JSFiddle - React, Tailwind, and code Playground

HTML

<div class="button big-btn">This is a big button</div>
<div class="button medium-btn">This is a medium button</div>
<div class="button small-btn">This is a small button</div>

CSS

.button {
    background-color: #000000;
    color: #FFFFFF;
    float: right;
    padding: 10px;
    border-radius: 10px;
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
}

.button.small-btn {
    width: 50px;
    height: 20px;
}

.button.medium-btn {
    width: 70px;
    height: 30px;
}

.button.big-btn {
    width: 90px;
    height: 40px;
}