* {
     margin: 0;
 }

 .w-full {
     width: 100%;
 }

 .h-full {
     height: 100%;
 }

 .img {
     width: 100%;
     display: flex;
 }

 * {
     margin: 0;
 }

 html {
     font-size: calc(100vw / 7.5);
     /* 默认使用动态 rem 计算 */
 }

 .wrap {
     width: 100%;
     max-width: 750px;
     min-height: 100vh;
     margin: 0 auto;
     padding-bottom: 1.5rem;
 }

 .top {
     position: relative;
 }

 .kf-btn {
     position: absolute;
     top: 5%;
     right: 3%;
     width: 15%;
 }

 .main {
     position: relative;
 }

 .go-play-btn {
     width: 65%;
     position: absolute;
     top: 25%;
     left: 50%;
     transform: translate(-50%, 0%);
 }

 .go-play-btn img {
     animation: breathe 1s infinite;
 }

 .footer {
     width: 100%;
     position: fixed;
     left: 0;
     bottom: 0;
     z-index: 999;
 }

 .footer-content {
     position: relative;
 }

 .download-btn {
     width: 40%;
     position: absolute;
     bottom: 5%;
     left: 50%;
     transform: translate(-50%, 0%);
 }

 .download-btn img {
     animation: breathe 1s infinite;
 }

 @keyframes breathe {
     from {
         transform: scale(1)
     }

     50% {
         transform: scale(.9)
     }

     to {
         transform: scale(1)
     }
 }