/* TABLETS (768px and below) */
@media (max-width: 768px) {
    nav .nav-links {
        gap: var(--spacing-md);
        font-size: var(--font-size-sm);
    }

    .hero .container {
        grid-template-columns: 1fr;
    }

    .hero-text h1 {
        font-size: 28px;
    }

    .hero-text p {
        font-size: var(--font-size-base);
    }

    .partnership-content {
        grid-template-columns: 1fr;
    }

    .founder-content {
        grid-template-columns: 1fr;
    }

    .features-grid,
    .testimonials {
        grid-template-columns: 1fr;
    }
}

/* MOBILE PHONES (480px and below) */
@media (max-width: 480px) {
    :root {
        --spacing-lg: 24px;
        --spacing-xl: 40px;
        --font-size-3xl: 32px;
        --font-size-2xl: 24px;
    }

    nav {
        padding: var(--spacing-sm) 12px;
    }

    nav .container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    nav .logo {
        font-size: 16px;
    }

    nav .nav-links {
        gap: var(--spacing-sm);
        font-size: 12px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero {
        padding: var(--spacing-lg) var(--spacing-sm);
    }

    .hero-text h1 {
        font-size: 24px;
        margin-bottom: var(--spacing-sm);
    }

    .hero-text p {
        font-size: 14px;
        margin-bottom: var(--spacing-md);
    }

    .cta-button {
        padding: 14px 28px;
        font-size: 14px;
        width: 100%;
    }

    .features,
    .specs,
    .video-section,
    .social-proof,
    .vietnam-partnership,
    .roadmap,
    .about-founder,
    .payment-section {
        padding: var(--spacing-lg) var(--spacing-sm);
    }

    .features-grid,
    .specs-grid,
    .testimonials {
        gap: var(--spacing-md);
    }

    .feature-card,
    .testimonial {
        padding: var(--spacing-md);
    }

    .trust-badge {
        padding: var(--spacing-md);
        margin-top: var(--spacing-md);
    }

    .trust-badge h3 {
        font-size: 13px;
    }

    .trust-badge p {
        font-size: 12px;
    }

    .price-display .amount {
        font-size: 36px;
    }

    .currency-toggle {
        flex-direction: column;
    }

    .currency-toggle button {
        width: 100%;
    }

    .modal-content {
        padding: 20px;
        margin: 20px;
        max-height: 90vh;
    }

    .modal-close {
        top: 10px;
        right: 10px;
        font-size: 24px;
    }

    .payment-container {
        padding: 0;
    }

    footer .container {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

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

/* EXTRA SMALL PHONES (320px and below) */
@media (max-width: 320px) {
    :root {
        --spacing-md: 16px;
        --spacing-lg: 20px;
        --font-size-3xl: 24px;
        --font-size-2xl: 20px;
    }

    nav .logo {
        font-size: 14px;
    }

    nav .nav-links {
        gap: 6px;
        font-size: 10px;
    }

    .hero-text h1 {
        font-size: 18px;
    }

    .cta-button {
        padding: 12px 20px;
        font-size: 12px;
    }

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

    .price-display .amount {
        font-size: 28px;
    }
}

/* PRINT STYLES */
@media print {
    nav,
    footer,
    .payment-section {
        display: none;
    }

    .modal {
        display: none;
    }
}