JSFiddle - React, Tailwind, and code Playground
CSS
div{
position:relative;
width:300px;height:300px;
overflow:hidden;
}
div:before{
content:'';
position:absolute;
left:0; bottom:0;
width:200%; height:200%;
-webkit-transform-origin: 15% 100%;
-ms-transform-origin: 15% 100%;
transform-origin: 15% 100%;
-webkit-transform:rotate(-45deg);
-ms-transform:rotate(-45deg);
transform:rotate(-45deg);
background:red;
}
body{background:url('http://lorempixel.com/output/people-q-c-640-480-8.jpg');background-size:cover;}