:root {
    --primary: #2563eb;
    --muted: #6b7280;
    --card-bg: #ffffff;
    --surface: #f8fafc;
}

body {
    background: var(--surface);
    color: #111827;
    font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.navbar-brand {
    font-weight: 700;
    color: var(--primary);
}

.nav-link {
    color: var(--muted);
}

    .nav-link:hover {
        color: var(--primary);
    }

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1rem;
}

.product-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 1rem;
    box-shadow: 0 6px 12px rgba(15, 23, 42, 0.06);
    transition: transform .12s ease, box-shadow .12s ease;
}

    .product-card:hover {
        transform: translateY(-4px);
        box-shadow: 0 10px 20px rgba(15,23,42,0.09);
    }

.product-title {
    font-weight: 600;
    font-size: 1.05rem;
    margin-bottom: .25rem;
}

.product-sub {
    color: var(--muted);
    font-size: .9rem;
    margin-bottom: .5rem;
}

.kv {
    font-weight: 600;
    color: var(--muted);
    font-size: .9rem;
}

.small-muted {
    color: var(--muted);
    font-size: .875rem;
}

.card-actions {
    display: flex;
    gap: .5rem;
    justify-content: flex-end;
    margin-top: .5rem;
}

@media (max-width:640px) {
    .main-content {
        padding: 0.9rem;
    }
}
@media (max-width: 768px) {
    .sidebar {
        width: 250px;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }

    .main-content {
        margin-left: 0 !important;
    }
    /* Toggle button cho mobile nếu cần */
    .sidebar-toggle {
        display: block;
    }
}

/* Toggle sidebar on click (optional JS) */
.sidebar-toggle {
    display: none;
}

@media (max-width: 768px) {
    .sidebar-toggle {
        display: block;
    }
}