.navf {
    width: 100%;
    max-width: 1200px;
}
.section-content {
    width: 100%;
    max-width: 1200px;
}
.mode04 {
    width: 100%;
    max-width: 1200px;
}
.footers {
    width: 100%;
    max-width: 1200px;
}
.mobile{width: 100%;position:relative;height: 40px;display: none;top:0;right: 0;z-index: 99;background-color: #274372}
.mobile-inner-header{width:100%;
    height: 40px;position: absolute;top: 0px;right: 0px;z-index: 2}
.mobile-inner-header-icon{
    color: #ffffff; height: 40px;font-size:25px;text-align: center;
    float:right;width: 40px;position: relative;
    -webkit-transition: background 0.5s;
    -moz-transition: background 0.5s;
    -o-transition: background 0.5s;
    transition: background 0.5s;
}
.mobile-inner-header-icon:hover{  cursor: pointer;}
.mobile-inner-header-icon span{
    position: absolute; left: calc((100% - 25px) / 2);
    top: calc((100% - 1px) / 3);  width: 25px;  height: 2px;  background-color: #fff;}
.mobile-inner-header-icon span:nth-child(1){transform: translateY(4px) rotate(0deg);}
.mobile-inner-header-icon span:nth-child(2){transform: translateY(-4px) rotate(0deg);}
.mobile-inner-header-icon-click span:nth-child(1){animation-duration: 0.5s; animation-fill-mode: both;animation-name: clickfirst;}
.mobile-inner-header-icon-click span:nth-child(2){animation-duration: 0.5s; animation-fill-mode: both;animation-name: clicksecond;}
.mobile-inner-header-icon{
    color: #fff; height: 40px;float:right;width: 50px;position: relative; cursor: pointer;margin-right: 5px;text-align: right;}
.mobile-inner-header-icon-click{margin-top: 5px;}
.mobile-inner-header-icon-out span{width: 22px;height: 2px;background-color:#fff;display: none;}
.mobile-inner-header-icon.iconfont{font-size: 30px;line-height: 40px;text-align: center;font-weight: bold;}
.mobile-inner-header-icon-out span:nth-child(1){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outfirst;
}
.mobile-inner-header-icon-out span:nth-child(2){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outsecond;
}
.mobile-inner-header-icon-out span:nth-child(2){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outthird;
}
.mobile-inner-header-icon span:nth-child(1){transform: translateY(4px) rotate(0deg);}
.mobile-inner-header-icon span:nth-child(2){transform: translateY(-4px) rotate(0deg);}
.mobile-inner-header-icon span:nth-child(3){transform: translateY(-4px) rotate(0deg);}
.mobile-inner-header-icon-click span:nth-child(1){animation-duration: 0.5s; animation-fill-mode: both;animation-name: clickfirst;}
.mobile-inner-header-icon-click span:nth-child(2){animation-duration: 0.5s; animation-fill-mode: both;animation-name: clicksecond;}
.mobile-inner-header-icon-click span:nth-child(3){animation-duration: 0.5s; animation-fill-mode: both;animation-name: clickthird;}
@keyframes clickfirst {
    0% {
        transform: translateY(4px) rotate(0deg);

    }

    100% {
        transform: translateY(0) rotate(45deg);
    }
}

@keyframes clicksecond {
    0% {
        transform: translateY(-4px) rotate(0deg);
    }

    100% {
        transform: translateY(0) rotate(-45deg);
    }
}

@keyframes clickthird {
    0% {
        opacity: 0
    }

    100% {
        opacity: 0
    }
}
.mobile-inner-header-icon-out span:nth-child(1){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outfirst;
}
.mobile-inner-header-icon-out span:nth-child(2){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outsecond;
}
.mobile-inner-header-icon-out span:nth-child(3){
    animation-duration: 0.5s;
    animation-fill-mode: both;
    animation-name: outthird;
}
@keyframes outfirst {
    0% {
        transform: translateY(0) rotate(-45deg);
    }

    100% {
        transform: translateY(-4px) rotate(0deg);
    }
}



@keyframes outsecond {
    0% {
        transform: translateY(0) rotate(45deg);
    }

    100% {
        transform: translateY(4px) rotate(0deg);
    }
}
@keyframes outthird {
    0% {
        transform: translateY(0) rotate(90deg);
    }

    100% {
        transform: translateY(12px) rotate(0deg);
    }
}

.mobile-inner-nav{  background: #1b508a;width: 100%; position: absolute;top: 40px;left: 0px;padding-top: 10px;padding-bottom: 25px;display: none;}
.mobile-inner-nav a{display: inline-block;line-height: 45px;
    text-decoration: none;  width: 100%;font-size: 14px;
    border-bottom: solid 1px #224a75;
    -webkit-transition: all 0.5s;   -moz-transition: all 0.5s;
    -o-transition: all 0.5s;    transition: all 0.5s;color:#fff; }
.mobile-inner-nav a:hover{color:#fff;}
.mobile-inner-nav li{position: relative;padding: 0 20px;}
.mobile-inner-nav li a{text-indent: 15px;letter-spacing: 1px}
.mobile-inner-nav li strong{position: absolute;right:20px;top:0;font-size: 25px;cursor: pointer;width: 40px;height: 45px;text-align: center;line-height: 40px;-webkit-transition: all 0.5s;   -moz-transition: all 0.5s;
    -o-transition: all 0.5s;    transition: all 0.5s; color: #fff;
    opacity: 0.8;
    font-weight: normal;}
.mobile-inner-nav a{-webkit-animation-duration: 0.5s;animation-duration: 0.5s;-webkit-animation-fill-mode: both;animation-fill-mode: both;-webkit-animation-name: returnToNormal;animation-name: returnToNormal;}
.mobile_search .search input {
    position: absolute;
    height: 34px;
    line-height: 34px;
    color: #262626;
    border: none;
    background: none;
    top: 0px;
    padding-left: 0px;
}
.mobile_search .search input.notxt {
    padding: 0 0 0 7px;
    font-size: 14px;
}

@-webkit-keyframes returnToNormal {
    from {
        opacity: 0;
        -webkit-transform: translate3d(0, 100%, 0);
        transform: translate3d(0, 100%, 0);
    }

    to {
        opacity: 1;
        -webkit-transform: none;
        transform: none;
    }
}

@keyframes returnToNormal {
    from {
        opacity: 0;
        -webkit-transform: translate3d(0, 100%, 0);
        transform: translate3d(0, 100%, 0);
    }

    to {
        opacity: 1;
        -webkit-transform: none;
        transform: none;
    }
}
.mobile_subNav{display: none;padding-left:10px;}
.mobile-inner-nav dd a{height: 35px;line-height: 35px;border-bottom: dotted 1px rgba(219,219,219,0.2);font-size: 13px;}
.mobile_search{clear: both;position: relative;height: 36px;margin:10px 20px 0;border-bottom:solid 1px #224a75;overflow: hidden;}
.mobile_search input.notxt{width: 90%;color:#fff;margin-left:45px;border:none;}
.mobile_search input.notxt1{width: 55px;background-color:#fff;right:auto;left:0;background:url("https://www.qalib.net/__xh__/mathedu.bnu.edu.cn/images/serBtn.png") no-repeat center center;border:none;}
.mobile-link{float: left;padding-left: 10px;}
.mobile-link a{color:#b8c1bc;margin:0 5px;height: 40px;line-height: 40px;    font-size: 15px;}
.mobile-link02{margin:0 20px;}
.mobile-inner-nav .mobile-link02 a {width: auto;float: left;margin:0 7px;}
.mobile-inner-nav a, .mobile_search {
    border-bottom-color: rgba(255,255,255,0.3);
}
@media screen and (max-width: 1350px){
    .banner-word {
        top: 175px;
    }
    .hbja {
        height: 185px;
    }
}
@media screen and (max-width: 1250px){
    .wp2 {
        width: 95%;
    }
    .logo {
        margin-left: 17px;
        width: 395px;
    }
    .banner-word {
        top: 160px;
    }
    .mode04 {
        width: 95%;
        max-width: 1200px;
    }
    .kstdc {
        width: 100%;
        max-width: 1115px;
    }
    li.kstdcsts {
        width: 245px;
    }
    .navs {
        margin-right: 10px;
    }
    .section-content {
        width: 95%;
        max-width: 1200px;
    }
    .section-c1 ul li {
        margin-left: 29px;
    }
    .imgewm {
        margin-left: 17px;
    }
    .section-c1 ul li .art-Date {
        background: url("https://www.qalib.net/__xh__/mathedu.bnu.edu.cn/images/time.png") no-repeat left 58.5% center;
    }
    .section-c1 ul li .art-Txt {
        margin-top: -60px;
    }
}
@media screen and (max-width: 1200px){
    .banner-word {
        top: 160px;
        height: 160px;
    }
    .banner-word .ban-p {
        height: 60px;
    }
    .section-c1 ul li {
        margin-left: 27px;
    }
    .section-c1 ul li .art-Date {
        background: url("https://www.qalib.net/__xh__/mathedu.bnu.edu.cn/images/time.png") no-repeat left 57% center;
    }
    .kstdcs {
        margin-left: 42px;
    }
    .section-c1 ul li .art-Txt {
        margin-top: -55px;
    }
    .section-c1 ul li .art-Img img {
        width: 100%;
        transition: all 0.3s ease;
        height: auto;
    }
    li.kstdcsts {
        width: 240px;
        margin-right: 35px;
    }
}
@media screen and (max-width: 1150px){
    .logo {
        margin-left: 16px;
        width: 380px;
    }
    .navs li a {
        padding: 17px 14px;
    }
    .navs li a:hover {
        padding: 17px 14px;
    }
    .navs {
        margin-right: 0;
    }
    .imgewm {
        display: block;
        float: left;
        width: 480px;
        margin-top: 45px;
        margin-left: 10px;
    }
    .ftzt {
        width: 390px;
        display: inline-block;
        margin-top: 41px;
    }
    .section-c1 ul li {
        margin-left: 26px;
    }
    .kstdcs {
        margin-left: 39px;
    }
    .section-c1 ul li .art-Txt {
        margin-top: -50px;
    }
    .section-c1 ul li .art-Img img {
        width: 100%;
        transition: all 0.3s ease;
        height: auto;
    }
    li.kstdcsts {
        width: 235px;
    }
    .section-c1 ul li .art-Date {
        background: url("https://www.qalib.net/__xh__/mathedu.bnu.edu.cn/images/time.png") no-repeat left 55.5% center;
    }
}
@media screen and (max-width: 1100px){
    li.kstdcsts {
        width: 226px;
        margin-right: 32px;
    }
    .m-section1 .section .txt {
        padding: 22px 0 22px 30px;
    }
    .logo {
        margin-left: 10px;
        margin-top: 20px;
        width: 350px;
    }
    .navs li a {
        padding: 17px 13px;
    }
    .navs li a:hover {
        padding: 17px 13px;
    }
    .banner-word {
        top: 140px;
        height: 150px;
    }
    .p3 {
        margin-top: 15px;
    }
    .section-c1 ul {
        overflow: hidden;
        height: 330px;
    }
    .section-c1 ul li {
        margin-left: 25px;
    }
    .section-c1 ul li .art-Date {
        background: url("https://www.qalib.net/__xh__/mathedu.bnu.edu.cn/images/time.png") no-repeat left 54% center;
    }
    .imgewm {
        float: left;
        width: 455px;
    }
    .ftzt {
        width: 370px;
        display: inline-block;
        margin-top: 41px;
    }
}
@media screen and (max-width: 1050px){
    .logo {
        margin-left: 5px;
        margin-top: 21px;
        width: 339px;
    }
    .navs li a {
        padding: 17px 11px;
    }
    .navs li a:hover {
        padding: 17px 11px;
    }
    .kstdcs {
        margin-left: 36px;
    }
    li.kstdcsts {
        width: 215px;
        margin-right: 25px;
    }
    .m-section1 .section .txt {
        padding: 22px 0 22px 25px;
    }
    .section-c1 ul li {
        margin-left: 24px;
    }
    .imgewm {
        float: left;
        margin-top: 48px;
        width: 430px;
    }
    .ftzt {
        width: 340px;
        display: inline-block;
        margin-top: 45px;
    }
    .navss {
        width: 170px;
    }
}
@media screen and (max-width: 1000px){
    nav{
        display: none;
    }
    .mobile {
        display: block;
    }
    .banner-word {
        display: none;
    }
    .hbja {
        display: none;
    }
    .top {
        display: block!important;
        padding: 0 15px;
        background: #1b508a;
    }
    .logo1 {
        width: 250px;
    }
    .logo1 {
        padding: 11px 0;
        float: none;
        margin: 0 auto;
    }
    .logo1 img {
        display: block;
        width: 100%;
    }
    .logo1 img {
        padding: 0;
    }
    .m-section1 .section p {
        display: none;
    }
}
@media screen and (max-width: 800px){
    .wp2 {
        width: 96%;
    }
    .mode04 {
        width: 96%;
        max-width: 1200px;
    }
    .kstdc {
        width: 98%;
        max-width: 1115px;
    }
    .kstdcs {
        margin-left: 14px;
    }
    .kstdc li {
        width: 23.5%;
    }
    li.kstdcsts {
        width: 170px;
        margin-right: 20px;
    }
    .m-section1 .section .txt {
        padding: 22px 0 22px 20px;
    }
    .section-content {
        width: 100%;
        max-width: 1200px;
    }
    .section-c1 ul {
        overflow: hidden;
        height: auto;
        margin-top: 0 !IMPORTANT;
    }
    .section-c1 ul li:first-child {
        width: 40%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 35px!IMPORTANT;
        margin-right: 35px;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 40%;
        display: inline-block;
        margin-left: 30px;
        height: 100%;
        position: relative;
        margin-top: 20px;
    }
    .section-c1 ul li:last-child {
        width: 40%;
        float: none;
    }
    .section-c1 ul li .art-Txt {
        margin-top: -65px;
    }
    .mb-span {
        margin-top: 0;
    }
    .section-c1 ul li .art-Date {
        background: none;
    }
    .imgewm2 {
        display: none;
    }
    .imgewm {
        float: none;
        width: 330px;
        margin: 0 auto;
        margin-top: 18px;
    }
    .footers {
        background:none;
    }
    .ftzt {
        width: 320px;
        display: block;
        margin: 0 auto;
        margin-top: 15px;
    }
}
@media screen and (max-width: 750px){
    .section-c1 ul li .art-Date {
        background: none;
    }
}
@media screen and (max-width: 600px){
    .m-section1 .section .txt {
        border-left: none;
        padding: 22px 0 22px 0;
    }
    li.kstdcsts {
        width: 200px;
        float: none;
        margin: 0 auto;
    }
    .m-section1 .section {
        overflow: hidden;
        padding: 20px 0 20px;
    }
    .wp2 {
        width: 95%;
    }
    .mode04 {
        width: 95%;
        max-width: 1200px;
        height: auto;
        padding-bottom: 30px;
    }
    .kstdc li {
        width: 40%;
        float: left;
        margin-left: 25px;
        margin-right: 20px;
    }
    .section-c1 ul li:first-child {
        width: 50%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 25%!IMPORTANT;
        margin-right: 25%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 50%;
    }
    .section-c1 ul li:last-child {
        width: 50%;
        float: none;
    }
}
@media screen and (max-width: 580px){
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 56%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 22%!IMPORTANT;
        margin-right: 22%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 56%;
    }
    .section-c1 ul li:last-child {
        width: 56%;
        float: none;
    }
}
@media screen and (max-width: 550px){
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 60%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 20%!IMPORTANT;
        margin-right: 20%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 60%;
    }
    .section-c1 ul li:last-child {
        width: 60%;
        float: none;
    }
    .kstdc li {
        width: 40%;
        float: left;
        margin-left: 20px;
        margin-right: 20px;
    }
}
@media screen and (max-width: 500px){
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 64%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 18%!IMPORTANT;
        margin-right: 18%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 64%;
    }
    .section-c1 ul li:last-child {
        width: 64%;
        float: none;
    }
}
@media screen and (max-width: 455px){
    .kstdc li {
        width: 42%;
        float: left;
        margin-left: 20px;
        margin-right: 0;
        height: 150px;
    }
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 68%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 16%!IMPORTANT;
        margin-right: 16%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 68%;
    }
    .section-c1 ul li:last-child {
        width: 68%;
        float: none;
    }
    .flex-control-nav {
        width: 100%;
        position: absolute;
        bottom: 7px;
        text-align: center;
    }
    .flex-control-paging li a {
        background: #fff;
        display: block;
        height: 10px;
        overflow: hidden;
        text-indent: -99em;
        width: 10px;
        cursor: pointer;
        border-radius: 50%;
    }
}
@media screen and (max-width: 414px){
    .imgewm {
        float: none;
        width: 305px;
        margin: 0 auto;
        margin-top: 20px;
    }
    .ftzt {
        width: 295px;
        display: block;
        margin: 0 auto;
        margin-top: 17px;
    }
    .fd-copy {
        background: #03162d;
        color: rgba(191, 190, 190, 0.9);
        height: 66px;
        line-height: 33px;
        font-size: 14px;
    }
}
@media screen and (max-width: 400px){
    li.kstdcsts {
        width: 185px;
        float: none;
        margin: 0 auto;
    }
    .kstdc li {
        width: 50%;
        float: left;
        margin-left: 70px;
        margin-right: 0;
        height: 155px;
    }
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 74%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 13%!IMPORTANT;
        margin-right: 13%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 74%;
    }
    .section-c1 ul li:last-child {
        width: 74%;
        float: none;
    }
}
@media screen and (max-width: 360px){
    .kstdc li {
        width: 57%;
        float: left;
        margin-left: 57px;
        margin-right: 0;
        height: 155px;
    }
    .section-c1 ul li .art-Date {
        background: none;
    }
    .section-c1 ul li:first-child {
        width: 88%;
        float: none!important;
    }
    .section-c1 ul li {
        margin-left: 6%!IMPORTANT;
        margin-right: 6%;
        padding-bottom: 50px;
    }
    .section-c1 ul li {
        width: 88%;
    }
    .section-c1 ul li:last-child {
        width: 88%;
        float: none;
    }
}