.header {
     position: fixed;
     top: 0;
     left: 0;
     height: 75px;
     width: 100%;
     z-index: 999;
     background-color: #fff;
     /* margin-bottom: 75px; */
 }

 .header .nav {
     width: 1200px;
     height: 100%;
     margin: 0 auto;
     justify-content: space-between;
     align-items: center;
 }

 /* 导航左侧样式 */
 .header .nav .nav-left {
     display: flex;
     align-items: center;
     height: 100%;
 }

 .header .nav .nav-left .logo {
     margin-right: 15px;
 }

 .header .nav .nav-left .logo img {
     vertical-align: middle;
 }

 .nav-left-href {
     display: flex;
     align-items: center;
     line-height: 40px;
     height: 100%;
 }

 .nav-left-href a {
     margin-left: 30px;
     font-weight: 500;
     font-size: 20px;
     color: #111;
 }

 .nav-left-href a:hover {
     color: #2978FF;
 }

 .nav-left-href .nav-left-active {
     color: #2978FF;
     border-bottom: 3px solid #2978FF;

 }

 .nav_industry {
     position: relative;
     display: flex;
     align-items: center;
     height: 100%;
 }

 .nav_industry:hover .nav_industry_tab {
     display: block;
 }

 .nav_industry_tab {
     display: none;
     position: absolute;
     top: 75px;
     left: 50%;
     transform: translateX(-50%);
     width: 150px;
     background-color: #fff;
     z-index: 99;
     border-radius: 0 0 2px 2px;
     box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1),
         /* 底部主阴影 */
         0 6px 20px rgba(0, 0, 0, 0.08),
         /* 外围弥散阴影 */
         inset 0 1px 0 rgba(255, 255, 255, 0.2);
     transition: all .3s ease;
 }

 .nav_industry_tab .tab_item {
     font-size: 16px;
     color: #333;
     margin-left: 0;
     text-align: center;
 }

 .nav_industry_tab .tab_item a {
     font-size: 16px;
     color: #333;
     margin-left: 0;
     font-weight: 400;
 }

 .nav_industry_tab .tab_item a:hover {
     color: #2978FF;
 }

 /* 导航右侧样式 */
 .header .nav .nav-actions {
     display: flex;
     align-items: center;
 }

 .header .nav .nav-actions .phone {
     font-weight: 600;
     font-size: 20px;
     color: #2978FF;
     margin-right: 20px;
 }

 .header .nav .nav-actions .phone .tel_phone {
     display: inline-block;
     width: 20px;
     height: 20px;
     background: url("../images/phone.png") no-repeat;
     vertical-align: middle;
     margin-right: 8px;
 }

 .header .nav .nav-actions .btn a {
     display: inline-block;
     padding: 8px 20px;
     background-color: #1890ff;
     color: #fff;
     border-radius: 20px;
     text-decoration: none;
     font-size: 16px;
     transition: all 0.3s;
 }

 .header .nav .nav-actions .btn a:hover {
     background-color: #40a9ff;
 }