.BetterList{
  width: 100%;
  height: 500px;
  position: fixed;
  top: 300px;
  background-color: antiquewhite;
  overflow: hidden;
  .c-content{
    background-color: aliceblue;
    .act-i{
      height: 200px;
      background-color: bisque;
    }
    &>div{
      height: 100px;
      line-height: 100px;
      text-align: center;
      background-color: aqua;
      &:nth-child(n+1){
        margin-top: 30px;
      }
    }
  }
}