Simple problem: How do I vertically align a col within a col using bootstrap? Example here (I want to vertically align child1a and child1b):
HTML
<div class="col-lg-12">
  <div class="col-lg-6 col-md-6 col-12 child1">
    <div class="col-12 child1a">Child content 1a</div>
    <div class="col-12 child1b">Child content 1b</div>
  </div>
  <div class="col-lg-6 col-md-6 col-12 child2">
  Child content 2<br>
  Child content 2<br>
  Child content 2<br>
  Child content 2<br>
  Child content 2<br>
  </div>
</div>
UPDATE
Some CSS:
.col-lg-12{
top:40px;
bottom:0px;
border:4px solid green;
}
  .child1a, .child1b{
  border:4px solid black;
  display:inline-block !important;
}
.child1{
  border:4px solid blue;
  height:300px;
  display:table-cell !important;
  vertical-align:middle;
}
.child2{
  border:4px solid red;
}
 
     
     
     
     
     
     
     
     
     
     
    