Drill 14: Explain each line — Accessibility and ARIA

<header>
  <nav aria-label="Primary">
    <a href="/courses">Courses</a>
  </nav>
</header>

<main>
  <h1>Apply for the certificate</h1>
  <form>
    <label for="email">Email address</label>
    <p id="email-hint">We send the result here.</p>
    <input
      id="email"
      name="email"
      type="email"
      autocomplete="email"
      aria-describedby="email-hint"
      required
    />
    <button type="submit">Apply</button>
  </form>
  <p role="status" aria-live="polite">Application received.</p>
</main>