CSS 实用技巧：制作三角形_html/css_WEB-ITnose

body{background:#faf7ef;}div{margin:20px auto}div.arrow-up {  width:0px;  height:0px;  border-left:50px solid transparent;    border-right:50px solid transparent;   border-bottom:50px solid #ff0000;   font-size:0px;  line-height:0px;} div.arrow-down {  width:0px;  height:0px;  border-left:50px solid transparent;  border-right:50px solid transparent;  border-top:50px solid #0000ff;  font-size:0px;  line-height:0px;} div.arrow-left {  width:0px;  height:0px;  border-bottom:50px solid transparent;    border-top:50px solid transparent;   border-right:50px solid #008000;   font-size:0px;  line-height:0px;} div.arrow-right {  width:0px;  height:0px;  border-bottom:50px solid transparent;   border-top:50px solid transparent;   border-left:50px solid #ffff00;   font-size:0px;  line-height:0px;}