@media (max-width: 900px) {
  body { padding-top: 0; }
  .site-header__inner { min-height: 68px; padding: 0 18px; }
  .desktop-nav { display: none; }
  .site-logo__image--pc { display: none; }
  .site-logo__image--sp { display: block; }
  .site-logo__text { font-size: 20px; }
  .mobile-menu-toggle {
    display: grid;
    gap: 5px;
    width: 42px;
    height: 42px;
    padding: 10px;
    border: 0;
    background: transparent;
    cursor: pointer;
  }
  .mobile-menu-toggle span { display: block; width: 22px; height: 2px; margin: auto; background: var(--aiwt-navy); }
  .mobile-nav-overlay {
    position: fixed;
    inset: 0;
    z-index: 1090;
    display: block;
    background: rgba(15, 23, 42, .38);
  }
  .mobile-nav-overlay[hidden] { display: none; }
  .mobile-nav {
    position: fixed;
    top: 0;
    right: 0;
    z-index: 1100;
    display: block;
    width: min(88vw, 380px);
    height: 100dvh;
    padding: 18px;
    background: #fff;
    overflow-y: auto;
    transform: translateX(102%);
    transition: transform .22s ease;
  }
  .mobile-nav.is-open { transform: translateX(0); }
  .mobile-nav__head { display: flex; align-items: center; justify-content: space-between; min-height: 44px; border-bottom: 1px solid var(--aiwt-border); }
  .mobile-nav__title { color: var(--aiwt-muted); font-size: 12px; font-weight: 800; letter-spacing: .12em; }
  .mobile-nav__close { width: 38px; height: 38px; border: 0; background: transparent; color: var(--aiwt-navy); font-size: 28px; cursor: pointer; }
  .header-cta--mobile { display: flex; min-height: 48px; margin: 18px 0; padding: 0 18px; font-size: 14px; }
  .mobile-nav__menu > li { position: relative; border-top: 1px solid #eef1f3; }
  .mobile-nav__menu > li > a { display: block; padding: 14px 42px 14px 4px; color: var(--aiwt-text); font-size: 14px; font-weight: 700; }
  .mobile-nav__menu .sub-menu { max-height: 0; overflow: hidden; padding-left: 12px; transition: max-height .2s ease; }
  .mobile-nav__menu .sub-menu a { display: block; padding: 9px 4px; color: #667085; font-size: 13px; }
  .mobile-submenu-toggle { position: absolute; top: 5px; right: 0; width: 40px; height: 40px; border: 0; background: transparent; color: var(--aiwt-accent-dark); font-size: 24px; cursor: pointer; transition: transform .18s ease; }
  .mobile-submenu-toggle.is-open { transform: rotate(90deg); }
  body.mobile-menu-open { overflow: hidden; }
  .site-footer__widgets { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 600px) {
  :root { --aiwt-site-padding: 18px; }
  .page-shell { padding: 48px 0 66px; }
  .site-footer__inner { width: calc(100% - 36px); padding-top: 46px; }
  .site-footer__widgets { grid-template-columns: 1fr; gap: 12px; padding-bottom: 34px; }
  .back-to-top { right: 16px; bottom: 16px; width: 42px; height: 42px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .mobile-nav, .mobile-nav__menu .sub-menu, .mobile-submenu-toggle, .back-to-top { transition: none; }
}