css 手写返回箭头
因为在开发App时，为了自定义返回栏，返回箭头，一般都用图片，当图片不方便，最好用css样式实现。
逻辑：
画出一个正方形，让它旋转45度，只显示你需要的两个边即可
代码
<!DOCTYPE html>
<html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><meta name="viewport"content="width=device-width,minimum-scale=1.0,maximum-scale=1.0,user-scalable=no,initial-scale=1"><meta name="format-detection" content="telephone=no"><meta name="apple-mobile-web-app-status-bar-style" content="white"><meta name="apple-mobile-web-app-capable" content="no"><title>Css arrow</title>
</head>
<style type="text/css">#triangle-facing-right {display: inline-block;margin: 72px;border-right: 24px solid;border-bottom: 24px solid;width: 120px;height: 120px;transform: rotate(-45deg);}#triangle-facing-left {display: inline-block;margin: 72px;border-left: 24px solid;border-bottom: 24px solid;width: 120px;height: 120px;transform: rotate(45deg);}
</style><body><div id="triangle-facing-right"></div><div id="triangle-facing-left"></div>
</body></html>