JSFiddle - React, Tailwind, and code Playground

HTML

<div class="diamond"></div>

CSS

.diamond {
    left: 50px;
    top: 50px;
    position: absolute;
    height: 88px;
    width: 300px;
    background-color: transparent;
    -webkit-perspective: 100px;
    -moz-perspective: 100px;
    perspective: 100px;
}

.diamond:before {
    content: '';
    width: 100%;
    height: 51%;
    left: 0%;
    top: 0%;
    position: absolute;
    border-color: red;
    border-style: solid;
    border-width: 3px 3px 0px 3px;
    -webkit-transform: rotateX(20deg);
    -moz-transform: rotateX(20deg);
    transform: rotateX(20deg);
    border-radius: 6px;
    background-color: blue;
}

.diamond:after {
    content: '';
    width: 100%;
    height: 111%;
    left: 0%;
    bottom: 0%;
    position: absolute;
    border-color: red;
    border-style: solid;
    border-width: 0px 3px 3px 3px;
    -webkit-transform: rotateX(-20deg);
    -moz-transform: rotateX(-20deg);
    transform: rotateX(-20deg);
    border-radius: 6px;
    background-color: lightblue;
}