动画（二）

<template lang="html">
  <div class="waveWrapper waveAnimation">
    <div class="waveWrapperInner bgTop">
      <div class="wave waveTop"></div>
    </div>
    <div class="waveWrapperInner bgMiddle">
      <div class="wave waveMiddle"></div>
    </div>
    <div class="waveWrapperInner bgBottom">
      <div class="wave waveBottom"></div>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {};
  },
  computed: {},
  created() {},
  mounted() {},
  methods: {},
  watch: {},
  components: {}
};
</script>

<style lang="scss" scoped>
@keyframes move_wave {
  0% {
    transform: translateX(0) translateZ(0) scaleY(1);
  }
  50% {
    transform: translateX(-25%) translateZ(0) scaleY(0.55);
  }
  100% {
    transform: translateX(-50%) translateZ(0) scaleY(1);
  }
}
.waveWrapper {
  overflow: hidden;
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  top: 0;
  margin: auto;
}
.waveWrapperInner {
  position: absolute;
  width: 100%;
  overflow: hidden;
  height: 100%;
  bottom: -1px;
  background-image: linear-gradient(to top, #86377b 20%, #27273c 80%);
}
.bgTop {
  z-index: 15;
  opacity: 0.5;
}
.bgMiddle {
  z-index: 10;
  opacity: 0.75;
}
.bgBottom {
  z-index: 5;
}
.wave {
  position: absolute;
  left: 0;
  width: 200%;
  height: 100%;
  background-repeat: repeat no-repeat;
  background-position: 0 bottom;
  transform-origin: center bottom;
}
.waveTop {
  background-size: 50% 100px;
  background-image: url("./../assets/images/wave-top.png");
}
.waveAnimation .waveTop {
  animation: move-wave 3s;
  -webkit-animation: move-wave 3s;
  -webkit-animation-delay: 1s;
  animation-delay: 1s;
}
.waveMiddle {
  background-size: 50% 120px;
  background-image: url("./../assets/images/wave-mid.png");
}
.waveAnimation .waveMiddle {
  animation: move_wave 10s linear infinite;
}
.waveBottom {
  background-size: 50% 100px;
  background-image: url("./../assets/images/wave-bot.png");
}
.waveAnimation .waveBottom {
  animation: move_wave 15s linear infinite;
}
</style>

这个动画我是写不出来，只能勉强看懂（能写出这个东西的人，脑回路是咋样子的），但是还是有很多学习的东西

• background-image: linear-gradient(to top, #86377b 20%, #27273c 80%);，这是整个背景的渐变
• background-repeat: repeat no-repeat; background-position: 0 bottom;这是背景图的设置，第一次见这种写法