I want to make the following layout:
However, since block 3 is quite high, and block 1 is rather narrow, the following view is obtained with a “hole” between block 1 and 2:
How can you get rid of the "hole" so that 1, 2 and 4 go in one column without breaks?
My workpiece, on which I tested:
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/> <div class="container"> <div class="row"> <div class="col-sm col-md-8"> <p class="bg-success">a1</p> </div> <div class="col-sm col-md-4"> <p class="bg-primary">b1<br><br><br><br><br><br></p> </div> <div class="col-sm col-md-8"> <p class="bg-danger">c1</p> <p class="bg-warning">c2</p> </div> </div> </div> 
