SOURCE

console 命令行工具 X clear

                    
>
console
<div></div>
div {
  width:20em;
  height:20em;
  background-color:#fff;
  background-image:linear-gradient(rgba(200, 0, 0, .5) 50%, transparent 50%), linear-gradient(90deg, transparent 50%, rgba(200, 0, 0, .5) 50%);
  background-size:30px 30px;
}