/* ─── Base & Reset ─── */
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; scroll-padding-top: 4rem; }
  body { margin: 0; }
  img, svg { display: block; max-width: 100%; }

  /* ─── Selection ─── */
  ::selection { background: #99f6e4; color: #134e4a; }

  /* ─── Scrollbar (subtle teal) ─── */
  ::-webkit-scrollbar { width: 8px; }
  ::-webkit-scrollbar-track { background: #f0fdfa; }
  ::-webkit-scrollbar-thumb { background: #5eead4; border-radius: 9999px; }
  ::-webkit-scrollbar-thumb:hover { background: #2dd4bf; }

  /* ─── Reduced motion ─── */
  @media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
    }
    .reveal { opacity: 1 !important; transform: none !important; }
  }

  /* ─── Scroll Reveal (progressive enhancement) ─── */
  @media (prefers-reduced-motion: no-preference) {
    .reveal {
      opacity: 0;
      transform: translateY(24px);
      transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
                  transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
    }
    .reveal.revealed {
      opacity: 1;
      transform: translateY(0);
    }
    .reveal-delay-1 { transition-delay: 0.1s; }
    .reveal-delay-2 { transition-delay: 0.2s; }
    .reveal-delay-3 { transition-delay: 0.3s; }
    .reveal-delay-4 { transition-delay: 0.4s; }
  }

  /* ─── Mobile menu animation ─── */
  @media (prefers-reduced-motion: no-preference) {
    #mobile-menu {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.35s cubic-bezier(0.22, 1, 0.36, 1);
    }
    #mobile-menu.open {
      max-height: 400px;
    }
  }