body { max-width: 800px; margin: 40px auto; padding: 0 20px; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; line-height: 1.6; }
h1 { color: #333; border-bottom: 1px solid #eee; padding-bottom: 0.3em; }
h2 { color: #444; margin-top: 1.5em; }
a { color: #0066cc; }
code { background: #f4f4f4; padding: 0.2em 0.4em; border-radius: 3px; }
.close-btn { position: fixed; top: 10px; right: 15px; background: #333; color: #fff; border: none; width: 30px; height: 30px; border-radius: 50%; font-size: 18px; cursor: pointer; display: flex; align-items: center; justify-content: center; }
.close-btn:hover { background: #555; }
.content { padding: 20px; }