/* ===== RESPONSIVE STYLES ===== */

/* Large Desktop (1400px+) */
@media (min-width: 1400px) {
    .container {
        max-width: 1320px;
    }

    .products-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 2rem;
    }

    .products-scroll {
        grid-template-columns: repeat(4, 1fr);
        gap: 24px;
    }
}

/* Large Desktop (1200px - 1400px) */
@media (max-width: 1400px) {
    .products-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 1.5rem;
    }

    .products-scroll {
        grid-template-columns: repeat(4, 1fr);
        gap: 20px;
    }
}

/* Desktop (1024px - 1200px) */
@media (max-width: 1200px) {
    .container {
        max-width: 1000px;
    }

    .products-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 1.5rem;
    }

    .products-scroll {
        grid-template-columns: repeat(4, 1fr);
        gap: 16px;
    }
}

/* Tablet (768px - 1024px) */
@media (max-width: 1024px) {
    .container {
        padding: 0 15px;
    }

    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.25rem;
    }

    .products-scroll {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .category-title {
        font-size: 1.6rem;
    }

    .backpack-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
}

/* Tablet Portrait (768px and below) */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    /* Header */
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: var(--bg-white);
        flex-direction: column;
        padding: 1rem;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        gap: 0;
    }

    .nav-menu.active {
        display: flex;
    }

    .nav-menu li {
        width: 100%;
        text-align: center;
        padding: 1rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .mobile-menu-toggle {
        display: flex;
    }

    /* Hero */
    .hero {
        padding: 4rem 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    /* 首页产品网格 手机2列 */
    .products-scroll {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    /* products.php 产品网格 手机2列 */
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
    }

    .product-image {
        aspect-ratio: 1/1;
        height: auto;
    }

    .product-info {
        padding: 12px;
    }

    .product-info h3,
    .product-info h4 {
        font-size: 0.85rem;
        margin-bottom: 6px;
    }

    .product-desc {
        font-size: 0.72rem;
        margin-bottom: 10px;
    }

    .product-specs {
        padding: 0.75rem;
        font-size: 0.85rem;
    }

    .product-specs li {
        padding: 0.3rem 0;
    }

    /* Backpack grid */
    .backpack-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .backpack-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .backpack-header-left h2 {
        font-size: 1.3rem;
    }

    /* Contact Grid */
    .contact-grid {
        grid-template-columns: 1fr;}

    /* Quote Content */
    .quote-content {
        grid-template-columns: 1fr;
    }

    /* Form Row */
    .form-row {
        grid-template-columns: 1fr;
    }

    /* Blog Grid */
    .blog-grid {
        grid-template-columns: repeat(2, 1fr);gap: 1rem;
    }

    .blog-image {
        height: 160px;
    }

    .blog-content {
        padding: 1rem;
    }

    .blog-content h2 {
        font-size: 1.1rem;}

    .blog-content p {
        font-size: 0.9rem;}

    /* Features & Industries Grid */
    .features-grid,
    .industries-grid {
        grid-template-columns: 1fr;
    }

    /* Stats Section */
    .stats-section {
        grid-template-columns: 1fr 1fr;
    }

    /* Footer */
    .footer-content {
        grid-template-columns: 1fr 1fr;
        text-align: left;
    }

    /* WhatsApp Float */
    .whatsapp-float {
        width: auto;
        height: 44px;
        bottom: 85px;
        right: 14px;
        padding: 0 14px 0 12px;
        border-radius: 22px;
    }

    /* Section Headers */
    .section-header h2 {
        font-size: 2rem;
    }

    .page-hero h1 {
        font-size: 2rem;
    }

    .category-title {
        font-size: 1.3rem;
    }

    /* Products Filter */
    .products-filter {
        gap: 0.5rem;
    }

    .filter-btn {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }

    /* Testimonials */
    .testimonials-section {
        padding: 48px 16px;
    }

    .testimonials-grid {
        display: flex;
        flex-direction: column;
        gap: 12px;
        margin-bottom: 24px;
    }

    /* Use Cases */
    .usecases-section {
        padding: 48px 16px;
    }

    .usecases-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 12px;
    }

    .usecase-card {
        padding: 18px 12px;
    }

    .usecase-icon {
        width: 48px;
        height: 48px;
        font-size: 22px;
        margin-bottom: 10px;
        border-radius: 14px;
    }

    .usecase-card h3 {
        font-size: 0.85rem;
        margin-bottom: 6px;
    }

    .usecase-card p {
        font-size: 0.78rem;
        line-height: 1.5;
    }
}

/* Mobile (480px and below) */
@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .category-title {
        font-size: 1.2rem;
    }

    .stats-section {
        grid-template-columns: 1fr;
    }

    .products-scroll {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .products-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }

    .product-image {
        aspect-ratio: 1/1;
        height: auto;
    }

    .blog-grid {
        grid-template-columns: 1fr;
    }

    .blog-image {
        height: 200px;
    }

    .products-filter {
        flex-direction: column;
    }

    .filter-btn {
        width: 100%;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    .whatsapp-float {
        width: auto;
        height: 42px;
        bottom: 80px;
        right: 12px;
        padding: 0 12px 0 10px;
        border-radius: 21px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .backpack-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .usecases-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .usecase-card {
        padding: 14px 10px;
    }

    .usecase-icon {
        width: 42px;
        height: 42px;
        font-size: 18px;
        border-radius: 12px;
        margin-bottom: 8px;
    }

    .usecase-card h3 {
        font-size: 0.78rem;
    }

    .usecase-card p {
        font-size: 0.72rem;
    }
}