PhonicsGame_master/pages/index/index.wxss

.container {
  background-color: #3E4349;
  justify-content: flex-start;
} 
.btn {
  width:100%;
  height:390rpx;
}
.line{
  width: 100%;
  height:20rpx;
  background-color: #1e1e1e;
}

.bottom{
  font-size:20rpx;
  color:#fff;
  text-align: center;
  margin: 100rpx 0 40rpx 0;
}