label class="toggle-item">
            <span class="toggle-text">
              <strong>Email notifications</strong>
              <span class="toggle-desc">Receive email for important updates</span>
            </span>
            <input type="checkbox" class="toggle-input" checked />
          </label>
          <label class="toggle-item">
            <span class="toggle-text">
              <strong>Push notifications</strong>
              <span class="toggle-desc">Browser push notifications for real-time alerts</span>
            </span>
            <input type="checkbox" class="toggle-input" />
          </label>
          <label class="toggle-item">
            <span class="toggle-text">
              <strong>Weekly digest</strong>
              <span class="toggle-desc">Summary email sent every Monday</span>
            </span>
            <input type="checkbox" class="toggle-input" checked />
          </label>
          <label class="toggle-item">
            <span class="toggle-text">
              <strong>Marketing emails</strong>
              <span class="toggle-desc">Product updates and feature announcements</span>
            </span>
            <input type="checkbox" class="toggle-input" />
          </label>
        </div>
      </div>

      <!-- Billing Panel -->
      <div role="tabpanel"
           id="panel-billing"
           aria-labelledby="tab-billing"
           tabindex="0"
           class="tabpanel"
           hidden>
        <h3 class="panel-heading">Billing Information</h3>
        <div class="billing-card">
          <div class="billing-plan">
            <span class="billing-plan-name">Pro Plan</span>
            <span class="billing-plan-price">$29<span class="billing-plan-period">/month</span></span>
          </div>
          <p class="billing-plan-desc">Unlimited projects, priority support, advanced analytics.</p>
          <div class="billing-meta">
            <span>Next billing date: <strong>April 1, 2026</strong></span>
            <span>Payment method: <strong>Visa ending in 4242</strong></span>
          </div>
        </div>
      </div>
    </div>

    <!-- ARIA Info Panel -->
    <div class="info-panel">
      <h3 class="info-title">ARIA Attributes Used</h3>
      <ul class="info-list">
        <li><code>role="tablist"</code> &mdash; Container for the tab buttons</li>
        <li><code>role="tab"</code> &mdash; Each clickable tab button</li>
        <li><code>role="tabpanel"</code> &mdash; Content panel associated with a tab</li>
        <li><code>aria-selected="true/false"</code> &mdash; Indicates the active tab</li>
        <li><code>aria-controls</code> &mdash; Links a tab to its panel</li>
        <li><code>aria-labelledby</code> &mdash; Links a panel back to its tab</li>
        <li><code>tabindex="0/-1"</code> &mdash; Roving tabindex for keyboard focus</li>
      </ul>
      <h4 class="info-subtitle">Keyboard Controls</h4>
      <div class="kbd-list">
        <span class="kbd-item"><kbd>Left</kbd> / <kbd>Right</kbd> &mdash; Move between tabs</span>
        <span class="kbd-item"><kbd>Home</kbd> &mdash; Go to first tab</span>
        <span class="kbd-item"><kbd>End</kbd> &mdash; Go to last tab</span>
        <span class="kbd-item"><kbd>Tab</kbd> &mdash; Enter/leave the tab panel</span>
      </div>
    </div>
  </div>

  <script src="script.js"></script>
</body>
</html>