JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" value="Next question" />
<input type="button" disabled="disabled" value="Next question" />

CSS

input[type=button]{
    background-color: #6CB300;
    color:#fff;
    border:0;
    font-size:1.5em;
    padding:2% 3%;
}
input[type=button][disabled]{
    background-color:#CCC;
}