:root {
      --primary-color: #4361ee;
      --secondary-color: #3a0ca3;
      --background-color: #f0f2f5;
      --card-bg-color: #ffffff;
      --text-color: #2d3748;
      --border-color: #e2e8f0;
      --success-color: #10b981;
      --error-color: #ef4444;
      --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
      --shadow-hover: 0 8px 20px rgba(0, 0, 0, 0.12);
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      height: 100%;
    }
    
    body {
      font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background-color: var(--background-color);
      color: var(--text-color);
      line-height: 1.6;
      height: 100vh;
      margin: 0;
      padding: 0;
      display: flex;
      justify-content: center;
      align-items: center;
      -webkit-text-size-adjust: 100%;
      -webkit-tap-highlight-color: transparent;
    }

    .login-wrapper {
      width: 100%;
      min-height: 100vh;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 1rem;
      box-sizing: border-box;
      position: relative;
    }
    
    .login-container {
      width: 100%;
      max-width: 400px;
      padding: 2rem;
      background-color: var(--card-bg-color);
      border-radius: 12px;
      box-shadow: var(--shadow);
      transition: box-shadow 0.3s ease;
      position: relative;
      margin: 0 auto;
      display: block;
    }

    .theme-toggle {
      position: absolute;
      top: 1rem;
      right: 1rem;
    }

    .theme-btn {
      background: none;
      border: 1px solid var(--border-color);
      border-radius: 50%;
      width: 36px;
      height: 36px;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      transition: all 0.3s ease;
      color: var(--text-color);
    }

    .theme-btn:hover {
      background-color: var(--background-color);
      transform: scale(1.1);
    }
    
    .login-container:hover {
      box-shadow: var(--shadow-hover);
    }
    
    .login-header {
      text-align: center;
      margin-bottom: 2rem;
    }
    
    .login-header .logo {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.75rem;
      margin-bottom: 1rem;
    }
    
    .login-header h1 {
      font-size: 1.5rem;
      font-weight: 600;
      background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
      background-clip: text;
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    
    .login-form {
      display: flex;
      flex-direction: column;
      gap: 1.5rem;
    }
    
    .form-group {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
    }
    
    .form-group label {
      font-weight: 500;
      font-size: 0.9rem;
    }
    
    .form-group input {
      padding: 0.75rem 1rem;
      border: 1px solid var(--border-color);
      border-radius: 6px;
      font-size: 1rem;
      transition: border-color 0.3s ease;
      background-color: var(--card-bg-color);
      color: var(--text-color);
      -webkit-appearance: none;
    }

    .form-group input:focus {
      outline: none;
      border-color: var(--primary-color);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
    }
    
    .btn {
      padding: 0.75rem 1.5rem;
      border: none;
      border-radius: 6px;
      font-size: 1rem;
      font-weight: 500;
      cursor: pointer;
      transition: all 0.3s ease;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
    }
    
    .btn-primary {
      background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
      color: white;
    }
    
    .btn-primary:hover {
      opacity: 0.9;
      transform: translateY(-2px);
    }
    
    .status {
      margin-top: 1rem;
      text-align: center;
      font-size: 0.9rem;
      height: 1.5rem;
    }
    
    .status.error {
      color: var(--error-color);
    }
    
    .status.success {
      color: var(--success-color);
    }

    /* 深色模式支持 */
    [data-theme="dark"] {
      --background-color: #1a1a1a;
      --card-bg-color: #2d2d2d;
      --text-color: #e0e0e0;
      --border-color: #404040;
    }

    [data-theme="dark"] .form-group input {
      background-color: var(--card-bg-color);
      color: var(--text-color);
      border-color: var(--border-color);
    }

    [data-theme="dark"] .form-group input:focus {
      border-color: var(--primary-color);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
    }

    [data-theme="dark"] .theme-btn {
      border-color: var(--border-color);
      color: var(--text-color);
    }

    [data-theme="dark"] .theme-btn:hover {
      background-color: var(--border-color);
    }

    /* 系统深色模式自动检测 */
    @media (prefers-color-scheme: dark) {
      :root:not([data-theme="light"]) {
        --background-color: #1a1a1a;
        --card-bg-color: #2d2d2d;
        --text-color: #e0e0e0;
        --border-color: #404040;
      }

      :root:not([data-theme="light"]) .form-group input {
        background-color: var(--card-bg-color);
        color: var(--text-color);
        border-color: var(--border-color);
      }

      :root:not([data-theme="light"]) .form-group input:focus {
        border-color: var(--primary-color);
        box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
      }

      :root:not([data-theme="light"]) .theme-btn {
        border-color: var(--border-color);
        color: var(--text-color);
      }

      :root:not([data-theme="light"]) .theme-btn:hover {
        background-color: var(--border-color);
      }
    }

    /* 响应式设计 */
    @media (max-width: 768px) {
      .login-wrapper {
        padding: 1rem;
      }

      .login-container {
        width: 100%;
        max-width: 500px;
        padding: 1.5rem;
        border-radius: 8px;
      }

      .login-header h1 {
        font-size: 1.25rem;
      }

      .login-header p {
        font-size: 0.9rem;
      }
    }

    @media (max-width: 480px) {
      .login-wrapper {
        padding: 0.75rem;
      }

      .login-container {
        padding: 1rem;
        border-radius: 6px;
        max-width: 100%;
      }

      .theme-toggle {
        top: 0.75rem;
        right: 0.75rem;
      }

      .theme-btn {
        width: 32px;
        height: 32px;
      }

      .login-header {
        margin-bottom: 1.5rem;
      }

      .login-header .logo {
        gap: 0.5rem;
        margin-bottom: 0.75rem;
      }

      .login-header h1 {
        font-size: 1.1rem;
      }

      .form-group input {
        padding: 0.75rem;
        font-size: 16px; /* 防止iOS缩放 */
      }

      .btn {
        padding: 0.75rem 1rem;
        font-size: 0.95rem;
      }
    }

    /* 触摸设备优化 */
    @media (hover: none) and (pointer: coarse) {
      .btn {
        min-height: 44px;
        padding: 0.75rem 1.5rem;
      }

      .form-group input {
        min-height: 44px;
        font-size: 16px; /* 防止iOS缩放 */
      }
    }

    /* 高分辨率屏幕优化 */
    @media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
      .btn svg, .logo svg {
        width: 20px;
        height: 20px;
      }
    }

    /* 横屏手机优化 */
    @media (max-width: 768px) and (orientation: landscape) {
      .login-wrapper {
        padding: 0.5rem;
      }

      .login-container {
        max-width: 450px;
        padding: 1.25rem;
      }
    }

    /* 超小屏幕优化 */
    @media (max-width: 360px) {
      .login-wrapper {
        padding: 0.5rem;
      }

      .login-container {
        padding: 0.75rem;
        max-width: 100%;
      }

      .theme-toggle {
        top: 0.5rem;
        right: 0.5rem;
      }

      .theme-btn {
        width: 28px;
        height: 28px;
      }

      .theme-btn svg {
        width: 12px;
        height: 12px;
      }

      .login-header h1 {
        font-size: 1rem;
      }

      .login-header p {
        font-size: 0.85rem;
      }

      .form-group input {
        padding: 0.5rem 0.75rem;
      }

      .btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
      }
    }