CSS3---绘制六边形

#hexagon {
width: 100px;
height: 55px;
background: red;
position: relative;
}
#hexagon:before {
content: "";
position: absolute;
top: -25px;
left: 0;
width: 0;
height: 0;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-bottom: 25px solid red;
}
#hexagon:after {
content: "";
position: absolute;
bottom: -25px;
left: 0;
width: 0;
height: 0;
border-left: 50px solid transparent;
border-right: 50px solid transparent;
border-top: 25px solid red;
}