css 三角
css border实现三角形绘制(带阴影)
HTML
<h1>带阴影的三角</h1>
<div class="box"></div>
CSS
.box {
position: absolute;
display: inline-block;
top: 380px;
left: 300px;
width: 0;
height: 0px;
content: '';
border-style: solid;
border-width: 20px;
border-color: red green transparent transparent;
/* transform: rotate(135deg); */
box-shadow: 2px -2px 2px #000;
}