/* 소개 사이트: 학교 남색 밤하늘 위에서 위키가 자라는 장면 + 미색 종이 위의 설명. 외부 라이브러리 없이 CSS·SVG·Canvas로 움직인다.
   색은 학교 색(진한 파랑, 하늘 파랑, 누리집 남색)과 교안 미색만. 움직임 줄이기 설정이면 완성된 상태를 바로 보여 준다. */
:root {
  --night: #172033;      /* 학교 누리집 남색: 첫 장면, 과정, 끝 */
  --night-2: #1f2b44;    /* 남색 위 판 */
  --night-line: #33415e;
  --on-night: #b8c2d1;   /* 남색 위 보조 글 (약 9:1) */
  --paper: #f7f6f3;      /* 교안 미색 */
  --surface: #ffffff;
  --ink: #333132;        /* 학교 먹색: 본문 */
  --head: #172033;       /* 미색 위 제목은 남색 */
  --muted: #6b6a66;
  --line: #e6e4df;
  --line-strong: #d6d4ce;
  --brand: #0066b3;
  --brand-ink: #00528f;
  --brand-soft: #e8f1f9;
  --sky: #00b6f1;        /* 남색 위 점·선·강조 (남색 대비 약 7:1) */
  --ok: #346538;
  --warn: #9f2f2d;
  --amber: #f2b544;      /* 남색 위 어긋난 숫자 */
  --amber-ink: #8a5a00;  /* 미색 위 어긋난 숫자 */
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --pad: clamp(16px, 4vw, 40px);
  --top-h: 68px;
  --mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
}
* { box-sizing: border-box; }
html { background: var(--night); scroll-padding-top: var(--top-h); }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font-family: 'Pretendard Variable', Pretendard, -apple-system, 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
  font-size: 17px; line-height: 1.7; word-break: keep-all; overflow-wrap: break-word; -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--brand); }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 3px; border-radius: 6px; }
.scene :focus-visible, .journey :focus-visible, .start :focus-visible { outline-color: var(--sky); }
h1, h2, h3 { margin: 0; color: var(--head); letter-spacing: -0.03em; }
h2 { font-size: clamp(30px, 4.6vw, 60px); line-height: 1.18; font-weight: 780; }
/* 줄바꿈: 제목은 뜻 단위로 줄(.ln)을 나누고 줄 안에서는 고르게, 글은 끝줄에 한 단어만 남지 않게 */
h1, h2, h3, .ln { text-wrap: balance; }
p, li, figcaption span { text-wrap: pretty; }
p { margin: 0; }
.lead { font-size: clamp(17px, 1.5vw, 20px); line-height: 1.7; max-width: 58ch; margin-top: 20px; }
.wrap { max-width: 1200px; margin: 0 auto; padding: 0 var(--pad); }
.mono { font-family: var(--mono); font-size: 0.92em; letter-spacing: -0.01em; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.ln { display: block; }
.nb { white-space: nowrap; }
.skip { position: absolute; left: 16px; top: -60px; z-index: 60; padding: 8px 16px; border-radius: 6px; background: var(--head); color: #fff; font-weight: 600; text-decoration: none; }
.skip:focus { top: 12px; }

/* 버튼 */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 44px; padding: 10px 18px;
  border-radius: 8px; border: 1px solid transparent; background: var(--brand); color: #fff; font-weight: 700; font-size: 15px;
  text-decoration: none; transition: background 0.2s, transform 0.4s var(--ease), border-color 0.2s;
}
.btn:hover { background: var(--brand-ink); }
.btn.big { min-height: 56px; padding: 14px 26px; font-size: 18px; border-radius: 10px; }
.btn.big:hover { transform: translateY(-2px); }
.btn.ghost { background: transparent; color: #fff; border-color: rgba(255, 255, 255, 0.4); }
.btn.ghost:hover { border-color: #fff; background: rgba(255, 255, 255, 0.06); }

/* 위 막대: 교안과 같은 학교 띠 + 시그니처 */
.top {
  position: fixed; inset: 0 0 auto 0; z-index: 30; height: var(--top-h);
  display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 4px var(--pad) 0;
  background: var(--paper); border-bottom: 1px solid var(--line);
}
.top::before { content: ''; position: absolute; inset: 0 0 auto 0; height: 4px; background: linear-gradient(90deg, var(--sky) 0 30vw, var(--brand) 30vw); }
.brand { display: flex; align-items: center; gap: 14px; min-width: 0; color: var(--head); text-decoration: none; font-size: 15px; font-weight: 650; line-height: 1.3; }
.brand .sig { height: 30px; width: auto; flex: none; }
.brand .sym { display: none; height: 30px; width: auto; flex: none; }
.sep { width: 2px; height: 22px; background: var(--sky); flex: none; }
.top-links { display: flex; align-items: center; gap: 6px; flex: none; }
.top-links .link { display: inline-flex; align-items: center; min-height: 44px; padding: 10px 14px; border-radius: 8px; color: var(--ink); font-weight: 600; font-size: 15px; text-decoration: none; }
.top-links .link:hover { background: #efeeea; }

/* ── 1. 첫 장면 ───────────────────────── */
.scene { position: relative; height: 330vh; background: var(--night); color: #fff; }
.scene-pin { position: sticky; top: 0; height: 100vh; height: 100svh; overflow: hidden; }
.scene-canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.scene-copy {
  position: absolute; left: 0; right: 0; margin: 0 auto; max-width: 1200px; padding: 0 var(--pad);
  top: calc(var(--top-h) + clamp(32px, 9vh, 120px)); will-change: opacity, transform;
}
.scene-copy h1, .scene-copy h2 { color: #fff; }
.scene h1 { margin-top: 0; font-size: clamp(44px, 7vw, 108px); line-height: 1.02; font-weight: 820; letter-spacing: -0.05em; }
.scene h1 .ln { overflow: hidden; padding-bottom: 0.06em; }
.scene .lead { color: var(--on-night); max-width: 34em; }
@media (min-width: 901px) { .copy-a { padding-right: calc(42% + var(--pad)); } .copy-a h1 { width: max-content; } }
.scene .lead strong { color: #fff; font-weight: 700; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }
.copy-b { top: auto; bottom: clamp(48px, 12vh, 140px); opacity: 0; pointer-events: none; }
.copy-b h2 { font-size: clamp(36px, 5.6vw, 80px); line-height: 1.08; font-weight: 800; letter-spacing: -0.045em; max-width: none; }
.scroll-cue { position: absolute; left: 50%; bottom: 22px; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; gap: 8px; color: var(--on-night); font-size: 13px; font-weight: 600; }
.scroll-cue span { width: 2px; height: 40px; background: linear-gradient(var(--sky), transparent); transform-origin: top; animation: cue 1.8s var(--ease) infinite; }
@keyframes cue { 0% { transform: scaleY(0); } 60% { transform: scaleY(1); opacity: 1; } 100% { transform: scaleY(1); opacity: 0; } }
/* 첫 글자 등장: 제목 줄이 아래에서 올라온다 */
.motion .copy-a .lead, .motion .copy-a .cta { animation: rise 1.1s var(--ease) both; }
.motion .copy-a .lead { animation-delay: 0.45s; }
.motion .copy-a .cta { animation-delay: 0.6s; }
.motion .copy-a h1 .w { display: inline-block; animation: rise-line 1.2s var(--ease) both; animation-delay: var(--d, 0s); }
.motion .copy-a h1 .ln:nth-child(1) .w { --d: 0.1s; }
.motion .copy-a h1 .ln:nth-child(2) .w { --d: 0.22s; }
@keyframes rise { from { opacity: 0; transform: translateY(24px); } }
@keyframes rise-line { from { transform: translateY(105%); } }

/* ── 2. 같은 사실, 다른 숫자 ───────────────── */
section:not(.scene) { padding: clamp(88px, 12vw, 160px) 0; }
.chats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; margin-top: 56px; }
.chat { margin: 0; padding: 20px; border-radius: 14px; background: var(--surface); border: 1px solid var(--line); display: flex; flex-direction: column; gap: 10px; min-height: 260px; }
.chat figcaption { font-size: 14px; font-weight: 700; color: var(--head); display: flex; justify-content: space-between; gap: 8px; padding-bottom: 12px; border-bottom: 1px solid var(--line); margin-bottom: 6px; }
.chat figcaption span { color: var(--muted); font-weight: 500; }
.msg { font-size: 15.5px; line-height: 1.6; padding: 10px 14px; border-radius: 14px; max-width: 92%; }
.msg.me { align-self: flex-end; background: var(--brand-soft); color: var(--head); border-bottom-right-radius: 4px; }
.msg.ai { align-self: flex-start; background: #f1f0ec; border-bottom-left-radius: 4px; }
.num { font-weight: 800; font-variant-numeric: tabular-nums; }
.num.ok { color: var(--brand); }
.num.bad { color: var(--warn); background: #fdebec; padding: 0 4px; border-radius: 4px; }
.drift-note { margin-top: 32px; font-size: clamp(18px, 1.7vw, 22px); color: var(--ink); max-width: 46ch; }
.drift-note b { color: var(--warn); }
/* 화면에 들어오면 대화가 차례로 쌓인다 */
.motion .chats .msg { opacity: 0; transform: translateY(12px); transition: opacity 0.6s var(--ease), transform 0.8s var(--ease); }
.motion .chats.play .msg { opacity: 1; transform: none; }
.motion .chats .chat:nth-child(1) .msg:nth-of-type(1) { transition-delay: 0.1s; }
.motion .chats .chat:nth-child(1) .msg:nth-of-type(2) { transition-delay: 0.5s; }
.motion .chats .chat:nth-child(2) .msg:nth-of-type(1) { transition-delay: 0.9s; }
.motion .chats .chat:nth-child(2) .msg:nth-of-type(2) { transition-delay: 1.3s; }
.motion .chats .chat:nth-child(3) .msg:nth-of-type(1) { transition-delay: 1.7s; }
.motion .chats .chat:nth-child(3) .msg:nth-of-type(2) { transition-delay: 2.1s; }
.motion .drift-note { opacity: 0; transition: opacity 0.8s var(--ease) 3.4s; }
.motion .chats.play + .drift-note { opacity: 1; }
.num.bad.flip { animation: flip 0.5s var(--ease); }
@keyframes flip { 0% { transform: translateY(0); } 40% { transform: translateY(-40%); opacity: 0; } 41% { transform: translateY(40%); } 100% { transform: none; opacity: 1; } }

/* ── 3. LLM Wiki ─────────────────────── */
.wiki { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.wiki-grid { display: grid; grid-template-columns: minmax(260px, 0.8fr) 1.4fr; gap: clamp(24px, 4vw, 64px); margin-top: 56px; align-items: start; }
.ops { display: flex; flex-direction: column; gap: 0; border-top: 1px solid var(--line); }
.ops button {
  position: relative; display: grid; gap: 4px; text-align: left; padding: 20px 4px 22px; border: 0; border-bottom: 1px solid var(--line);
  background: none; font: inherit; color: var(--muted); cursor: pointer; min-height: 44px;
}
.ops b { font-family: var(--mono); font-size: 22px; letter-spacing: 0.01em; color: var(--muted); transition: color 0.3s; }
.ops span { font-size: 16px; line-height: 1.55; }
.ops button[aria-selected="true"] b { color: var(--brand); }
.ops button[aria-selected="true"] span { color: var(--ink); }
.ops button:hover b { color: var(--head); }
.ops .bar { position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: var(--brand); transform: scaleX(0); transform-origin: left; }
.ops button[aria-selected="true"] .bar { transform: scaleX(1); }
.ops.auto button[aria-selected="true"] .bar { animation: fill var(--op-dur, 5s) linear both; }
@keyframes fill { from { transform: scaleX(0); } to { transform: scaleX(1); } }
.diagram { margin: 0; background: var(--paper); border: 1px solid var(--line); border-radius: 16px; padding: clamp(12px, 2vw, 24px); }
.diagram svg { width: 100%; height: auto; display: block; overflow: visible; }
.diagram-cap { margin-top: 12px; font-size: 15.5px; color: var(--ink); min-height: 3.2em; }
.diagram text { font-family: inherit; font-size: 16px; fill: var(--ink); font-weight: 600; }
.diagram .col-h { font-size: 14px; fill: var(--muted); font-weight: 700; text-anchor: middle; }
.diagram .file rect { fill: var(--surface); stroke: var(--line-strong); stroke-width: 1.5; }
.diagram .rule { fill: var(--head); }
.diagram .agent text { fill: #fff; }
.diagram .agent .mono { font-family: var(--mono); font-size: 16px; }
.diagram .agent .sub { font-size: 13px; fill: var(--on-night); font-weight: 500; }
.diagram .page circle { fill: var(--brand-soft); stroke: var(--brand); stroke-width: 1.5; transition: fill 0.4s, stroke 0.4s; }
.diagram .page text { font-size: 14px; fill: var(--head); }
.diagram .link-l { stroke: var(--brand); stroke-width: 1.5; fill: none; opacity: 0.45; }
.diagram .wire { fill: none; stroke: var(--line-strong); stroke-width: 2; stroke-dasharray: 5 6; }
.diagram .packet { fill: var(--sky); }
.diagram .arr { fill: var(--warn); }
.diagram .flow { opacity: 0; transition: opacity 0.4s; }
.diagram .ask rect { fill: var(--surface); stroke: var(--brand); stroke-width: 1.5; }
.diagram .ask text { font-size: 14px; fill: var(--head); }
.diagram .answer rect { fill: var(--brand); }
.diagram .answer text { fill: #fff; font-size: 13px; }
.diagram .warn { stroke: var(--warn); stroke-dasharray: 4 5; }
.diagram .warn-ask rect { stroke: var(--warn); fill: #fdebec; }
.diagram .warn-ask text { fill: var(--warn); }
.diagram .bad-file rect { stroke: var(--warn); fill: #fdebec; }
.diagram .bad-file text { fill: var(--warn); font-weight: 800; font-size: 15px; }
.diagram .raw .file { transition: opacity 0.4s; }
/* 상태별 */
.diagram[data-state="ingest"] .f-ingest, .diagram[data-state="query"] .f-query, .diagram[data-state="lint"] .f-lint { opacity: 1; }
.diagram[data-state="lint"] .raw .new { opacity: 0; }
.diagram[data-state="ingest"] .p2 circle { animation: soak 2.4s var(--ease) infinite; }
.diagram[data-state="query"] .p2 circle { fill: var(--brand); }
.diagram[data-state="query"] .p2 text { fill: #fff; }
.diagram[data-state="query"] .answer { animation: pop 2s var(--ease) infinite; }
.diagram[data-state="lint"] .raw .f1 { opacity: 0; }
.diagram[data-state="lint"] .bad-file rect { animation: ring 1.4s var(--ease) infinite; }
.diagram .wire { animation: march 1.2s linear infinite; }
@keyframes march { to { stroke-dashoffset: -22; } }
@keyframes soak { 0%, 45% { fill: var(--brand-soft); } 60% { fill: var(--sky); } 100% { fill: var(--brand-soft); } }
@keyframes pop { 0%, 40% { opacity: 0; transform: translateY(6px); } 55%, 90% { opacity: 1; transform: none; } 100% { opacity: 0; } }
@keyframes ring { 0% { stroke-width: 1.5; } 50% { stroke-width: 5; } 100% { stroke-width: 1.5; } }
.diagram .answer { transform-box: fill-box; }

/* ── 4. 과정 (남색) ───────────────────── */
.journey { background: var(--night); color: var(--on-night); }
.journey h2, .journey h3 { color: #fff; }
.journey .lead { color: var(--on-night); }
.journey-grid { display: grid; grid-template-columns: 1.1fr 1fr; gap: clamp(32px, 5vw, 80px); margin-top: 48px; }
.stage { position: relative; }
.stage-in { position: sticky; top: calc(var(--top-h) + 24px); height: calc(100vh - var(--top-h) - 48px); display: flex; flex-direction: column; justify-content: center; gap: 16px; }
.rail { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; }
.rail li { position: relative; font-size: 14px; font-weight: 700; color: #7f8aa0; padding-top: 12px; transition: color 0.4s; }
.rail li::before { content: ''; position: absolute; left: 0; right: 0; top: 0; height: 3px; border-radius: 2px; background: var(--night-line); }
.rail li::after { content: ''; position: absolute; left: 0; top: 0; height: 3px; border-radius: 2px; width: 100%; background: var(--sky); transform: scaleX(0); transform-origin: left; transition: transform 0.6s var(--ease); }
.rail li.done, .rail li.on { color: #fff; }
.rail li.done::after, .rail li.on::after { transform: scaleX(1); }
.big-graph { width: 100%; max-height: 62vh; overflow: visible; }
.big-graph line { stroke: var(--sky); stroke-width: 1.6; opacity: 0.45; transition: opacity 0.6s; }
.big-graph circle { fill: var(--sky); transition: opacity 0.5s, transform 0.7s var(--ease); transform-box: fill-box; transform-origin: center; }
.big-graph circle.hot { fill: #fff; }
.big-graph .off { opacity: 0; transform: scale(0.2); }
.big-graph line.off { opacity: 0; transform: none; }
.big-graph circle.fresh { animation: fresh 1.6s var(--ease); }
.big-graph .halo { fill: none; stroke: var(--sky); stroke-width: 2; opacity: 0; transform-box: fill-box; transform-origin: center; }
.big-graph .halo.go { animation: halo 1.4s var(--ease); }
.big-graph text { font-family: inherit; font-size: 17px; font-weight: 700; fill: #fff; paint-order: stroke; stroke: var(--night); stroke-width: 6px; stroke-linejoin: round; transition: opacity 0.5s; }
.big-graph text.off { opacity: 0; }
@keyframes fresh { 0% { fill: #fff; } 100% { fill: var(--sky); } }
@keyframes halo { 0% { opacity: 0.9; transform: scale(1); } 100% { opacity: 0; transform: scale(3.2); } }
.stage-cap { display: flex; align-items: baseline; gap: 12px; color: #fff; font-size: 20px; font-weight: 700; }
.stage-cap b { font-size: 56px; line-height: 1; font-weight: 800; color: var(--sky); font-variant-numeric: tabular-nums; letter-spacing: -0.04em; }
.steps { list-style: none; margin: 0; padding: 18vh 0 30vh; }
.steps li { display: grid; grid-template-columns: 48px 1fr; gap: 16px; padding: 28px 0; border-top: 1px solid var(--night-line); opacity: 0.38; transition: opacity 0.5s; }
.steps li.on { opacity: 1; }
.steps .no { width: 40px; height: 40px; border-radius: 10px; display: grid; place-items: center; font-weight: 800; color: #fff; background: var(--night-2); border: 1px solid var(--night-line); transition: background 0.4s, border-color 0.4s; }
.steps li.on .no { background: var(--brand); border-color: var(--sky); }
.steps h3 { font-size: 24px; font-weight: 750; }
.steps p { margin-top: 8px; font-size: 16.5px; line-height: 1.7; }
.vol { display: inline-block; margin-top: 12px; font-size: 14px; font-weight: 600; color: #fff; border: 1px solid var(--night-line); border-radius: 999px; padding: 4px 12px; }

/* ── 5. 결과물 ────────────────────────── */
.res-grid { display: grid; grid-template-columns: 1.5fr 1fr; grid-template-rows: auto auto; gap: 28px; margin-top: 56px; }
.res { margin: 0; display: flex; flex-direction: column; gap: 14px; }
.res figcaption { display: grid; gap: 2px; }
.res figcaption b { font-size: 19px; color: var(--head); }
.res figcaption span { font-size: 15.5px; color: var(--muted); }
.res-site { grid-row: span 2; }
.browser { border-radius: 14px; overflow: hidden; border: 1px solid var(--line-strong); background: var(--surface); }
.browser .bar { display: flex; align-items: center; gap: 6px; padding: 10px 14px; border-bottom: 1px solid var(--line); background: #f1f0ec; }
.browser .bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--line-strong); }
.browser .bar span { margin-left: 10px; font-size: 13px; color: var(--muted); background: var(--surface); border-radius: 6px; padding: 2px 12px; flex: 1; max-width: 260px; }
.viewport { aspect-ratio: 1440 / 900; overflow: hidden; }
.viewport img { width: 100%; height: auto; }
.motion .viewport img { animation: pan 14s ease-in-out infinite alternate; }
@keyframes pan { 0%, 15% { transform: translateY(0); } 85%, 100% { transform: translateY(-27.2%); } }
.res-paper .paper { background: var(--surface); border: 1px solid var(--line-strong); border-radius: 6px; padding: 10px; max-height: 360px; overflow: hidden; }
.res-paper img { width: 100%; transition: transform 0.9s var(--ease); }
.res-paper:hover img { transform: translateY(-18%); }
.essay { background: var(--surface); border: 1px solid var(--line-strong); border-radius: 12px; padding: 22px; min-height: 230px; }
.essay .q { font-size: 14px; font-weight: 700; color: var(--brand); padding-bottom: 10px; border-bottom: 1px solid var(--line); margin-bottom: 12px; }
.essay .body { font-size: 15.5px; line-height: 1.8; }
.essay .caret { display: inline-block; width: 2px; height: 1.1em; vertical-align: -0.2em; background: var(--brand); margin-left: 1px; animation: blink 1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.res-tree { grid-column: 1 / -1; }
.tree { list-style: none; margin: 0; padding: 22px 24px; background: var(--head); border-radius: 12px; display: grid; grid-template-columns: repeat(5, 1fr); gap: 12px; }
.tree li { display: grid; gap: 4px; color: #fff; padding: 14px; border-radius: 8px; background: var(--night-2); }
.tree li.f .mono { color: var(--sky); }
.tree .mono { font-weight: 600; }
.tree em { font-style: normal; font-size: 14px; color: var(--on-night); }
.motion .tree li { opacity: 0; transform: translateY(10px); transition: opacity 0.6s var(--ease), transform 0.7s var(--ease); }
.motion .tree.play li { opacity: 1; transform: none; }
.motion .tree li:nth-child(2) { transition-delay: 0.12s; }
.motion .tree li:nth-child(3) { transition-delay: 0.24s; }
.motion .tree li:nth-child(4) { transition-delay: 0.36s; }
.motion .tree li:nth-child(5) { transition-delay: 0.48s; }

/* ── 6. GROW ──────────────────────────── */
.grow { background: var(--surface); border-top: 1px solid var(--line); }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(32px, 6vw, 96px); align-items: center; }
.grow-stack { position: relative; list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.grow-stack li {
  position: relative; display: grid; grid-template-columns: 1fr auto; grid-template-areas: 'b s' 'e s'; align-items: center;
  padding: 18px 22px; border-radius: 12px; background: var(--brand-soft); color: var(--head); overflow: hidden;
}
.grow-stack li:nth-child(1) { background: var(--head); color: #fff; }
.grow-stack li:nth-child(2) { background: var(--brand); color: #fff; }
.grow-stack li:nth-child(3) { background: #cfe2f2; }
.grow-stack b { grid-area: b; font-size: 26px; font-weight: 800; letter-spacing: -0.02em; }
.grow-stack em { grid-area: e; font-style: normal; font-size: 15px; opacity: 0.85; }
.grow-stack .mono { grid-area: s; font-size: 14px; opacity: 0.85; }
/* 아래 층부터 차례로 쌓이고, 점이 위로 올라간다 */
.motion .grow-stack li { opacity: 0; transform: translateY(24px); transition: opacity 0.6s var(--ease), transform 0.8s var(--ease); }
.motion .grow-stack.play li { opacity: 1; transform: none; }
.motion .grow-stack li:nth-child(4) { transition-delay: 0s; }
.motion .grow-stack li:nth-child(3) { transition-delay: 0.18s; }
.motion .grow-stack li:nth-child(2) { transition-delay: 0.36s; }
.motion .grow-stack li:nth-child(1) { transition-delay: 0.54s; }
.grow-stack .dot { position: absolute; left: var(--x); bottom: 0; width: 8px; height: 8px; border-radius: 50%; background: var(--sky); z-index: 2; pointer-events: none; animation: climb var(--t, 4s) linear infinite; animation-delay: var(--dl, 0s); opacity: 0; }
@keyframes climb { 0% { transform: translateY(0); opacity: 0; } 10% { opacity: 1; } 90% { opacity: 1; } 100% { transform: translateY(var(--h, -300px)); opacity: 0; } }

/* ── 7. 시작 (남색) ───────────────────── */
.start { position: relative; overflow: hidden; background: var(--night); color: var(--on-night); }
.start h2 { color: #fff; max-width: none; font-size: clamp(36px, 5.6vw, 76px); line-height: 1.1; font-weight: 800; letter-spacing: -0.045em; }
.start .wrap { position: relative; z-index: 1; }
.start-graph { position: absolute; right: -14%; top: 50%; width: min(70vw, 760px); transform: translateY(-50%); opacity: 0.28; }
.start-graph line { stroke: var(--sky); stroke-width: 1.2; opacity: 0.35; }
.start-graph circle { fill: var(--sky); opacity: 0.8; }
.start-graph circle.hot { fill: #fff; }
.motion .start-graph { animation: spin 120s linear infinite; }
@keyframes spin { to { transform: translateY(-50%) rotate(360deg); } }
.need-list { list-style: none; margin: 40px 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; max-width: 980px; border-top: 1px solid var(--night-line); }
.need-list li { display: grid; gap: 6px; padding: 22px 24px 22px 0; }
.need-list li + li { padding-left: 24px; border-left: 1px solid var(--night-line); }
.need-list b { color: #fff; font-size: 19px; }
.need-list span { font-size: 15.5px; }
.fine { margin-top: 8px; font-size: 14px; }
.btn.inv { background: #fff; color: var(--head); }
.btn.inv:hover { background: var(--brand-soft); }
.btn.ghost.inv { background: transparent; color: #fff; }

.foot { background: var(--night); border-top: 1px solid var(--night-line); color: var(--on-night); padding: 28px 0 40px; font-size: 14px; }
.foot .wrap { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 20px; }
.foot img { height: 30px; width: auto; background: var(--night); }

/* ── 좁은 화면 ─────────────────────────── */
@media (max-width: 960px) {
  .wiki-grid, .journey-grid, .two { grid-template-columns: 1fr; }
  .ops { flex-direction: row; border-top: 0; overflow-x: auto; gap: 8px; }
  .ops button { flex: 1 0 200px; border: 1px solid var(--line); border-radius: 10px; padding: 14px; }
  .ops .bar { left: 10px; right: 10px; }
  .chats { grid-template-columns: 1fr; max-width: 560px; }
  .chat { min-height: 0; }
  .res-grid { grid-template-columns: 1fr; }
  .res-site { grid-row: auto; }
  .tree { grid-template-columns: repeat(2, 1fr); }
  .tree li.f { grid-column: 1 / -1; }
  .need-list { grid-template-columns: 1fr; }
  .need-list li, .need-list li + li { padding: 18px 0; border-left: 0; border-bottom: 1px solid var(--night-line); }
  /* 과정: 그래프가 위에 붙고 단계가 그 아래로 지나간다 */
  .stage { display: contents; }
  .stage-in { position: sticky; align-self: start; top: var(--top-h); height: auto; padding: 16px 0 12px; background: var(--night); z-index: 2; gap: 10px; }
  .big-graph { max-height: 26vh; }
  .big-graph text { font-size: 26px; }
  .stage-cap { font-size: 16px; }
  .stage-cap b { font-size: 36px; }
  .steps { padding: 4vh 0 20vh; }
  .start-graph { width: 120vw; right: -40%; opacity: 0.25; }
}
@media (max-width: 720px) {
  .brand .sig { display: none; }
  .brand .sym { display: block; }
  .brand { gap: 10px; font-size: 14px; }
  .top-links .link { display: none; }
  .btn { padding: 10px 14px; }
  .copy-b { bottom: 56px; }
  .scroll-cue { display: none; }
  .scene .lead { font-size: 16px; }
  .cta .btn.big { flex: 1 1 100%; }
}
@media (max-width: 560px) {
  /* 그림 글자가 너무 작아지지 않게 그림은 가로로 밀어 본다 */
  .diagram { overflow-x: auto; }
  .diagram svg { min-width: 560px; }
}
@media (max-width: 400px) {
  .brand .course { font-size: 13px; }
  .sep { display: none; }
}

/* ── 움직임 줄이기: 장면을 펼쳐 완성된 모습만 ─────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .scene { height: auto; }
  /* 한 화면: 왼쪽 글, 오른쪽 완성된 위키 그래프 (좁은 화면은 글만) */
  .scene-pin { position: relative; height: auto; min-height: 100svh; padding: calc(var(--top-h) + 48px) 0 64px; }
  .scene-copy { position: relative; top: auto; bottom: auto; opacity: 1 !important; transform: none !important; }
  .copy-b { display: none; }
  .scroll-cue { display: none; }
  .diagram .flow { transition: none; }
}
@media (prefers-reduced-motion: reduce) and (max-width: 900px) {
  .scene-canvas { display: none; }
}