JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <div class="a"></div>
    <div class="b"></div>
    <div class="c"></div>
</div>

CSS

.wrapper {
    position:absolute;
    border:solid #000 thick;
    width:150px;
        height:150px;
}
.a {
    background:#ff0;
    position:absolute;
    top:0;
    left:0;
     width:30px;
    height:30px;
}
.b {
    background:#ff0;
    position:absolute;
    top:0;
    right:0;
     width:30px;
    height:30px;
}
.c {
    background:#eee;
    position:absolute;
    bottom:0;
    left:0;
     width:30px;
    height:30px;
}