fastNetwork/pages/exchange/exchange.wxss

.main {
  float: left;
  width: 100%;
}

.main .one {
  position: fixed;
  z-index: 9999;
  width: 100%;
  height: 80rpx;
  line-height: 80rpx;
  background-color: #409eff;
  color: #ffffff;
  text-align: center;
}

.main .two {
  position: absolute;
  top: 80rpx;
  width: 100%;
  height: 15000px;
}