:root {
  --track-bg: #f5f5f5;
  --track-card: rgba(255,255,255,.92);
  --track-border: rgba(17,24,39,.10);
  --track-ink: #0a0a0a;
  --track-muted: #6b7280;
}

html { scroll-behavior: smooth; }
body.tracking-shell {
  background:
    radial-gradient(circle at 12% 12%, rgba(17,24,39,.06), transparent 26rem),
    radial-gradient(circle at 88% 16%, rgba(17,24,39,.045), transparent 24rem),
    linear-gradient(180deg, #fafafa 0%, #f5f5f5 52%, #fafafa 100%);
  min-height: 100vh;
}
.tracking-shell::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(rgba(17,24,39,.025) 1px, transparent 1px), linear-gradient(90deg, rgba(17,24,39,.025) 1px, transparent 1px);
  background-size: 38px 38px;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,.45), transparent 72%);
}
.track-glass {
  background: rgba(255,255,255,.82);
  border: 1px solid rgba(17,24,39,.09);
  box-shadow: 0 24px 70px rgba(17,24,39,.08);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}
.track-dark {
  position: relative;
  overflow: hidden;
  background: linear-gradient(145deg, #050505 0%, #171717 64%, #0a0a0a 100%);
  box-shadow: 0 32px 80px rgba(0,0,0,.16);
}
.track-dark::after {
  content: "";
  position: absolute;
  width: 18rem;
  height: 18rem;
  right: -6rem;
  top: -8rem;
  border-radius: 9999px;
  background: radial-gradient(circle, rgba(255,255,255,.15), rgba(255,255,255,0) 68%);
}
.track-input-wrap { position: relative; }
.track-input-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.1rem;
  height: 1.1rem;
  color: #9ca3af;
  pointer-events: none;
}
.track-input {
  width: 100%;
  border-radius: 1rem;
  border: 1px solid #d1d5db;
  background: rgba(255,255,255,.96);
  padding: .95rem 1rem .95rem 2.85rem;
  font-size: .925rem;
  color: #111827;
  outline: none;
  transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}
.track-input:focus {
  border-color: #111827;
  box-shadow: 0 0 0 4px rgba(17,24,39,.08);
}
.track-input::placeholder { color: #9ca3af; }
.track-primary {
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.track-primary:hover { transform: translateY(-1px); box-shadow: 0 12px 30px rgba(0,0,0,.16); }
.track-primary:disabled { transform: none; box-shadow: none; cursor: wait; opacity: .7; }
.track-step {
  position: relative;
  min-width: 0;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.track-step:hover { transform: translateY(-2px); box-shadow: 0 14px 34px rgba(17,24,39,.07); }
.track-step::before {
  content: "";
  position: absolute;
  top: 1.55rem;
  left: calc(50% + 1.55rem);
  width: calc(100% - 3.1rem);
  height: 1px;
  background: #e5e7eb;
  display: none;
}
.track-copy {
  transition: background .15s ease, color .15s ease, border-color .15s ease;
}
.track-copy:hover { border-color: #111827; color: #111827; }
.track-section-card {
  border: 1px solid rgba(17,24,39,.09);
  background: rgba(255,255,255,.94);
  box-shadow: 0 16px 46px rgba(17,24,39,.055);
}
.track-pulse-dot { box-shadow: 0 0 0 0 rgba(16,185,129,.45); animation: track-pulse 1.9s infinite; }
@keyframes track-pulse {
  0% { box-shadow: 0 0 0 0 rgba(16,185,129,.38); }
  70% { box-shadow: 0 0 0 9px rgba(16,185,129,0); }
  100% { box-shadow: 0 0 0 0 rgba(16,185,129,0); }
}
.track-spinner {
  width: 1rem;
  height: 1rem;
  border-radius: 999px;
  border: 2px solid rgba(255,255,255,.4);
  border-top-color: #fff;
  animation: track-spin .7s linear infinite;
}
@keyframes track-spin { to { transform: rotate(360deg); } }
@media (min-width: 768px) {
  .track-step:not(:last-child)::before { display: block; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}