JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <h1>EQUAL WIDTH COLUMNS</h1>
  <p>Add display:flex to the parent and flex:1 to the boxes</p>
  <div class="equalHWrap eqWrap">
    <div class="equalHW eq">boo <br> boo</div>
    <div class="equalHW eq">shoo</div>
    <div class="equalHW eq">shoo</div>
  </div>
</div>

CSS

html, body  { height: 100%; width: 100%; }

.eqWrap { display: flex; }

.eq { padding-left: 10px; }
.eq:nth-of-type(odd) { background: yellow; }
.eq:nth-of-type(even) { background: lightblue; }
.equalHW { flex: 1; }