html,body{margin:0;padding:0;height:100%;font-family:Arial,sans-serif}body{background-color:#f8f9fa;color:#333}.text-center{text-align:center}.mt-3{margin-top:1rem}.mb-3{margin-bottom:1rem}.p-3{padding:1rem}.btn{display:inline-block;padding:8px 16px;border:none;border-radius:4px;cursor:pointer;font-size:16px;text-align:center;text-decoration:none;transition:background-color .3s}.btn-primary{background-color:#007bff;color:#fff}.btn-primary:hover{background-color:#0069d9}.btn-secondary{background-color:#6c757d;color:#fff}.btn-secondary:hover{background-color:#5a6268}