鼠标悬停动画效果

<a href="#">
    Button
</a>

body {
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
a {
  position: relative;
  padding: 20px 20px 20px 30px;
  color: #262626;
  font-size: 24px;
  font-family: sans-serif;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 10px;
  &:before {
    content: "";
    position: absolute;
    bottom: 0;
    right: 0;
    width: 100%;
    height: 2px;
    background: #262626;
    transform-style: linear;
    transition-property: height, width;
    transition-delay: 0.5s, 1s;
    transition-duration: 0.5s;
  }
  &:after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 100%;
    height: 100%;
    background: #fbff1e;
    transform: scaleX(0);
    transition: 0.5s;
    transition-delay: 0s;
    transform-origin: right;
    z-index: -1;
  }
  &:hover {
    &:before {
      width: 2px;
      height: 100%;
      transition-property: width, height;
    }
    &:after {
      transform: scaleX(1);
    }
  }
}