UI Components Easy
Semantic Landmarks
Demonstration of HTML5 semantic landmarks (header, nav, main, aside, footer) with proper ARIA labeling for screen reader navigation.
Open in Lab
MCP
html css
Targets: JS HTML
Code
*,
*::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;
}
/* Toggle Controls */
.demo-controls {
position: sticky;
top: 0;
z-index: 100;
background: rgba(10, 10, 10, 0.85);
backdrop-filter: blur(12px);
border-bottom: 1px solid #27272a;
padding: 0.75rem 1.5rem;
display: flex;
justify-content: center;
}
.btn {
display: inline-flex;
align-items: center;
gap: 0.4rem;
padding: 0.5rem 1rem;
font-size: 0.8rem;
font-weight: 500;
font-family: inherit;
border: 1px solid #27272a;
border-radius: 8px;
background: #18181b;
color: #e4e4e7;
cursor: pointer;
transition: all 0.15s;
}
.btn:hover {
background: #27272a;
}
.btn:focus-visible {
outline: 2px solid #3b82f6;
outline-offset: 2px;
}
.btn--icon {
width: 36px;
height: 36px;
padding: 0;
justify-content: center;
border-radius: 50%;
}
.btn--toggle[aria-pressed="true"] {
background: rgba(59, 130, 246, 0.15);
border-color: rgba(59, 130, 246, 0.3);
color: #60a5fa;
}
/* Landmark Page */
.landmark-page {
max-width: 960px;
margin: 0 auto;
padding: 0 1rem;
}
/* Landmark outlines */
.landmark {
position: relative;
}
.show-outlines .landmark::after {
content: attr(data-landmark);
position: absolute;
top: 4px;
right: 4px;
font-size: 0.6rem;
font-weight: 600;
text-transform: uppercase;
letter-spacing: 0.05em;
padding: 0.15rem 0.45rem;
border-radius: 4px;
pointer-events: none;
z-index: 10;
line-height: 1.4;
}
/* Color coding per landmark type */
.show-outlines header.landmark {
outline: 2px dashed rgba(244, 63, 94, 0.4);
outline-offset: -2px;
}
.show-outlines header.landmark::after {
background: rgba(244, 63, 94, 0.2);
color: #fb7185;
border: 1px solid rgba(244, 63, 94, 0.3);
}
.show-outlines nav.landmark {
outline: 2px dashed rgba(245, 158, 11, 0.4);
outline-offset: -2px;
}
.show-outlines nav.landmark::after {
background: rgba(245, 158, 11, 0.2);
color: #fbbf24;
border: 1px solid rgba(245, 158, 11, 0.3);
}
.show-outlines main.landmark {
outline: 2px dashed rgba(59, 130, 246, 0.4);
outline-offset: -2px;
}
.show-outlines main.landmark::after {
background: rgba(59, 130, 246, 0.2);
color: #60a5fa;
border: 1px solid rgba(59, 130, 246, 0.3);
}
.show-outlines aside.landmark {
outline: 2px dashed rgba(139, 92, 246, 0.4);
outline-offset: -2px;
}
.show-outlines aside.landmark::after {
background: rgba(139, 92, 246, 0.2);
color: #a78bfa;
border: 1px solid rgba(139, 92, 246, 0.3);
}
.show-outlines footer.landmark {
outline: 2px dashed rgba(34, 197, 94, 0.4);
outline-offset: -2px;
}
.show-outlines footer.landmark::after {
background: rgba(34, 197, 94, 0.2);
color: #4ade80;
border: 1px solid rgba(34, 197, 94, 0.3);
}
/* Header */
.page-header {
padding: 1rem 0;
border-bottom: 1px solid #27272a;
}
.header-inner {
display: flex;
align-items: center;
gap: 1.5rem;
}
.logo {
display: flex;
align-items: center;
gap: 0.5rem;
color: #fafafa;
text-decoration: none;
font-weight: 700;
font-size: 1rem;
}
.nav-primary {
flex: 1;
}
.nav-list {
display: flex;
gap: 0.25rem;
list-style: none;
}
.nav-link {
padding: 0.4rem 0.75rem;
font-size: 0.825rem;
color: #71717a;
text-decoration: none;
border-radius: 6px;
transition: all 0.15s;
}
.nav-link:hover {
color: #e4e4e7;
background: #1e1e22;
}
.nav-link--active {
color: #fafafa;
background: #1e1e22;
}
.nav-link:focus-visible {
outline: 2px solid #3b82f6;
outline-offset: 2px;
}
.header-actions {
display: flex;
align-items: center;
gap: 0.5rem;
}
.avatar {
width: 32px;
height: 32px;
border-radius: 50%;
background: #3b82f6;
color: #fff;
font-size: 0.7rem;
font-weight: 600;
display: flex;
align-items: center;
justify-content: center;
}
/* Content Layout */
.content-layout {
display: grid;
grid-template-columns: 1fr 240px;
gap: 1.5rem;
padding: 1.5rem 0;
}
/* Main */
.page-main {
min-height: 400px;
}
.main-title {
font-size: 1.4rem;
font-weight: 700;
color: #fafafa;
letter-spacing: -0.02em;
}
.main-desc {
font-size: 0.875rem;
color: #71717a;
margin-top: 0.25rem;
}
.stats-grid {
display: grid;
grid-template-columns: repeat(3, 1fr);
gap: 0.75rem;
margin-top: 1.5rem;
}
.stat-card {
background: #111113;
border: 1px solid #27272a;
border-radius: 10px;
padding: 1rem;
display: flex;
flex-direction: column;
gap: 0.25rem;
}
.stat-label {
font-size: 0.75rem;
color: #71717a;
}
.stat-value {
font-size: 1.5rem;
font-weight: 700;
color: #fafafa;
}
.content-section {
margin-top: 1.5rem;
}
.section-title {
font-size: 1rem;
font-weight: 600;
color: #fafafa;
margin-bottom: 0.75rem;
}
.activity-list {
display: flex;
flex-direction: column;
}
.activity-item {
display: flex;
gap: 0.75rem;
padding: 0.65rem 0;
}
.activity-item + .activity-item {
border-top: 1px solid #1e1e22;
}
.activity-dot {
width: 8px;
height: 8px;
border-radius: 50%;
margin-top: 0.45rem;
flex-shrink: 0;
}
.activity-info {
display: flex;
flex-direction: column;
}
.activity-text {
font-size: 0.85rem;
color: #d4d4d8;
}
.activity-text strong {
color: #fafafa;
}
.activity-time {
font-size: 0.75rem;
color: #52525b;
}
/* Pagination nav */
.nav-pagination {
margin-top: 1.5rem;
display: flex;
gap: 0.3rem;
}
.page-link {
width: 32px;
height: 32px;
display: flex;
align-items: center;
justify-content: center;
border-radius: 6px;
background: #18181b;
border: 1px solid #27272a;
color: #a1a1aa;
text-decoration: none;
font-size: 0.8rem;
transition: all 0.15s;
}
.page-link:hover {
background: #27272a;
color: #fafafa;
}
.page-link[aria-current="page"] {
background: #3b82f6;
border-color: #3b82f6;
color: #fff;
}
.page-link:focus-visible {
outline: 2px solid #3b82f6;
outline-offset: 2px;
}
/* Aside */
.page-aside {
padding: 1rem;
background: #111113;
border: 1px solid #27272a;
border-radius: 12px;
height: fit-content;
}
.aside-title {
font-size: 0.85rem;
font-weight: 600;
color: #fafafa;
margin-bottom: 0.5rem;
}
.aside-list {
list-style: none;
display: flex;
flex-direction: column;
}
.aside-link {
display: block;
padding: 0.35rem 0;
font-size: 0.825rem;
color: #a1a1aa;
text-decoration: none;
transition: color 0.15s;
}
.aside-link:hover {
color: #3b82f6;
}
.aside-link:focus-visible {
outline: 2px solid #3b82f6;
outline-offset: 2px;
}
.aside-team {
display: flex;
flex-direction: column;
gap: 0.4rem;
}
.team-member {
display: flex;
align-items: center;
gap: 0.5rem;
font-size: 0.8rem;
color: #d4d4d8;
}
.member-dot {
width: 8px;
height: 8px;
border-radius: 50%;
}
.member-dot--online {
background: #22c55e;
}
.member-dot--away {
background: #f59e0b;
}
/* Footer */
.page-footer {
border-top: 1px solid #27272a;
padding: 1rem 0;
}
.footer-inner {
display: flex;
align-items: center;
justify-content: space-between;
}
.footer-copy {
font-size: 0.78rem;
color: #52525b;
}
.nav-footer {
display: flex;
gap: 1rem;
}
.footer-link {
font-size: 0.78rem;
color: #71717a;
text-decoration: none;
transition: color 0.15s;
}
.footer-link:hover {
color: #e4e4e7;
}
.footer-link:focus-visible {
outline: 2px solid #3b82f6;
outline-offset: 2px;
}
/* Legend */
.legend {
max-width: 960px;
margin: 1rem auto 3rem;
padding: 1.5rem;
background: #111113;
border: 1px solid #27272a;
border-radius: 12px;
}
.legend-title {
font-size: 1rem;
font-weight: 600;
color: #fafafa;
margin-bottom: 0.75rem;
}
.legend-items {
display: flex;
flex-wrap: wrap;
gap: 0.75rem 1.5rem;
}
.legend-item {
display: flex;
align-items: center;
gap: 0.5rem;
font-size: 0.825rem;
color: #a1a1aa;
}
.legend-swatch {
width: 14px;
height: 14px;
border-radius: 3px;
flex-shrink: 0;
}
.legend-swatch--header {
background: rgba(244, 63, 94, 0.3);
border: 1px solid rgba(244, 63, 94, 0.5);
}
.legend-swatch--nav {
background: rgba(245, 158, 11, 0.3);
border: 1px solid rgba(245, 158, 11, 0.5);
}
.legend-swatch--main {
background: rgba(59, 130, 246, 0.3);
border: 1px solid rgba(59, 130, 246, 0.5);
}
.legend-swatch--aside {
background: rgba(139, 92, 246, 0.3);
border: 1px solid rgba(139, 92, 246, 0.5);
}
.legend-swatch--footer {
background: rgba(34, 197, 94, 0.3);
border: 1px solid rgba(34, 197, 94, 0.5);
}
.legend-item code {
background: #1e1e22;
padding: 0.1rem 0.35rem;
border-radius: 4px;
font-size: 0.75rem;
color: #d4d4d8;
font-family: "SF Mono", "Fira Code", monospace;
}
.legend-note {
margin-top: 0.75rem;
font-size: 0.78rem;
color: #52525b;
line-height: 1.5;
}
.legend-note code {
background: #1e1e22;
padding: 0.08rem 0.3rem;
border-radius: 3px;
font-size: 0.72rem;
color: #a1a1aa;
font-family: "SF Mono", "Fira Code", monospace;
}
@media (max-width: 640px) {
.content-layout {
grid-template-columns: 1fr;
}
.stats-grid {
grid-template-columns: 1fr;
}
.header-inner {
flex-wrap: wrap;
}
}(() => {
const toggleBtn = document.getElementById("toggle-outlines");
const page = document.getElementById("landmark-page");
toggleBtn.addEventListener("click", () => {
const isActive = page.classList.toggle("show-outlines");
toggleBtn.setAttribute("aria-pressed", isActive ? "true" : "false");
});
})();<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Semantic Landmarks</title>
<link rel="stylesheet" href="style.css" />
</head>
<body>
<div class="demo-controls">
<button class="btn btn--toggle" id="toggle-outlines" aria-pressed="true">
<svg 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="3" y="3" width="18" height="18" rx="2" ry="2"/><line x1="3" y1="9" x2="21" y2="9"/><line x1="9" y1="21" x2="9" y2="9"/></svg>
Toggle Landmark Outlines
</button>
</div>
<div class="landmark-page show-outlines" id="landmark-page">
<!-- HEADER (banner) -->
<header class="page-header landmark" data-landmark="header (banner)">
<div class="header-inner">
<a href="#" class="logo" aria-label="Acme Dashboard Home">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polygon points="12 2 2 7 12 12 22 7 12 2"/><polyline points="2 17 12 22 22 17"/><polyline points="2 12 12 17 22 12"/></svg>
<span>Acme</span>
</a>
<!-- Primary NAV -->
<nav aria-label="Primary navigation" class="nav-primary landmark" data-landmark='nav (aria-label="Primary")'>
<ul class="nav-list">
<li><a href="#" class="nav-link nav-link--active">Dashboard</a></li>
<li><a href="#" class="nav-link">Projects</a></li>
<li><a href="#" class="nav-link">Reports</a></li>
<li><a href="#" class="nav-link">Settings</a></li>
</ul>
</nav>
<div class="header-actions">
<button class="btn btn--icon" aria-label="Notifications">
<svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" 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>
</button>
<div class="avatar" aria-label="User profile">JD</div>
</div>
</div>
</header>
<div class="content-layout">
<!-- MAIN -->
<main class="page-main landmark" data-landmark="main">
<h1 class="main-title">Dashboard Overview</h1>
<p class="main-desc">Welcome back! Here is a summary of your recent activity.</p>
<div class="stats-grid">
<div class="stat-card">
<span class="stat-label">Active Projects</span>
<span class="stat-value">12</span>
</div>
<div class="stat-card">
<span class="stat-label">Open Tasks</span>
<span class="stat-value">47</span>
</div>
<div class="stat-card">
<span class="stat-label">Team Members</span>
<span class="stat-value">8</span>
</div>
</div>
<section class="content-section" aria-labelledby="recent-heading">
<h2 id="recent-heading" class="section-title">Recent Activity</h2>
<div class="activity-list">
<div class="activity-item">
<div class="activity-dot" style="background:#3b82f6;" aria-hidden="true"></div>
<div class="activity-info">
<span class="activity-text">Alice pushed 3 commits to <strong>feature/auth</strong></span>
<span class="activity-time">2 hours ago</span>
</div>
</div>
<div class="activity-item">
<div class="activity-dot" style="background:#8b5cf6;" aria-hidden="true"></div>
<div class="activity-info">
<span class="activity-text">Bob completed code review on <strong>PR #142</strong></span>
<span class="activity-time">5 hours ago</span>
</div>
</div>
<div class="activity-item">
<div class="activity-dot" style="background:#22c55e;" aria-hidden="true"></div>
<div class="activity-info">
<span class="activity-text">Deployment to <strong>staging</strong> succeeded</span>
<span class="activity-time">1 day ago</span>
</div>
</div>
</div>
</section>
<!-- Secondary NAV inside main -->
<nav aria-label="Pagination" class="nav-pagination landmark" data-landmark='nav (aria-label="Pagination")'>
<a href="#" class="page-link" aria-current="page">1</a>
<a href="#" class="page-link">2</a>
<a href="#" class="page-link">3</a>
</nav>
</main>
<!-- ASIDE (complementary) -->
<aside class="page-aside landmark" data-landmark="aside (complementary)" aria-label="Sidebar">
<h2 class="aside-title">Quick Links</h2>
<ul class="aside-list">
<li><a href="#" class="aside-link">Documentation</a></li>
<li><a href="#" class="aside-link">API Reference</a></li>
<li><a href="#" class="aside-link">Changelog</a></li>
<li><a href="#" class="aside-link">Support</a></li>
</ul>
<h2 class="aside-title" style="margin-top:1.5rem;">Team Online</h2>
<div class="aside-team">
<div class="team-member">
<div class="member-dot member-dot--online" aria-hidden="true"></div>
<span>Alice Lin</span>
</div>
<div class="team-member">
<div class="member-dot member-dot--online" aria-hidden="true"></div>
<span>Bob Kim</span>
</div>
<div class="team-member">
<div class="member-dot member-dot--away" aria-hidden="true"></div>
<span>Carol Rivera</span>
</div>
</div>
</aside>
</div>
<!-- FOOTER (contentinfo) -->
<footer class="page-footer landmark" data-landmark="footer (contentinfo)">
<div class="footer-inner">
<span class="footer-copy">Acme Inc. 2026. All rights reserved.</span>
<nav aria-label="Footer navigation" class="nav-footer landmark" data-landmark='nav (aria-label="Footer")'>
<a href="#" class="footer-link">Privacy</a>
<a href="#" class="footer-link">Terms</a>
<a href="#" class="footer-link">Contact</a>
</nav>
</div>
</footer>
</div>
<!-- Landmark Legend -->
<div class="legend" id="legend">
<h3 class="legend-title">Landmark Map</h3>
<div class="legend-items">
<div class="legend-item"><span class="legend-swatch legend-swatch--header"></span><code><header></code> (banner)</div>
<div class="legend-item"><span class="legend-swatch legend-swatch--nav"></span><code><nav></code> (navigation)</div>
<div class="legend-item"><span class="legend-swatch legend-swatch--main"></span><code><main></code> (main)</div>
<div class="legend-item"><span class="legend-swatch legend-swatch--aside"></span><code><aside></code> (complementary)</div>
<div class="legend-item"><span class="legend-swatch legend-swatch--footer"></span><code><footer></code> (contentinfo)</div>
</div>
<p class="legend-note">Screen readers let users jump between landmarks. Multiple <code><nav></code> elements should use <code>aria-label</code> to distinguish them.</p>
</div>
<script src="script.js"></script>
</body>
</html>A full page layout demonstrating all HTML5 semantic landmarks — header (banner), nav (with distinct aria-labels for primary and secondary navigation), main, aside (complementary), and footer (contentinfo). Each landmark is visually labeled and color-coded for learning purposes.