JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Repellendus ipsam quod numquam repudiandae, totam deleniti quis, quos commodi delectus sit illo officia. Nulla assumenda facere alias quasi eveniet harum, doloremque ducimus deleniti ut sit adipisci laborum accusamus odio fuga.</p>
</div>

CSS

.container {
    position: relative;
    width: 300px;
    height: 300px;
    background-color: #03a9f4;
}

.container:before {
    content: '';
    display: block;
    height: 100%;
    width: 300px;
    background-color: #fff;
    right: 0;
    bottom: 0;
    -webkit-shape-outside: polygon(100% 0, 100% 100%, 0 100%);
    shape-outside: polygon(100% 0, 100% 100%, 0 100%);
    -webkit-clip-path: polygon(100% 0, 100% 100%, 0 100%);
    clip-path: polygon(100% 0, 100% 100%, 0 100%);
    float: right;
}