col order bootstrap code example

Example 1: col offset in bootstrap

.col-md-3 .offset-md-3

Example 2: change order columns bootstrap

<div class="row">
    <div class="col-md-3">
        sidebar
    </div>
    <div class="col-md-9 ">
        main
    </div>
</div>

//  CSS

.row{
   display: flex;
    flex-flow: column-reverse;
     }