.nav_container {
    position: fixed;
    width: 100%;
    height: 160px;
    top: 0;
    z-index: 999;
}

.nav_container::after {
    display: block;
    content: "";
    visibility: hidden;
    clear: both;
}

.main_bgcolor {
    background-color: #ff6600;
}

.main_bgcolor::after {
    display: block;
    content: "";
    visibility: hidden;
    clear: both;
}

.logo_wrapper {
    height: 100%;
    padding: 40px 0;
    float: left;
    margin-left: 20px;
    max-width: 25%;
    display: flex;
    flex-direction: row;
}

.logo {
    margin-right: 4px;
}

.nav_wrapper {
    height: 100%;
    padding: 32px 0;
    float: right;
    margin-right: 60px;
    max-width: 73%;
}

.U_logo{
    max-width: 98%;}

img[src*="school_logo"] {
    max-width: 98%;}

.nav_func {
    position: relative;
}

.nav_func::after {
    display: block;
    content: "";
    visibility: hidden;
    clear: both;
}

.nav_func a {
    display: block;
    float: right;
    padding: 0 8px;
    color: rgb(250, 250, 250);
    height: 48px;
    line-height: 48px;
    transition: all 300ms ease;
    cursor: pointer;
}

.nav_func a:hover {
    opacity: .6;
}

.nav_func .english {
    padding-right: 24px;
}

.search_t {
    position: relative;
}

.search {
    display: block;
    float: right;
    padding: 0 24px;
    width: 120px;
    height: 48px;
    font-size: 1.6rem;
    background-color: rgb(250, 250, 250);
    border: 0;
    outline: 0;
    border-radius: 24px;
    transition: all 300ms ease;
    opacity: .6;
    cursor: pointer;
}

.search:focus {
    width: 320px;
    opacity: 1;
}

.search_icon {
    width: 20px;
    height: 20px;
    border-radius: 10px;
    border: 2px solid #ff6600;
    position: absolute;
    top: 12px;
    right: 16px;
}

.search_icon::before {
    display: block;
    content: "";
    width: 8px;
    height: 2px;
    position: absolute;
    top: 18px;
    left: 12px;
    transform: rotateZ(45deg);
    background-color: #ff6600;
}

.submit {
    background: url(https://webvpn.zqu.edu.cn/https/34263054423230556a6d256d76542e4be78a1be6c0250f315746a422383fb5/https/77726476706e69737468656265737421eaff40923625661e700a9cb8d65027208618d0/system/_owners/rwys2024/_webprj/images/icon1_03.png) no-repeat 0 0;
    width: 18px;
    height: 18px;
    border: none;
    outline: none;
    position: absolute;
    right: 16px;
    top: 17px;
}

nav {
    position: relative;
}

nav > ul {
    list-style: none;
    display: flex;
}

nav > ul > li {
    float: left;
    position: relative;
    list-style: none;
}

nav::after {
    display: block;
    content: "";
    visibility: hidden;
    clear: both;
}

nav li > a {
    display: block;
    padding: 16px;
    color: rgb(250, 250, 250);
    padding-top: 32px;
    transition: all 300ms ease;
    font-weight: 500;
    cursor: pointer;
}

nav li:hover > a {
    color: #ff6600
}

.navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%2833, 37, 41, 0.75%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
    width: 50%;
    padding: 0;
}

.sec_nav {
    position: absolute;
    top: 70px;
    left: 0;
    width: 240px;
    padding: 24px 0;
    background-color: #ff6600;
    visibility: hidden;
    opacity: 0;
    transition: all 300ms ease;
    border-radius: 0 0 16px 16px;
    list-style: none;
}

.sec_nav li a {
    display: block;
    padding: 8px 24px;
}

.sec_nav li:hover a {
    color: #431b00;
}

nav li:hover .sec_nav {
    visibility: visible;
    opacity: 1;
}

.navbtn_bg {
    width: 86px;
    height: 32px;
    border-radius: 16px;
    background-color: white;
    position: absolute;
    top: 26px;
    left: 10px;
    z-index: -1;
    transition: all 300ms ease 0s;
}


.now {
    color: #ff6600;
}

nav:hover li .now {
    color: rgb(250, 250, 250);
}

nav li:hover .now {
    color: #ff6600;
}

:root {
    --menu-2: 64px; /* 2个字的菜单 */
    --menu-3: calc(var(--menu-2) + 16px); /* 3个字的菜单：80 */
    --menu-4: calc(var(--menu-2) + 16 * 2px); /* 4个字的菜单：96 */
    --menu-5: calc(var(--menu-2) + 16 * 3px); /* 5个字的菜单：112 */
    --ul-left-padding: 20px;
}

/* ul有左内边距20 */


/* 折叠样式 */
.nav-toggle {
    display: none;
    position: absolute;
    top: 12rem;
    left: 180px;
    cursor: pointer;
    font-size: 24px;
    background: white;
    color: #fff;
    border: none;
    border-radius: 4px;
    padding: 5px 10px;
}

/* 响应式样式 */
@media (max-width: 768px) {
    .nav_func {
        display: none;
    }

    .nav-toggle {
        display: block;
        position: absolute;
        z-index: 999;
        width: 4rem;
        padding: 0;
    }

    .nav_wrapper {
        padding: 0;
        clear: both;
        float: left;
    }

    nav > ul {
        display: none; /* 默认隐藏所有列表项 */
        width: 100vw;
    }

    nav > ul.open {
        display: block;
        margin: 0;
        padding: 0;
    }

    nav > ul.open > li {
        display: block; /* 当类名为.open时显示列表项 */
        background-color: var(--title-color);
        color: white;
        text-align: center;
        clear: both;
        width: 100vw;
    }

    nav li > a {
        padding: 0;
    }

    nav li > a:hover {
        color: black;
        background-color: white;
    }

    .now {
        color: white;
    }

    .sec_nav {
        display: none;
        position: relative;
        top: 0;
        left: 0;
        width: 100%;
        padding: 0;
    }

    .sec_nav li a {
        padding: 0;
        margin: 0;
    }

    .sec_nav li {
        background-color: #3366FF;
    }
}

@media screen and (max-width: 1024px) {
    .nav_container {
        position: fixed;
        width: 1024px;
        height: 160px;
        top: 0;
        z-index: 999;
    }
}

@media screen and (max-width: 1366px) {
    .nav_container {
        position: fixed;
        width: 1366px;
        height: 160px;
        top: 0;
        z-index: 999;
    }
}