JSFiddle - React, Tailwind, and code Playground
by adelura
HTML
<div class="arrow">
<div class="arrow-border"></div>
</div>
CSS
:root {
--arrow-size: 40px;
--border-width: 2px;
margin: 100px;
}
.arrow {
border: var(--arrow-size) solid transparent;
transform: rotate(45deg);
border-top-color: red;
border-left-color: blue;
height: 0;
width: 0;
position: relative;
}
.arrow-border {
position: absolute;
border-top: var(--border-width) solid black;
border-left: var(--border-width) solid black;
top: calc(var(--arrow-size) * -1 - var(--border-width));
right: calc(var(--arrow-size) * -1);
bottom: calc(var(--arrow-size) * -1);
left: calc(var(--arrow-size) * -1 - var(--border-width));
}