@moritzbrue this is very customized. you can find out how such layouts work by inspecting the code in your browsers developer tools. in this case the rows are:
#leftrow {
overflow:auto;
height: 98vh;
/border-right:solid 1px black;/
}
#rightrow {
overflow:auto;
height: 98vh;
}
so they have different content mass but the same height. you would have to build your layout around that concept.