#scrollTopBtn {
      display: none;
      position: fixed;
      bottom: 20px;
      right: 20px;
      background-color: red;
      color: white; 
      border: none;
      border-radius: 50%;
      width: 50px;
      height: 50px;
      font-size: 20px;
      cursor: pointer;
      box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
      z-index: 1000;
      transition: background-color 0.3s ease;
    }

    #scrollTopBtn:hover {
      background-color: darkred;
    }