.bg{width:375px;margin:20px auto}.myTip{font-size:13px;color:#555;margin:5px 15px;text-align:left}#app{font-family:Avenir,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;text-align:center;color:#2c3e50}