JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    Hi
</div>

CSS

div{
    background-color: blue;
    border: 4px solid blue;
-webkit-transition: border-color 1s ease;
         -moz-transition: border-color 1s ease;
           -o-transition: border-color 1s ease;
          -ms-transition: border-color 1s ease;
              transition: border-color 1s ease;    
}

    div:hover{
      border-color: red;
    background: green;
    }