body{font-family:Arial,sans-serif;margin:0;background-color:#f0f0f0}header{background-color:#222;color:#fff;padding:15px;text-align:center}.card{max-width:800px;margin:20px auto;background:#fff;padding:20px;border-radius:8px;text-align:center}.image,.video{max-width:100%;margin:10px 0}.explanation{text-align:justify;margin-top:15px}.loader{text-align:center;margin:50px;font-size:18px}