/* =====================================================================
   건축설비 자율화 연구실 v3 — 연구실 홈페이지 스타일
   방향: 편집 디자인 톤. 흰 바탕, 잉크 텍스트, 가는 괘선, 사진·도판 중심.
   - 서체: Pretendard Variable. 본문 400, 메뉴·보조 강조 500, 제목 600.
   - 제목·본문·라벨의 크기와 행간을 구분하고, 자간과 강조는 절제한다.
   - 카드·그림자·그라디언트·아이콘 없음. 색은 강철 블루 1색만.
   ===================================================================== */

@font-face {
  font-family: "Pretendard Variable";
  font-weight: 45 920;
  font-style: normal;
  font-display: swap;
  src: url("fonts/PretendardVariable.woff2") format("woff2");
}

/* ---------- 토큰 ---------- */
:root {
  --ink: #20262d;
  --ink-2: #46505a;
  --muted: #66707a;
  --rule: #e0e4e8;
  --rule-strong: #b9c1c9;
  --paper: #ffffff;
  --paper-2: #f6f7f8;
  --accent: #1e5fa8;
  --accent-ink: #164a84;
  --sans: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  --text-body: 1rem;
  --text-small: 0.875rem;
  --text-caption: 0.8125rem;
  --text-label: 0.71875rem;
  --weight-body: 400;
  --weight-medium: 500;
  --weight-heading: 600;
  --maxw: 1160px;
}

/* ---------- 리셋 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 100px; }
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

body {
  font-family: var(--sans);
  font-weight: var(--weight-body);
  font-size: var(--text-body);
  line-height: 1.75;
  letter-spacing: -0.012em;
  font-kerning: normal;
  color: var(--ink);
  background: var(--paper);
  word-break: keep-all;
  -webkit-font-smoothing: antialiased;
}
b, strong { font-weight: var(--weight-heading); }
em, i { font-style: italic; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

/* ---------- 타이포 ---------- */
h1, h2, h3, h4 { font-weight: var(--weight-heading); line-height: 1.4; letter-spacing: -0.03em; text-wrap: balance; }
h1 { font-size: clamp(1.75rem, 3vw, 2.25rem); line-height: 1.35; max-width: 32ch; }
h2 { font-size: clamp(1.375rem, 2.2vw, 1.625rem); }
h3 { font-size: 1.125rem; letter-spacing: -0.02em; }
.label, .kicker {
  font-size: var(--text-label); font-weight: var(--weight-heading); letter-spacing: 0.08em; text-transform: uppercase; line-height: 1.5;
}
.kicker { color: var(--muted); }
.lead { font-size: 1.0625rem; font-weight: var(--weight-body); line-height: 1.8; color: var(--ink-2); letter-spacing: -0.018em; }
.muted { color: var(--muted); }
.small { font-size: var(--text-small); }
.mono { font-family: var(--sans); font-size: var(--text-caption); letter-spacing: 0; font-variant-numeric: tabular-nums; }
p + p { margin-top: 1em; }
.prose p { max-width: 68ch; }
.prose li { position: relative; padding-left: 18px; margin: 6px 0; }
.prose li::before { content: "–"; position: absolute; left: 0; color: var(--muted); }
a.link, .prose a { color: var(--accent-ink); border-bottom: 1px solid rgba(30, 95, 168, 0.35); }
a.link:hover, .prose a:hover { border-bottom-color: var(--accent-ink); }
.arrow::after { content: " →"; }

/* ---------- 상단 내비 ---------- */
.nav { border-bottom: 1px solid var(--rule); background: var(--paper); position: sticky; top: 0; z-index: 50; }
.nav__in { display: flex; align-items: center; justify-content: space-between; gap: 12px 24px; min-height: 72px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 12px; width: min(380px, 100%); padding: 8px 0; }
/* 편집한 심볼 옆에 영문 정식명을 웹 텍스트로 표시 */
.brand__logo { flex: 0 0 auto; width: 92px; height: auto; object-fit: contain; }
.brand__wordmark { font-size: 1rem; font-weight: var(--weight-heading); line-height: 1.3; letter-spacing: -0.02em; white-space: nowrap; }
.brand__group { display: block; margin-top: 3px; font-size: 0.875em; font-weight: var(--weight-body); color: var(--ink-2); letter-spacing: 0; }
.brand__name { font-weight: var(--weight-heading); font-size: 1rem; letter-spacing: -0.025em; }
.brand__sub { font-size: 0.6875rem; line-height: 1.45; letter-spacing: 0; color: var(--muted); padding-left: 12px; border-left: 1px solid var(--rule); max-width: 225px; }
.nav__links { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.nav__links a { display: inline-block; padding: 10px 0; font-size: var(--text-small); font-weight: var(--weight-medium); letter-spacing: -0.01em; color: var(--ink-2); border-bottom: 1px solid transparent; }
.nav__links a:hover { color: var(--ink); }
.nav__links a.is-active { color: var(--ink); border-bottom-color: var(--ink); }
.nav__links a.nav__mail { margin-left: 8px; color: var(--accent-ink); }
.nav__group { position: relative; flex-shrink: 0; padding: 0; margin: 0; border: 0; }
.nav__group summary { display: block; padding: 10px 0; font-size: var(--text-small); font-weight: var(--weight-medium); letter-spacing: -0.01em; color: var(--ink-2); border-bottom: 1px solid transparent; cursor: pointer; list-style: none; white-space: nowrap; }
.nav__group summary::-webkit-details-marker { display: none; }
.nav__group > summary::after, .nav__group[open] > summary::after { content: none; }
.nav__group summary:hover, .nav__group[open] summary { color: var(--ink); }
.nav__group summary.is-active { color: var(--ink); border-bottom-color: var(--ink); }
.nav__submenu { position: absolute; right: 0; top: 100%; min-width: 160px; padding: 4px 0; background: var(--paper); border: 1px solid var(--rule-strong); }
.nav__submenu a { display: block; padding: 10px 18px; border: 0; white-space: nowrap; }
.nav__submenu a:hover, .nav__submenu a.is-active { color: var(--accent-ink); background: var(--paper-2); }

/* ---------- 섹션 공통 ---------- */
.section { padding: 76px 0; border-top: 1px solid var(--rule); }
.section--flush { border-top: 0; }
.sec-head { display: grid; grid-template-columns: 200px 1fr; gap: 20px 32px; align-items: baseline; margin-bottom: 36px; }
.sec-head .kicker { padding-top: 6px; }
.sec-head p { margin-top: 12px; color: var(--ink-2); max-width: 66ch; }
.sec-head--stack { grid-template-columns: 1fr; gap: 16px; }
body[data-page="index"] .sec-head > .kicker { font-size: 1.375rem; font-weight: var(--weight-heading); letter-spacing: 0.015em; line-height: 1.4; color: var(--ink); }
.more { margin-top: 32px; font-size: var(--text-small); }
.more a { color: var(--accent-ink); font-weight: var(--weight-medium); }
.more .sep { color: var(--rule-strong); margin: 0 10px; }

/* ---------- 히어로 ---------- */
.hero { padding: 72px 0 80px; }
.hero__grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center; }
.hero h1 { font-size: clamp(1.875rem, 3.5vw, 2.75rem); font-weight: var(--weight-heading); letter-spacing: -0.03em; line-height: 1.2; }
.hero__name { margin-top: 16px; font-size: 1.25rem; font-weight: var(--weight-medium); letter-spacing: -0.025em; line-height: 1.5; }
.hero .tagline { margin-top: 16px; font-size: clamp(1.0625rem, 1.6vw, 1.25rem); color: var(--ink-2); font-weight: var(--weight-body); letter-spacing: -0.025em; line-height: 1.5; }
.hero .lead { margin-top: 28px; font-size: 1rem; }
.hero .lead > span { display: block; }
.facts { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; margin-top: 40px; padding-top: 22px; border-top: 1px solid var(--rule); }
.facts dt { font-size: var(--text-label); font-weight: var(--weight-medium); letter-spacing: 0.065em; text-transform: uppercase; color: var(--muted); }
.facts dd { margin-top: 8px; font-size: var(--text-caption); line-height: 1.75; color: var(--ink-2); }
.hero__fig img { width: 100%; aspect-ratio: 4 / 5; object-fit: cover; }

/* ---------- 도판 (figure) ---------- */
.fig { margin: 0; }
.fig img { width: 100%; border: 1px solid var(--rule); background: #fff; }
.fig--frame img { aspect-ratio: var(--ar, 4 / 3); object-fit: contain; padding: 14px; }
.fig--photo img { object-fit: cover; aspect-ratio: var(--ar, 3 / 2); }
.fig figcaption { margin-top: 12px; font-size: var(--text-caption); line-height: 1.65; color: var(--muted); }
.fig figcaption .src { font-size: 0.75rem; display: block; margin-top: 4px; letter-spacing: 0; }
/* 이미지 파일이 아직 없을 때: 도면식 해칭 자리표시 */
.fig__ph { display: none; }
.fig.is-missing img { display: none; }
.fig.is-missing .fig__ph {
  display: flex; flex-direction: column; justify-content: flex-end; gap: 6px;
  aspect-ratio: var(--ar, 3 / 2); padding: 16px 18px;
  border: 1px dashed var(--rule-strong);
  background: repeating-linear-gradient(-45deg, #fbfbf8 0 9px, #efefe9 9px 18px);
  color: var(--ink-2);
}
.fig__ph-tag { font-family: var(--sans); font-size: var(--text-label); font-weight: var(--weight-medium); letter-spacing: 0.025em; color: var(--muted); }
.fig__ph-note { font-size: var(--text-caption); line-height: 1.6; }

/* ---------- 홈: 이름의 의미 3열 ---------- */
.name-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--ink); }
.name-grid > div { padding: 30px 32px 34px 0; border-bottom: 1px solid var(--rule); }
.name-grid > div + div { padding-left: 32px; border-left: 1px solid var(--rule); }
.name-grid .word { font-size: 1.5rem; font-weight: var(--weight-medium); line-height: 1.3; letter-spacing: -0.035em; }
.name-grid .role { margin-top: 10px; font-size: var(--text-label); font-weight: var(--weight-medium); letter-spacing: 0.04em; text-transform: uppercase; color: var(--muted); }
.name-grid p { margin-top: 18px; color: var(--ink-2); font-size: 0.9375rem; line-height: 1.75; }
.name-note { margin-top: 28px; max-width: 74ch; color: var(--ink-2); }

/* ---------- 홈: 비전 3행 ---------- */
.vision { border-top: 1px solid var(--ink); }
.vision > div { display: grid; grid-template-columns: 200px 1fr 1.5fr; gap: 16px 40px; padding: 32px 0; border-bottom: 1px solid var(--rule); align-items: start; }
.vision .en { font-size: 0.76rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-ink); padding-top: 8px; }
.vision h3 { font-size: 1.4rem; line-height: 1.3; letter-spacing: -0.015em; }
.vision p { color: var(--ink-2); max-width: 60ch; }

/* ---------- 홈: 자율화 5단계 ---------- */
.levels { display: grid; grid-template-columns: repeat(5, 1fr); border-top: 1px solid var(--ink); }
.levels > div { padding: 24px 22px 28px 0; border-bottom: 1px solid var(--rule); }
.levels > div + div { padding-left: 22px; border-left: 1px solid var(--rule); }
.levels .lv { font-size: 0.74rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent-ink); }
.levels h3 { margin-top: 8px; font-size: 1.08rem; }
.levels p { margin-top: 10px; font-size: 0.9rem; color: var(--ink-2); line-height: 1.7; }
.levels .ev { margin-top: 14px; font-size: 0.8rem; color: var(--muted); line-height: 1.6; }
.levels .ev a { color: var(--accent-ink); }
.levels .is-next .lv, .levels .is-next h3 { color: var(--muted); }

/* ---------- 홈: 이름 풀이 (두 구절) ---------- */
.gloss { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 32px; }
.gloss > div { border-left: 2px solid var(--ink); padding: 4px 0 4px 18px; }
.gloss .en { display: block; font-size: 1.0625rem; font-weight: var(--weight-medium); color: var(--ink); letter-spacing: -0.02em; }
.gloss span + span { display: block; margin-top: 6px; font-size: 0.9375rem; color: var(--ink-2); }

/* ---------- 인라인 SVG 도식 공통 ---------- */
.diagram { width: 100%; height: auto; display: block; overflow: visible; }
.diagram text { font-family: var(--sans); font-size: 12px; font-weight: var(--weight-body); fill: var(--ink-2); letter-spacing: 0; }
.d-ink { fill: none; stroke: var(--ink); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.d-rule { fill: none; stroke: var(--rule-strong); stroke-width: 1; stroke-dasharray: 3 4; }
.d-muted { fill: none; stroke: var(--rule-strong); stroke-width: 1.5; }
.d-accent { fill: none; stroke: var(--accent); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.d-fill { fill: rgba(30, 95, 168, 0.14); stroke: var(--accent); stroke-width: 2; stroke-linejoin: round; }
.d-fill-solid { fill: var(--accent); }
.d-rule-rect { fill: none; stroke: var(--rule-strong); stroke-width: 1; }
.d-ink-rect { fill: none; stroke: var(--ink); stroke-width: 1.5; }
.d-label { font-size: 12px; letter-spacing: 0.02em; }
.d-accent-text { fill: var(--accent-ink); }
.d-muted-text { fill: var(--muted); }
.d-on-accent { fill: #fff; }

/* ---------- 홈: 비전 도식 3열 ---------- */
.vis { display: grid; grid-template-columns: repeat(3, 1fr); gap: 36px; border-top: 1px solid var(--ink); padding-top: 32px; }
.vis__panel { margin: 0; }
.vis__panel .en { display: block; font-size: var(--text-label); font-weight: var(--weight-heading); letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.vis__panel .diagram { margin-top: 14px; border: 1px solid var(--rule); background: var(--paper); }
.vis__panel img.diagram { aspect-ratio: 8 / 5; object-fit: contain; }
.vis__panel figcaption { margin-top: 16px; font-size: 0.9375rem; line-height: 1.75; color: var(--ink-2); }
.vis__panel figcaption > strong { display: block; margin-bottom: 6px; font-size: 1.125rem; font-weight: var(--weight-heading); line-height: 1.5; letter-spacing: -0.025em; color: var(--accent-ink); }
.vis__panel figcaption > span { display: block; }

/* ---------- 홈: 자율화 5단계 계단 도식 ---------- */
.stair { margin-top: 4px; }
.stair .s-done { fill: rgba(30, 95, 168, 0.12); stroke: var(--ink); stroke-width: 1.5; }
.stair .s-next { fill: none; stroke: var(--ink); stroke-width: 1.5; stroke-dasharray: 6 5; }
.stair .s-lv { font-size: 11px; font-weight: var(--weight-medium); letter-spacing: 0.06em; text-transform: uppercase; fill: var(--accent-ink); }
.stair .s-title { font-size: 18px; font-weight: var(--weight-heading); fill: var(--ink); letter-spacing: -0.02em; }
.stair .s-sub { font-size: 13px; fill: var(--muted); }
.stair .s-next-text .s-lv, .stair .s-next-text .s-title { fill: var(--muted); }
.stair .s-now { fill: var(--accent); }
.stair .s-now-text { font-size: 12px; font-weight: var(--weight-medium); fill: var(--accent-ink); letter-spacing: 0; }
.levels-list { display: none; }
.levels-refs { margin-top: 16px; font-size: 0.82rem; color: var(--muted); line-height: 1.8; }
.levels-refs a { color: var(--accent-ink); }
.levels-refs .sep { margin: 0 8px; color: var(--rule-strong); }

/* ---------- 홈: 모집 한 줄 ---------- */
.cta { font-size: clamp(1.25rem, 2.2vw, 1.625rem); font-weight: var(--weight-medium); line-height: 1.6; letter-spacing: -0.03em; }
.cta a { display: inline-block; margin-top: 12px; font-size: 1rem; font-weight: var(--weight-body); letter-spacing: 0; color: var(--accent-ink); border-bottom: 1px solid rgba(30, 95, 168, 0.35); }
.cta a:hover { border-bottom-color: var(--accent-ink); }
#join .fig { margin-top: 8px; }

/* ---------- 홈: 연구 분야 3열 ---------- */
.areas { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px 36px; }
.area__no { font-size: var(--text-label); font-weight: var(--weight-heading); letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); }
.area h3 { margin-top: 14px; font-size: 1.125rem; line-height: 1.5; }
.area h3 small { display: block; font-size: 0.74rem; font-weight: 500; color: var(--muted); letter-spacing: 0.04em; margin-top: 6px; }
.area p { margin-top: 12px; color: var(--ink-2); font-size: 0.9375rem; line-height: 1.75; }
.area__points { margin-top: 12px; color: var(--ink-2); font-size: 0.9375rem; line-height: 1.75; }
.area__points li { position: relative; padding-left: 14px; }
.area__points li::before { content: "·"; position: absolute; left: 0; }
.area .fig { margin-top: 18px; }
.area .link { display: inline-block; margin-top: 14px; font-size: var(--text-small); font-weight: var(--weight-medium); }

/* ---------- 홈: 데모 ---------- */
.demos { display: grid; grid-template-columns: 1fr; gap: 56px; }
.demo h3 { font-size: 1.125rem; line-height: 1.5; }
.demo__frame { display: block; width: 100%; aspect-ratio: 16 / 9; border: 0; margin-top: 16px; background: #fff; }

/* ---------- 홈: 대표 성과 ---------- */
.feature { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 48px; align-items: center; }
.feature h3 { font-size: 1.1875rem; font-weight: var(--weight-medium); line-height: 1.65; letter-spacing: -0.025em; text-wrap: pretty; }
.feature p { margin-top: 14px; color: var(--ink-2); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 24px; padding-top: 18px; border-top: 1px solid var(--rule); }
.stats b { display: block; font-size: 1.875rem; font-weight: var(--weight-medium); line-height: 1.25; letter-spacing: -0.045em; font-variant-numeric: tabular-nums; }
.stats span { display: block; margin-top: 10px; font-size: var(--text-caption); line-height: 1.65; color: var(--muted); }

/* ---------- 프로젝트 목록 ---------- */
.projects { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px 36px; }
.project .meta { font-size: 0.78rem; letter-spacing: 0.04em; color: var(--muted); margin-top: 14px; }
.project h3 { margin-top: 8px; font-size: 1.08rem; line-height: 1.45; }
.project p { margin-top: 8px; font-size: 0.95rem; color: var(--ink-2); }
.project .tag { display: inline-block; margin-top: 10px; font-size: 0.74rem; color: var(--accent-ink); letter-spacing: 0.06em; }

/* 프로젝트 상세 (프로젝트 페이지) */
.proj-row { display: grid; grid-template-columns: 200px 1fr 340px; gap: 28px 40px; padding: 36px 0; border-top: 1px solid var(--rule); }
.proj-row:last-child { border-bottom: 1px solid var(--rule); }
.proj-row .meta { font-size: var(--text-caption); line-height: 1.85; color: var(--muted); font-variant-numeric: tabular-nums; }
.proj-row .meta b { display: block; margin-bottom: 4px; font-size: var(--text-small); color: var(--ink); font-weight: var(--weight-medium); }
.proj-row h3 { font-size: 1.125rem; line-height: 1.5; }
.proj-row p { margin-top: 12px; color: var(--ink-2); font-size: 0.9375rem; line-height: 1.8; }
.proj-row ul { margin-top: 10px; }
.proj-row li { position: relative; padding-left: 16px; font-size: 0.9375rem; color: var(--ink-2); margin: 6px 0; }
.proj-row li::before { content: "–"; position: absolute; left: 0; color: var(--muted); }

/* ---------- 표 ---------- */
.table { width: 100%; border-collapse: collapse; font-size: var(--text-small); line-height: 1.7; }
.table th, .table td { text-align: left; padding: 12px 14px 12px 0; border-top: 1px solid var(--rule); vertical-align: top; }
.table th { font-size: var(--text-label); letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); font-weight: var(--weight-medium); }
.table tr:last-child td { border-bottom: 1px solid var(--rule); }
.table td.mono { font-family: var(--sans); font-size: var(--text-caption); white-space: nowrap; color: var(--muted); letter-spacing: 0; }

/* ---------- 논문 목록 ---------- */
.pubs { border-top: 1px solid var(--rule); }
.pub { display: grid; grid-template-columns: 76px 1fr; gap: 20px; padding: 24px 0; border-bottom: 1px solid var(--rule); }
.pub__year { font-size: var(--text-caption); font-weight: var(--weight-medium); color: var(--muted); padding-top: 3px; letter-spacing: 0; font-variant-numeric: tabular-nums; }
.pub__title { font-size: 1.0625rem; font-weight: var(--weight-medium); line-height: 1.6; letter-spacing: -0.012em; }
.pub__title a { color: inherit; }
.pub__title a:hover { color: var(--accent-ink); }
.pub__meta { margin-top: 8px; font-size: var(--text-small); color: var(--muted); line-height: 1.75; }
.pub__meta b { font-weight: var(--weight-medium); color: var(--ink-2); }
.pub__meta i { font-style: italic; }
.pub__meta .doi { font-size: 0.75rem; color: var(--accent-ink); letter-spacing: 0; overflow-wrap: anywhere; }
.pub__flag { display: inline-block; margin-left: 10px; font-size: 0.6875rem; font-weight: var(--weight-medium); letter-spacing: 0.04em; text-transform: uppercase; color: var(--accent-ink); vertical-align: middle; }
.pub--compact { grid-template-columns: 76px 1fr; padding: 12px 0; }
.pub--compact .pub__title { font-weight: var(--weight-medium); font-size: 0.9375rem; }
details { border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); padding: 14px 0; margin-top: 28px; }
summary { cursor: pointer; font-size: var(--text-small); font-weight: var(--weight-medium); list-style: none; display: flex; justify-content: space-between; gap: 20px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "펼치기 +"; flex: none; font-size: 0.75rem; font-weight: var(--weight-body); color: var(--muted); letter-spacing: 0; }
details[open] summary::after { content: "접기 −"; }
details .pubs { margin-top: 14px; border-top: 0; }

/* ---------- 연구 페이지 ---------- */
.flow { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 16px; align-items: stretch; margin-top: 8px; }
.flow__step { padding: 20px 22px; border: 1px solid var(--rule); }
.flow__step .kicker { color: var(--muted); }
.flow__step h3 { margin-top: 10px; font-size: 1.0625rem; }
.flow__step p { margin-top: 10px; font-size: var(--text-small); line-height: 1.8; color: var(--ink-2); }
.flow__arrow { align-self: center; color: var(--muted); }
.topic { display: grid; grid-template-columns: 200px 1fr; gap: 24px 40px; padding: 68px 0; border-top: 1px solid var(--rule); }
.topic__side { position: sticky; top: 90px; align-self: start; }
.topic__side .kicker { display: block; }
.topic__side h2 { margin-top: 12px; font-size: 1.3125rem; line-height: 1.5; }
.topic__side h2 small { display: block; font-size: 0.75rem; font-weight: var(--weight-body); line-height: 1.7; color: var(--muted); margin-top: 10px; letter-spacing: 0; }
.topic__side .papers { margin-top: 24px; padding-top: 16px; border-top: 1px solid var(--rule); font-size: var(--text-caption); line-height: 1.85; color: var(--ink-2); }
.topic__side .papers .label { display: block; color: var(--muted); margin-bottom: 4px; }
.topic__side .papers a { color: var(--accent-ink); }
.topic__body h3 { margin-top: 32px; font-size: 1.0625rem; }
.topic__body h3:first-child { margin-top: 0; }
.topic__body p { margin-top: 12px; color: var(--ink-2); line-height: 1.85; max-width: 70ch; }
.figs-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; margin-top: 26px; }
.figs-1 { margin-top: 26px; }
.figs-1 .fig img { max-height: 620px; object-fit: contain; }
.numbers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin-top: 24px; }
.numbers div { padding: 16px 18px; border: 1px solid var(--rule); }
.numbers b { display: block; font-size: 1.5rem; font-weight: var(--weight-medium); line-height: 1.3; letter-spacing: -0.03em; font-variant-numeric: tabular-nums; }
.numbers span { display: block; margin-top: 10px; font-size: var(--text-caption); color: var(--muted); line-height: 1.65; }

/* ---------- 구성원 / 연락 ---------- */
.group-heading { padding-bottom: 0; }
.group-heading .sec-head { margin-bottom: 28px; }
.group-nav { display: flex; gap: 28px; border-bottom: 1px solid var(--rule); }
.group-nav a { padding: 12px 0; font-size: var(--text-small); font-weight: var(--weight-medium); color: var(--muted); border-bottom: 2px solid transparent; margin-bottom: -1px; }
.group-nav a:hover { color: var(--ink); }
.group-nav a[aria-current="page"] { color: var(--accent-ink); border-bottom-color: var(--accent); }
.group-content { padding-top: 48px; border-top: 0; }
.profile { display: grid; grid-template-columns: 300px 1fr; gap: 48px; align-items: start; }
.profile--professor { grid-template-columns: 240px 1fr; }
body[data-page="professor"] #pi { padding-bottom: 0; }
body[data-page="professor"] #background { padding-top: 0; border-top: 0; }
body[data-page="professor"] #background .kv { margin-top: 44px; }
.professor-intro { margin-top: 24px; color: var(--ink-2); font-size: 1rem; line-height: 1.85; }
.professor-intro__lead { font-size: 1.25rem; font-weight: var(--weight-heading); line-height: 1.6; letter-spacing: -0.025em; color: var(--ink); }
.profile__fig img { aspect-ratio: 3 / 4; object-fit: cover; }
.profile h2 { font-size: 1.75rem; }
.profile h2 small { display: block; font-size: var(--text-small); font-weight: var(--weight-body); line-height: 1.6; color: var(--muted); margin-top: 10px; letter-spacing: 0; }
.profile .lead { margin-top: 16px; }
.kv { margin-top: 26px; border-top: 1px solid var(--rule); }
.kv > div { display: grid; grid-template-columns: 120px 1fr; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--rule); font-size: 0.9375rem; }
.kv dt { font-size: var(--text-label); font-weight: var(--weight-medium); letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted); padding-top: 4px; }
.kv dd ul li { margin: 4px 0; }
.members { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; }
.member .fig img { aspect-ratio: 3 / 4; object-fit: cover; }
.member h3 { margin-top: 12px; font-size: 1rem; }
.member p { margin-top: 4px; font-size: var(--text-small); color: var(--muted); }
.join-intro { container-type: inline-size; }
.join-intro p { max-width: none; }
.join-topics__title { margin-bottom: 16px; font-size: 1.25rem; line-height: 1.5; }
.join-topics { border-top: 1px solid var(--rule-strong); }
.join-topic { padding: 24px 0; border-bottom: 1px solid var(--rule); }
.join-topic h3 { font-size: 1.0625rem; line-height: 1.6; }
.join-topic ul { margin-top: 12px; }
.cols-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.cols-2 h3 { font-size: 1.0625rem; }
.cols-2 ul { margin-top: 12px; }
.cols-2 li { position: relative; padding-left: 18px; margin: 8px 0; color: var(--ink-2); }
.cols-2 li::before { content: "–"; position: absolute; left: 0; color: var(--muted); }
.contact-line { margin-top: 24px; font-size: 0.9375rem; line-height: 1.8; }
.contact-line a { color: var(--accent-ink); border-bottom: 1px solid rgba(30, 95, 168, 0.35); }

/* ---------- 풋터 ---------- */
.footer { border-top: 1px solid var(--rule-strong); margin-top: 40px; padding: 48px 0 32px; font-size: var(--text-small); color: var(--ink-2); }
.footer__grid { display: grid; grid-template-columns: 1.2fr 1fr 1fr; gap: 32px; }
.footer .brand__name { font-size: 0.9375rem; }
.footer p { margin-top: 10px; font-size: var(--text-caption); line-height: 1.8; }
.footer .small { font-size: var(--text-caption); }
.footer .kicker { color: var(--muted); }
.footer a:hover { color: var(--accent-ink); }
.footer__bottom { margin-top: 32px; padding-top: 16px; border-top: 1px solid var(--rule); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 0.75rem; color: var(--muted); letter-spacing: 0; }

/* ---------- 반응형 ---------- */
@media (min-width: 700px) {
  .join-intro p { font-size: clamp(0.875rem, 2.3cqw, 1rem); }
}
@media (max-width: 1100px) {
  .brand__sub { display: none; }
}
@media (max-width: 1000px) {
  html { scroll-padding-top: 168px; }
  .hero__grid, .feature, .profile, .cols-2, .footer__grid { grid-template-columns: 1fr; }
  .profile--professor .profile__text { grid-row: 1; }
  .profile--professor .profile__fig { grid-row: 2; max-width: 240px; }
  .areas, .projects { grid-template-columns: 1fr 1fr; }
  .members { grid-template-columns: repeat(3, 1fr); }
  .proj-row { grid-template-columns: 1fr; gap: 16px; }
  .topic { grid-template-columns: 1fr; padding: 52px 0; }
  .topic__side { position: static; }
  .sec-head { grid-template-columns: 1fr; gap: 8px; }
  .flow { grid-template-columns: 1fr; }
  .flow__arrow { transform: rotate(90deg); justify-self: center; }
  .hero__fig img { aspect-ratio: 3 / 2; }
  .vision > div { grid-template-columns: 1fr; gap: 8px; }
  .levels { grid-template-columns: 1fr 1fr; }
  .levels > div + div { padding-left: 0; border-left: 0; }
  .levels > div:nth-child(even) { padding-left: 22px; border-left: 1px solid var(--rule); }
  .vis { grid-template-columns: 1fr; gap: 40px; }
  .vis__panel .diagram { max-width: 520px; }
}
@media (max-width: 760px) {
  .stair { display: none; }
  .levels-list { display: block; border-top: 1px solid var(--ink); }
  .levels-list li { display: grid; grid-template-columns: 72px 1fr; gap: 14px; padding: 14px 0; border-bottom: 1px solid var(--rule); font-size: 0.95rem; color: var(--ink-2); }
  .levels-list li span { font-size: var(--text-label); font-weight: var(--weight-medium); letter-spacing: 0.04em; text-transform: uppercase; color: var(--accent-ink); padding-top: 4px; }
  .levels-list li b { color: var(--ink); }
  .levels-list li.is-next span, .levels-list li.is-next b { color: var(--muted); }
  .gloss { grid-template-columns: 1fr; gap: 14px; }
}
@media (max-width: 640px) {
  html { scroll-padding-top: 142px; }
  .wrap { padding: 0 20px; }
  .section { padding: 56px 0; }
  .sec-head { margin-bottom: 28px; }
  .sec-head--stack { gap: 12px; }
  .lead { font-size: 1rem; }
  .hero { padding: 44px 0 52px; }
  .hero__grid { gap: 32px; }
  .hero h1 { font-size: clamp(1.75rem, 7.5vw, 2.25rem); }
  .hero__name { font-size: 1.125rem; }
  .hero .tagline { font-size: 1.0625rem; margin-top: 12px; }
  .hero .lead { margin-top: 22px; }
  .areas, .projects, .figs-2, .numbers, .stats, .facts, .name-grid, .levels { grid-template-columns: 1fr; }
  .name-grid > div + div, .levels > div, .levels > div:nth-child(even) { padding-left: 0; border-left: 0; }
  .name-grid > div { padding-right: 0; }
  .members { grid-template-columns: 1fr 1fr; }
  .brand__sub { display: none; }
  .nav__in { gap: 0; min-height: 0; }
  .brand { gap: 10px; width: min(360px, 100%); padding: 8px 0 2px; }
  .brand__logo { width: clamp(64px, 18vw, 92px); }
  .brand__wordmark { font-size: clamp(0.75rem, 3.4vw, 1rem); }
  .brand__name { font-size: 0.9375rem; }
  .nav__links { width: 100%; justify-content: space-between; gap: 8px; flex-wrap: nowrap; }
  .nav__links > a, .nav__group summary { padding: 9px 0 11px; font-size: clamp(0.6875rem, 3.2vw, 0.78125rem); }
  .nav__links a.nav__mail { margin-left: 0; }
  .group-heading { padding-bottom: 0; }
  .group-content { padding-top: 32px; }
  .professor-intro { font-size: 1rem; }
  .professor-intro__lead { font-size: 1.125rem; }
  body[data-page="professor"] #background .kv { margin-top: 32px; }
  .pub { grid-template-columns: 1fr; gap: 4px; }
  .pub__title { font-size: 1rem; }
  .kv > div { grid-template-columns: 1fr; gap: 4px; }
}
/* 그림 클릭 확대 (Research·Projects, site.js 가 .zoom 을 만든다) */
.is-zoomable { cursor: zoom-in; }
.zoom { position: fixed; inset: 0; z-index: 100; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 64px 28px 32px; background: rgba(255, 255, 255, 0.97); cursor: zoom-out; }
.zoom[hidden] { display: none; }
.zoom__img { display: block; width: auto; height: auto; max-width: min(1400px, 100%); max-height: calc(100vh - 160px); border: 1px solid var(--rule); background: #fff; }
.zoom__cap { margin-top: 14px; max-width: 72ch; font-size: var(--text-caption); line-height: 1.65; color: var(--muted); text-align: center; }
.zoom__close { position: absolute; top: 18px; right: 28px; padding: 2px 0; font: inherit; font-size: var(--text-small); color: var(--ink); background: none; border: 0; border-bottom: 1px solid var(--ink); cursor: pointer; }
body.is-zoomed { overflow: hidden; }
@media (max-width: 720px) {
  .zoom { padding: 56px 16px 24px; }
  .zoom__img { max-height: calc(100vh - 140px); }
  .zoom__close { right: 16px; }
}
/* 언어 전환 링크 (English ↔ 한국어). 상단 메뉴 맨 오른쪽, site.js 가 만든다 */
.nav__links a.nav__lang { margin-left: 8px; padding-left: 16px; border-left: 1px solid var(--rule); color: var(--muted); }
.nav__links a.nav__lang:hover { color: var(--ink); }
@media (max-width: 640px) {
  .nav__links a.nav__lang { margin-left: 0; padding-left: 8px; }
}

@media print {
  .nav, .footer__bottom { display: none; }
}