<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style>
.caret0{
width:0;
height:0;
border: 5px solid #000;
}
.caret1{
width:0;
height:0;
border-top: 5px solid #000;
border-left: 5px solid #fff;
border-right: 5px solid #fff;
border-bottom: 5px solid #000;
}
.caret2{
width:0;
height:0;
border-top: 5px solid #fff;
border-left: 5px solid #f00;
border-right: 5px solid #f00;
border-bottom: 5px solid #fff;
}
.caret2{
width:0;
height:0;
border-top: 5px solid #fff;
border-left: 5px solid #f00;
border-right: 5px solid #f00;
border-bottom: 5px solid #fff;
}
.caret3{
width:0px;
height: 0px;
border-bottom: 5px solid #000;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
}
.caret4{
width:0px;
height: 0px;
border-right: 5px solid #000;
border-top: 5px solid transparent;
border-bottom: 5px solid transparent;
}
.caret5{
width:0px;
height: 0px;
border-top: 5px solid #000;
border-left: 5px solid transparent;
border-right: 5px solid transparent;
}
.caret6{
width:0px;
height: 0px;
border-left: 5px solid #000;
border-top: 5px solid transparent;
border-bottom: 5px solid transparent;
}
</style>
</head>
<body>
<h1>通过border的设置的三角形</h1>
<div class="caret0"></div>
<div class="caret1"></div>
<br>
<div class="caret0"></div>
<br>
<div class="caret1"></div>
<br>
<div class="caret2"></div>
<br>
向上的三角形
<div class="caret3"></div>
<br>
向左的三角形
<div class="caret4"></div>
<br>
向下的三角形
<div class="caret5"></div>
<br>
向右的三角形
<div class="caret6"></div>
</body>
</html>