我是新的网络开发。我尝试React与顺风为我的第一个项目。但我添加了免费的动画背景从互联网上。背景组成正常的css和html。这是css文件：

@import url("https://fonts.googleapis.com/css?family=Exo:400,700");

* {
  margin: 0px;
  padding: 0px;
}

body {
  font-family: "Exo", sans-serif;
}

.context {
  width: 100%;
  position: absolute;
}

.context h1 {
  text-align: center;
  color: #fff;
  font-size: 50px;
}

.area {
  background: #b3ffab;
  background: -webkit-linear-gradient(25deg, #b3ffab 0%, #12fff7 100%);
  background: linear-gradient(25deg, #b3ffab 0%, #12fff7 100%);
  width: 100%;
  height: 100vh;
}

.circles {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  overflow: hidden;
}

.circles li {
  position: absolute;
  display: block;
  list-style: none;
  width: 20px;
  height: 20px;
  background: rgb(17, 218, 94, 0.4);
  animation: animate 25s linear infinite;
  bottom: -150px;
}

.circles li:nth-child(1) {
  left: 25%;
  width: 80px;
  height: 80px;
  animation-delay: 0s;
}

.circles li:nth-child(2) {
  left: 10%;
  width: 20px;
  height: 20px;
  animation-delay: 2s;
  animation-duration: 12s;
}

.circles li:nth-child(3) {
  left: 70%;
  width: 20px;
  height: 20px;
  animation-delay: 4s;
}

.circles li:nth-child(4) {
  left: 40%;
  width: 60px;
  height: 60px;
  animation-delay: 0s;
  animation-duration: 18s;
}

.circles li:nth-child(5) {
  left: 65%;
  width: 20px;
  height: 20px;
  animation-delay: 0s;
}

.circles li:nth-child(6) {
  left: 75%;
  width: 110px;
  height: 110px;
  animation-delay: 3s;
}

.circles li:nth-child(7) {
  left: 35%;
  width: 150px;
  height: 150px;
  animation-delay: 7s;
}

.circles li:nth-child(8) {
  left: 50%;
  width: 25px;
  height: 25px;
  animation-delay: 15s;
  animation-duration: 45s;
}

.circles li:nth-child(9) {
  left: 20%;
  width: 15px;
  height: 15px;
  animation-delay: 2s;
  animation-duration: 35s;
}

.circles li:nth-child(10) {
  left: 85%;
  width: 150px;
  height: 150px;
  animation-delay: 0s;
  animation-duration: 11s;
}

@keyframes animate {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
    border-radius: 0;
  }

  100% {
    transform: translateY(-1000px) rotate(720deg);
    opacity: 0;
    border-radius: 50%;
  }
}

在我的jsx文件中，我使用：

function Dashboard(props) {
  const percentage = 80;
  return (
    <div className="area w-screen">
/* all other web components*/
      <div>
        <ul className="circles z-1 ">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
      </div>

      /*some footer*/

    </div>
  );
}

export default Dashboard;

基本上它只是应用一些动画丹效果到<li>组件。我发现我所有的悬停效果不工作。当我删除这个：

<div>
        <ul className="circles z-1 ">
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
          <li></li>
        </ul>
      </div>

它工作。为什么会发生这种情况？以及如何解决这个问题？