/* 基础样式 */
    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: #f5f5f7;
      margin: 0;
      padding: 0;
      color: #333;
      line-height: 1.6;
    }

    .container {
      max-width: 600px;
      margin: 50px auto;
      padding: 30px;
      background: #fff;
      border-radius: 12px;
      box-shadow: 0 4px 20px rgba(0,0,0,0.12);
      border: 1px solid #e5e5e5;
      text-align: center;
    }

    h1 {
      color: #333;
      font-size: 26px;
      margin-bottom: 25px;
      font-weight: 600;
      text-align: center;
      line-height: 1.4;
    }

    p {
      color: #666;
      font-size: 16px;
      margin: 15px 0;
      line-height: 1.6;
    }

    .card {
      background: #f8f9fa;
      border-radius: 8px;
      padding: 20px;
      margin: 15px 0;
      box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    }

    .divider {
      height: 1px;
      background: #eee;
      margin: 20px 0;
      border: none;
    }

    /* 头部样式 */
    .header {
      background: #006e1d;
      color: white;
      padding: 15px 20px;
      display: flex;
      align-items: center;
      border-radius: 8px 8px 0 0;
      margin: -30px -30px 20px -30px;
    }

    .header-title {
      margin-left: 10px;
      font-size: 18px;
      font-weight: 500;
    }

    /* 按钮样式 */
    .btn {
      display: inline-block;
      background: #006e1d;
      color: white;
      border: none;
      border-radius: 4px;
      padding: 10px 16px;
      margin: 5px;
      font-size: 14px;
      cursor: pointer;
      transition: background 0.3s;
      outline: none;
    }

    .btn:hover {
      background: #005718;
    }

    .btn:disabled {
      background: #cccccc;
      cursor: not-allowed;
    }

    .btn-text {
      color: #666;
      background: transparent;
      border: none;
      padding: 8px 12px;
      cursor: pointer;
      text-decoration: underline;
    }

    /* 输入框样式 */
    .text-field {
      width: 100%;
      padding: 12px;
      margin: 8px 0;
      border: 1px solid #ddd;
      border-radius: 4px;
      font-size: 14px;
      box-sizing: border-box;
    }

    /* 对话框样式 */
    .dialog {
      display: none;
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background: rgba(0, 0, 0, 0.5);
      z-index: 1000;
      overflow: auto;
    }

    .dialog-content {
      background: white;
      margin: 50px auto;
      max-width: 500px;
      padding: 20px;
      border-radius: 8px;
      box-shadow: 0 4px 20px rgba(0,0,0,0.2);
      position: relative;
    }

    /* 验证码相关样式 */
    .captcha-container {
      position: relative;
      width: 80%;
      margin: 15px auto;
    }

    .captcha-image {
      width: 100%;
      height: auto;
      display: block;
      min-height: 120px; /* 设置最小高度避免布局跳动 */
      background: #f8f9fa url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="40" height="40" viewBox="0 0 40 40"><rect width="40" height="40" fill="%23e9ecef"/><text x="20" y="24" text-anchor="middle" font-family="Arial" font-size="12" fill="%236c757d">加载中</text></svg>') center center no-repeat;
      border: 1px solid #dee2e6;
      border-radius: 4px;
    }

    .captcha-image.loading {
      /* 加载状态时隐藏图片内容，只显示背景占位符 */
      opacity: 0;
    }

    .captcha-image.loaded {
      /* 加载完成后显示图片内容，隐藏背景 */
      background: none;
      opacity: 1;
      transition: opacity 0.3s ease-in-out;
    }

    .captcha-cell {
      position: absolute;
      border: 2px solid transparent;
      cursor: pointer;
      background-color: rgba(0, 0, 0, 0);
      border-radius: 0;
    }

    .selected {
      border-color: #28a745;
      background-color: rgba(40, 167, 69, 0.3);
    }

    /* 复选框样式 */
    .checkbox-container {
      display: flex;
      align-items: center;
      margin: 15px 0;
      justify-content: center;
      padding: 15px;
      background: #f8f9fa;
      border-radius: 8px;
      border: 1px solid #e9ecef;
    }

    .checkbox-container input[type="checkbox"] {
      appearance: none;
      -webkit-appearance: none;
      width: 20px;
      height: 20px;
      border: 2px solid #006e1d;
      border-radius: 4px;
      margin-right: 12px;
      position: relative;
      cursor: pointer;
      background: white;
      transition: all 0.3s ease;
      flex-shrink: 0;
    }

    .checkbox-container input[type="checkbox"]:checked {
      background: #006e1d;
      border-color: #006e1d;
    }

    .checkbox-container input[type="checkbox"]:checked::after {
      content: '✓';
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      color: white;
      font-size: 14px;
      font-weight: bold;
    }

    .checkbox-container input[type="checkbox"]:hover {
      border-color: #005718;
      box-shadow: 0 0 0 3px rgba(0, 110, 29, 0.1);
    }

    .checkbox-container input[type="checkbox"]:focus {
      outline: none;
      box-shadow: 0 0 0 3px rgba(0, 110, 29, 0.2);
    }

    .checkbox-container label {
      cursor: pointer;
      user-select: none;
      line-height: 1.5;
      color: #333;
    }

    .checkbox-container label a {
      color: #006e1d;
      text-decoration: none;
      font-weight: 600;
    }

    .checkbox-container label a:hover {
      text-decoration: underline;
    }

    /* 加载动画 */
    .loading-spinner {
      display: inline-block;
      width: 24px;
      height: 24px;
      border: 3px solid #e3e3e3;
      border-top: 3px solid #006e1d;
      border-radius: 50%;
      animation: spin 1s linear infinite;
      margin: 0 10px;
    }

    @keyframes spin {
      0% { transform: rotate(0deg); }
      100% { transform: rotate(360deg); }
    }

    /* 纸片样式 */
    .chip {
      display: inline-block;
      padding: 5px 12px;
      background: #e0e0e0;
      border-radius: 16px;
      margin: 5px;
      font-size: 14px;
    }

    /* 页脚样式 */
    .footer-text {
      color: #999;
      font-size: 12px;
      margin-top: 40px;
      border-top: 1px solid #eee;
      padding-top: 20px;
      text-align: center;
    }

    /* 开关样式 */
    .switch {
      position: relative;
      display: inline-block;
      width: 50px;
      height: 24px;
      margin: 0 10px;
      vertical-align: middle;
    }

    .switch input {
      opacity: 0;
      width: 0;
      height: 0;
    }

    .slider {
      position: absolute;
      cursor: pointer;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: #ccc;
      transition: .4s;
      border-radius: 24px;
    }

    .slider:before {
      position: absolute;
      content: "";
      height: 18px;
      width: 18px;
      left: 3px;
      bottom: 3px;
      background-color: white;
      transition: .4s;
      border-radius: 50%;
    }

    input:checked + .slider {
      background-color: #006e1d;
    }

    input:checked + .slider:before {
      transform: translateX(26px);
    }

    #load-circle {
      position: fixed;
      left: 50%;
      top: 50%;
      transform: translate(-50%, -50%);
      z-index: 9999;
    }

    .status-icon {
      font-size: 48px;
      margin-bottom: 20px;
      text-align: center;
    }

    .verification-complete {
      display: none;
      color: #28a745;
      font-weight: bold;
      font-size: 18px;
      margin: 20px 0;
      text-align: center;
    }

    .verification-complete .check-icon {
      font-size: 32px;
      margin-bottom: 10px;
      display: inline-block;
      vertical-align: middle;
      margin-right: 8px;
    }

    /* 优化验证码按钮组布局 */
    .button-group {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      margin: 25px 0;
      padding: 0;
    }

    /* 验证按钮样式优化 */
    .button-group .btn:not(:last-child) {
      position: relative;
      padding: 16px 20px;
      font-size: 14px;
      font-weight: 500;
      border-radius: 8px;
      border: 2px solid transparent;
      background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
      color: #333;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
      overflow: hidden;
      text-align: left;
      display: flex;
      align-items: center;
      justify-content: flex-start;
      min-height: 60px;
    }

    /* 为每个验证按钮添加不同的颜色主题 */
    .button-group #start-btn {
      background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%);
      border-color: #2196f3;
    }

    .button-group #start-btn::before {
      content: "🖼️ ";
      margin-right: 8px;
      font-size: 16px;
    }

    .button-group #alt-start-btn {
      background: linear-gradient(135deg, #f3e5f5 0%, #e1bee7 100%);
      border-color: #9c27b0;
    }

    .button-group #alt-start-btn::before {
      content: "🔐 ";
      margin-right: 8px;
      font-size: 16px;
    }

    .button-group #block-start-btn {
      background: linear-gradient(135deg, #fff3e0 0%, #ffcc02 100%);
      border-color: #ff9800;
    }

    .button-group #block-start-btn::before {
      content: "🧱 ";
      margin-right: 8px;
      font-size: 16px;
    }

    .button-group #cap-start-btn {
      background: linear-gradient(135deg, #e8f5e8 0%, #c8e6c9 100%);
      border-color: #4caf50;
    }

    .button-group #cap-start-btn::before {
      content: "🔤 ";
      margin-right: 8px;
      font-size: 16px;
    }

    /* 验证按钮悬停效果 */
    .button-group .btn:not(:last-child):hover {
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
      border-color: currentColor;
    }

    .button-group #start-btn:hover {
      background: linear-gradient(135deg, #bbdefb 0%, #90caf9 100%);
      color: #1976d2;
    }

    .button-group #alt-start-btn:hover {
      background: linear-gradient(135deg, #e1bee7 0%, #ce93d8 100%);
      color: #7b1fa2;
    }

    .button-group #block-start-btn:hover {
      background: linear-gradient(135deg, #ffcc02 0%, #ffa726 100%);
      color: #f57c00;
    }

    .button-group #cap-start-btn:hover {
      background: linear-gradient(135deg, #c8e6c9 0%, #a5d6a7 100%);
      color: #388e3c;
    }

    /* 验证按钮激活效果 */
    .button-group .btn:not(:last-child):active {
      transform: translateY(0);
      box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    }

    /* 添加按钮描述文字 */
    .button-group .btn:not(:last-child)::after {
      content: attr(data-description);
      display: block;
      font-size: 11px;
      opacity: 0.7;
      margin-top: 2px;
      font-weight: normal;
    }

    /* 优化提交按钮样式 */
    .button-group .btn:last-child {
      grid-column: 1 / -1;
      margin-top: 20px;
      padding: 16px 20px;
      font-size: 16px;
      font-weight: 600;
      background: linear-gradient(135deg, #006e1d 0%, #005718 100%);
      box-shadow: 0 4px 15px rgba(0, 110, 29, 0.3);
      border-radius: 8px;
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      position: relative;
      overflow: hidden;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    /* 提交按钮文字容器 */
    .button-group .btn:last-child .btn-text {
      transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
      will-change: transform;
      display: flex;
      align-items: center;
    }

    .button-group .btn:last-child:hover:not(:disabled) {
      background: linear-gradient(135deg, #005718 0%, #004612 100%);
      box-shadow: 0 6px 20px rgba(0, 110, 29, 0.4);
      transform: translateY(-3px);
    }

    .button-group .btn:last-child:disabled {
      background: linear-gradient(135deg, #cccccc 0%, #999999 100%);
      box-shadow: none;
      transform: none;
      cursor: not-allowed;
    }

    /* 禁用状态下确保文字居中 */
    .button-group .btn:last-child:disabled .btn-text {
      transform: translateX(0);
    }

    /* 提交按钮加载状态优化 */
    .button-group .btn:last-child.loading {
      position: relative;
      pointer-events: none;
    }

    /* 加载状态下文字向左移动 - 减少移动距离并增加缓动效果 */
    .button-group .btn:last-child.loading .btn-text {
      transform: translateX(-8px);
      transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

    /* 旋转进度条样式 - 调整位置更靠近文字 */
    .button-group .btn:last-child.loading::after {
      content: "";
      position: absolute;
      width: 16px;
      height: 16px;
      top: 50%;
      right: 25px;
      margin-top: -8px;
      border: 2px solid transparent;
      border-top: 2px solid #ffffff;
      border-right: 2px solid #ffffff;
      border-radius: 50%;
      opacity: 0;
      animation: spinFadeIn 0.4s ease-out 0.1s forwards, spin 0.8s linear 0.5s infinite;
    }

    /* 提交完成状态 - 更平滑的返回动画 */
    .button-group .btn:last-child.completed .btn-text {
      transform: translateX(0);
      transition: transform 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

    .button-group .btn:last-child.completed::after {
      opacity: 0;
      animation: none;
      transition: opacity 0.3s ease-out;
    }

    /* 移动端响应式设计 */
    @media (max-width: 768px) {
      .button-group {
        grid-template-columns: 1fr;
        gap: 12px;
      }

      .button-group .btn:not(:last-child) {
        min-height: 50px;
        padding: 12px 16px;
      }

      .button-group .btn:last-child {
        margin-top: 15px;
      }
    }

    @media (max-width: 600px) {
      .container {
        margin: 10px;
        padding: 20px;
      }

      .dialog-content {
        width: 90%;
        margin: 30px auto;
      }
    }

    /* 页面内提示信息样式 */
    .message-box {
      padding: 12px 16px;
      margin: 15px 0;
      border-radius: 6px;
      font-size: 14px;
      line-height: 1.5;
      display: none;
      animation: slideDown 0.3s ease-out;
      transition: opacity 0.3s ease-out, transform 0.3s ease-out;
    }

    .message-box.success {
      background-color: #d4edda;
      color: #155724;
      border: 1px solid #c3e6cb;
    }

    .message-box.error {
      background-color: #f8d7da;
      color: #721c24;
      border: 1px solid #f5c6cb;
    }

    .message-box.warning {
      background-color: #fff3cd;
      color: #856404;
      border: 1px solid #ffeaa7;
    }

    .message-box.info {
      background-color: #d1ecf1;
      color: #0c5460;
      border: 1px solid #bee5eb;
    }

    @keyframes slideDown {
      from {
        opacity: 0;
        transform: translateY(-10px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    @keyframes slideUp {
      from {
        opacity: 1;
        transform: translateY(0);
      }
      to {
        opacity: 0;
        transform: translateY(-10px);
      }
    }

    .message-box.fade-out {
      animation: slideUp 0.3s ease-out forwards;
    }

    .message-box .close-btn {
      float: right;
      background: none;
      border: none;
      font-size: 16px;
      cursor: pointer;
      color: inherit;
      opacity: 0.7;
      margin-left: 10px;
      transition: opacity 0.2s ease;
    }

    .message-box .close-btn:hover {
      opacity: 1;
    }