箭头 < >
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
.box{
position: relative;
}
.box:before{
content: '';
position: absolute;
height: 20px;
width: 20px;
border-width: 0 2px 2px 0;
border-style: solid;
color: orange;
transform: rotate(-45deg);
}
</style>
</head>
<body>
<div class="box"></div>
</body>
</html>
三角形
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
.box{
width: 0px;
position: relative;
border: 10px solid orange;
border-bottom-color: transparent;
border-top-color: transparent;
border-right: transparent;
}
</style>
</head>
<body>
<div class="box"></div>
</body>
</html>