.head {
    width: 100%;
    transition: all 0.7s ease-out 0s;
    z-index: 1000;

    position: fixed;
}

.ching {
    width: 100%;
    height: 30px;
    border-bottom: 0px solid white;

}

.chinglish {
    height: 30px;
    line-height: 30px;
    float: right;
    text-align: center;
   margin-right:15px;
}

.chinglish a {
    text-align: center;
    float: left;
    display: block;
    width: 60px;
    line-height: 30px;
    color: white;
    text-decoration: none;
}

.chinglish>img {
    float: left;
    width: 30px;
    height: 30px;
}

.code {
    display: none;
    position: relative;
    right: 8px;
    width: 80px;
    height: 80px;
    z-index: 1000;
}

.code img {
    width: 80px;
    height: 80px;
}

.navbar-brand img {
    height: 80px;
    /* Adjust the height as needed */
}

@media (max-width: 420px) {
    .navbar-brand .xueyuanlogo {
        width: 280px;
    }
}

.search-bar {
    flex-grow: 1;
    max-width: 300px;
    /* Limit the width of the search bar */
    margin-left: auto;
    /* Push search bar to the right */
    padding-right: 10px;
}

.dropdown-menu {
    background-color: #f8f9fa;
    z-index: 2000;
    /* Light background for dropdown */
}

.dropdown-item:hover {
    background-color: #e2e6ea;

    /* Highlight color for dropdown items */
}

.nav-item {
    padding: 0px 25px;
    font-size: 18px;
    font-weight: 600;
}

.navbarb {
    border-bottom: solid 3px rgba(0, 0, 0, .1);
    /* Add a subtle shadow to the navbar */
}

.navbar-nav {
    justify-content: center;
    /* Center align nav items */
}



.navbar-custom .navbar-nav .nav-link {
    color: rgba(255, 255, 255, 0.9);
    /* Lighten text color for contrast */
}

.navbar-custom .navbar-nav .nav-link:hover,
.navbar-custom .navbar-nav .nav-link:focus,
.navbar-custom .navbar-nav .nav-link.active {
    color: #ffffff;
    /* White text color for active/hover state */
}

.navbar-custom .navbar-toggler {
    color: #ffffff;
    /* White color for toggler */
    border-color: transparent;
    /* Remove border */
}

.navbar-toggler-icon {
    background-image: none;
    /* Remove default style */
    display: inline-block;
    width: 30px;
    height: 2px;
    position: relative;
    transition: all .2s;
    background-color: #ffffff;
    /* White color for bars */
}

.navbar-toggler[aria-expanded="true"] .navbar-toggler-icon {
    background-color: transparent;
}

.navbar-toggler[aria-expanded="true"] .navbar-toggler-icon:before,
.navbar-toggler[aria-expanded="true"] .navbar-toggler-icon:after {
    top: 0;
    transform: rotate(45deg);
}

.navbar-toggler[aria-expanded="true"] .navbar-toggler-icon:after {
    transform: rotate(-45deg);
}

.navbar-toggler-icon:before,
.navbar-toggler-icon:after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: #ffffff;
    /* White color for bars */
    transition: all .2s;
}

.navbar-toggler-icon:before {
    top: -8px;
}

.navbar-toggler-icon:after {
    top: 8px;
}

@media (max-width: 1350px) {

    /* 假设768px为响应式断点 */
    .nav-item {
        padding: 0px 10px;
    }
}



@media (min-width: 768px) {

    /* 假设768px为响应式断点 */
    .navbar-nav .dropdown:hover .dropdown-menu {
        display: block;
    }

    .navbar-collapse {

        /* Dark background for mobile navbar */
        padding: 10px;
        /* Padding for mobile navbar */
    }

    .search-bar {
        margin-top: 10px;
        /* Margin for search bar in mobile navbar */
    }

    .navbar-toggler {
        margin-top: 10px;
        color: #ffffff;
        /* White color for toggler */
    }
}