/* ============================================
   响应式样式
   ============================================ */

/* --- 大屏 (1025px - 1200px) --- */
@media (max-width: 1200px) {
  .container {
    padding: 0 20px;
  }

  .hero-title {
    font-size: 2.8rem;
  }

  .about-grid {
    gap: 48px;
  }

  .services-grid {
    gap: 20px;
  }

  .service-card {
    padding: 32px 24px;
  }

  .cases-grid {
    gap: 16px;
  }

  .footer-grid {
    gap: 32px;
  }
}

/* --- 平板 (769px - 1024px) --- */
@media (max-width: 1024px) {
  :root {
    --section-padding: 70px 0;
  }

  h1 { font-size: 2.4rem; }
  h2 { font-size: 1.8rem; }
  .section-title { font-size: 1.8rem; }

  /* Nav */
  .nav-links {
    display: none;
  }

  .nav-contact {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  /* Hero */
  .hero-title {
    font-size: 2.4rem;
  }

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

  /* About */
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  /* Services */
  .services-grid {
    grid-template-columns: 1fr;
    max-width: 560px;
    margin: 0 auto;
  }

  /* Advantages */
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  /* Cases */
  .cases-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
  }

  /* Sub pages */
  .about-page-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .service-detail {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .service-detail.reverse {
    direction: ltr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
}

/* --- 手机横屏 (577px - 768px) --- */
@media (max-width: 768px) {
  :root {
    --section-padding: 56px 0;
  }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.6rem; }
  .section-title { font-size: 1.6rem; }

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

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

  .hero-subtitle {
    font-size: 0.9rem;
  }

  .hero-subtitle .divider {
    display: block;
    width: 0;
    height: 0;
    margin: 0;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .hero-buttons .btn {
    width: 100%;
    max-width: 280px;
  }

  /* About */
  .about-stats {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .stat-card {
    padding: 20px 16px;
  }

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

  /* Advantages */
  .advantages-grid {
    grid-template-columns: 1fr 1fr;
  }

  /* Cases */
  .cases-grid {
    grid-template-columns: 1fr;
  }

  /* News */
  .news-item {
    flex-direction: column;
    gap: 12px;
  }

  .news-date {
    display: flex;
    align-items: baseline;
    gap: 8px;
  }

  .news-date .day {
    font-size: 1.5rem;
  }

  /* Footer */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

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

  /* Page header */
  .page-header {
    padding: 130px 0 60px;
  }

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

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

  .contact-form {
    padding: 24px;
  }

  /* Partners */
  .partners-grid {
    gap: 28px;
  }

  .partner-logo {
    padding: 16px 24px;
    font-size: 1.1rem;
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }
}

/* --- 手机竖屏 (320px - 576px) --- */
@media (max-width: 576px) {
  .container {
    padding: 0 16px;
  }

  .hero-title {
    font-size: 1.7rem;
  }

  .about-stats {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
  }

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

  .stat-label {
    font-size: 0.8rem;
  }

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

  .service-card {
    padding: 28px 20px;
  }

  .btn {
    padding: 12px 24px;
    font-size: 0.9rem;
  }

  .btn-lg {
    padding: 14px 28px;
    font-size: 1rem;
  }

  .mobile-menu {
    width: 100%;
    max-width: none;
  }
}