JSFiddle - React, Tailwind, and code Playground

by Kolichikov

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.0/umd/popper.min.js"></script>
<script src="//code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<link rel="stylesheet" href="//stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">
<script src="//stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<!-- 
  Bootstrap docs: https://getbootstrap.com/docs
-->

<div class="container">
<div class="left_half row">
  <div class="col-sm-12">
    Level 1: .col-sm-12
    <div class="row">
      <div class="rnr1 col-8 col-sm-6">
        Level 2: .col-8 .col-sm-6
      </div>
      <div class="rnr2 col-4 col-sm-6">
        Level 2: .col-4 .col-sm-6
      </div>
    </div>
  </div>
</div>
</div>

<div class="container">
<div class="row">
  <div class="right_half col-sm-12 col-lg-6 d-flex flex-column">
    <div class="row">
      <div class="rnr1 col-sm-6">Right nested row #1</div>
      <div class="rnr1 col-sm-6">Right nested row #1</div>
    </div>
    <div class="row">
      <div class="rnr2 col-sm-12">Right nested row #2</div>
    </div>
  </div>
</div>

</div>

CSS

.row {
  background: #f8f9fa;
  margin-top: 20px;
}

.col {
  border: solid 1px #6c757d;
  padding: 10px;
}

.left_half
{
  border: 1px solid red;
}

.right_half
{
  border: 1px solid blue;
}

.rnr1
{
  border:1px solid green;
}

.rnr2
{
  border:1px solid purple;
}