纯css实现一个带箭头阴影的手风琴动效

效果如图：

可以移入展开。

特征：
1，带有箭头
2，箭头处带有阴影
3，有交互操作

箭头，可以用border来实现：

width: 0;
height: 0;
border: 190px solid transparent;
border-left: 60px solid transparent;

引用可用box-shadow实现，但是如果是贴合非规则图形的阴影，可以用到滤镜：

filter: drop-shadow(5px 0 5px rgba(0, 0, 0, .2));

交互：当前放大，其他兄弟节点渐入透明

.parent{
    .child{
        opation: 1
    }
    &:hover{
        .child{
            opation: .2;
            &:hover{
                opation: 1
            }
        }
    }
}

代码：vue3
demo.vue

<template>
  <div class="step">
    <div class="item" v-for="item in list">
      <div class="content">
        <h2>
          <Ellipsis>
            {{ item.count }}
            <small>项</small>
          </Ellipsis>
        </h2>
        <h3>
          <Ellipsis>
            {{ item.title }}
          </Ellipsis>
        </h3>
        <Ellipsis class="desc">
          {{ item.desc }}
        </Ellipsis>
      </div>
    </div>
  </div>
</template>
<script setup>
const list = [
  {
    count: 13,
    title: '测试的标题啊',
    desc: '测试的内容测试的内容'
  },
  {
    count: 17,
    title: '测试的标题啊',
    desc: '测试的内容测试的内容'
  },
  {
    count: 12,
    title: '测试的标题啊',
    desc: '测试的内容测试的内容'
  },
  {
    count: 38,
    title: '测试的标题啊',
    desc: '测试的内容测试的内容'
  },
]
</script>
<style scoped lang="scss">
.step {
  display: flex;
  align-items: stretch;
  overflow: hidden;
  position: relative;

  .item {
    width: 25%;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    flex-direction: column;
    position: relative;
    height: 375px;
    color: #fff;
    filter: drop-shadow(5px 0 5px rgba(0, 0, 0, .2));
    z-index: 0;
    transition-duration: .3s;
    cursor: default;

    .content {
      position: absolute;
      left: 0;
      top: 0;
      z-index: 0;
      transition-duration: .3s;
      height: 100%;
      width: 100%;
      display: flex;
      align-items: flex-start;
      justify-content: center;
      flex-direction: column;
      padding-left: 20%;
    }

    &:before {
      content: '';
      display: block;
      position: absolute;
      z-index: 0;
      width: 0;
      height: 0;
      right: -249px;
      border: 190px solid transparent;
      border-left: 60px solid transparent;
      pointer-events: none;
    }

    &:nth-child(1) {
      background-color: #7C97CA;
      z-index: 3;

      &:before {
        border-left-color: #7C97CA;
      }
    }

    &:nth-child(2) {
      background-color: #5F7CB2;
      z-index: 2;

      &:before {
        border-left-color: #5F7CB2;
      }
    }

    &:nth-child(3) {
      background-color: #5771A0;
      z-index: 1;

      &:before {
        border-left-color: #5771A0;
      }
    }

    &:nth-child(4) {
      background-color: #294A87;
      z-index: 0;
    }

    h2 {
      font-size: 80px;
      font-weight: bold;
      color: #FFFFFF;
      line-height: 117px;
      margin: 0;
      transition-duration: .3s;

      small {
        font-size: 28px;
        font-weight: 400;
        color: #FFFFFF;
        line-height: 45px;
        transition-duration: .3s;
      }
    }

    h3 {
      font-size: 36px;
      font-weight: 400;
      color: #FFFFFF;
      line-height: 56px;
      margin: 0;
      transition-duration: .3s;
    }

    .desc {
      margin-top: 14px;
      font-size: 24px;
      font-weight: 300;
      color: #FFFFFF;
      line-height: 33px;
      transition-duration: .3s;
    }
  }
}

.step {
  &:hover {
    .item {
      .content {
        opacity: .1;
      }

      &:hover {
        width: 40%;

        .content {
          padding-left: 30%;
          opacity: 1;
        }

        h2 {
          font-size: 100px;

          small {
            font-size: 32px;
          }
        }

        h3 {
          font-size: 40px;
        }

        .desc {
          font-size: 24px;
        }
      }
    }
  }
}
</style>