/*nav*/
.nav{ position: absolute; right:18%; z-index:11;}

.sy1_ul{ }
.sy1_li a{ padding:20px 30px; display:block; font-size:18px; color:#FFF;font-weight:600; }
.sy1_ul li{ float:left;    margin: 20px 0; }
.sy2_ul{ position:absolute; left:-22%; z-index:1112; display:none; background:rgba(0, 0, 0, 0.9); width:145%; padding:5%; }

.sy2_li_1{ display:inline-block; width:100%; }
.sy2_li_1 dt{ font-size:16px; color:#fff; font-weight:bold; padding:20px 0; }
.sy2_li_1 dd{ width:33%; float:left; }
.sy2_li_1 dd a{ display:block; font-size:14px; padding:10px; margin:5px 0; border-left:1px solid #ff3300; }
.sy2_li_1 dd a:hover{ background:#333; }

.sy2_li_1 .service_btn dd a{ padding-left:50px; border:none; background:url("../images/menu_service_icon.png")  no-repeat; }
.sy2_li_1 .service_btn dd a.icon1{ background-position:0 0; }
.sy2_li_1 .service_btn dd a.icon2{ background-position:0 -40px; }
.sy2_li_1 .service_btn dd a.icon3{ background-position:0 -80px; }
.sy2_li_1 .service_btn dd a.icon4{ background-position:0 -120px; }
.sy2_li_1 .service_btn dd a.icon5{ background-position:0 -160px; }
.sy2_li_1 .service_btn dd a.icon6{ background-position:0 -200px; }
.sy2_li_1 .service_btn dd a:hover{ background-color:#333; }

.sy2_li_1 .project_btn dd a{ border:none; background-color:#eee; padding:20px 0 20px 30px; color:#000; font-size:16px; margin:5px; }
.sy2_li_1 .project_btn dd a img{ height:30px; margin-right:30px; }
.sy2_li_1 .project_btn dd a:hover{ background-color:#009ad6; }

.sy2_li_2{ width:25%; float:left; }
.sy2_li_2 a{ display:block; margin:10px; overflow:hidden; text-align:center; border:1px solid #222; border-bottom:1px solid #ff3300; }
.sy2_li_2 a.bg1{ background:url("../images/case_icon_1.png")  center 30px  no-repeat; }
.sy2_li_2 a.bg2{ background:url("../images/case_icon_2.png") center 30px  no-repeat; }
.sy2_li_2 a.bg3{ background:url("../images/case_icon_1.png")  center 30px  no-repeat; }
.sy2_li_2 a.bg4{ background:url("../images/case_icon_2.png") center 30px  no-repeat; }
.sy2_li_2 a h3{ padding:130px 0 20px 0; font-size:16px; letter-spacing:12px; font-weight:100; }
.sy2_li_2 a p{ font-size:12px; }
.sy2_li_2 a:hover{ background-color:#ff3300; border-color:#ff3300; }

.sy2_li_3, .sy2_li_3_2{ float:left; }
.sy2_li_3{ width:20%; }
.sy2_li_3 a{ font-size:14px; padding:7px 0; margin:3% 10% 3% 0; background-color:#333; text-align:center; }
.sy2_li_3 a:hover{ background-color:orange; color:#000; }
.sy2_li_3_2{ width:80%; }
.sy2_li_3_2 h3 a{ font-size:22px; line-height:150%; margin:5px 0 20px 20px; padding:0; font-weight:500; }
.sy2_li_3_2 h3::after{ 
	display:block;
	width:50px;
	margin:0 0 20px 20px;
	border-bottom: 2px solid #666;
	content: '';
}
.sy2_li_3_2 p{ color:#ddd; margin:5px 0 10px 20px; font-style:italic; }
.sy2_li_3_2 a.enter{ display:block; width:100px; padding:10px 0; text-align:center; font-size:26px; margin:25px 0 20px 20px; background-color:#333; color:#fff; border-left:1px solid #ff3300; }
.sy2_li_3_2 a:hover.enter{ background-color:#ff3300; }
.sy2_li_3_2 div{ color:orange; font-size:14px; font-weight:bold; margin:5px 0 10px 20px; float:right; text-align:center; }
.sy2_li_3_2 div span{ font-size:100px; line-height:120%; display:block; }

.sy2_li_4{ clear:both; width:100%; }
.sy2_li_4 ul{ padding:30px 0; overflow:hidden; }
.sy2_li_4 ul li{ width:33%; text-align:center; color:#fff; }
.sy2_li_4 ul li h4{ font-size:14px; font-weight:100; padding:20px 0; }
.sy2_li_4 ul li p{ font-size:16px; font-weight:500; line-height:150%; color:orange; }
.sy2_li_4 a{ display:block; width:18%; padding:10px 0; margin:0 1%; text-align:center; float:left; background:#333; font-size:14px; }
.sy2_li_4 a:hover{ background-color:orange; color:#000; }

.sy1_li{
    position: relative;
    overflow: hidden;
}
.sy1_li:before,.sy1_li:after{
    position:absolute;
    display: block;
    content: '';
    width: 0;
    height: 4px; /*下划线高度*/
    background:#f8b931;
    position: absolute;
    bottom: 0;
    left: 50%;
    transition: all .5s ; /*css动画效果，0.8秒完成*/
}
.sy1_li_bg:before{/*动画效果是从中间向左延伸至50%的宽度*/
    left:0%; 
    width:50%;
}
.sy1_li_bg:after{/*动画效果是从中间向右延伸至50%的宽度*
    left: 50%; /*这句多余，主要是为了对照*/
    width: 50%;
}