/* 底部菜单栏样式 */
   .bottom-menu {
      position: fixed;
      bottom: 0;
      left: 0;
      width: 100%;
      background-color: #333;
      display: flex;
      justify-content: space-around;
      padding: 10px 0;
    }

   .bottom-menu a {
      color: white;
      text-decoration: none;
      font-size: 3vw;
    }

   .bottom-menu a:hover {
      color: #ff9900;
    }