.intro {
  --intro-bg: var(--ui-bg, #eef3f4);
  --intro-ink: var(--ui-ink, #18343b);
  --intro-muted: var(--ui-muted, #5e777d);
  --intro-line: var(--ui-line, rgba(24, 52, 59, 0.18));
  --intro-accent: var(--ui-accent, #08766f);
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  overflow: hidden;
  padding: 24px;
  background: var(--intro-bg);
  color: var(--intro-ink);
  opacity: 0;
  transition: opacity 240ms ease;
}
.intro[hidden] { display: none; }
.intro.is-active { opacity: 1; }
.intro.is-leaving { opacity: 0; }
.intro-grid {
  position: absolute;
  inset: -12%;
  background-image: linear-gradient(var(--intro-line) 1px, transparent 1px), linear-gradient(90deg, var(--intro-line) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.32;
  transform: rotate(-5deg) scale(1.08);
}
.intro-shell {
  position: relative;
  z-index: 1;
  width: min(100%, 680px);
  display: grid;
  justify-items: center;
  text-align: center;
}
.intro-kicker {
  margin: 0 0 20px;
  color: var(--intro-accent);
  font: 700 11px/1.2 Consolas, "Cascadia Mono", monospace;
  letter-spacing: 0.18em;
}
.intro-module {
  border-radius: var(--r-lg, 20px);
  position: relative;
  display: grid;
  place-items: center;
  width: min(624px, calc(100vw - 48px), calc(100dvh - 240px));
  aspect-ratio: 1;
  border: 1px solid var(--intro-line);
  background: color-mix(in srgb, var(--ui-surface) 76%, transparent);
  box-shadow: var(--ui-shadow), inset 0 0 0 12px color-mix(in srgb, var(--ui-bg) 82%, transparent);
}
.intro-chameleon {
  display: block;
  width: min(78%, 472px);
  height: auto;
  filter: var(--ui-logo-contour) drop-shadow(0 14px 18px rgba(24, 52, 59, 0.2));
  transform: scale(0.92);
  animation: intro-image 4.6s cubic-bezier(0.22, 1, 0.36, 1) both;
}
.intro-orbit {
  position: absolute;
  inset: 18px;
  border: 1px solid var(--intro-line);
  border-radius: 50%;
  opacity: 0.6;
}
.intro-orbit-b { inset: 38px; border-style: dashed; transform: rotate(22deg); }
.intro-scan {
  position: absolute;
  z-index: 2;
  left: 14%;
  right: 14%;
  top: 16%;
  height: 2px;
  background: var(--intro-accent);
  box-shadow: 0 0 18px rgba(8, 118, 111, 0.7);
  opacity: 0;
  transform: translateY(0);
  animation: intro-scan 2.5s ease-in-out 120ms both;
}
.intro-corner { position: absolute; width: 36px; height: 36px; border-color: var(--intro-accent); opacity: 0.9; }
.intro-corner-a { left: -1px; top: -1px; border-left: 3px solid; border-top: 3px solid; border-top-left-radius: var(--r-lg, 20px); }
.intro-corner-b { right: -1px; bottom: -1px; border-right: 3px solid; border-bottom: 3px solid; border-bottom-right-radius: var(--r-lg, 20px); }
.intro-copy { min-height: 104px; margin-top: 26px; }
.intro-copy h2 { margin: 0 0 10px; font: 400 clamp(1.65rem, 4.5vw, 2.45rem)/1.08 Georgia, "Times New Roman", serif; letter-spacing: -0.025em; }
.intro-status { position: absolute; left: 0; right: 0; margin: 0; color: var(--intro-muted); font: 700 12px/1.4 Consolas, "Cascadia Mono", monospace; letter-spacing: 0.08em; text-transform: uppercase; opacity: 0; transform: translateY(8px); transition: opacity 220ms ease, transform 220ms ease; }
.intro[data-phase="scan"] .intro-status-scan,
.intro[data-phase="rebuild"] .intro-status-rebuild,
.intro[data-phase="ready"] .intro-status-ready { opacity: 1; transform: translateY(0); }
.intro-skip {
  min-width: 148px;
  min-height: 46px;
  padding: 0 16px;
  border: 1px solid var(--intro-line);
  border-radius: var(--r-sm, 8px);
  background: color-mix(in srgb, var(--ui-surface) 84%, transparent);
  color: var(--intro-ink);
  font: 700 14px/1 "Segoe UI", Tahoma, sans-serif;
  cursor: pointer;
}
.intro-skip span { margin-left: 12px; color: var(--intro-muted); font: 12px Consolas, monospace; }
.intro-skip:hover { border-color: var(--intro-accent); }
.intro-skip:focus-visible { outline: 3px solid var(--intro-accent); outline-offset: 3px; }
body.intro-open { overflow: hidden; }

@keyframes intro-scan {
  0% { opacity: 0; transform: translateY(0); }
  10%, 88% { opacity: 0.95; }
  100% { opacity: 0; transform: translateY(210px); }
}
@keyframes intro-image {
  0% { opacity: 0.34; transform: scale(0.88); }
  38% { opacity: 0.72; transform: scale(0.94); }
  72%, 100% { opacity: 1; transform: scale(1); }
}

@media (max-width: 520px) {
  .intro { padding: 18px; }
  .intro-grid { background-size: 36px 36px; }
  .intro-kicker { margin-bottom: 14px; }
  .intro-copy { min-height: 96px; margin-top: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  .intro { display: none !important; }
  .intro *, .intro *::before, .intro *::after { animation: none !important; transition: none !important; }
}