html, body {
  margin: 0;
  padding: 0;
}
.main {
  width: 100%;
  background-color: #00cbe8;
  overflow: hidden;
}
.banner {
  width: 100%;
  height: 8.2rem;
  background: url('../images/banner.png') no-repeat;
  background-size: 121%;
  background-position: 28%;
}
.btn {
  width: 3.6rem;
  margin: -1rem auto;
}
.logo {
  width: 1.8rem;
  margin: 0.5rem auto 0;
}
.footer {
  width: 100%;
  height: 3rem;
  position: absolute;
  bottom: 0; 
  /* background: url('../images/trash.png') no-repeat;
  background-size: 130%;
  background-position: center 0; */
}
.footer-img {
  position: absolute;
  top: 0px;
  left: 52%;
  transform: translateX(-50%);
}
.clearfix:before,.clearfix:after { 
  content:"";
  display:table;  /* 这句话可以出发BFC BFC可以清除浮动,BFC我们后面讲 */
}
.clearfix:after {
 clear:both;
}
.clearfix {
  *zoom:1;
}