/* 导航栏基础样式 */
.navbar {
    height: 70px;
    background: linear-gradient(to right, #f0f7ff, #f5f9ff) !important;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.03);
    position: fixed !important; /* 固定在顶部 */
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 9999 !important; /* 确保导航栏在所有内容之上 */
}

/* Logo样式 */
.navbar-brand {
    padding: 0;
    display: flex;
    align-items: center;
    gap: 12px;
}

.navbar-brand img {
    height: 36px;
    transition: transform 0.3s;
}

.navbar-brand:hover img {
    transform: scale(1.05);
}

/* 修改导航栏品牌标题样式 */
.navbar-brand .brand-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: #1890ff;
    text-shadow: 0 2px 10px rgba(24, 144, 255, 0.1);
}

.navbar-brand:hover .brand-text {
    animation: textGlow 1.5s ease-in-out infinite alternate;
}

@keyframes textGlow {
    from {
        text-shadow: 0 2px 10px rgba(24, 144, 255, 0.1);
    }
    to {
        text-shadow: 0 2px 20px rgba(24, 144, 255, 0.2);
    }
}

/* 导航菜单样式 */
.navbar-nav {
    margin-left: 60px;
}

.nav-item {
    margin: 0 8px;
    position: relative;
}

.nav-link {
    color: #333 !important;
    font-size: 15px;
    font-weight: 500;
    padding: 8px 16px !important;
    border-radius: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}


/* 导航项悬浮特效 */
.nav-item::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #1890ff, #36cfc9);
    transition: all 0.3s ease;
    transform: translateX(-50%);
    opacity: 0;
}

.nav-item:hover::after,
.nav-item.active::after {
    width: 80%;
    opacity: 1;
}

/* “数据集”下拉：不要底部标识线、不要小三角 */
.nav-item.nav-datasets::after {
    display: none !important;
}
.nav-item.nav-datasets > .dropdown-toggle::after {
    display: none !important;
}

/* 用户菜单样式 */
.nav-btns {
    display: flex;
    align-items: center;
}

.search-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    cursor: pointer;
    color: #666;
    transition: all 0.3s;
    background: rgba(0, 0, 0, 0.02);
}

.search-icon:hover {
    background: rgba(24, 144, 255, 0.1);
    color: #1890ff;
    transform: translateY(-1px);
}

/* 登录注册按钮样式 */
.guest-btns .btn {
    padding: 8px 20px;
    font-size: 14px;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.guest-btns .btn-outline-primary {
    border: 2px solid rgba(24, 144, 255, 0.8);
    color: #1890ff;
}

.guest-btns .btn-outline-primary:hover {
    background: rgba(24, 144, 255, 0.1);
    border-color: #1890ff;
    color: #1890ff;
    transform: translateY(-1px);
}

.guest-btns .btn-primary {
    background: linear-gradient(45deg, #1890ff, #36cfc9);
    border: none;
    box-shadow: 0 2px 8px rgba(24, 144, 255, 0.3);
}

.guest-btns .btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(24, 144, 255, 0.4);
}

/* 用户头像和下拉菜单 */
.user-menu .nav-link {
    display: flex;
    align-items: center;
    padding: 5px 10px !important;
    background: rgba(0, 0, 0, 0.02);
    border-radius: 30px;
    transition: all 0.3s;
}

.user-menu .nav-link:hover {
    background: rgba(24, 144, 255, 0.1);
}

/* 修复header顶部空白问题 */
body, html {
    margin: 0;
    padding: 0;
}

header.navbar {
    margin-top: 0;
    margin-bottom: 0;
    position: fixed !important; /* 固定在顶部 */
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 9999 !important; /* 确保header在所有内容之上 */
}

.site-name {
    font-size: 1.5rem;
    font-weight: 700;
    margin-left: 1rem;
    background: linear-gradient(135deg, #2c3e50 0%, #3498db 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
    display: inline-block;
    vertical-align: middle;
    letter-spacing: 0.5px;
}

.site-name::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, #2c3e50, #3498db);
    transform: scaleX(0);
    transition: transform 0.3s ease;
    transform-origin: right;
}

.site-name:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.navbar-brand {
    display: flex;
    align-items: center;
    text-decoration: none !important;
}

.navbar-brand img {
    height: 32px;
    width: auto;
}

/* 导航链接样式 */
.navbar-nav .nav-link {
    text-decoration: none !important;
    position: relative;
    color: #1e293b;
    font-size: 16px;
    font-weight: 350;
    padding: 8px 16px;
    transition: color 0.3s ease;
}

.navbar-nav .nav-link:hover {
    color: #3b82f6;
}

.navbar-nav .nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: #3b82f6;
    transition: width 0.3s ease;
}

.navbar-nav .nav-link:hover::after {
    width: calc(100% - 32px);
}

.navbar-nav .nav-link.active {
    color: #3b82f6 !important; /* 覆盖默认深色，文字变蓝 */
    font-weight: 600;
}

.navbar-nav .nav-link.active::after {
    width: calc(100% - 32px);
}

/* 仅在激活状态去掉下划线，保留 hover 下划线效果 */
.nav-item.active::after,
.navbar-nav .nav-link.active::after {
    display: none !important;
}

/* 用户信息区域样式 */
.nav-user-area {
    display: flex;
    align-items: center;
    position: relative;
    z-index: 10000 !important; /* 确保用户区域在导航栏之上 */
}

.nav-user-area .dropdown-toggle {
    text-decoration: none !important;
    padding: 0;
    border: none;
    background: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-user-area .dropdown-toggle::after {
    display: none;
}

/* 确保dropdown容器有正确的定位上下文 */
.nav-user-area .dropdown {
    position: relative;
    z-index: 10000 !important;
}

.nav-user-area .avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
}

.nav-user-area .username {
    color: #333;
    font-size: 14px;
    margin-left: 8px;
}

/* 下拉菜单样式 - 确保最高优先级 */
.dropdown-menu {
    margin-top: 8px;
    border-radius: 8px;
    border: 1px solid rgba(0,0,0,0.1);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    z-index: 10001 !important; /* 确保下拉菜单在所有内容之上，优先级最高 */
    position: absolute !important; /* 确保使用absolute定位 */
}

.dropdown-item {
    padding: 8px 16px;
    font-size: 14px;
}

.nav-user-area .dropdown-divider,
.nav-user-area .user-menu-divider {
    display: block;
    height: 1px;
    margin: 4px 12px !important;
    padding: 0;
    list-style: none;
    background: rgba(148, 163, 184, 0.28);
    border: 0 !important;
    opacity: 1 !important;
}

/* 数据集下拉菜单：桌面端悬停展开（移动端仍用点击展开） */
@media (min-width: 992px) {
    .navbar-nav .nav-item.dropdown.nav-datasets:hover > .dropdown-menu {
        display: block;
    }
    .navbar-nav .nav-item.dropdown.nav-datasets > .dropdown-menu {
        /* 让菜单紧贴主菜单，避免鼠标移动出现缝隙导致消失 */
        top: 100%;
        margin-top: 0;
        transform: none;
    }
}

/* 数据集下拉菜单外观：更贴合导航风格 */
.nav-datasets .dropdown-menu {
    padding: 7px;
    min-width: 180px;      /* 下拉框窄一点 */
    border-radius: 5px;    /* 圆角更小一点 */
}
.nav-datasets .dropdown-item {
    border-radius: 8px;
    padding: 12px 12px;    /* 单行高度更高一点 */
    font-size: 14px;
    color: #334155;
    transition: background 0.2s ease, color 0.2s ease;
}
.nav-datasets .dropdown-menu li + li {
    border-top: 1px solid rgba(0, 0, 0, 0.06); /* 行之间浅灰分隔线 */
    margin-top: 6px;
    padding-top: 6px;
}
.nav-datasets .dropdown-item:hover {
    background: rgba(24, 144, 255, 0.08);
    color: #1890ff;
}

/* 登录注册按钮样式 */
.nav-login-area .btn {
    text-decoration: none !important;
    height: 36px;
    padding: 0 18px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 5px;
    font-size: 14px;
    font-weight: 500;
    line-height: 36px;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

/* 登录：清爽描边按钮 */
.nav-login-area .btn-outline-primary {
    border: 1px solid rgba(24, 144, 255, 0.5);
    color: #1890ff;
    background: transparent; /* 登录按钮不需要背景色 */
    backdrop-filter: blur(6px);
}
.nav-login-area .btn-outline-primary:hover {
    border-color: rgba(24, 144, 255, 0.65);
    background: rgba(24, 144, 255, 0.08);
    color: #1890ff;
    transform: translateY(-1px);
}

/* 注册：柔和渐变主按钮 */
.nav-login-area .btn-primary {
    border: none;
    background: linear-gradient(45deg, #1677ff, #13c2c2); /* 更深一点的渐变 */
    box-shadow: 0 8px 18px rgba(22, 119, 255, 0.26);
}
.nav-login-area .btn-primary:hover {
    background: linear-gradient(45deg, #0958d9, #08979c);
    box-shadow: 0 10px 22px rgba(22, 119, 255, 0.3);
    transform: translateY(-1px);
}