展开收起动画 grid.container { display: grid; grid-template-rows: 0

<div class="container">
  <div class="child">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
  </div>
</div>

<style scoped lang="scss">
.container {
  padding: 20px;
  width: 200px;
  background: red;
  display: grid;
  grid-template-rows: 0fr;
  overflow: hidden;
  transition: all .3s;
}

.container:hover {
  grid-template-rows: 1fr;
}

.container .child {
  min-height: 0;
}
</style>