html · chain · Sonnet 5 · step 064 of 64

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="description" content="My Page">
  <meta name="robots" content="index, follow">
  <meta name="theme-color" content="#ffffff" media="(prefers-color-scheme: light)" id="theme-color-light">
  <meta name="theme-color" content="#111214" media="(prefers-color-scheme: dark)" id="theme-color-dark">
  <meta property="og:title" content="My Page">
  <meta property="og:description" content="My Page">
  <meta property="og:type" content="website">
  <meta property="og:url" content="https://example.com/">
  <meta property="og:image" content="https://example.com/og-image.png">
  <meta property="og:image:width" content="1200">
  <meta property="og:image:height" content="630">
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:title" content="My Page">
  <meta name="twitter:description" content="My Page">
  <link rel="canonical" href="https://example.com/">
  <link rel="icon" href="data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20viewBox='0%200%2016%2016'%3E%3Ccircle%20cx='8'%20cy='8'%20r='7'%20fill='%232563eb'/%3E%3C/svg%3E">
  <link rel="apple-touch-icon" href="data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20viewBox='0%200%2016%2016'%3E%3Ccircle%20cx='8'%20cy='8'%20r='7'%20fill='%232563eb'/%3E%3C/svg%3E">
  <meta name="twitter:image" content="https://example.com/og-image.png">
  <title>My Page</title>
  <script type="application/ld+json">
  {
    "@context": "https://schema.org",
    "@type": "WebSite",
    "name": "My Page",
    "url": "https://example.com/"
  }
  </script>
  <style>
    :root {
      color-scheme: light dark;
      --bg: #ffffff;
      --fg: #1a1a1a;
      --muted: #555;
      --accent: #2563eb;
      --border: #e5e7eb;
    }

    @media (prefers-color-scheme: dark) {
      :root {
        --bg: #111214;
        --fg: #e8e8e8;
        --muted: #aaa;
        --accent: #60a5fa;
        --border: #2a2b2e;
      }
    }

    :root[data-theme="light"] {
      color-scheme: light;
      --bg: #ffffff;
      --fg: #1a1a1a;
      --muted: #555;
      --accent: #2563eb;
      --border: #e5e7eb;
    }

    :root[data-theme="dark"] {
      color-scheme: dark;
      --bg: #111214;
      --fg: #e8e8e8;
      --muted: #aaa;
      --accent: #60a5fa;
      --border: #2a2b2e;
    }

    * {
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
    }

    @media (prefers-reduced-motion: reduce) {
      html {
        scroll-behavior: auto;
      }
    }

    ::selection {
      background: var(--accent);
      color: var(--bg);
    }

    body {
      font-family: system-ui, -apple-system, sans-serif;
      max-width: 40rem;
      margin: 3rem auto;
      padding: 0 1rem;
      line-height: 1.6;
      color: var(--fg);
      background: var(--bg);
    }

    @media (max-width: 30rem) {
      body {
        margin: 1.5rem auto;
      }
    }

    h1 {
      font-size: clamp(1.75rem, 5vw, 2.5rem);
      margin-bottom: 0.5rem;
    }

    p {
      color: var(--muted);
      max-width: 34rem;
    }

    a {
      color: var(--accent);
      transition: opacity 0.15s ease;
    }

    a:hover {
      opacity: 0.8;
    }

    a:focus-visible,
    button:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }

    .skip-link {
      position: absolute;
      left: -9999px;
      top: 0;
      background: var(--accent);
      color: var(--bg);
      padding: 0.5rem 1rem;
      border-radius: 0.25rem;
      z-index: 10;
    }

    .skip-link:focus {
      left: 1rem;
      top: 1rem;
    }

    main:focus {
      outline: none;
    }

    nav {
      display: flex;
      align-items: center;
      gap: 1rem;
      margin-bottom: 2rem;
    }

    nav ul {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      list-style: none;
      padding: 0;
      margin: 0;
    }

    nav a {
      text-decoration: none;
      font-weight: 500;
      opacity: 1;
    }

    nav a:hover {
      text-decoration: underline;
    }

    nav a[aria-current="page"] {
      text-decoration: underline;
      color: var(--fg);
      font-weight: 700;
    }

    .theme-toggle {
      margin-left: auto;
      background: none;
      border: 1px solid var(--border);
      color: var(--fg);
      border-radius: 0.375rem;
      padding: 0.25rem 0.6rem;
      font: inherit;
      font-size: 0.875rem;
      cursor: pointer;
    }

    .theme-toggle:hover {
      border-color: var(--accent);
    }

    h2 {
      margin-top: 2rem;
      margin-bottom: 0.5rem;
    }

    section + section {
      margin-top: 1.5rem;
    }

    section {
      scroll-margin-top: 1.5rem;
    }

    footer {
      margin-top: 3rem;
      padding-top: 1.5rem;
      border-top: 1px solid var(--border);
      font-size: 0.875rem;
      color: var(--muted);
    }

    @media print {
      .skip-link,
      nav {
        display: none;
      }
    }
  </style>
  <script>
    (function () {
      try {
        const stored = localStorage.getItem('theme');
        if (stored === 'light' || stored === 'dark') {
          document.documentElement.dataset.theme = stored;
        }
      } catch (e) {
        // localStorage may be unavailable (e.g. private browsing); fall back to OS preference.
      }
    })();
  </script>
</head>
<body>
  <a class="skip-link" href="#main">Skip to content</a>
  <header>
    <nav aria-label="Primary">
      <ul>
        <li><a href="#home" data-nav-link aria-current="page">Home</a></li>
        <li><a href="#about" data-nav-link>About</a></li>
        <li><a href="#contact" data-nav-link>Contact</a></li>
      </ul>
      <button type="button" class="theme-toggle" id="theme-toggle" aria-label="Toggle color theme" aria-pressed="false"><span aria-hidden="true">🌙</span></button>
    </nav>
  </header>
  <main id="main" tabindex="-1">
    <section id="home" aria-labelledby="home-heading">
      <h1 id="home-heading">My Page</h1>
      <p>Welcome. This page is a starting point — replace this text with your own content.</p>
    </section>

    <section id="about" aria-labelledby="about-heading">
      <h2 id="about-heading">About</h2>
      <p>Add a short description of what this page or project is about here.</p>
    </section>

    <section id="contact" aria-labelledby="contact-heading">
      <h2 id="contact-heading">Contact</h2>
      <p>Reach out at <a href="mailto:hello@example.com">hello@example.com</a>.</p>
    </section>
  </main>
  <footer>
    <p>&copy; <span id="year">2026</span> My Page. All rights reserved.</p>
  </footer>
  <script>
    const yearEl = document.getElementById('year');
    if (yearEl) yearEl.textContent = String(new Date().getFullYear());

    const themeToggle = document.getElementById('theme-toggle');
    const prefersDark = window.matchMedia('(prefers-color-scheme: dark)');

    const currentTheme = () =>
      document.documentElement.dataset.theme || (prefersDark.matches ? 'dark' : 'light');

    const updateToggleLabel = () => {
      const isDark = currentTheme() === 'dark';
      themeToggle.querySelector('span').textContent = isDark ? '☀️' : '🌙';
      themeToggle.setAttribute('aria-pressed', String(isDark));
      themeToggle.setAttribute('aria-label', isDark ? 'Switch to light theme' : 'Switch to dark theme');
    };

    updateToggleLabel();

    const themeColorMetas = [
      document.getElementById('theme-color-light'),
      document.getElementById('theme-color-dark'),
    ].filter(Boolean);

    const syncThemeColorMeta = () => {
      const color = getComputedStyle(document.documentElement).getPropertyValue('--bg').trim();
      themeColorMetas.forEach(meta => meta.setAttribute('content', color));
    };

    syncThemeColorMeta();

    themeToggle.addEventListener('click', () => {
      const next = currentTheme() === 'dark' ? 'light' : 'dark';
      document.documentElement.dataset.theme = next;
      try {
        localStorage.setItem('theme', next);
      } catch (e) {
        // localStorage may be unavailable; theme still applies for this session.
      }
      updateToggleLabel();
      syncThemeColorMeta();
    });

    prefersDark.addEventListener('change', () => {
      if (!document.documentElement.dataset.theme) updateToggleLabel();
    });

    const navLinks = document.querySelectorAll('[data-nav-link]');
    const sections = [...navLinks]
      .map(link => document.querySelector(link.getAttribute('href')))
      .filter(Boolean);

    const setActive = (id) => {
      navLinks.forEach(link => {
        if (link.getAttribute('href') === `#${id}`) {
          link.setAttribute('aria-current', 'page');
        } else {
          link.removeAttribute('aria-current');
        }
      });
    };

    setActive(sections[0]?.id);

    navLinks.forEach(link => {
      link.addEventListener('click', () => setActive(link.getAttribute('href').slice(1)));
    });

    if ('IntersectionObserver' in window) {
      const observer = new IntersectionObserver((entries) => {
        const visible = entries
          .filter(entry => entry.isIntersecting)
          .sort((a, b) => b.intersectionRatio - a.intersectionRatio)[0];
        if (visible) setActive(visible.target.id);
      }, { rootMargin: '-40% 0px -50% 0px' });
      sections.forEach(section => section && observer.observe(section));

      // The rootMargin above can leave the last section unhighlighted once the
      // page is scrolled all the way to the bottom, so force it explicitly.
      window.addEventListener('scroll', () => {
        const atBottom = window.innerHeight + window.scrollY >= document.documentElement.scrollHeight - 1;
        if (atBottom) setActive(sections[sections.length - 1]?.id);
      }, { passive: true });
    }
  </script>
</body>
</html>