console 命令行工具 X clear
console
<!DOCTYPE html>
<html>

<head>
	<meta charset="UTF-8">
	<title>炫酷的 transform:translate3D Demo</title>
	<style>
		.triangle {
			width: 0px;
			height: 0px;
			border: 40px solid;
			border-color: transparent transparent #d9534f transparent;
            position: relative;
		}

		.triangle:after {
			content: '';
			border: 30px solid;
			border-color: transparent transparent #fff;;
			position: absolute;
			top: -24px;
			left: -30px;
		}
	</style>
</head>

<body>
	<div class="triangle" id="triangle"></div>
</body>

</html>