.wave {        position: relative;     width: 200px;    height: 200px;    background: @color;    border: 5px solid #76daff;    border-radius: 50%;    overflow: hidden;}.wave-box::before,.wave-box::after {      content: '';      position: absolute;      top: 0;      left: 50%;      width: 400px;      height: 400px;      border-radius: 45%;      -webkit-transform: translate(-50%, -70%);      transform: translate(-50%, -70%);      background: rgba(255, 255, 255, 0.5);      -webkit-animation: rotate 10s linear infinite;      animation: rotate 10s linear infinite;      z-index: 10;}@keyframes rotate {  50% {            -webkit-transform: translate(-50%, -75%) rotate(180deg);            transform: translate(-50%, -75%) rotate(180deg);  }  100% {            -webkit-transform: translate(-50%, -70%) rotate(180deg);            transform: translate(-50%, -70%) rotate(180deg);  }}//或者使用預編譯語言更方便，這里使用less.wave(@width; @height; @color) {    position: relative;     width: @width;    height: @height;    background: @color;    border: 5px solid @color;    border-radius: 50%;    overflow: hidden;    &::before,    &::after {        content: '';        position: absolute;        top: 0;        left: 50%;        width: @width * 2;        height: @height * 2;        border-radius: 45%;        transform: translate(-50%, -70%);        background: rgba(255,255,255,0.5);        animation: rotate 10s linear infinite;        z-index: 10;    }    &::after {        border-radius: 47%;        background: rgba(255,255,255,0.5);        animation: rotate 10s linear -5s infinite;        z-index: 20;    }}//調用.wave-box {    .wave(200px; 200px; #76daff);}<!-- 頁面上調用 --><div class="wave-box"></div>