JSFiddle - React, Tailwind, and code Playground

HTML

<a class='button red'>Sign In</a>
<a class='button green'>Sign In</a>
<a class='button blue'>Sign In</a>

CSS

.button {
    display: inline-block;
    color: #fff;
    text-shadow: 0 0 2px rgba(0,0,0,.3);
    font-family: sans-serif;
    box-shadow:
        inset 0 0 2px 0 rgba(255,255,255,.4),
        inset 0 0 3px 0 rgba(0,0,0,.4),
        inset 0 0 3px 5px rgba(0,0,0,.05),
        2px 2px 4px 0 rgba(0,0,0,.25);
    border-radius: 4px;
    padding: 8px 16px;;
    font-size: 12px;
    line-height: 14px;
    position: relative;
}
.button.red { background: #EA3D33; }
.button.green { background: #7ED321; }
.button.blue { background: #4A90E2; }
.button:before, .button:after {
    content: '';
    display: block;
    position: absolute;
    left: 2px;
    right: 2px;
    height: 3px;
}
.button:before {
    top: 0;
    border-bottom-left-radius: 4px;
    border-bottom-right-radius: 4px;
    background: rgba(255,255,255,.6);
    box-shadow: 0 1px 2px 0 rgba(255,255,255,.6);
}
.button:after {
    bottom: 0;
    border-top-left-radius: 4px;
    border-top-right-radius: 4px;
    background: rgba(0,0,0,.15);
    box-shadow: 0 -1px 2px 0 rgba(0,0,0,.15);
}