@charset "UTF-8";

:root {
  --intro-night: #100d22;
  --intro-night-2: #18122f;
  --intro-ink: #fffaf0;
  --intro-soft: #d9d1ec;
  --intro-muted: #aaa0c6;
  --intro-line: rgba(255, 255, 255, .16);
  --intro-gold: #ffc857;
  --intro-pink: #ff72a5;
  --intro-violet: #a38cff;
  --intro-blue: #69a8ff;
  --intro-teal: #50dec7;
}

html { background: var(--intro-night); }

body[data-page="intro"] {
  display: block;
  min-height: 100%;
  color: var(--intro-ink);
  background: var(--intro-night);
  font-family: ui-rounded, "SF Pro Rounded", "Nunito Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.55;
}

body[data-page="intro"]::before { display: none; }

body[data-page="intro"] button,
body[data-page="intro"] a { -webkit-tap-highlight-color: transparent; }

.intro-topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 68px;
  padding: .72rem clamp(1rem, 3vw, 2.7rem);
  color: var(--intro-ink);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
  background: rgba(16, 13, 34, .74);
  backdrop-filter: blur(18px) saturate(130%);
  transition: opacity .25s ease, background .25s ease;
}

.intro-brand {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  color: var(--intro-ink);
  font-size: 1rem;
  font-weight: 760;
  letter-spacing: -.01em;
}

.intro-brand:hover { color: var(--intro-ink); text-decoration: none; }
.intro-brand > span:first-child { font-size: 1.35rem; filter: drop-shadow(0 0 9px rgba(255, 200, 87, .55)); }
.intro-brand b { color: var(--intro-gold); }

.intro-top-actions,
.intro-languages { display: flex; align-items: center; gap: .5rem; }

.draft-chip {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: .25rem .65rem;
  border: 1px solid rgba(255, 200, 87, .25);
  border-radius: 999px;
  color: #f9e6bd;
  background: rgba(255, 200, 87, .08);
  font-size: .72rem;
  font-weight: 720;
  letter-spacing: .04em;
}

.intro-languages {
  padding: .2rem;
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: 999px;
  background: rgba(255, 255, 255, .05);
}

.intro-languages a {
  min-width: 42px;
  padding: .28rem .55rem;
  border-radius: 999px;
  color: var(--intro-muted);
  font-size: .78rem;
  font-weight: 780;
  text-align: center;
}

.intro-languages a:hover,
.intro-languages a[aria-current="true"] {
  color: #21172f;
  background: var(--intro-ink);
  text-decoration: none;
}

.intro-mode-button,
.intro-controls button {
  appearance: none;
  border: 1px solid rgba(255, 255, 255, .14);
  color: var(--intro-ink);
  background: rgba(255, 255, 255, .08);
  font: inherit;
  font-weight: 760;
  cursor: pointer;
}

.intro-mode-button {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  min-height: 42px;
  padding: .55rem .85rem;
  border-radius: 12px;
}

.intro-mode-button:hover,
.intro-controls button:hover { background: rgba(255, 255, 255, .16); }

#intro-deck { overflow: clip; }

.intro-slide {
  position: relative;
  isolation: isolate;
  display: grid;
  align-items: center;
  min-height: 100vh;
  min-height: 100svh;
  padding: clamp(7.2rem, 12vh, 9rem) clamp(1.2rem, 6vw, 6rem) clamp(4.5rem, 8vh, 6.5rem);
  overflow: hidden;
  letter-spacing: .012em;
  border-bottom: 1px solid rgba(255, 255, 255, .055);
  background:
    radial-gradient(circle at 85% 18%, rgba(124, 92, 255, .18), transparent 34%),
    radial-gradient(circle at 12% 84%, rgba(11, 179, 162, .09), transparent 30%),
    linear-gradient(145deg, #100d22 0%, #18122f 54%, #0e172a 100%);
}

.intro-slide:nth-of-type(4n + 2) {
  background:
    radial-gradient(circle at 12% 20%, rgba(255, 93, 143, .14), transparent 32%),
    radial-gradient(circle at 88% 78%, rgba(245, 166, 35, .11), transparent 31%),
    linear-gradient(145deg, #110d22 0%, #201231 58%, #13142a 100%);
}

.intro-slide:nth-of-type(4n + 3) {
  background:
    radial-gradient(circle at 82% 26%, rgba(59, 130, 246, .15), transparent 30%),
    radial-gradient(circle at 15% 72%, rgba(80, 222, 199, .1), transparent 34%),
    linear-gradient(150deg, #0d1326 0%, #171430 58%, #151022 100%);
}

.intro-slide::before {
  content: "";
  position: absolute;
  z-index: -1;
  width: min(32vw, 440px);
  aspect-ratio: 1;
  right: -12vw;
  bottom: -26%;
  border: 1px solid rgba(255, 255, 255, .08);
  border-radius: 50%;
  box-shadow: 0 0 0 60px rgba(255, 255, 255, .015), 0 0 0 120px rgba(255, 255, 255, .01);
}

.slide-inner {
  width: min(100%, 1180px);
  margin: 0 auto;
}

.narrow-slide { width: min(100%, 880px); text-align: center; }
.split-layout { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(300px, .92fr); align-items: center; gap: clamp(2.2rem, 7vw, 7rem); }

.slide-kicker {
  margin: 0 0 1.1rem;
  color: var(--intro-gold);
  font-size: clamp(.72rem, 1.2vw, .86rem);
  font-weight: 830;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.intro-slide h1,
.intro-slide h2,
.intro-slide h3 {
  color: var(--intro-ink);
  text-wrap: balance;
}

.intro-slide h1,
.intro-slide h2 {
  margin: 0;
  font-size: clamp(2.65rem, 6.4vw, 6.4rem);
  font-weight: 840;
  letter-spacing: -.018em;
  line-height: 1.03;
}

.intro-slide h3 { margin: 0 0 .7rem; font-size: clamp(1.35rem, 2.5vw, 2.25rem); line-height: 1.16; letter-spacing: -.005em; }

.slide-lead {
  max-width: 38em;
  margin: clamp(1.3rem, 3vw, 2rem) 0 0;
  color: var(--intro-soft);
  font-size: clamp(1.05rem, 2.05vw, 1.48rem);
  line-height: 1.72;
}

.narrow-slide .slide-lead { margin-inline: auto; }

.slide-note {
  max-width: 64em;
  margin: clamp(1.8rem, 4vw, 3.2rem) 0 0;
  color: var(--intro-muted);
  font-size: clamp(.88rem, 1.35vw, 1.02rem);
  line-height: 1.75;
}

.center-note { margin-inline: auto; text-align: center; }
.tentative-note { color: var(--intro-muted); font-size: clamp(.8rem, 1.2vw, .92rem); line-height: 1.65; }

.slide-actions { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; margin-top: 2rem; }

.intro-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: .8rem 1.2rem;
  border-radius: 14px;
  color: #2b1c00;
  background: linear-gradient(135deg, #ffe09b, var(--intro-gold));
  box-shadow: 0 16px 44px rgba(255, 200, 87, .18);
  font-weight: 820;
}

.intro-primary:hover { color: #2b1c00; text-decoration: none; transform: translateY(-1px); }
.url-note { color: var(--intro-muted); font: 700 .78rem/1.4 ui-monospace, "SFMono-Regular", Menlo, monospace; }

/* Opening portal */
.portal-visual { position: relative; width: min(34vw, 430px); aspect-ratio: 1; justify-self: center; }
.portal-ring,
.portal-core { position: absolute; inset: 50% auto auto 50%; border-radius: 50%; transform: translate(-50%, -50%); }
.portal-ring { border: 2px solid; animation: portal-drift 9s ease-in-out infinite alternate; }
.ring-a { width: 95%; aspect-ratio: 1; border-color: rgba(163, 140, 255, .3); box-shadow: 0 0 55px rgba(124, 92, 255, .17); }
.ring-b { width: 67%; aspect-ratio: 1; border-color: rgba(255, 200, 87, .5); animation-delay: -3s; }
.portal-core {
  display: grid;
  place-items: center;
  width: 42%;
  aspect-ratio: 1;
  color: var(--intro-gold);
  background: radial-gradient(circle at 38% 32%, #47375f, #140f29 68%);
  box-shadow: 0 0 70px rgba(255, 200, 87, .2), inset 0 0 28px rgba(163, 140, 255, .25);
  font-size: clamp(3rem, 7vw, 6.5rem);
  font-weight: 250;
}
.portal-star { position: absolute; color: var(--intro-ink); }
.star-a { top: 12%; left: 13%; font-size: 1.5rem; color: var(--intro-violet); }
.star-b { top: 24%; right: 3%; font-size: 3rem; color: var(--intro-gold); }
.star-c { bottom: 12%; left: 7%; font-size: 2rem; color: var(--intro-teal); }
@keyframes portal-drift { to { transform: translate(-50%, -50%) rotate(11deg) scale(1.025); } }

/* Questions and answer paths */
.question-stack { margin-top: clamp(2.5rem, 6vw, 5rem); }
.question-stack p { margin: .5rem 0; color: var(--intro-soft); font-size: clamp(1.22rem, 3vw, 2.35rem); font-weight: 680; }
.question-stack .answer-cloud { margin-block: 1.3rem; color: var(--intro-gold); font-size: clamp(.9rem, 1.6vw, 1.12rem); font-weight: 780; letter-spacing: .06em; }

.two-voices { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(1rem, 2.4vw, 1.8rem); margin-top: clamp(2.4rem, 5vw, 4rem); }
.voice {
  position: relative;
  min-height: 240px;
  padding: clamp(1.5rem, 3vw, 2.5rem);
  overflow: hidden;
  border: 1px solid var(--intro-line);
  border-radius: 28px;
  background: rgba(255, 255, 255, .065);
}
.voice::after { content: ""; position: absolute; inset: auto -12% -45% auto; width: 220px; aspect-ratio: 1; border-radius: 50%; background: currentColor; opacity: .08; }
.voice-gold { color: var(--intro-gold); }
.voice-violet { color: var(--intro-violet); }
.voice h3 { color: var(--intro-ink); }
.voice p:not(.voice-mark) { max-width: 34em; margin: 0; color: var(--intro-soft); font-size: 1.05rem; }
.voice-mark { height: 2.5rem; margin: -1rem 0 0; font-family: Georgia, serif; font-size: 4rem; line-height: 1; opacity: .75; }

/* Promise and tools */
.giant-answer { color: var(--intro-gold) !important; font-size: clamp(6rem, 21vw, 17rem) !important; line-height: .78 !important; }
.promise-line { margin: 1.7rem 0 0; color: var(--intro-soft); font-size: clamp(1.3rem, 3.5vw, 2.5rem); font-weight: 720; }
.course-promise { display: grid; gap: .75rem; margin-top: clamp(2.3rem, 5vw, 4rem); padding-top: 1.5rem; border-top: 1px solid var(--intro-line); }
.course-promise strong { color: var(--intro-ink); font-size: clamp(1.1rem, 2vw, 1.45rem); }
.course-promise span { max-width: 56em; margin: 0 auto; color: var(--intro-muted); }

.tool-line { display: flex; align-items: center; gap: clamp(.45rem, 1.6vw, 1.2rem); flex-wrap: wrap; margin-top: clamp(3rem, 8vw, 6rem); }
.tool-word { font-size: clamp(1.55rem, 4vw, 4.2rem); font-weight: 850; letter-spacing: -.012em; }
.tool-dot { color: rgba(255, 255, 255, .25); font-size: 1.5rem; }
.pink { color: var(--intro-pink); }
.gold { color: var(--intro-gold); }
.blue { color: var(--intro-blue); }
.teal { color: var(--intro-teal); }
.violet { color: var(--intro-violet); }
.white { color: var(--intro-ink); }

/* Guided discovery */
.guided-columns { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(1rem, 3vw, 2.5rem); margin-top: clamp(2.8rem, 6vw, 5rem); }
.guided-columns > div { padding-top: 1.2rem; border-top: 2px solid var(--intro-line); }
.guided-columns > div:nth-child(1) { border-color: var(--intro-gold); }
.guided-columns > div:nth-child(2) { border-color: var(--intro-pink); }
.guided-columns > div:nth-child(3) { border-color: var(--intro-teal); }
.role-label { color: var(--intro-ink); font-size: 1rem; font-weight: 830; }
.guided-columns p { color: var(--intro-soft); }
.slide-guided blockquote { margin: clamp(2.6rem, 5vw, 4.3rem) 0 0; color: var(--intro-gold); font-size: clamp(1.4rem, 3vw, 2.7rem); font-weight: 800; letter-spacing: 0; }

/* Course process */
.process-line { position: relative; display: grid; grid-template-columns: repeat(5, 1fr); gap: 1rem; margin: clamp(3rem, 7vw, 6rem) 0 0; padding: 0; list-style: none; }
.process-line::before { content: ""; position: absolute; top: 1.15rem; left: 4%; right: 4%; height: 1px; background: linear-gradient(90deg, var(--intro-gold), var(--intro-pink), var(--intro-violet), var(--intro-blue), var(--intro-teal)); }
.process-line li { position: relative; display: grid; align-content: start; gap: .45rem; padding-right: .4rem; }
.process-line li > span { position: relative; z-index: 1; display: grid; place-items: center; width: 2.3rem; height: 2.3rem; border-radius: 50%; color: #1d1428; background: var(--intro-ink); font-size: .72rem; font-weight: 900; }
.process-line strong { margin-top: .8rem; color: var(--intro-ink); font-size: clamp(1rem, 1.8vw, 1.35rem); }
.process-line small { max-width: 14em; color: var(--intro-muted); font-size: clamp(.76rem, 1.2vw, .9rem); line-height: 1.5; }

/* Tracks */
.track-choice { display: grid; grid-template-columns: 1fr auto 1fr; align-items: stretch; gap: clamp(.8rem, 2vw, 1.3rem); margin-top: clamp(2.6rem, 5vw, 4.4rem); }
.track-summary { padding: clamp(1.4rem, 3.2vw, 2.7rem); border: 1px solid var(--intro-line); border-radius: 28px; background: rgba(255, 255, 255, .055); }
.track-summary h3 { max-width: 15em; }
.track-symbol { display: block; margin-bottom: 1.4rem; font-size: 2rem; }
.art-track .track-symbol,
.art-track .track-age { color: var(--intro-pink); }
.engineering-track .track-symbol,
.engineering-track .track-age { color: var(--intro-teal); }
.track-age { font-size: .82rem; font-weight: 840; letter-spacing: .06em; text-transform: uppercase; }
.meeting-line { display: grid; place-items: center; }
.meeting-line span { padding: .45rem .7rem; border: 1px solid var(--intro-line); border-radius: 999px; color: var(--intro-muted); font-size: .7rem; font-weight: 830; writing-mode: vertical-rl; letter-spacing: .08em; }
.schedule-strip { display: flex; justify-content: center; gap: .7rem 2rem; flex-wrap: wrap; margin-top: 1.5rem; color: var(--intro-soft); font-size: .9rem; font-weight: 730; }
.slide-choice > .slide-inner > .tentative-note { text-align: center; }

.slide-track-detail h2 { font-size: clamp(2.4rem, 5.4vw, 5.3rem); }
.art-detail { background: radial-gradient(circle at 76% 24%, rgba(255, 93, 143, .19), transparent 36%), linear-gradient(140deg, #170e24, #25122c 55%, #16142e); }
.engineering-detail { background: radial-gradient(circle at 80% 22%, rgba(11, 179, 162, .17), transparent 36%), linear-gradient(140deg, #0d1825, #101c31 52%, #18122d); }
.track-list { display: grid; gap: .8rem; margin: 0; padding: 0; list-style: none; }
.track-list li { position: relative; padding: .8rem .9rem .8rem 2.4rem; border-bottom: 1px solid var(--intro-line); color: var(--intro-soft); font-size: clamp(.92rem, 1.55vw, 1.13rem); }
.track-list li::before { content: "↗"; position: absolute; left: .45rem; color: var(--intro-gold); font-weight: 850; }

/* Collaboration and boundaries */
.collaboration-pairs { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(1.2rem, 3vw, 2.5rem); margin-top: clamp(3rem, 7vw, 6rem); }
.collaboration-pairs > div { padding: clamp(1.4rem, 3vw, 2.4rem); border-left: 3px solid var(--intro-gold); background: rgba(255, 255, 255, .045); }
.collaboration-pairs > div:last-child { border-color: var(--intro-blue); }
.collaboration-pairs strong { font-size: clamp(1.25rem, 2.6vw, 2rem); }
.collaboration-pairs p { color: var(--intro-soft); }
.big-principle { margin: clamp(2rem, 4vw, 3.5rem) 0 0; color: var(--intro-gold); font-size: clamp(1.4rem, 3.2vw, 2.8rem); font-weight: 840; }

.boundary-list { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; margin: clamp(2.8rem, 5vw, 4.2rem) 0 0; padding: 1px; list-style: none; background: var(--intro-line); }
.boundary-list li { display: grid; grid-template-columns: auto 1fr; gap: 1rem; align-items: start; min-height: 150px; padding: clamp(1.2rem, 2.8vw, 2.1rem); background: rgba(16, 13, 34, .9); }
.boundary-list span { color: var(--intro-gold); font-size: .72rem; font-weight: 900; }
.boundary-list p { margin: 0; color: var(--intro-soft); font-size: clamp(1rem, 1.8vw, 1.28rem); font-weight: 660; }

/* Close and appendices */
.closing-question { display: grid; gap: .4rem; margin: clamp(2.8rem, 6vw, 5rem) 0 1.5rem; }
.closing-question span { color: var(--intro-muted); }
.closing-question strong { color: var(--intro-gold); font-size: clamp(1.5rem, 4vw, 3.4rem); }
.intro-secondary-link { color: var(--intro-soft); border-bottom: 1px solid var(--intro-line); font-weight: 760; }
.intro-secondary-link:hover { color: var(--intro-gold); text-decoration: none; }

.blank-slide {
  place-items: center;
  border: 0;
  background:
    radial-gradient(circle at 50% 48%, rgba(163, 140, 255, .055), transparent 24%),
    #0b0916 !important;
  text-align: center;
}
.blank-slide::before { display: none; }
.blank-slide.blank-silent { background: #07060d !important; }
.blank-message {
  margin: 0;
  color: rgba(255, 250, 240, .74);
  font-size: clamp(2.2rem, 6vw, 5.5rem);
  font-weight: 650;
  letter-spacing: .025em;
}
.blank-message.quieter { color: rgba(255, 250, 240, .48); font-size: clamp(1.6rem, 4vw, 3.5rem); }
.blank-message.dots { color: rgba(255, 200, 87, .45); font-family: Georgia, serif; font-size: clamp(3rem, 9vw, 8rem); letter-spacing: .2em; transform: translateX(.1em); }
.blank-message.looking { color: rgba(217, 209, 236, .68); font-size: clamp(1.5rem, 4.5vw, 4rem); }

html[lang="zh"] .intro-slide { letter-spacing: .035em; }
html[lang="zh"] .intro-slide h1,
html[lang="zh"] .intro-slide h2,
html[lang="zh"] .intro-slide h3 { letter-spacing: .015em; }

.curiosity-slide { text-align: center; }
.kid-curiosity { background: radial-gradient(circle at 50% 52%, rgba(255, 200, 87, .18), transparent 27%), linear-gradient(145deg, #100d22, #1c112f 60%, #0c1723); }
.adult-curiosity { background: radial-gradient(circle at 50% 52%, rgba(80, 222, 199, .15), transparent 29%), linear-gradient(145deg, #0d1324, #141934 60%, #161024); }
.curiosity-symbol { margin: 0; color: var(--intro-gold); font-size: clamp(7rem, 20vw, 17rem); font-weight: 250; line-height: .75; }
.adult-curiosity .curiosity-symbol { color: var(--intro-teal); }
.english-whisper { margin-top: 2.5rem; color: rgba(255, 255, 255, .35); font-size: clamp(.72rem, 1.2vw, .9rem); letter-spacing: .08em; text-transform: uppercase; }

.appendix-slide { background: radial-gradient(circle at 90% 10%, rgba(255, 200, 87, .11), transparent 30%), linear-gradient(145deg, #151021, #1d1630 58%, #111928); }
.appendix-answer strong { color: var(--intro-gold); font-size: clamp(4rem, 10vw, 8rem); line-height: .9; }
.appendix-answer > p:not(.tentative-note) { color: var(--intro-soft); font-size: clamp(1.05rem, 2vw, 1.4rem); }
.kid-ai-slide { background: radial-gradient(circle at 83% 18%, rgba(124, 92, 255, .16), transparent 31%), radial-gradient(circle at 12% 88%, rgba(255, 200, 87, .1), transparent 30%), linear-gradient(145deg, #121023, #1b1732 58%, #101b2b); }
.agency-lines { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; margin-top: clamp(2.4rem, 5vw, 4rem); }
.agency-lines > div { display: grid; gap: .65rem; min-height: 145px; padding: clamp(1.2rem, 2.7vw, 2rem); border: 1px solid rgba(255, 200, 87, .2); border-radius: 20px; background: rgba(255, 255, 255, .045); }
.agency-lines span { color: var(--intro-muted); font-size: clamp(.8rem, 1.25vw, .95rem); font-weight: 820; letter-spacing: .06em; text-transform: uppercase; }
.agency-lines strong { color: var(--intro-soft); font-size: clamp(1.18rem, 2.35vw, 1.9rem); line-height: 1.2; }
.role-contrasts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; margin-top: clamp(2.4rem, 5vw, 4rem); }
.role-contrasts article { display: grid; align-content: start; gap: .55rem; min-height: 210px; padding: clamp(1.25rem, 2.6vw, 2rem); border: 1px solid rgba(255, 200, 87, .22); border-radius: 22px; background: rgba(255, 200, 87, .045); }
.role-contrasts article:nth-child(2) { border-color: rgba(80, 222, 199, .24); background: rgba(80, 222, 199, .045); }
.role-contrasts article:nth-child(3) { border-color: rgba(163, 140, 255, .25); background: rgba(163, 140, 255, .05); }
.role-contrasts strong { color: var(--intro-ink); font-size: clamp(1.55rem, 3vw, 2.4rem); line-height: 1.05; }
.role-contrasts span { color: var(--intro-gold); font-size: clamp(.82rem, 1.3vw, 1rem); font-weight: 830; letter-spacing: .05em; text-transform: uppercase; }
.role-contrasts p { margin: .55rem 0 0; color: var(--intro-soft); line-height: 1.6; }
.thinking-trail { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 1px; margin: clamp(2.5rem, 5vw, 4rem) 0 0; padding: 1px; list-style: none; background: var(--intro-line); }
.thinking-trail li { display: grid; align-content: start; gap: 1rem; min-height: 160px; padding: clamp(1rem, 2.2vw, 1.6rem); background: rgba(16, 13, 34, .93); }
.thinking-trail span { color: var(--intro-gold); font-size: .72rem; font-weight: 900; }
.thinking-trail strong { color: var(--intro-soft); font-size: clamp(.98rem, 1.75vw, 1.3rem); line-height: 1.35; }
.named-question-slide { background: radial-gradient(circle at 72% 30%, rgba(255, 200, 87, .16), transparent 26%), radial-gradient(circle at 20% 80%, rgba(80, 222, 199, .1), transparent 30%), linear-gradient(145deg, #111025, #22142d 55%, #101d2d); }
.world-requirements { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: clamp(2.5rem, 5vw, 4.2rem); }
.world-requirements > div { display: grid; grid-template-columns: auto 1fr; gap: 1rem; padding: clamp(1.1rem, 2.5vw, 1.8rem); border: 1px solid var(--intro-line); border-radius: 18px; background: rgba(255, 255, 255, .04); }
.world-requirements span { display: grid; place-items: center; width: 2rem; height: 2rem; border-radius: 50%; color: #20142b; background: var(--intro-gold); font-weight: 900; }
.world-requirements p { margin: 0; color: var(--intro-soft); }

.adult-appendix { background: radial-gradient(circle at 88% 12%, rgba(80, 222, 199, .1), transparent 32%), linear-gradient(145deg, #0d1724, #15182e 58%, #181024); }
.skill-constellation { display: flex; justify-content: center; gap: .8rem; flex-wrap: wrap; margin: clamp(2.6rem, 5vw, 4rem) auto 0; max-width: 980px; }
.skill-constellation span { padding: .75rem 1rem; border: 1px solid rgba(80, 222, 199, .24); border-radius: 999px; color: var(--intro-soft); background: rgba(80, 222, 199, .055); font-weight: 720; }
.adult-appendix .slide-note { margin-inline: auto; text-align: center; }
.contrast-pairs { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: clamp(2.4rem, 5vw, 4rem); }
.contrast-pairs > div { display: grid; gap: .85rem; min-height: 155px; padding: clamp(1.2rem, 2.8vw, 2rem); border: 1px solid rgba(80, 222, 199, .2); border-radius: 20px; background: rgba(80, 222, 199, .045); }
.contrast-pairs > div:first-child { border-color: rgba(255, 255, 255, .13); background: rgba(255, 255, 255, .035); }
.contrast-pairs span { color: var(--intro-muted); font-size: .82rem; font-weight: 850; letter-spacing: .06em; text-transform: uppercase; }
.contrast-pairs strong { color: var(--intro-soft); font-size: clamp(1.2rem, 2.5vw, 2rem); line-height: 1.25; }
.logic-chain { display: flex; align-items: stretch; gap: .65rem; flex-wrap: wrap; margin-top: clamp(2.3rem, 4.6vw, 3.8rem); counter-reset: logic-step; }
.logic-chain span { position: relative; display: grid; place-items: center; flex: 1 1 125px; min-height: 76px; padding: .8rem 1rem; border: 1px solid rgba(80, 222, 199, .22); border-radius: 16px; color: var(--intro-soft); background: rgba(80, 222, 199, .05); text-align: center; font-weight: 780; }
.logic-chain span:not(:last-child)::after { content: "→"; position: absolute; z-index: 1; right: -.58rem; color: var(--intro-teal); }
.logic-contributions { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 1.2rem; }
.logic-contributions p { display: grid; gap: .35rem; margin: 0; padding: 1rem 1.2rem; border-left: 3px solid var(--intro-gold); background: rgba(255, 255, 255, .035); }
.logic-contributions p:last-child { border-color: var(--intro-teal); }
.logic-contributions strong { color: var(--intro-soft); }
.logic-contributions span { color: var(--intro-muted); }
.practice-boundaries { margin-top: clamp(2rem, 4vw, 3rem); }
.practice-boundaries li { min-height: 120px; }
.compact-process li { align-content: start; }
.compact-process strong { font-size: clamp(.95rem, 1.6vw, 1.2rem); line-height: 1.25; }
.contribution-chain span { flex-basis: 135px; }
.funding-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; margin-top: clamp(2.4rem, 5vw, 4rem); }
.funding-grid > div { display: grid; gap: .8rem; min-height: 170px; padding: clamp(1.15rem, 2.5vw, 1.8rem); border: 1px solid rgba(80, 222, 199, .2); border-radius: 20px; background: rgba(80, 222, 199, .045); }
.funding-grid span { color: var(--intro-teal); font-size: .8rem; font-weight: 880; letter-spacing: .06em; text-transform: uppercase; }
.funding-grid strong { color: var(--intro-soft); font-size: clamp(1.1rem, 2vw, 1.55rem); line-height: 1.3; }
.adult-principles { display: grid; gap: 1rem; }
.adult-principles p { margin: 0; padding: 0 0 1rem; border-bottom: 1px solid var(--intro-line); color: var(--intro-soft); }
.adult-principles strong { margin-top: 1rem; color: var(--intro-teal); font-size: clamp(1.25rem, 2.5vw, 2rem); }
.closing-tagline { margin: 2.2rem 0; color: var(--intro-teal); font-size: clamp(1.2rem, 2.5vw, 1.8rem); font-weight: 820; }
.final-slide .intro-primary { width: fit-content; margin-inline: auto; }

/* Presentation mode */
.intro-controls {
  position: fixed;
  z-index: 120;
  right: 1.2rem;
  bottom: 1.2rem;
  display: none;
  align-items: center;
  gap: .45rem;
  padding: .45rem;
  border: 1px solid rgba(255, 255, 255, .13);
  border-radius: 16px;
  background: rgba(10, 8, 20, .76);
  box-shadow: 0 12px 40px rgba(0, 0, 0, .28);
  backdrop-filter: blur(16px);
  transition: opacity .2s ease;
}

.intro-controls button { min-width: 42px; min-height: 42px; padding: .45rem .7rem; border-radius: 11px; }
.intro-controls .exit-button { padding-inline: .9rem; font-size: .78rem; }
.page-indicator { display: grid; min-width: 52px; place-items: center; color: var(--intro-soft); font: 800 .8rem/1 ui-monospace, "SFMono-Regular", Menlo, monospace; }

body.presenting { height: 100vh; height: 100svh; overflow: hidden; }
body.presenting #intro-deck { height: 100vh; height: 100svh; overflow: hidden auto; overscroll-behavior: contain; scroll-snap-type: y mandatory; }
body.presenting .intro-slide {
  height: 100vh;
  height: 100svh;
  min-height: 100vh;
  min-height: 100svh;
  overflow-y: auto;
  scroll-snap-align: start;
  scroll-snap-stop: always;
}
body.presenting .intro-topbar { background: rgba(16, 13, 34, .35); border-color: transparent; }
body.presenting .intro-controls { display: flex; }
body.presenting.on-blank .intro-topbar,
body.presenting.on-blank .intro-controls { opacity: .06; }
body.presenting.on-blank .intro-topbar:hover,
body.presenting.on-blank .intro-topbar:focus-within,
body.presenting.on-blank .intro-controls:hover,
body.presenting.on-blank .intro-controls:focus-within { opacity: 1; }

.noscript-note { position: fixed; z-index: 200; left: 1rem; bottom: 1rem; max-width: 35em; margin: 0; padding: .7rem 1rem; border-radius: 12px; color: #26190a; background: var(--intro-gold); }

@media (max-width: 760px) {
  .intro-topbar { align-items: flex-start; min-height: 60px; padding: .55rem .75rem; }
  .intro-brand { padding-top: .35rem; }
  .intro-brand > span:last-child { display: none; }
  .draft-chip { display: none; }
  .intro-mode-button > span:last-child { display: none; }
  .intro-mode-button { min-width: 42px; justify-content: center; padding-inline: .6rem; }
  .intro-slide { padding: 6.6rem 1.15rem 4.5rem; }
  .intro-slide h1,
  .intro-slide h2 { font-size: clamp(2.4rem, 13vw, 4.6rem); }
  .split-layout,
  .two-voices,
  .guided-columns,
  .collaboration-pairs,
  .boundary-list,
  .world-requirements,
  .agency-lines,
  .role-contrasts,
  .contrast-pairs,
  .logic-contributions,
  .funding-grid { grid-template-columns: 1fr; }
  .thinking-trail { grid-template-columns: 1fr; gap: 1px; }
  .thinking-trail li { min-height: 0; grid-template-columns: auto 1fr; align-items: start; }
  .role-contrasts article { min-height: 0; }
  .logic-chain span { flex-basis: calc(50% - .65rem); min-height: 66px; }
  .logic-chain span:not(:last-child)::after { display: none; }
  .portal-visual { width: min(72vw, 330px); order: -1; }
  .slide-demo .split-layout { gap: 1.3rem; }
  .slide-demo .portal-visual { width: min(45vw, 210px); }
  .voice { min-height: 0; border-radius: 20px; }
  .process-line { grid-template-columns: 1fr; gap: 1.25rem; padding-left: 0; }
  .process-line::before { top: 1rem; bottom: 1rem; left: 1.1rem; right: auto; width: 1px; height: auto; }
  .process-line li { grid-template-columns: auto 1fr; grid-template-rows: auto auto; column-gap: 1rem; }
  .process-line li > span { grid-row: 1 / 3; }
  .process-line strong { margin-top: 0; }
  .track-choice { grid-template-columns: 1fr; }
  .meeting-line span { writing-mode: initial; }
  .meeting-line::before,
  .meeting-line::after { content: ""; width: 1px; height: 16px; background: var(--intro-line); }
  .track-summary { border-radius: 20px; }
  .boundary-list li { min-height: 0; }
  .intro-controls { right: .65rem; bottom: .65rem; left: .65rem; justify-content: center; }
  .intro-controls .exit-button { margin-left: auto; }
}

@media (max-height: 820px) and (min-width: 761px) {
  .intro-slide { padding-top: 5.7rem; padding-bottom: 2.4rem; }
  .intro-slide h1,
  .intro-slide h2 { font-size: clamp(2.45rem, 5.2vw, 4.6rem); }
  .slide-lead { margin-top: 1rem; font-size: clamp(1rem, 1.7vw, 1.3rem); }
  .slide-note { margin-top: 1.3rem; line-height: 1.55; }
  .slide-actions { margin-top: 1.25rem; }
  .two-voices,
  .guided-columns,
  .process-line,
  .track-choice,
  .collaboration-pairs,
  .boundary-list,
  .world-requirements,
  .skill-constellation,
  .agency-lines,
  .role-contrasts,
  .thinking-trail,
  .contrast-pairs,
  .logic-chain,
  .funding-grid { margin-top: 1.6rem; }
  .voice { min-height: 168px; padding: 1.35rem 1.55rem; }
  .voice-mark { height: 1.8rem; font-size: 3rem; }
  .tool-line { margin-top: 2.2rem; }
  .tool-word { font-size: clamp(1.5rem, 3.4vw, 3.2rem); }
  .slide-guided blockquote { margin-top: 1.8rem; }
  .guided-columns p { margin-block: .65rem 0; }
  .process-line strong { margin-top: .45rem; }
  .process-line small { line-height: 1.35; }
  .track-summary { padding: 1.2rem 1.5rem; }
  .track-symbol { margin-bottom: .55rem; }
  .track-summary h3 { font-size: clamp(1.2rem, 2.1vw, 1.7rem); }
  .schedule-strip { margin-top: .8rem; }
  .slide-choice > .slide-inner > .tentative-note { margin-block: .65rem 0; }
  .track-list { gap: .35rem; }
  .track-list li { padding-block: .55rem; }
  .collaboration-pairs > div { padding: 1.2rem 1.5rem; }
  .big-principle { margin-top: 1.4rem; }
  .boundary-list li { min-height: 104px; padding: 1rem 1.2rem; }
  .world-requirements > div { padding: 1rem 1.15rem; }
  .skill-constellation { gap: .55rem; }
  .skill-constellation span { padding: .55rem .8rem; }
  .agency-lines > div,
  .contrast-pairs > div { min-height: 125px; padding: 1rem 1.2rem; }
  .role-contrasts article { min-height: 170px; padding: 1rem 1.2rem; }
  .thinking-trail li { min-height: 135px; padding: 1rem; }
  .logic-chain span { min-height: 64px; }
  .funding-grid > div { min-height: 140px; padding: 1rem 1.2rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .portal-ring { animation: none; }
  * { transition-duration: .01ms !important; }
}

/* Programs-page integration: one in-page story stage, the existing catalog
   immediately below it, and the same deck expanded for presentation. */
body[data-page="programs"] {
  --program-story-opening-background:
    radial-gradient(circle at 78% 18%, rgba(124, 92, 255, .12), transparent 34%),
    radial-gradient(circle at 12% 82%, rgba(245, 166, 35, .12), transparent 30%),
    linear-gradient(145deg, #fffdf8 0%, #fff7eb 55%, #f7f2ff 100%);
}

body[data-page="programs"] header.site { z-index: 110; }

.program-story-switch {
  position: sticky;
  top: var(--program-header-height, 68px);
  z-index: 105;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .35rem;
  min-height: 52px;
  padding: .42rem 1rem;
  border-bottom: 1px solid var(--line);
  background: rgba(255, 253, 248, .9);
  backdrop-filter: blur(14px) saturate(140%);
}

.program-story-switch a,
.program-story-switch button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .38rem;
  min-height: 38px;
  padding: .42rem .85rem;
  border: 1px solid transparent;
  border-radius: 999px;
  color: var(--ink-soft);
  background: transparent;
  font: inherit;
  font-size: .86rem;
  font-weight: 780;
  cursor: pointer;
}

.program-story-switch a:hover,
.program-story-switch button:hover,
.program-story-switch a[aria-current] {
  color: var(--gold-ink);
  border-color: var(--line);
  background: var(--surface);
  text-decoration: none;
}

.program-story-switch button {
  color: #2b1c00;
  border-color: rgba(245, 166, 35, .35);
  background: #fff3d6;
}

.intro-experience {
  position: relative;
  min-height: clamp(520px, calc(100svh - var(--program-header-height, 68px) - 52px), 820px);
  padding: 0;
  overflow: hidden;
  scroll-margin-top: calc(var(--program-header-height, 68px) + 52px);
  background: #fffdf8;
}

.intro-loading {
  position: relative;
  isolation: isolate;
  display: grid;
  align-content: center;
  min-height: inherit;
  padding: clamp(3.3rem, 8vh, 5rem) clamp(1.2rem, 6vw, 6rem) clamp(3.8rem, 8vh, 5rem);
  overflow: hidden;
  color: var(--ink);
  background: var(--program-story-opening-background);
}

.intro-loading::before {
  content: "?";
  position: absolute;
  z-index: -1;
  top: 50%;
  right: clamp(8%, 16vw, 19%);
  display: grid;
  place-items: center;
  width: min(25vw, 330px);
  aspect-ratio: 1;
  border: 2px solid rgba(124, 92, 255, .25);
  border-radius: 50%;
  color: var(--gold-ink);
  background: radial-gradient(circle at 38% 32%, #fff9e9, #eee7ff 72%);
  box-shadow:
    0 0 70px rgba(245, 166, 35, .18),
    0 0 0 58px rgba(164, 101, 10, .09),
    inset 0 0 28px rgba(124, 92, 255, .12);
  font-size: clamp(3rem, 7vw, 5rem);
  transform: translateY(-50%);
}

.intro-loading h1 {
  max-width: min(52%, 640px);
  margin: 0;
  color: var(--ink);
  font-size: clamp(2.65rem, 6.4vw, 6.4rem);
  line-height: 1;
  letter-spacing: -.018em;
}

.intro-loading > p:not(.slide-kicker) { max-width: min(48%, 38em); color: var(--ink-soft); font-size: clamp(1rem, 2vw, 1.35rem); }
.intro-loading-note { margin-top: 1.2rem; color: var(--muted); font-size: .8rem; }

.intro-carousel #intro-deck[data-mode="carousel"] {
  position: relative;
  height: clamp(520px, calc(100svh - var(--program-header-height, 68px) - 52px), 820px);
  overflow: hidden;
}

.intro-carousel #intro-deck[data-mode="carousel"] .intro-slide {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  min-height: 0;
  padding-top: clamp(3.3rem, 8vh, 5rem);
  padding-bottom: clamp(3.8rem, 8vh, 5rem);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  overflow: hidden;
  transform: translateX(1.5%);
  transition: opacity .28s ease, transform .4s ease, visibility 0s linear .4s;
}

.intro-carousel #intro-deck[data-mode="carousel"] .intro-slide.is-active {
  z-index: 1;
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
  transition: opacity .28s ease, transform .4s ease;
}

.intro-carousel #intro-deck[data-mode="carousel"] .giant-answer { font-size: clamp(5rem, 14vw, 11rem) !important; }

/* The embedded story opens in the Programs page's warm daylight language,
   then crosses into the dark Space Museum world on slide two. */
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo {
  color: var(--ink);
  background: var(--program-story-opening-background);
}

.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo::before {
  border-color: rgba(31, 26, 51, .08);
  box-shadow: 0 0 0 60px rgba(31, 26, 51, .018), 0 0 0 120px rgba(31, 26, 51, .012);
}

.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo h1 { color: var(--ink); }
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo .slide-lead { color: var(--ink-soft); }
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo .url-note { color: var(--muted); }
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo .portal-core {
  color: var(--gold-ink);
  background: radial-gradient(circle at 38% 32%, #fff9e9, #eee7ff 72%);
  box-shadow: 0 0 70px rgba(245, 166, 35, .18), inset 0 0 28px rgba(124, 92, 255, .12);
}
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo .ring-a { border-color: rgba(124, 92, 255, .25); }
.intro-carousel #intro-deck[data-mode="carousel"] .slide-demo .ring-b { border-color: rgba(164, 101, 10, .36); }

.intro-carousel:not(.presenting) .intro-controls {
  position: fixed;
  inset: auto clamp(.8rem, 3vw, 1.2rem) clamp(.8rem, 3vw, 1.2rem) auto;
  display: flex;
}

.intro-carousel:not(.presenting) .intro-controls .exit-button { display: none; }
body.viewing-programs.intro-carousel:not(.presenting) .intro-controls { opacity: 0; pointer-events: none; }
.program-index-hero { padding: clamp(3.8rem, 8vw, 6.5rem) 0 clamp(2.6rem, 5vw, 4rem); scroll-margin-top: calc(var(--program-header-height, 68px) + 52px); }
.program-index-hero .lead { margin-inline: auto; }

body.presenting.intro-carousel header.site,
body.presenting.intro-carousel .program-story-switch,
body.presenting.intro-carousel > main > :not(.intro-experience),
body.presenting.intro-carousel footer { display: none !important; }

body.presenting.intro-carousel .intro-experience {
  position: fixed;
  inset: 0;
  z-index: 100;
  width: 100%;
  height: 100vh;
  height: 100svh;
  min-height: 0;
}

body.presenting.intro-carousel #intro-deck[data-mode="carousel"] { height: 100vh; height: 100svh; overflow: hidden; }
body.presenting.intro-carousel #intro-deck[data-mode="carousel"] .intro-slide { height: 100vh; height: 100svh; overflow-y: auto; }
body.presenting.intro-carousel .intro-controls { position: fixed; }

@media (max-width: 760px) {
  .program-story-switch { justify-content: stretch; padding-inline: .5rem; }
  .program-story-switch a,
  .program-story-switch button { flex: 1 1 auto; padding-inline: .45rem; font-size: .78rem; }
  .intro-experience,
  .intro-carousel #intro-deck[data-mode="carousel"] { min-height: 0; height: max(600px, calc(100svh - var(--program-header-height, 110px) - 52px)); }
  .intro-loading h1,
  .intro-loading > p:not(.slide-kicker) { max-width: 100%; }
  .intro-loading::before { right: -16%; width: min(54vw, 260px); opacity: .28; }
  .intro-carousel #intro-deck[data-mode="carousel"] .intro-slide { padding-top: 4.7rem; padding-bottom: 5.2rem; overflow-y: auto; }
  .intro-carousel:not(.presenting) .intro-controls {
    right: .45rem;
    bottom: .45rem;
    left: auto;
    gap: .25rem;
    padding: .3rem;
  }
  .intro-carousel:not(.presenting) .intro-controls button { min-width: 36px; min-height: 36px; padding: .35rem .5rem; }
  .intro-carousel:not(.presenting) .page-indicator { min-width: 38px; }
  .intro-carousel:not(.presenting) .slide-demo .intro-primary { max-width: 210px; text-align: center; }
}

@media print {
  @page { size: 13.333in 7.5in; margin: 0; }

  html,
  body[data-page="intro"] { margin: 0; background: var(--intro-night); }
  body[data-page="intro"] { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
  .intro-topbar,
  .intro-controls,
  .noscript-note { display: none !important; }
  #intro-deck { overflow: visible !important; }
  .intro-slide {
    width: 13.333in;
    height: 7.5in;
    min-height: 0;
    padding: .7in .85in;
    break-after: page;
    page-break-after: always;
  }
  .intro-slide:last-child { break-after: auto; page-break-after: auto; }
  .intro-slide h1,
  .intro-slide h2 { font-size: 42pt; }
  .slide-lead { font-size: 15pt; }
  .blank-slide { background: #0b0916 !important; }
}