/* 页脚样式 */
    .footer {
      background-color: var(--neutral);
      color: var(--white);
      padding: 5rem 0 2rem;
    }
    
    .footer-logo {
      display: flex;
      align-items: center;
      gap: 0.75rem;
      font-weight: 700;
      font-size: 1.25rem;
      margin-bottom: 1.5rem;
    }
    
    .footer-logo-icon {
      width: 2.5rem;
      height: 2.5rem;
      background-color: var(--white);
      color: var(--primary);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    
    .footer-desc {
      color: var(--gray-400);
      margin-bottom: 1.5rem;
    }
    
    .footer-social {
      display: flex;
      gap: 1rem;
    }
    
    .footer-social a {
      color: var(--gray-400);
      font-size: 1.25rem;
    }
    
    .footer-social a:hover {
      color: var(--white);
    }
    
    .footer-title {
      font-size: x-large;
      font-weight: 600;
      margin-bottom: 1.5rem;
    }
    
    .footer-links {
      list-style: none;
    }
    
    .footer-links li {
      font-size: larger;
      margin-bottom: 0.75rem;
    }
    
    .footer-links a {
      color: var(--gray-400);
    }
    
    .footer-links a:hover {
      color: var(--white);
    }
    
    .footer-bottom {
      margin-top: 4rem;
      padding-top: 2rem;
      border-top: 1px solid var(--gray-800);
      text-align: center;
      color: var(--gray-500);
      font-size: 0.875rem;
    }
    
    /* 返回顶部按钮 */
    .back-to-top {
      position: fixed;
      bottom: 2rem;
      right: 2rem;
      width: 3rem;
      height: 3rem;
      background-color: var(--primary);
      color: var(--white);
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
      opacity: 0;
      visibility: hidden;
      transition: all 0.3s ease;
      z-index: 40;
    }
    
    .back-to-top.visible {
      opacity: 1;
      visibility: visible;
    }
    
    .back-to-top:hover {
      background-color: rgba(22, 93, 255, 0.9);
      transform: scale(1.1);
    }