JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">

    <div class="floatleft" id="box1">
    
    </div>
    </div>

CSS

.wrap {
width: 100%;
height:400px;
overflow:hidden;
}

#box1 {
  background-color:red;
  text-align:left;
  cursor: pointer;
  -webkit-transition: width 1s;
  transition: width 1s;
}

#box1:active {
  width: 100%;
  background-color: red;

}

.floatleft {
    float:left; 
    width: 33.33%;
    background-color: black;
    height: 400px;
}