body{margin:0;background:#0d1117;color:#fff;font-family:Microsoft YaHei}.nav{display:flex;gap:20px;padding:16px;background:#161b22}.nav a{color:#fff;text-decoration:none}.hero{text-align:center;padding:60px}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:20px;padding:20px}.card{background:#161b22;padding:20px;border-radius:16px}.btn{background:#238636;color:#fff;padding:8px 12px;border-radius:8px;text-decoration:none}