<ul class="bg-bubbles">    <li v-for="(item, index) in bubbles" :key="index"></li></ul>

created() {    this.bubbles.length = 10; },

.bg-bubbles {    position: absolute;    // 使氣泡背景充滿整個屏幕    top: 0;    left: 0;    width: 100%;    height: 100%;    li {      position: absolute;      // bottom 的設(shè)置是為了營造出氣泡從頁面底部冒出的效果；      bottom: -160px;      // 默認(rèn)的氣泡大??；      width: 40px;      height: 40px;      background-color: rgba(255, 255, 255, 0.15);      list-style: none;      // 使用自定義動畫使氣泡漸現(xiàn)、上升和翻滾；      animation: square 15s infinite;      transition-timing-function: linear;      // 分別設(shè)置每個氣泡不同的位置、大小、透明度和速度，以顯得有層次感；      &:nth-child(1) {        left: 10%;      }      &:nth-child(2) {        left: 20%;        width: 90px;        height: 90px;        animation-delay: 2s;        animation-duration: 7s;      }      &:nth-child(3) {        left: 25%;        animation-delay: 4s;      }      &:nth-child(4) {        left: 40%;        width: 60px;        height: 60px;        animation-duration: 8s;        background-color: rgba(255, 255, 255, 0.3);      }      &:nth-child(5) {        left: 70%;      }      &:nth-child(6) {        left: 80%;        width: 120px;        height: 120px;        animation-delay: 3s;        background-color: rgba(255, 255, 255, 0.2);      }      &:nth-child(7) {        left: 32%;        width: 160px;        height: 160px;        animation-delay: 2s;      }      &:nth-child(8) {        left: 55%;        width: 20px;        height: 20px;        animation-delay: 4s;        animation-duration: 15s;      }      &:nth-child(9) {        left: 25%;        width: 10px;        height: 10px;        animation-delay: 2s;        animation-duration: 12s;        background-color: rgba(255, 255, 255, 0.3);      }      &:nth-child(10) {        left: 85%;        width: 160px;        height: 160px;        animation-delay: 5s;      }    }    // 自定義 square 動畫；    @keyframes square {      0% {        opacity: 0.5;        transform: translateY(0px) rotate(45deg);      }      25% {        opacity: 0.75;        transform: translateY(-400px) rotate(90deg)      }      50% {        opacity: 1;        transform: translateY(-600px) rotate(135deg);      }      100% {        opacity: 0;        transform: translateY(-1000px) rotate(180deg);      }    }  }