JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="EXTENDER">
    <div class="COLS">
      <div class="CELL _100px" style="background-color:blue">100px</div>
      <div class="CELL _FLEX" style="background-color:red">flex</div>
    </div>
  </div>
</div>

CSS

.container {
    height: 200px;
    width: 500px;
    position:relative;
}

/*!   flexScaffolding 0.2 ...