.about-mian{margin-top:25px;justify-content:space-between}
.about-bg{display:flex;height:224px;background:url(../tpimg/about_bg.jpg) no-repeat 50%;align-items:flex-end}
.about-nav{display:flex;width:100%;height:40px;background:rgba(0,0,0,.2);line-height:40px}
.about-nav li{width:110px;text-align:center}
.about-nav li.active,.about-nav li:hover{background:hsla(0,0%,100%,.2)}
.about-nav li a{color:#fff;font-size:16px}
.about-content{margin:20px 0 60px;color:#555;text-indent:2em;font-size:16px;line-height:35px}