JSFiddle - React, Tailwind, and code Playground

HTML

<div id="square">
        <div id="ctr"></div>
</div>

CSS

#square {
    border: 1px solid #CCCCCC;
    display: block;
    height: 400px;
    line-height: 400px;
    margin: 50px auto;
    overflow: hidden;
    position: relative;
    text-align: center;
    width: 400px;
}

#ctr{
 -webkit-transform: rotate(-45deg);  
     -moz-transform: rotate(-45deg); 
      -ms-transform: rotate(-45deg); 
       -o-transform: rotate(-45deg); 
          transform: rotate(-45deg);
    -webkit-transform-origin: 0 0;
    -moz-transform-origin: 0 0;
    -ms-transform-origin: 0 0;
    -o-transform-origin: 0 0;
    transform-origin: 0 0;
    right: 0;
    top: 0;
    background-color: blue;
    display: block;
    height: 150px;
    position: absolute;
    width: 100px;
}

#ctr:hover{
    background-color: green;
}

#ctr:active{
    background-color: red;
}