bV9mBs.gif

bV9mwZ.gif

.div1 {
    font-size: 20px;
    position: relative;
    width: 200px;
    height: 60px;
    line-height: 60px;
    margin: 20px;
}
.div1::before {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 200px;
    background: aquamarine;
    height: 2px;
    transition: transform .5s;
    transform: scaleX(0);
  }
.div1:hover::before {
    transform: scaleX(1);
  }

实现的效果都是用css实现的
主要用到的就是transform-origin
仓库中还有好多的效果
仓库地址