as expected in the figure, child element 2 extends the parent element, but child element 1 cannot be highly adaptive and has always been 0. How can I set child element 1 to be as high as child element 2? It is better to use pure css method 
father{
  width:680rpx;
  display:flex;
  align-items: center;  
}
son2{
    display:inline-block;
    width:60%;
    margin:..;
    padding:..;//
}
son1{
    width:40%;
    height:100%;//0
    display:inline-block;
}
						