JSFiddle - React, Tailwind, and code Playground

HTML

<div class="diag" style="width: 300px; height: 100px;"></div>

CSS

.diag {
    background: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' version='1.1' preserveAspectRatio='none' viewBox='0 0 100 100'><path d='M1 0 L0 1 L99 100 L100 99' fill='black' /><path d='M0 99 L99 0 L100 1 L1 100' fill='black' /></svg>");
    background-repeat:no-repeat;
    background-position:center center;
    background-size: 100% 100%, auto;
}