/* ============================================================
   Responsive Breakpoints
   1400px / 1024px / 768px / 480px
   ============================================================ */

/* --- Max 1400px --- */
@media (max-width: 1400px) {
    .container {
        max-width: 1140px;
    }
}

/* --- Max 1024px --- */
@media (max-width: 1024px) {
    .container {
        max-width: 960px;
    }

    .stats {
        grid-template-columns: repeat(2, 1fr);
    }

    .card-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    /* Timeline adjustments */
    .timeline::before {
        left: 30px;
    }

    .timeline-item {
        padding-left: 70px;
        padding-right: 0;
    }

    .timeline-item:nth-child(even) {
        padding-left: 70px;
    }

    .timeline-dot {
        left: 22px !important;
        right: auto !important;
    }

    .timeline-content {
        text-align: left !important;
    }
}

/* --- Max 768px (Tablet) --- */
@media (max-width: 768px) {
    html {
        font-size: 15px;
    }

    .section {
        padding: 60px 0;
    }

    .section-header {
        margin-bottom: 40px;
    }

    /* Nav mobile */
    .nav-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        width: 100%;
        height: calc(100vh - 72px);
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: stretch;
        padding: 24px;
        gap: 4px;
        transform: translateX(100%);
        transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
        overflow-y: auto;
    }

    .nav-menu.open {
        transform: translateX(0);
    }

    .nav-link {
        padding: 14px 16px;
        font-size: 1rem;
        border-bottom: 1px solid var(--border-color);
        border-radius: 0;
    }

    .nav-dropdown .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        border: none;
        background: transparent;
        padding: 0 0 0 16px;
    }

    .lang-switch {
        margin: 16px 0 0;
        align-self: flex-start;
    }

    /* Hero */
    .hero {
        min-height: auto;
        padding: 120px 0 60px;
    }

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

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

    .hero-btns .btn {
        width: 100%;
        justify-content: center;
    }

    /* Grids */
    .card-grid,
    .card-grid-2,
    .card-grid-4 {
        grid-template-columns: 1fr;
    }

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

    .stat-card {
        padding: 24px 16px;
    }

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

    /* Footer */
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    /* Page header */
    .page-header {
        padding: 110px 0 40px;
    }

    .page-header h1 {
        font-size: 1.8rem;
    }

    /* Partners */
    .partner-row {
        gap: 16px;
    }

    .partner-item {
        min-width: 120px;
        padding: 12px 20px;
        font-size: 0.85rem;
    }

    /* Back to top */
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
    }

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

    /* News grid */
    .news-grid {
        grid-template-columns: 1fr !important;
    }

    /* About team grid */
    .team-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    /* Process steps */
    .process-steps {
        grid-template-columns: 1fr !important;
    }
}

/* --- Max 480px (Mobile) --- */
@media (max-width: 480px) {
    html {
        font-size: 14px;
    }

    .container {
        padding: 0 16px;
    }

    .section {
        padding: 48px 0;
    }

    .nav {
        padding: 0 16px;
    }

    .nav-logo .logo-text .logo-cn {
        font-size: 0.88rem;
    }

    .nav-logo .logo-text .logo-en {
        font-size: 0.58rem;
    }

    .hero {
        padding: 100px 0 48px;
    }

    .hero h1 {
        font-size: 1.6rem;
    }

    .hero p {
        font-size: 0.95rem;
    }

    .stats {
        grid-template-columns: 1fr 1fr;
        gap: 12px;
    }

    .stat-number {
        font-size: 1.6rem;
    }

    .stat-label {
        font-size: 0.78rem;
    }

    .card {
        padding: 24px 20px;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .section-desc {
        font-size: 0.9rem;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.88rem;
    }

    .btn-lg {
        padding: 12px 24px;
        font-size: 0.95rem;
    }

    .page-header {
        padding: 100px 0 32px;
    }

    .page-header h1 {
        font-size: 1.5rem;
    }

    /* Team */
    .team-grid {
        grid-template-columns: 1fr !important;
    }

    /* Footer */
    .footer {
        padding: 40px 0 0;
    }

    .footer-grid {
        gap: 24px;
    }
}