background-color:transparent;就是把背景色设置为透明。
实际上background默认的颜色就是透明的属性。所以写和不写都是一样的
span{
width: 0;
height: 0;
display: inline-block;
}
border-top: 60px solid #ff4d52;
border-right: 30px solid transparent ;
border-left: 60px solid #ff4d52;
border-bottom: 30px transparent solid;
border-right: 30px solid transparent;
border-left: 30px solid transparent;
border-bottom: 60px solid #ff4d52;
border-top: 30px solid transparent;
border-bottom: 30px solid transparent;
border-left: 60px solid #ff4d52;
border-right: 30px solid transparent;
border-left: 30px solid transparent;
border-top: 60px solid #ff4d52;
border-top: 30px solid transparent;
border-bottom: 30px solid transparent;
border-right: 60px solid #ff4d52;