body{
  background: #172F9D;
}

.main{
  width: 100%;
  height: 42rem;
  background: url('../img/index.png');
  background-size: 100% 100%;
  position: relative;
}

.main header{
  width: 100%;
  height: 1.21rem;
  background: url('../img/header.png');
  background-size: 100% 100%;
  position: fixed;
  left: 0;
  top: 0;
  z-index: 1;
}