/* ========== 顶部导航 ========== */
.navbar {
    background: #fff;
    padding-bottom: 20px;
    position: relative;
}

.navbar-brand {
    font-weight: 700;
    color: #1a1a1a !important;
    font-size: 28px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.navbar-subtitle {
    font-size: 18px;
    font-weight: 400;
    color: #7f838f;
}

.navbar-nav .nav-link {
    color: #000;
    font-size: 16px;
    font-weight: 600;
    padding: 28px 16px 20px !important;
    position: relative;
    transition: all 0.3s ease;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
    color: #2563eb;
}

.navbar-nav .nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: #2563eb;
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.navbar-nav .nav-link:hover::after,
.navbar-nav .nav-link.active::after {
    transform: scaleX(1);
}

@media (max-width: 768px) {
    .navbar-toggler {
        width: 36px;
        height: 36px;
        padding: 6px;
        font-size: 14px;
        border: 1px solid #ddd;
    }
    .navbar-toggler-icon {
        width: 20px;
        height: 20px;
    }
    .navbar-collapse {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: #fff;
        box-shadow: 0 4px 12px rgba(0,0,0,0.1);
        z-index: 999;
    }
    .navbar-nav {
        width: 100%;
    }
    .navbar-nav .nav-item {
        width: 100%;
        text-align: center;
    }
    .navbar-nav .nav-link {
        padding: 14px 16px !important;
        text-align: center;
        font-size: 15px;
    }
    .navbar-nav .nav-link::after {
        display: none;
    }
}