JSFiddle - React, Tailwind, and code Playground

by mvasilkov

HTML

<div class="wrapper">
    <div class="container">
        <div class="fold"></div>
        <div class="left nothing"></div>
        <div class="bottom nothing"></div>
    </div>
</div>

CSS

body {
    background: #101010;
}
.wrapper {
    overflow: hidden;
    width: 372px;
}
.container {
    background: #0080ff;
    margin: -28px 0 0;
    width: 400px;
    height: 400px;
    position: relative;
    overflow: hidden;
}
.fold {
    border: 200px solid rgba(0,0,0,0);
    border-left-color: #fff;
    border-bottom-color: #fff;
}
.nothing {
    background: #f2f2f2;
    position: absolute;
    box-shadow: inset 0 0 20px rgba(0,0,0,0.5);
}
.left {
    left: -449px;
    top: -320px;
    width: 500px;
    height: 1000px;
    border-radius: 0 500px 500px 0;
}
.bottom {
    left: -280px;
    bottom: -449px;
    width: 1000px;
    height: 500px;
    border-radius: 500px 500px 0 0;
}