html,body,.wrap {
   height: 100%;
}
.wrap .inner {
   width: 100%;
   height: 13.2rem;
   background:url('../images/bg.png') no-repeat; 
   background-size: cover;
   position: relative;
}
.wrap .inner .top {
  width: .7rem;
  height: .7rem;
  border-radius: 50%;
  position: absolute;
  left: .3rem;
  top: .22rem;
}
.wrap .inner .btns {
   position: absolute;
   top: 3.6rem;
   width: 100%;
   height: 1.2rem;
   /* border: 1px solid red; */
   display: flex;
   justify-content: center;
   align-items: center;
   /* padding: 0 1rem; */
}
.wrap .inner .btns .btn1 {
   width: 2.4rem;
   height: .7rem;
   border-radius: .3rem;
}
.wrap .inner .btns .btn2 {
   width: 2.4rem;
   height: .7rem;
   margin-left: 1.1rem;
   border-radius: .3rem;
}
.wrap .inner .next {
  position: absolute;
  width: 100%;
  top: 4.7rem;
  display: flex;
  justify-content: center;
}
.wrap .inner .next .img {
   width: 5.8rem;
   height: 5.2rem;
   background:url('../images/element.png') no-repeat; 
   background-size: cover;
   margin-left: -.4rem;
   animation: breathing 3s infinite
}
@keyframes breathing {
   0%, 100% {
     transform: scale(1); /* 初始大小 */
   }
   50% {
     transform: scale(1.1); /* 放大到1.1倍 */
   }
 }
 .wrap .inner .download {
   position: absolute;
   width: 100%;
   height: 1.4rem;
   top: 10rem;
   display: flex;
   justify-content: center;
   align-items: center;
 }
 .wrap .inner .download .down-btn {
   width: 4rem;
   height: 1rem;
   border-radius: .3rem;
 }