.scroll-up {
    height: 40px;
    width: 40px;
    display: block;
    border: 1px solid #666;
    position: fixed;
    bottom: 20px;
    right: 20px;
    cursor: pointer;
    transition: all 0.5s cubic-bezier(0.25, 1.7, 0.35, 1.5);
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s;
  }
  
  .scroll-up.show {
    opacity: 1;
    visibility: visible;
  }
  
  .scroll-slide {
    left: 0;
    top: -100%;
    width: 100%;
    height: 100%;
    background: #666;
    position: absolute;
    display: block;
    z-index: 0;
  }
  
  .left-side {
    position: absolute;
    z-index: 1;
    background-color: transparent;
    top: 19px;
    left: 3px;
    width: 20px;
    display: block;
    transform: rotate(-45deg);
  }
  .left-side:after {
    content: "";
    background-color: #666;
    width: 20px;
    height: 1px;
    display: block;
    border-radius: 1px;
    transition: all 0.5s cubic-bezier(0.25, 1.7, 0.35, 1.5);
    transform-origin: right center;
    z-index: -1;
  }
  
  .right-side {
    position: absolute;
    z-index: 1;
    background-color: transparent;
    top: 19px;
    left: 17px;
    width: 20px;
    display: block;
    transform: rotate(45deg);
    border-radius: 2px;
  }
  .right-side:after {
    content: "";
    background-color: #666;
    width: 20px;
    height: 1px;
    display: block;
    border-radius: 1px;
    transition: all 0.5s cubic-bezier(0.25, 1.7, 0.35, 1.5);
    transform-origin: left center;
    z-index: -1;
  }
  
  .scroll-up:hover {
    transition: all 0.1s;
  }
  .scroll-up:hover .left-side:after {
    transform: rotate(-10deg);
  }
  .scroll-up:hover .right-side:after {
    transform: rotate(10deg);
  }
  .scroll-up:hover .scroll-slide {
    transition: all 0.4s ease-in-out;
    transform: translateY(200%);
  }