/* ── Base & Utilities ── */
  *, *::before, *::after { box-sizing: border-box; }
  html { scroll-behavior: smooth; scroll-padding-top: 80px; }
  body { overflow-x: hidden; }

  /* ── Reveal Animations ── */
  .reveal-up, .reveal-left, .reveal-right {
    opacity: 0;
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
  }
  .reveal-up { transform: translateY(40px); }
  .reveal-left { transform: translateX(-40px); }
  .reveal-right { transform: translateX(40px); }
  .reveal-visible { opacity: 1; transform: translate(0, 0); }

  /* ── Header Scroll State ── */
  #site-header.scrolled {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: 0 1px 0 rgba(0,0,0,0.06), 0 8px 32px rgba(0,0,0,0.04);
  }
  #site-header.scrolled .font-display { color: #0f172a; }

  /* ── Nav Links ── */
  .nav-link { position: relative; }
  .nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: #0d9488;
    border-radius: 1px;
    transition: width 0.3s ease;
  }
  .nav-link:hover::after { width: 100%; }

  /* ── Mobile Menu ── */
  #mobile-menu.open { opacity: 1; pointer-events: all; }
  .mobile-link { transition: color 0.3s ease; }
  .mobile-link:hover { color: #0d9488; }

  /* ── Hamburger Animation ── */
  #menu-toggle.active .menu-line:nth-child(1) { transform: rotate(45deg) translate(4px, 4px); }
  #menu-toggle.active .menu-line:nth-child(2) { opacity: 0; }
  #menu-toggle.active .menu-line:nth-child(3) { transform: rotate(-45deg) translate(4px, -4px); width: 20px; }

  /* ── Image Hover ── */
  .group img { transition: transform 0.7s cubic-bezier(0.16, 1, 0.3, 1); }

  /* ── Selection ── */
  ::selection { background: #ccfbf1; color: #134e4a; }

  /* ── Focus Ring ── */
  :focus-visible { outline: 2px solid #0d9488; outline-offset: 2px; }

  /* ── Responsive Tweaks ── */
  @media (max-width: 767px) {
    .font-serif { font-size: clamp(2rem, 8vw, 3rem); }
  }

  /* ── Subtle gradient border on cards ── */
  .group:hover { transform: translateY(-2px); }
  .group { transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1); }