header {
    width: 100%;
    height: 90px; /* 固定高度90px */
    position: fixed;
    top: 0;
    left: 0;
    text-align: center;
    background-color: white;
    /* 平滑过渡效果 */
    transition: all 0.1s ease;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    justify-content: space-between;
    align-items: center;
    padding: 0;
}

/* 导航栏样式 */
.navbar {
    height: 90px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 0;
    position: relative;
    z-index: 1000;
    filter: none;
}

.logo-container {
    display: flex;
    align-items: center;
    margin-left: 0;
}

.logo {
    width: 255px;
    height: 75px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 1.4rem;
}

.nav-menu {
    display: none;
    color: white;
}

.slide-nav-menu {
    display: none;
    color: white;
    background: #262626;
    border-bottom: 1px solid #313131;
}

.nav-items {
    display: flex;
    height: 100%;
    align-items: center;
}

.nav-item {
    height: 100%;
    padding: 0 25px;
    display: flex;
    align-items: center;
    position: relative;
    font-family: "Open Sans" !important;
    font-weight: 400;
    color: #333;
    cursor: pointer;
    transition: all 0.1s ease;
    text-decoration: none;
}

.navbar.scrolled {
    background-color: rgba(45, 45, 45, 0.8);
    z-index: 1000;
}

.navbar .logo img {
    width: 188px;
    transition: filter 0.3s; /* 颜色过渡效果 */
}

.navbar.scrolled .logo img {
    filter: brightness(0) invert(1);
}

.navbar.scrolled .nav-item {
    color: white;
}

.nav-item:hover {
    text-decoration: underline;
    text-decoration-thickness: 2px;
    text-underline-offset: 6px;
}

.nav-icons {
    display: flex;
    margin-left: 20px;
    padding-right: 10px;
}

.nav-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 10px;
    cursor: pointer;
    color: #3498db;
    fill: #3498db;
    transition: filter 0.3s;
}

.nav-icon:hover img {
    fill: #3498db;
    filter: grayscale(80%) brightness(50%) sepia(100%) hue-rotate(180deg) saturate(700%);
}

.navbar.scrolled .nav-icon img {
    filter: brightness(0) invert(1);
}

.navbar.scrolled .nav-icon:hover img {
    filter: hue-rotate(160deg) saturate(80%) brightness(50%);
}

.nav-icon:hover {
    color: white;
}

.dropdown {
    position: absolute;
    top: 90px;
    left: 0;
    width: 600px;
    background: white;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    padding: 30px 40px;
    display: none;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.1s ease;
    border-radius: 0 0 12px 12px;
    z-index: 999;
}

.nav-item:hover .dropdown {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.dropdown-content {
    display: flex;
    justify-content: space-between;
    gap: 30px;
}

.dropdown-column {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.dropdown-title {
    font-size: 1rem;
    color: black;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #f0f0f0;
    font-weight: 700;
}

.dropdown-title:hover {
    font-size: 1rem;
    color: #3498db;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #f0f0f0;
    font-weight: 700;
}

.dropdown2 {
    position: absolute;
    top: 90px;
    left: 0;
    width: 180px;
    background: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    display: none;
    opacity: 0;
    transform: translateY(-10px);
    transition: all 0.1s ease;
    border-radius: 0 0 10px 10px;
    z-index: 999;
}

.nav-item:hover .dropdown2 {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.dropdown2-content {

}

.dropdown2-column {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.dropdown2-list {
    list-style: none;
    padding: 10px 0;
}

.dropdown2-list li {
    padding: 10px 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
    text-align: left;
}

.dropdown2-list li:hover {
    padding-left: 10px;
    background: #0C75C1;
}

.dropdown2-list li a {
    text-decoration: none;
    color: #333;
    transition: all 0.3s ease;
    flex-grow: 1;
}

.dropdown2-list li:hover a {
    color: white;
    text-align: left;
}

.popup-panel {
    position: absolute;
    top: calc(100%);
    left: 0;
    width: 600px;
    background-color: white;
    border-radius: 0 0 8px 8px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    padding: 10px;
    visibility: hidden;
    opacity: 0;
    transform: translate(-40%, 0);
    transition: opacity 0.1s ease, visibility 0.1s ease;
    z-index: 1000;
}

.nav-item:hover .popup-panel {
    visibility: visible;
    opacity: 1;
}

.tab-header {
    display: flex;
    padding-top: 6px;
}

.tab-item {
    flex: 1;
    text-align: center;
    padding: 2px 0;
    cursor: pointer;
    transition: all 0.1s ease;
    font-size: 1.2rem;
    color: #666666;
    border-bottom: 3px solid transparent;
}

/* 标题悬停/激活状态 */
.tab-item:hover {
    color: #3498db;
}

.tab-item.active {
    color: #3498db;
    font-weight: bold;
    /*border-bottom-color: #3498db; !* 激活时底部边框颜色 *!*/
}

.nav-a {
    color: #666666;
    font-weight: normal;
    font-size: 1.1rem;
}

.nav-a:hover {
    color: #3498db;
    font-weight: bold;
    text-decoration: none;
    border-bottom-color: #3498db; /* 激活时底部边框颜色 */
    text-decoration-thickness: 2px; /* 控制下划线粗细 */
}

.nav-a.active {
    color: #3498db;
    font-weight: bold;
    text-decoration: underline;
    border-bottom-color: #3498db; /* 激活时底部边框颜色 */
    text-decoration-thickness: 2px; /* 控制下划线粗细 */
}


/* 底部内容区域 */
.tab-content {
    padding: 10px 0;
    min-height: 160px; /* 最小高度 */
}

.content-item {
    display: none; /* 默认隐藏所有内容 */
    animation: fadeIn 0.1s ease; /* 淡入动画（可选） */
}

.content-item.active {
    display: block; /* 激活时显示 */
}


.nav-item-container {
    display: flex;
    justify-content: center; /* 整体水平居中 */
    flex-wrap: wrap; /* 允许换行 */
    gap: 20px; /* 图片之间的间距 */
    padding: 2px;
}

.nav-item-container-item {
    flex: 1 1 240px;
    display: flex;
    flex-direction: column;
    justify-items: left;
    text-align: left;
    background: #EEEEEE;
}

.nav-item-title {
    color: black;
    font-weight: bold;
    font-size: 16px;
    padding: 20px 0;
    text-decoration: none;
}

.nav-item-title:hover {
    color: #014d87;
    text-decoration: none;
    /*text-decoration: underline;*/
    /*border-bottom-color: #014d87; !* 激活时底部边框颜色 *!*/
    /*text-decoration-thickness: 2px; !* 控制下划线粗细 *!*/
}

.nav-left-right-container {
    display: grid;
    grid-template-columns: 1fr 1fr; /* 两列等分 */
    gap: 2px;
    justify-items: center;
    text-align: left;
    background: #EEEEEE;
}

.nav-container-left-list {
    padding: 10px 10px;
    line-height: 2em;
}

.nav-container-left-list span {

}

.nav-container-left-list a {
    color: #666666;
    font-weight: 400;
    text-decoration: none;
}

.nav-container-left-list a:hover {
    color: #014d87;
    font-weight: 600;
    text-decoration: none;
    border-bottom-color: #014d87; /* 激活时底部边框颜色 */
    text-decoration-thickness: 2px; /* 控制下划线粗细 */
}

.nav-container-right {
    display: flex;
    justify-content: center; /* 水平居中 */
    align-items: flex-end; /* 垂直居底 */
    padding: 0 10px 10px 0;
}

.nav-container-right-image img {
    max-width: 100%; /* 防止图片溢出 */
    bottom: 0;
    height: auto;
    object-fit: cover;
}

/* 弹窗基础样式 */
.modal {
    display: none;
    position: absolute; /* 相对于导航栏定位 */
    top: 100%; /* 位于触发按钮下方 */
    width: 240px;
    right: 0;
    background: white;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    min-width: 120px;
}

.modal-content {
    padding: 12px 0;
}

/* 语言选项样式 */
.lang-option {
    padding: 8px 16px;
    cursor: pointer;
}

.lang-option:hover {
    background: #f5f5f5;
}


.side-menu {
    display: none;
}

.overlay {
    display: none;
}


/* 淡入动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}


/* 响应式设计 */
@media (max-width: 768px) {
    .modal-content {
        top: auto;
        bottom: 0;
        width: 100%;
        border-radius: 16px 16px 0 0;
    }

    .nav-items {
        display: none;
    }

    .nav-menu {
        width: 40px;
        height: 40px;
        display: block;
        align-content: center;
        background: #00A0E3;
    }

    .slide-nav-menu {
        width: 100%;
        height: 50px;
        padding-left: 20px;
        display: block;
        align-content: center;
    }

    .dropdown-content {
        flex-direction: column;
    }

    .nav-item {
        padding: 0 15px;
    }

    .logo-container {
        margin-left: 20px;
    }

    .logo {
        justify-content: left;
    }


    /* 菜单容器（初始隐藏） */
    .side-menu {
        display: block;
        position: fixed;
        top: 0;
        left: -80%;
        width: 80%;
        height: 100%;
        background: #333;
        transition: left 0.3s ease;
        text-align: left;
        z-index: 1000;
        color: white;
        font-size: 20px;

    }

    /* 菜单激活状态 */
    .side-menu.active {
        left: 0;
    }

    /* 遮罩层 */
    .overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
    }

    .side-menu.active .overlay {
        display: block;
    }

    /* 菜单内容区 */
    .menu-container {
        flex-grow: 1;
        background: #262626;
    }

    /* 主菜单项 */
    .menu-section {
        color: #707070;
    }

    .menu-title {
        display: flex;
        height: 50px;
        padding: 0 1em;
        font-weight: 400;
        justify-content: space-between;
        align-items: center;
        text-align: left;
        cursor: pointer;
        font-size: 16px;
        color: #444;
        border-bottom: 1px solid #313131;
    }

    .menu-title:hover {
        color: white;
    }

    .menu-title.active {
        color: white;
    }

    .menu-title .arrow {
        transition: transform 0.3s;
        color: #777;
    }

    .menu-title.active .arrow {
        transform: rotate(180deg);
        color: white;
    }

    .menu-title.active span {
        transform: rotate(180deg);
        color: white;
    }

    /* 子菜单项 */
    .submenu {
        max-height: 0;
        overflow: hidden;
        display: none;
        font-size: 16px;
    }

    .submenu.active {
        max-height: 500px;
        display: inline-block;
    }

    .submenu-item {
        width: 100%;
        padding: 0.9rem 1.5rem 0.9rem 2.5rem;
        text-decoration: none;
        color: #707070;
        transition: all 0.2s;
        position: relative;
        border-bottom: 1px solid #313131;
        display: inline-block;
    }

    .submenu-item:before {
        position: absolute;
        left: 1.8rem;
        font-size: 1.4rem;
    }

    .submenu-item:hover {
        color: white;
        transform: translateX(5px);
    }


}