body{font-family:Arial;background:#111;color:#fff;margin:0;padding:0;text-align:center}header{padding:40px;background:#000}nav a{color:#4db8ff;text-decoration:none;margin:0 10px}.card{display:inline-block;width:220px;margin:12px;padding:20px;background:#222;border:1px solid #444;border-radius:8px}footer{padding:20px;margin-top:40px;background:#000}