JSFiddle - React, Tailwind, and code Playground
by phloe
HTML
<div class="box">
</div>
CSS
.box {
border: 20px solid;
border-image: url('data:image/svg+xml;utf8,<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg"><rect width="100" height="20" fill="%23F004" /><rect x="80" width="20" height="100" fill="%230F04" /><rect y="80" width="100" height="20" fill="%2300F4" /></svg>') 20 / 20;
}
.box::after {
content: "";
display: block;
padding-bottom: 56.25%;
}