/* ===== Responsive Styles ===== */

/* Large Desktop (≥1400px) */
@media (min-width: 1600px) {
  :root {
    --max-width: 1340px;
  }
}

/* Tablet (≤1024px) */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .download-content {
    flex-direction: column;
    align-items: center;
    gap: 48px;
  }

  .footer-top {
    flex-direction: column;
    gap: 40px;
  }

  .hero {
    padding: 72px 0 40px;
  }
}

/* Mobile (≤768px) */
@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .header-nav {
    display: none;
  }

  .header-menu-btn {
    display: flex;
  }

  .mobile-menu {
    display: block;
  }

  /* Hero */
  .hero {
    padding: 64px 0 36px;
  }

  .hero-slogan {
    font-size: clamp(20px, 4vw, 24px);
  }

  .hero-desc {
    font-size: 15px;
  }

  .hero-divider {
    margin-bottom: 20px;
  }

  .btn {
    width: 100%;
    max-width: 320px;
    justify-content: center;
  }

  /* Stats */
  .stats {
    padding: 0 0 48px;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

  .stat-num {
    font-size: 28px;
  }

  /* Section titles */
  .section-title {
    font-size: 28px;
  }

  .section-subtitle {
    font-size: 15px;
    margin-bottom: 40px;
  }

  /* Features */
  .features {
    padding: 72px 0;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .feature-card {
    padding: 28px 24px;
  }

  .feature-icon {
    width: 56px;
    height: 56px;
    margin-bottom: 16px;
  }

  /* Models */
  .models {
    padding: 72px 0;
  }

  .models-grid {
    gap: 12px;
  }

  .model-chip {
    padding: 12px 24px;
    font-size: 16px;
  }

  /* Philosophy */
  .philosophy {
    padding: 72px 0;
  }

  .philosophy-grid {
    gap: 16px;
  }

  .philosophy-card {
    padding: 28px;
  }

  /* Download */
  .download {
    padding: 72px 0;
  }

  .download-content {
    gap: 40px;
  }

  .qrcode-img {
    width: 220px;
    height: 220px;
  }

  .download-info {
    text-align: center;
  }

  .download-steps {
    text-align: left;
    max-width: 360px;
    margin: 0 auto 28px;
  }

  .download-note {
    padding: 16px 20px;
  }

  /* Footer */
  .footer {
    padding: 48px 0 32px;
  }

  .footer-links {
    gap: 40px;
  }

  /* Back to top */
  .back-to-top {
    bottom: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
  }
}

/* ===== Promo Banner Responsive ===== */
@media (max-width: 1024px) {
  .promo-card {
    padding: 32px 36px;
    gap: 32px;
  }

  .promo-visual {
    display: none;
  }

  .promo-desc {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .promo-banner {
    padding: 84px 0 0;
    margin-top: 0;
  }

  .promo-card {
    flex-direction: column;
    padding: 28px 24px;
    gap: 0;
    border-radius: 16px;
  }

  .promo-badge {
    font-size: 12px;
  }

  .promo-title {
    font-size: 20px;
  }

  .promo-desc {
    font-size: 14px;
  }

  .promo-features {
    gap: 10px;
    margin-bottom: 20px;
  }

  .promo-feature-item {
    font-size: 13px;
    flex: 0 0 calc(50% - 5px);
  }

  .btn-promo {
    width: 100%;
    justify-content: center;
    padding: 12px 24px;
    font-size: 15px;
  }
}

@media (max-width: 480px) {
  .promo-banner {
    padding: 80px 0 0;
    margin-top: 0;
  }

  .promo-card {
    padding: 24px 20px;
    border-radius: 14px;
  }

  .promo-title {
    font-size: 18px;
  }
}

/* Small Mobile (≤480px) */
@media (max-width: 480px) {
  .container {
    padding: 0 20px;
  }

  .hero {
    padding: 56px 0 32px;
  }

  .hero-badge {
    padding: 8px 16px;
    font-size: 13px;
  }

  .hero-slogan {
    font-size: clamp(18px, 5vw, 20px);
  }

  .btn {
    padding: 12px 24px;
    font-size: 15px;
    max-width: 280px;
  }

  .stats-grid {
    gap: 16px;
  }

  .stat-num {
    font-size: 24px;
  }

  .stat-label {
    font-size: 13px;
  }

  .section-title {
    font-size: 24px;
  }

  .section-subtitle {
    font-size: 14px;
    margin-bottom: 32px;
  }

  .feature-card {
    padding: 24px 20px;
  }

  .feature-name {
    font-size: 17px;
  }

  .feature-desc {
    font-size: 14px;
  }

  .feature-tag {
    top: 20px;
    right: 20px;
    padding: 4px 10px;
    font-size: 11px;
  }

  .philosophy-card {
    padding: 24px;
  }

  .philosophy-title {
    font-size: 19px;
  }

  .philosophy-desc {
    font-size: 14px;
  }

  .qrcode-img {
    width: 180px;
    height: 180px;
  }

  .download-heading {
    font-size: 20px;
  }

  .download-steps li {
    font-size: 15px;
  }

  .footer-links {
    flex-direction: column;
    gap: 28px;
  }

  .footer-brand-name {
    font-size: 18px;
  }

  .footer-brand-desc {
    font-size: 14px;
  }
}

/* Hover effects only on non-touch devices */
@media (hover: hover) {
  .feature-card:hover {
    transform: translateY(-4px);
  }

  .model-chip:hover {
    transform: translateY(-2px);
  }

  .philosophy-card:hover {
    transform: translateY(-2px);
  }

  .back-to-top:hover {
    transform: translateY(-4px);
  }
}

/* Disable animations for users who prefer reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .animate-on-scroll {
    opacity: 1;
    transform: none;
  }
}