# Local testing (cross-platform options)
python -m http.server 8000   # Windows
python3 -m http.server 8000  # macOS/Linux
npx serve .                  # Node.js (recommended - all platforms)

# Visual inspection
# - Test in Chrome, Firefox, Safari
# - Test at 375px, 768px, 1024px
# - Lighthouse audit

<!-- Semantic structure -->
<header>
  <nav><a href="#">Link</a></nav>
</header>
<main>
  <article>
    <h1>Title</h1>
    <p>Content</p>
  </article>
</main>
<footer></footer>

<!-- Void elements (no closing slash needed in HTML5) -->
<img src="image.jpg" alt="Description" />
<br />
<input type="text" />

/* CSS custom properties for theming */
:root {
  --bg-primary: #000000;
  --text-primary: #ffffff;
  --accent: #00ff00;
}

/* Mobile-first responsive */
.container {
  padding: 1rem;
}

@media (min-width: 768px) {
  .container {
    padding: 2rem;
  }
}

/* Avoid !important - signals specificity problems */

// ES6+ syntax (modern browsers support it)
const items = document.querySelectorAll(".item");
const handler = (e) => console.log(e.target);

// Event delegation (preferred)
document.body.addEventListener("click", (e) => {
  if (e.target.matches(".button")) {
    handleClick(e.target);
  }
});

// No jQuery dependencies
// No framework overhead