CSS流光按钮

<!-- run -->
<style>
  .btn {
    position: absolute;
    top: 2%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 230px;
    height: 90px;
    line-height: 90px;
    text-align: center;
    color: #fff;
    font-size: 25px;
    text-transform: uppercase;
    cursor: pointer;
    background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
    background-size: 400%;
    border-radius: 60px;
  }
.content-bg{
 width: 100%;
 height: 2000vh;
 background: #fff;
 background-image: linear-gradient(rgba(182, 128, 102, .8) 8px, transparent 0),
                      linear-gradient(90deg, rgba(182, 128, 102, .8) 8px, transparent 0);
 background-size: 8px 14px, 14px 8px;
}
  .btn:hover {
    animation: animate 8s linear infinite;
  }

  @keyframes animate {
    0% {
      background-position: 0%;
    }

    100% {
      background-position: 400%;
    }
  }

  .btn::before {
    content: '';
    position: absolute;
    top: -5px;
    left: -5px;
    right: -5px;
    bottom: -5px;
    z-index: -1;
    background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
    background-size: 400%;
    border-radius: 40px;
    opacity: 0;
    transition: 0.5s;
  }

  .btn:hover::before {
    filter: blur(20px);
    opacity: 1;
    animation: animate 8s linear infinite;
  }
</style>

<div class="content-bg">
  <b href="#top" class="btn">流光按钮</b>
</div>