JSFiddle - React, Tailwind, and code Playground

HTML

<button>foo</button>

CSS

button {
    background: lightblue;
    border: 1px solid #fff;
    outline: 1px solid #000;
    cursor: pointer;
    -webkit-transition: background-color ease 0s 2s;
    -moz-transition: background-color ease 0s 2s;
    -o-transition: background-color ease 0s 2s;
    transition: background-color ease 0s 2s;
}
button:focus,
button:hover {
    border-color: blue;
}
button:active {
    background-color: blue;
    -webkit-transition: background-color ease 0s 0s;
    -moz-transition: background-color ease 0s 0s;
    -o-transition: background-color ease 0s 0s;
    transition: background-color ease 0s 0s;
}