JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    <div>A</div>
    <div>B</div>
    <div>C</div>
</div>

CSS

.box {
  /* basic styling */
  width: 100%;
  height: 95px;
  border: 1px solid #555;
  font: 14px Arial;
  /* flexbox setup */
  display: -webkit-box;
  -webkit-box-orient: horizontal;
  display: -moz-box;
  -moz-box-orient: horizontal;
  display: box;
  box-orient: horizontal;
}

.box > div {
  -webkit-box-flex: 1;
  -moz-box-flex: 1;
  box-flex: 1;
}

/* our colors */
.box > div:nth-child(1){ background : #FCC; }
.box > div:nth-child(2){ background : #CFC; }
.box > div:nth-child(3){ background : #CCF; }