/* Base */
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; scroll-padding-top: 80px; }
  body { margin: 0; }

  /* Reveal animations — progressive enhancement, gated behind prefers-reduced-motion */
  @media (prefers-reduced-motion: no-preference) {
    .reveal {
      opacity: 0;
      transform: translateY(30px);
      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);
    }
  }
  /* Fallback: always visible if JS disabled or reduced-motion */
  @media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; }
  }

  /* Navbar transition */
  #nav.scrolled {
    background: rgba(2, 6, 23, 0.92);
    backdrop-filter: blur(12px);
    box-shadow: 0 1px 0 rgba(255,255,255,0.08);
  }

  /* Mobile menu animation */
  #mobile-menu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }
  #mobile-menu.open {
    max-height: 500px;
  }

  /* Custom scrollbar */
  ::-webkit-scrollbar { width: 8px; }
  ::-webkit-scrollbar-track { background: #0f172a; }
  ::-webkit-scrollbar-thumb { background: #0d9488; border-radius: 4px; }
  ::-webkit-scrollbar-thumb:hover { background: #14b8a6; }

  /* Selection */
  ::selection { background: rgba(13, 148, 136, 0.3); color: #f8fafc; }