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

/* ── Header Scroll State ── */
#site-header {
  background: transparent;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}
#site-header.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(12px);
  box-shadow: 0 1px 20px rgba(0,0,0,0.08);
}

/* ── Nav Links ── */
.nav-link { position: relative; }
.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  width: 0;
  height: 2px;
  background: #0D9488;
  border-radius: 1px;
  transition: width 0.2s, left 0.2s;
}
.nav-link:hover::after { width: 50%; left: 25%; }

/* ── Floating Stat Cards ── */
@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-12px); }
}
@keyframes float-delay {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-8px); }
}
.stat-card {
  animation: float 4s ease-in-out infinite;
}
.card-1 { animation-delay: 0s; }
.card-2 { animation-delay: 0.8s; }
.card-3 { animation-delay: 1.6s; }

/* ── Service Cards ── */
.service-card { cursor: default; }
.service-card:hover { transform: translateY(-4px); }

/* ── Review Cards ── */
.review-card { transition: transform 0.3s ease, box-shadow 0.3s ease; }
.review-card:hover { transform: translateY(-4px); }

/* ── Scroll Reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible {
  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; }

/* ── Back to Top ── */
#back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: #0D9488;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(13,148,136,0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.3s, visibility 0.3s, transform 0.3s, background 0.2s;
  z-index: 40;
  border: none;
  cursor: pointer;
}
#back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
#back-to-top:hover { background: #0f766e; }

/* ── Mobile Menu Animation ── */
#mobile-menu {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}
#mobile-menu.open {
  max-height: 400px;
  padding: 0.5rem 0;
}
.mobile-link {
  border-radius: 0.75rem;
}

/* ── Stagger children ── */
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.stagger-children.visible > *:nth-child(1) { transition-delay: 0.05s; opacity: 1; transform: none; }
.stagger-children.visible > *:nth-child(2) { transition-delay: 0.1s; opacity: 1; transform: none; }
.stagger-children.visible > *:nth-child(3) { transition-delay: 0.15s; opacity: 1; transform: none; }
.stagger-children.visible > *:nth-child(4) { transition-delay: 0.2s; opacity: 1; transform: none; }
.stagger-children.visible > *:nth-child(5) { transition-delay: 0.25s; opacity: 1; transform: none; }
.stagger-children.visible > *:nth-child(6) { transition-delay: 0.3s; opacity: 1; transform: none; }