JSFiddle - React, Tailwind, and code Playground

HTML

<div class='c1'>
</div>
<div class='c2'>
</div>
<div class='c3'>
</div>

CSS

.c1, .c2, .c3{
  min-height: 100px;
  float: left;
}
.c1{
  background: red;
  width: calc(50% - 50px);
  
}
.c2{
  background: blue;
  width: 100px;
}
.c3{
  background: green;
  width: calc(50% - 50px);
}