body {
      background: #f4f7fc;  /* 柔和背景 */
      font-family: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    }
    .survey-card {
      border: none;
      border-radius: 1.25rem;
      box-shadow: 0 10px 25px rgba(0,0,0,0.05);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .survey-card:hover {
      box-shadow: 0 15px 35px rgba(0,0,0,0.08);
    }
    .card-header-custom {
      background: linear-gradient(135deg, #4a6cf7 0%, #6c85f7 100%);
      color: white;
      border-bottom: none;
      padding: 2.5rem;
      margin-bottom: 0;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 1.25rem;
      border-radius: 1.25rem 1.25rem 0 0;
      box-shadow: 0 4px 12px rgba(74, 108, 247, 0.3);
      position: relative;
      overflow: hidden;
    }
    
    /* 装饰元素 */
    .card-header-custom::before {
      content: '';
      position: absolute;
      top: -50%;
      right: -50%;
      width: 200%;
      height: 200%;
      background: rgba(255, 255, 255, 0.1);
      border-radius: 50%;
      transform: translate(50%, 50%);
      z-index: 0;
    }
    
    .card-header-custom::after {
      content: '';
      position: absolute;
      bottom: -30%;
      left: -30%;
      width: 150%;
      height: 150%;
      background: rgba(255, 255, 255, 0.05);
      border-radius: 50%;
      transform: translate(-20%, -20%);
      z-index: 0;
    }
    
    .card-header-custom > * {
      position: relative;
      z-index: 1;
    }
    
    .card-header-custom i {
      font-size: 2.5rem;
      color: #4a6cf7;
      background: white;
      width: 80px;
      height: 80px;
      border-radius: 50%;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      transition: all 0.3s ease;
    }
    
    .card-header-custom:hover i {
      transform: scale(1.05);
      box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
    }
    
    .card-header-custom h2 {
      color: white;
      margin: 0;
      font-size: 1.75rem;
      font-weight: 700;
      text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    }
    
    .card-header-custom p {
      color: rgba(255, 255, 255, 0.7);
      margin: 0;
      font-size: 1rem;
      line-height: 1.5;
      max-width: 800px;
      text-align: center;
    }
    .question-title {
      font-weight: 600;
      margin-bottom: 0.25rem;
      color: #1e293b;
      display: flex;
      align-items: center;
    }
    .question-title .badge {
      font-size: 0.8rem;
      font-weight: 600;
      min-width: 24px;
      height: 24px;
      display: flex;
      align-items: center;
      justify-content: center;
      margin-right: 8px;
    }
    .form-check-input:checked {
      background-color: #0d6efd;
      border-color: #0d6efd;
    }
    .btn-primary {
      background: #0d6efd;
      border: none;
      padding: 12px 30px;
      font-weight: 500;
      border-radius: 50px;
      box-shadow: 0 8px 18px rgba(13,110,253,0.25);
      transition: all 0.2s;
    }
    .btn-primary:hover {
      background: #0b5ed7;
      transform: translateY(-2px);
      box-shadow: 0 12px 22px rgba(13,110,253,0.3);
    }
    .btn-primary i {
      margin-right: 8px;
    }
    .btn-secondary {
      background: #6c757d;
      border: none;
      padding: 12px 30px;
      font-weight: 500;
      border-radius: 50px;
      box-shadow: 0 8px 18px rgba(108, 117, 125, 0.25);
      transition: all 0.2s;
    }
    .btn-secondary:hover {
      background: #5a6268;
      transform: translateY(-2px);
      box-shadow: 0 12px 22px rgba(108, 117, 125, 0.3);
    }
    .btn-secondary i {
      margin-right: 8px;
    }
    footer i {
      color: #6c757d;
      transition: color 0.2s;
    }
    footer i:hover {
      color: #0d6efd;
    }
    /* 让选项图标与文字对齐 */
    .form-check-label i {
      width: 1.4rem;
      text-align: center;
      color: #0d6efd;
    }
    /* 确保复选框和标签正确对齐 */
    .form-check {
      position: relative;
      padding-left: 1.75rem;
      margin-bottom: 0.5rem;
    }
    .form-check-input {
      position: absolute;
      margin-top: 0.375rem;
      margin-left: -1.75rem;
    }
    .form-check-label {
      margin-bottom: 0;
      padding-left: 0.25rem;
    }
    .input-group-text {
      background: white;
      border-right: none;
    }
    .input-group-text i {
      color: #0d6efd;
    }
    /* 统一表单元素高度 */
    .form-control, .form-select, .btn {
      height: 48px !important;
      font-size: 1rem !important;
      border-radius: 8px !important;
      box-sizing: border-box !important;
    }
    
    .form-control {
      border-left: none;
      padding-left: 0;
    }
    
    .form-control:focus, .form-select:focus {
      border-color: #dee2e6;
      box-shadow: none;
      border-left: none;
    }
    
    /* 按钮样式 */
    .btn {
      display: flex !important;
      align-items: center !important;
      justify-content: center !important;
      padding: 0 16px !important;
    }
    
    .btn i {
      margin-right: 8px;
    }
    
    /* 统一输入组样式 */
    .input-group {
      height: 48px !important;
    }
    
    .input-group-text {
      height: 100% !important;
      border-radius: 8px 0 0 8px !important;
      box-sizing: border-box !important;
    }
    
    /* 批量操作按钮组 */
    .btn-group {
      height: 48px !important;
    }
    
    .btn-group .btn {
      height: 100% !important;
      border-radius: 0 !important;
      flex-grow: 1 !important;
    }
    
    .btn-group .btn:first-child {
      border-radius: 8px 0 0 8px !important;
    }
    
    .btn-group .btn:last-child {
      border-radius: 0 8px 8px 0 !important;
    }
    
    /* 确保链接按钮与普通按钮高度一致 */
    .btn-outline-secondary {
      height: 48px !important;
      display: flex !important;
      align-items: center !important;
      justify-content: center !important;
    }
    
    /* 美化验证信息 */
    .alert {
      border-radius: 12px;
      border: none;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
      padding: 16px 20px;
      margin-bottom: 20px;
      animation: slideIn 0.3s ease-out;
    }
    
    .alert-danger {
      background: linear-gradient(135deg, #fee2e2 0%, #fecaca 100%);
      color: #dc2626;
      border-left: 4px solid #dc2626;
    }
    
    .alert-danger ul {
      margin-bottom: 0;
      padding-left: 20px;
    }
    
    .alert-danger li {
      margin-bottom: 8px;
      position: relative;
      padding-left: 10px;
    }
    
    .alert-danger li:last-child {
      margin-bottom: 0;
    }
    
    .alert-info {
      background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
      color: #1e40af;
      border-left: 4px solid #1e40af;
    }
    
    .alert-warning {
      background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
      color: #92400e;
      border-left: 4px solid #92400e;
    }
    
    @keyframes slideIn {
      from {
        opacity: 0;
        transform: translateY(-10px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }
    
    /* 成功和错误页面样式 */
    .success-container, .error-container {
      text-align: center;
      max-width: 800px;
      width: 90%;
      padding: 60px;
      background-color: white;
      border-radius: 20px;
      box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      position: relative;
      overflow: hidden;
    }
    
    .success-container::before, .error-container::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 10px;
    }
    
    .success-container::before {
      background: linear-gradient(90deg, #28a745, #4caf50);
    }
    
    .error-container::before {
      background: linear-gradient(90deg, #dc3545, #e74c3c);
    }
    
    .success-container:hover, .error-container:hover {
      transform: translateY(-5px);
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    }
    
    .success-icon, .error-icon {
      font-size: 5rem;
      margin-bottom: 30px;
      position: relative;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 120px;
      height: 120px;
      border-radius: 50%;
      margin-bottom: 30px;
    }
    
    .success-icon {
      background: linear-gradient(135deg, rgba(40, 167, 69, 0.1), rgba(76, 175, 80, 0.1));
      color: #28a745;
      animation: bounce 1s ease-in-out;
    }
    
    .error-icon {
      background: linear-gradient(135deg, rgba(220, 53, 69, 0.1), rgba(231, 76, 60, 0.1));
      color: #dc3545;
      animation: shake 1s ease-in-out;
    }
    
    .success-icon i, .error-icon i {
      position: relative;
      z-index: 1;
    }
    
    .success-icon::after, .error-icon::after {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 80px;
      height: 80px;
      border-radius: 50%;
      background: white;
      z-index: 0;
    }
    
    .success-title, .error-title {
      font-size: 2.2rem;
      margin-bottom: 20px;
      color: #343a40;
      font-weight: 700;
      text-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
      position: relative;
      z-index: 1;
    }
    
    .success-message, .error-message {
      font-size: 1.2rem;
      margin-bottom: 40px;
      color: #6c757d;
      line-height: 1.6;
      position: relative;
      z-index: 1;
      max-width: 500px;
      margin-left: auto;
      margin-right: auto;
    }
    
    .back-button {
      font-size: 1rem;
      padding: 14px 32px;
      font-weight: 600;
      border-radius: 50px;
      transition: all 0.3s ease;
      position: relative;
      z-index: 1;
      box-shadow: 0 8px 18px rgba(13, 110, 253, 0.25);
    }
    
    .back-button:hover {
      transform: translateY(-3px);
      box-shadow: 0 12px 22px rgba(13, 110, 253, 0.35);
    }
    
    @keyframes bounce {
      0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
      }
      40% {
        transform: translateY(-20px);
      }
      60% {
        transform: translateY(-10px);
      }
    }
    
    @keyframes shake {
      0%, 100% {
        transform: translateX(0);
      }
      10%, 30%, 50%, 70%, 90% {
        transform: translateX(-10px);
      }
      20%, 40%, 60%, 80% {
        transform: translateX(10px);
      }
    }
    
    /* 响应式设计 */
    @media (max-width: 768px) {
      .success-container, .error-container {
        padding: 40px 30px;
        margin: 0 20px;
      }
      
      .success-icon, .error-icon {
        font-size: 4rem;
        width: 100px;
        height: 100px;
      }
      
      .success-icon::after, .error-icon::after {
        width: 60px;
        height: 60px;
      }
      
      .success-title, .error-title {
        font-size: 1.8rem;
      }
      
      .success-message, .error-message {
        font-size: 1.1rem;
      }
    }