/* =========================================
   铭赞网络·短视频矩阵营销
   responsive.css - 响应式 (Desktop-first)
   断点: 1200 / 992 / 768 / 576
   ========================================= */

/* ----- ≤ 1200 ----- */
@media (max-width: 1200px) {
  .container { padding: 0 28px; }
  .hero-title-main { font-size: 3.1em; }
  .hero-inner { gap: 40px; }
  .hero-visual { height: 420px; }
  .hero-card { width: 220px; }
  .timeline { grid-template-columns: repeat(3, 1fr); }
  .footer-col-wide .footer-links { grid-template-columns: repeat(3, 1fr); }
}

/* ----- ≤ 992 (平板) ----- */
@media (max-width: 992px) {
  .topbar-inner { font-size: 12px; height: 34px; }
  .nav-inner { height: 68px; }

  /* 启用汉堡菜单 */
  .nav-burger {
    display: inline-flex;
    flex-direction: column;
    justify-content: space-between;
    width: 28px;
    height: 22px;
    cursor: pointer;
    z-index: 110;
  }
  .nav-burger span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--c-navy);
    border-radius: 2px;
    transition: transform .25s var(--ease), opacity .2s var(--ease);
  }
  .nav-toggle:checked + .nav-burger span:nth-child(1) { transform: translateY(10px) rotate(45deg); }
  .nav-toggle:checked + .nav-burger span:nth-child(2) { opacity: 0; }
  .nav-toggle:checked + .nav-burger span:nth-child(3) { transform: translateY(-10px) rotate(-45deg); }

  .nav {
    position: fixed;
    inset: 68px 0 auto 0;
    background: #fff;
    padding: 18px 24px 28px;
    box-shadow: var(--shadow-md);
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: transform .3s var(--ease), opacity .25s var(--ease);
    max-height: calc(100vh - 68px);
    overflow-y: auto;
  }
  .nav-toggle:checked ~ .nav {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
  }
  .nav-list a {
    display: block;
    padding: 14px 12px;
    font-size: 16px;
    border-radius: var(--radius-sm);
  }
  .nav-list a:hover { background: var(--c-bg-alt); }
  .nav-list a::after { display: none; }
  .nav-cta { margin: 12px 0 0; text-align: center; }

  /* Hero 上下排版 */
  .hero { padding: 60px 0 80px; }
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 50px;
  }
  .hero-visual { height: 360px; max-width: 460px; margin: 0 auto; }
  .hero-title-main { font-size: 2.6em; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 18px; }

  /* Section */
  .section { padding: 80px 0; }
  .section-title { font-size: 30px; }

  /* Services */
  .services-grid { grid-template-columns: 1fr; gap: 20px; }
  .service-card { padding: 34px 28px; }

  /* Expanded 9 -> 2 col */
  .expanded-grid { grid-template-columns: repeat(2, 1fr); }

  /* Platforms */
  .platforms-grid { grid-template-columns: repeat(3, 1fr); }

  /* Advantage */
  .advantage-grid { grid-template-columns: repeat(2, 1fr); }
  .timeline { grid-template-columns: repeat(2, 1fr); }
  .timeline::before { display: none; }
  .timeline li { padding-top: 36px; }

  /* Process */
  .process-list { grid-template-columns: repeat(3, 1fr); }

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

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

  /* Footer */
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 36px; }
  .footer-col-wide { grid-column: 1 / -1; }
  .footer-col-wide .footer-links { grid-template-columns: repeat(4, 1fr); }
}

/* ----- ≤ 768 (大手机) ----- */
@media (max-width: 768px) {
  .container { padding: 0 20px; }
  .topbar { display: none; }
  .nav-inner { height: 60px; }
  .nav { inset: 60px 0 auto 0; padding: 14px 20px 22px; }
  .logo-mark { font-size: 20px; }
  .logo-tag { font-size: 13px; }
  .logo-divider { height: 18px; }

  .hero { padding: 44px 0 70px; }
  .hero-eyebrow { font-size: 12px; padding: 5px 12px; }
  .hero-title-main { font-size: 2.1em; }
  .hero-desc { font-size: 15px; }
  .hero-actions .btn { padding: 12px 22px; font-size: 14.5px; }
  .hero-stats { padding-top: 22px; gap: 14px; }
  .stat-num { font-size: 30px; }
  .hero-visual { height: 320px; }
  .hero-card { width: 200px; padding: 16px 18px; }
  .hero-card-1 { left: 0; top: 16px; }
  .hero-card-3 { bottom: 16px; }
  .hero-scroll { display: none; }

  .section { padding: 64px 0; }
  .section-head { margin-bottom: 40px; }
  .section-title { font-size: 26px; }
  .section-desc { font-size: 14.5px; }
  .section-eyebrow { font-size: 11px; letter-spacing: 0.2em; }

  .services-grid .service-card { padding: 30px 24px; }
  .service-title { font-size: 22px; }
  .expanded-grid { grid-template-columns: 1fr; }
  .ex-card { padding: 24px 22px; }

  .platforms-grid { grid-template-columns: repeat(2, 1fr); }
  .pf { font-size: 13px; padding: 12px 10px; }

  .advantage-grid { grid-template-columns: 1fr 1fr; gap: 14px; }
  .adv-card { padding: 26px 18px; }
  .adv-num { font-size: 36px; }

  .timeline { grid-template-columns: 1fr; }
  .timeline li { text-align: left; padding: 18px 0 18px 50px; }
  .timeline li::before { left: 16px; top: 22px; transform: none; }
  .tl-year { display: inline-block; margin-right: 10px; }

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

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

  .faq-item summary { font-size: 15.5px; padding: 18px 18px; }
  .faq-a { padding: 0 18px 18px 60px; font-size: 14.5px; }
  .faq-q { width: 28px; height: 28px; font-size: 12px; }

  .contact-cards { grid-template-columns: 1fr; }
  .ct-card { padding: 18px 16px; }
  .ct-value { font-size: 15px; }
  .qr-card { padding: 28px 20px; }
  .qr-img { width: 180px; height: 180px; }

  .footer-grid { grid-template-columns: 1fr; gap: 30px; padding-bottom: 30px; }
  .footer-col-wide .footer-links { grid-template-columns: repeat(2, 1fr); }
  .footer-bottom p { font-size: 12px; padding: 0 8px; }
}

/* ----- ≤ 576 (小屏手机) ----- */
@media (max-width: 576px) {
  .container { padding: 0 16px; }
  .hero { padding: 36px 0 60px; }
  .hero-title-main { font-size: 1.85em; }
  .hero-title-sub.title-line-sub { font-size: 0.5em; }
  .hero-desc { font-size: 14px; }
  .hero-actions { gap: 10px; }
  .hero-actions .btn { flex: 1; padding: 11px 16px; font-size: 14px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .stat-num { font-size: 26px; }
  .stat-label { font-size: 12px; }
  .hero-visual { height: 280px; }
  .hero-card { width: 180px; padding: 14px 16px; }
  .hc-title { font-size: 12.5px; }
  .hc-meta { font-size: 12px; }
  .hero-orb { width: 240px; height: 240px; }

  .section { padding: 50px 0; }
  .section-title { font-size: 23px; }
  .section-desc { font-size: 14px; }
  .section-head { margin-bottom: 30px; }

  .service-card { padding: 26px 20px; }
  .service-icon { width: 56px; height: 56px; margin-bottom: 18px; }
  .service-icon svg { width: 32px; height: 32px; }
  .service-title { font-size: 20px; }
  .service-list li { font-size: 13.5px; padding: 5px 0 5px 20px; }

  .ex-card { padding: 20px 18px; }
  .ex-num { font-size: 26px; }
  .ex-card h4 { font-size: 17px; }

  .adv-card { padding: 22px 14px; }
  .adv-num { font-size: 30px; }
  .adv-card h4 { font-size: 16px; }
  .adv-card p { font-size: 13px; }

  .proc { padding: 22px 14px; }
  .proc h4 { font-size: 15px; }
  .proc p { font-size: 12.5px; }

  .ind-card { padding: 26px 20px; }
  .ind-card h4 { font-size: 18px; }

  .contact-cards { gap: 12px; }
  .ct-card { gap: 12px; padding: 16px 14px; }
  .ct-icon { width: 42px; height: 42px; }
  .ct-icon svg { width: 20px; height: 20px; }
  .ct-value { font-size: 14.5px; }
  .ct-value br { display: inline; }
  .ct-addr .ct-value { font-size: 14px; }

  .qr-card { padding: 24px 16px; }
  .qr-img { width: 160px; height: 160px; padding: 8px; }
  .qr-tip { font-size: 15.5px; }
  .qr-desc { font-size: 12.5px; }

  .back-top { right: 14px; bottom: 14px; width: 40px; height: 40px; }
}