.student-container{max-width:1200px;margin:40px auto;padding:30px;border-radius:12px;background-color:#fff;box-shadow:0 4px 16px #000;font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif}h2,h3{color:#333;margin-bottom:10px}input,select{padding:10px;margin:8px 0;width:100%;border:1px solid #ccc;border-radius:6px;box-sizing:border-box}.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.btn-group{margin-top:10px}button{padding:10px 16px;margin:10px 8px 10px 0;border:none;color:#fff;border-radius:6px;cursor:pointer;transition:background-color .2s ease-in-out}.btn-blue{background-color:#007bff}.btn-blue:hover{background-color:#0056b3}.btn-green{background-color:#28a745}.btn-green:hover{background-color:#1c7c34}.btn-red{background-color:#dc3545}.btn-red:hover{background-color:#a71d2a}.btn-gray{background-color:#6c757d}.btn-gray:hover{background-color:#565e64}table{width:100%;border-collapse:collapse;margin-top:20px;background-color:#fff;border-radius:6px;overflow:hidden;box-shadow:0 2px 8px #0000000d}th,td{padding:12px 14px;text-align:left;border-bottom:1px solid #e0e0e0;vertical-align:middle}th{background-color:#f1f1f1;font-weight:600}.action-buttons{display:flex;gap:8px}pre{background-color:#f0f0f0;padding:10px;border-radius:6px;overflow-x:auto}.message{margin-top:20px;color:#dc3545;font-weight:500}.message-banner{position:fixed;top:10px;left:50%;transform:translate(-50%);background-color:#4caf50;color:#fff;padding:12px 24px;border-radius:6px;font-weight:700;z-index:1000;text-align:center;min-width:300px;max-width:80%;box-shadow:0 2px 8px #0003}.message-banner.error{background-color:#f44336}.message-banner.success{background-color:#4caf50}