/* 导航栏基础样式 */
.navbar {
    background-color: var(--nav-bg, #fff);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

/* 固定导航栏样式 */
.navbar-fixed {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1030;
    background-color: var(--nav-bg, #fff);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

/* 导航链接样式 */
.nav-link {
    color: var(--nav-text, #333);
    font-weight: 500;
    padding: 0.5rem 1rem;
    margin: 0 0.2rem;
    border-radius: 4px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color, #0d6efd);
    background-color: rgba(var(--primary-rgb, 13, 110, 253), 0.05);
}

/* 下拉菜单样式 */
.dropdown-menu {
    min-width: 220px;
    padding: 0.5rem;
    margin: 0;
    background-color: #fff;
    border: 1px solid rgba(0, 0, 0, 0.15);
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

/* 下拉菜单显示状态 */
.dropdown-menu.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* 下拉菜单项样式 */
.dropdown-item {
    padding: 0.6rem 1rem;
    font-weight: 400;
    color: var(--nav-text, #333);
    border-radius: 4px;
    transition: all 0.2s ease;
}

.dropdown-item:hover,
.dropdown-item:focus,
.dropdown-item.active {
    color: var(--primary-color, #0d6efd);
    background-color: rgba(var(--primary-rgb, 13, 110, 253), 0.05);
}

/* 桌面端悬停显示下拉菜单 */
@media (min-width: 992px) {
    .dropdown:hover > .dropdown-menu {
        display: block;
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    /* 创建触发区域 */
    .dropdown {
        position: relative;
    }

    .dropdown::after {
        content: '';
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        height: 20px;
        background: transparent;
    }

    .dropdown-menu.scrollable-dropdown-menu {
        max-height: calc(100vh - 90px);
        overflow-y: auto;
    }
}

/* 移动端样式 */
@media (max-width: 991.98px) {
    .navbar-collapse {
        background-color: var(--nav-bg, #fff);
        border-radius: 8px;
        box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
        padding: 1rem;
        margin-top: 0.5rem;
    }

    .dropdown-menu {
        position: static;
        float: none;
        width: 100%;
        margin-top: 0.5rem;
        padding-left: 1rem;
        border: none;
        box-shadow: none;
        background-color: transparent;
    }

    .dropdown-item {
        padding: 0.5rem 1rem;
    }

    .dropdown-menu.scrollable-dropdown-menu {
        max-height: calc(100vh - 70px);
        overflow-y: auto;
    }
}

/* 顶部信息栏样式 */
.top-bar {
    background-color: var(--nav-bg-light, #f8f9fa);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

/* 导航栏占位符 */
.navbar-placeholder {
    height: 72px; /* 适配导航栏实际高度 */
    transition: height 0.3s ease;
}

/* 可滚动下拉菜单 */
.scrollable-dropdown-menu {
    max-height: 400px;
    overflow-y: auto;
}

/* 导航栏分隔符 */
.nav-with-separators .nav-item:not(:last-child)::after {
    content: '';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    height: 20px;
    width: 1px;
    background-color: rgba(0, 0, 0, 0.1);
}

/* 导航项动画 */
.nav-item-animation {
    transition: transform 0.2s ease;
}

.nav-item-animation:hover {
    transform: translateY(-2px);
}

/* 固定主导航栏在页面顶部 */
#main-navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1050;
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    background: #fff;
    transition: box-shadow 0.2s, background 0.2s;
}

@media (max-width: 991.98px) {
    .navbar-placeholder {
        height: 56px;
    }
}