<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
#box {
width: 0px;
height: 0px;
border: 100px solid transparent;
border-top-color: deeppink;
border-left-color: deeppink;
/*border-right-color: deeppink;*/
/*border-bottom-color: deeppink;*/
}
</style>
</head>
<body>
<div id="box"></div>
</body>
<script type="text/javascript">
window.onload = function () {
var box = document.getElementById('box');
}
</script>
</html>
运行结果