body{font-family:"Helvetica Neue",Arial,sans-serif;max-width:600px;margin:20px auto;padding:25px;border:1px solid #e0e0e0;border-radius:12px;line-height:1.6}.form-group{margin-bottom:20px}label{display:block;margin-bottom:8px;font-weight:700;font-size:.9em}input,select{width:100%;padding:10px;border:1px solid #ccc;border-radius:5px;box-sizing:border-box}button{width:100%;padding:15px;background-color:#c0392b;color:#fff;border:none;border-radius:5px;cursor:pointer;font-size:1.1em;font-weight:700}button:hover{background-color:#a93226}#result{margin-top:25px;padding:20px;border-radius:8px;display:none}.success{background-color:#fdf2f2;border:1px solid #f5c6cb}.warning{background-color:#fff3cd;border:1px solid #ffeeba}.amount{font-size:2em;color:#c0392b;font-weight:700;display:block;margin:10px 0}.notice{font-size:.85em;color:#666;margin-top:15px;border-top:1px solid #eee;pt:10px}