JSFiddle - React, Tailwind, and code Playground

by Vadim

HTML

<div class="container">
  <div class="c1">1</div>
  <div class="c2">2</div>
</div>

CSS

.container {  
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr;
  gap: 0px 0px;
  grid-auto-flow: row;
  width: 100px;
  height: 100px;
}

.c1 { 
  grid-column-start: 1;
  grid-row-start: 1;
  background: #ff0000;
}

.c2 { 
  grid-column-start: 1;
  grid-row-start: 1;
  background: #0000ff;
  opacity: 1;
}