/* ============================================================
   AM&D Lab — Applied Mechanics and Design Laboratory
   Design system: charcoal ink + amber accent (from lab logo)
   ============================================================ */

:root {
  --ink: #16181d;
  --ink-2: #3a3f47;
  --ink-3: #6b7280;
  --paper: #fbfaf7;
  --paper-2: #f3f1ea;
  --line: #e5e2d9;
  --amber: #e8b820;
  --amber-deep: #c79a0a;
  --amber-soft: rgba(232, 184, 32, 0.14);
  --dark: #101216;
  --dark-2: #191c22;
  --dark-line: rgba(255, 255, 255, 0.09);
  --radius: 16px;
  --radius-sm: 10px;
  /* 전체 Paperlogy 단일 서체. 위계는 굵기·크기·자간으로만 표현한다.
     Paperlogy는 100~900 고정 굵기이므로 550/650 같은 중간값은 쓰지 않는다. */
  --font-display: "Paperlogy", "Wanted Sans Variable", "Pretendard Variable", Pretendard, sans-serif;
  --font-body: "Paperlogy", "Wanted Sans Variable", "Pretendard Variable", Pretendard,
    -apple-system, BlinkMacSystemFont, system-ui, Roboto, "Helvetica Neue", "Segoe UI",
    "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
  --shadow-sm: 0 1px 2px rgba(22, 24, 29, 0.05), 0 4px 12px rgba(22, 24, 29, 0.05);
  --shadow-md: 0 2px 6px rgba(22, 24, 29, 0.06), 0 16px 40px rgba(22, 24, 29, 0.1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font: inherit; border: none; background: none; cursor: pointer; color: inherit; }

.container { max-width: 1160px; margin: 0 auto; padding: 0 24px; }
.center { text-align: center; margin-top: 40px; }

/* ---------- typography ---------- */
h1, h2, h3 { font-family: var(--font-display); letter-spacing: -0.02em; }
.eyebrow {
  font-family: var(--font-display);
  font-size: 12.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--amber-deep);
  margin-bottom: 14px;
}
.kr { font-family: var(--font-body); font-weight: 500; font-size: 0.62em; color: var(--ink-3); margin-left: 8px; letter-spacing: 0; }
.text-link {
  font-weight: 600; color: var(--ink);
  border-bottom: 2px solid var(--amber);
  padding-bottom: 2px; transition: color 0.2s;
}
.text-link:hover { color: var(--amber-deep); }

/* ---------- reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.7s ease var(--d, 0s), transform 0.7s ease var(--d, 0s); }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- nav ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  transition: background 0.3s, box-shadow 0.3s, border-color 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.solid {
  background: rgba(251, 250, 247, 0.86);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}
.nav.on-dark:not(.solid) { color: #fff; }
.nav-inner {
  max-width: 1160px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 68px;
}
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 700; font-size: 19px; }
.brand img { width: 34px; height: auto; }
.brand em { font-style: normal; color: var(--amber-deep); }
.nav.on-dark:not(.solid) .brand em { color: var(--amber); }
.menu { display: flex; align-items: center; gap: 30px; font-weight: 500; font-size: 15px; }
.menu > a, .dropdown > a { opacity: 0.82; transition: opacity 0.2s; display: inline-flex; align-items: center; gap: 5px; padding: 6px 0; }
.menu > a:hover, .dropdown > a:hover { opacity: 1; }
.menu > a.active, .dropdown > a.active { opacity: 1; box-shadow: inset 0 -2px 0 var(--amber); }
.nav-cta {
  background: var(--ink); color: #fff !important; opacity: 1 !important;
  padding: 9px 20px !important; border-radius: 999px; font-size: 14px;
  transition: background 0.2s, transform 0.2s;
}
.nav-cta:hover { background: var(--amber-deep); transform: translateY(-1px); }
.nav.on-dark:not(.solid) .nav-cta { background: var(--amber); color: var(--ink) !important; }

.dropdown { position: relative; }
.dropdown-panel {
  position: absolute; top: calc(100% + 10px); left: -18px; min-width: 218px;
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  box-shadow: var(--shadow-md); padding: 8px;
  opacity: 0; visibility: hidden; transform: translateY(8px);
  transition: opacity 0.22s, transform 0.22s, visibility 0.22s;
  color: var(--ink);
}
.dropdown:hover .dropdown-panel, .dropdown:focus-within .dropdown-panel {
  opacity: 1; visibility: visible; transform: none;
}
.dropdown-panel a {
  display: block; padding: 9px 14px; border-radius: 8px; font-size: 14.5px;
  transition: background 0.15s, color 0.15s;
}
.dropdown-panel a:hover { background: var(--amber-soft); color: var(--amber-deep); }

.lang-btn {
  font-family: var(--font-display); font-size: 12.5px; font-weight: 600;
  letter-spacing: 0.06em; padding: 7px 14px; border-radius: 999px;
  border: 1.5px solid var(--line); color: var(--ink-2); background: transparent;
  transition: all 0.2s; margin-left: 20px; white-space: nowrap;
}
.lang-btn:hover { border-color: var(--amber); color: var(--amber-deep); }
.nav.on-dark:not(.solid) .lang-btn { border-color: rgba(255,255,255,0.3); color: rgba(255,255,255,0.85); }
.nav.on-dark:not(.solid) .lang-btn:hover { border-color: var(--amber); color: var(--amber); }

.hamburger { display: none; flex-direction: column; gap: 5px; padding: 8px; z-index: 110; }
.hamburger span { width: 22px; height: 2px; background: currentColor; transition: transform 0.3s, opacity 0.3s; }
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- hero ---------- */
.hero {
  position: relative; min-height: 100svh;
  background: radial-gradient(1200px 700px at 75% 20%, #1d2129 0%, var(--dark) 55%);
  color: #fff;
  display: flex; align-items: center;
  overflow: hidden;
}
#wave-canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-inner { position: relative; z-index: 2; padding-top: 110px; padding-bottom: 80px; }
.hero .eyebrow { color: var(--amber); }
.hero h1 {
  font-size: clamp(44px, 7.2vw, 84px);
  font-weight: 700; line-height: 1.04; margin-bottom: 26px;
}
.hero .accent { color: var(--amber); }
.hero-lead { font-size: clamp(16px, 2vw, 19px); max-width: 640px; color: rgba(255, 255, 255, 0.9); margin-bottom: 10px; }
.hero-lead-en { font-size: 14.5px; max-width: 620px; color: rgba(255, 255, 255, 0.55); margin-bottom: 34px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 54px; }
.hero-stats { display: flex; gap: 54px; flex-wrap: wrap; }
.hero-stats div { display: flex; flex-direction: column; }
.hero-stats strong { font-family: var(--font-display); font-size: 34px; font-weight: 700; color: var(--amber); line-height: 1.2; }
.hero-stats span { font-size: 13px; color: rgba(255, 255, 255, 0.55); letter-spacing: 0.04em; text-transform: uppercase; }
.hero-scroll { position: absolute; bottom: 26px; left: 50%; transform: translateX(-50%); z-index: 2; }
.hero-scroll span {
  display: block; width: 22px; height: 36px; border: 2px solid rgba(255, 255, 255, 0.35);
  border-radius: 12px; position: relative;
}
.hero-scroll span::after {
  content: ""; position: absolute; top: 6px; left: 50%; width: 4px; height: 8px;
  background: var(--amber); border-radius: 2px; transform: translateX(-50%);
  animation: scrolldot 1.8s infinite ease;
}
@keyframes scrolldot { 0% { opacity: 1; top: 6px; } 70% { opacity: 0; top: 18px; } 100% { opacity: 0; top: 6px; } }

/* ---------- buttons ---------- */
.btn {
  display: inline-block; padding: 13px 28px; border-radius: 999px;
  font-weight: 600; font-size: 15px;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s, color 0.2s;
}
.btn:hover { transform: translateY(-2px); }
.btn-accent { background: var(--amber); color: var(--ink); }
.btn-accent:hover { box-shadow: 0 8px 24px rgba(232, 184, 32, 0.35); }
.btn-ghost { border: 1.5px solid rgba(255, 255, 255, 0.35); color: #fff; }
.btn-ghost:hover { border-color: var(--amber); color: var(--amber); }
.btn-dark { background: var(--ink); color: #fff; }
.btn-dark:hover { background: var(--amber-deep); }

/* ---------- sections ---------- */
.section { padding: 104px 0; }
.section-alt { background: var(--paper-2); }
.section-head { max-width: 640px; margin-bottom: 56px; }
.section-head h2, .about-text h2, .contact-grid h2 {
  font-size: clamp(28px, 3.6vw, 40px); font-weight: 700; line-height: 1.2;
}
.section-sub { color: var(--ink-3); margin-top: 14px; font-size: 16.5px; }

/* ---------- page hero (subpages) ---------- */
.page-hero {
  background: radial-gradient(900px 500px at 80% 0%, #1d2129 0%, var(--dark) 60%);
  color: #fff; padding: 168px 0 84px; position: relative; overflow: hidden;
}
.page-hero > .container { position: relative; z-index: 2; }
.page-hero .eyebrow { color: var(--amber); }
.page-hero h1 { font-size: clamp(36px, 5.5vw, 60px); font-weight: 700; line-height: 1.08; }
.page-hero-sub { margin-top: 18px; max-width: 620px; color: rgba(255, 255, 255, 0.65); font-size: 16.5px; }

/* ---------- about ---------- */
.about-grid { display: grid; grid-template-columns: 1.05fr 1fr; gap: 64px; align-items: center; }
.about-text h2 { margin-bottom: 22px; }
.about-text p { color: var(--ink-2); margin-bottom: 26px; }
.video-frame {
  position: relative; padding-top: 56.25%; border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow-md); background: var(--dark);
}
.video-frame iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }

/* ---------- research cards (home) ---------- */
.rcard-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 26px; }
.rcard {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; display: flex; flex-direction: column;
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}
.rcard:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: transparent; }
.rcard-img { aspect-ratio: 16 / 10; overflow: hidden; background: var(--paper-2); }
.rcard-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s ease; }
.rcard:hover .rcard-img img { transform: scale(1.05); }
.rcard-body { padding: 26px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.rcard-num { font-family: var(--font-display); font-size: 13px; font-weight: 600; color: var(--amber-deep); letter-spacing: 0.12em; }
.rcard-body h3 { font-size: 21px; font-weight: 700; }
.rcard-body p { font-size: 14.5px; color: var(--ink-3); flex: 1; }
.rcard-link { font-size: 14px; font-weight: 600; color: var(--ink); margin-top: 6px; }
.rcard-link .arr { display: inline-block; transition: transform 0.25s; color: var(--amber-deep); }
.rcard:hover .rcard-link .arr, .rrow:hover .rcard-link .arr { transform: translateX(5px); }

/* ---------- research rows (overview page) ---------- */
.rrow-list { display: flex; flex-direction: column; gap: 34px; }
.rrow {
  display: grid; grid-template-columns: 1fr 1.15fr; gap: 0;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.3s, box-shadow 0.3s;
}
.rrow:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.rrow-flip { grid-template-columns: 1.15fr 1fr; }
.rrow-flip .rrow-img { order: 2; }
.rrow-img { min-height: 300px; background: var(--paper-2); }
.rrow-img img { width: 100%; height: 100%; object-fit: cover; }
.rrow-body { padding: 44px 46px; }
.rrow-body h2 { font-size: 27px; margin: 8px 0 4px; }
.rrow-tagline { font-family: var(--font-display); font-size: 13.5px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--amber-deep); margin-bottom: 12px; }
.rrow-desc { color: var(--ink-2); margin-bottom: 16px; }
.dot-list { list-style: none; }
.dot-list li { position: relative; padding-left: 20px; font-size: 14.5px; color: var(--ink-2); margin-bottom: 7px; }
.dot-list li::before { content: ""; position: absolute; left: 2px; top: 9px; width: 7px; height: 7px; border-radius: 50%; background: var(--amber); }
.rrow .rcard-link { display: inline-block; margin-top: 18px; }

/* ---------- research detail ---------- */
.topic-list { display: flex; flex-direction: column; gap: 72px; }
.topic-head { display: flex; align-items: baseline; gap: 18px; margin-bottom: 28px; }
.topic-num { font-family: var(--font-display); font-size: 15px; font-weight: 700; color: var(--amber-deep); }
.topic-head h2 { font-size: clamp(19px, 2.4vw, 24px); font-weight: 700; line-height: 1.35; }
.fig-grid { display: grid; gap: 20px; }
.fig-grid.cols-1 { grid-template-columns: minmax(0, 760px); }
.fig-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.fig-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.fig {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 14px; display: flex; align-items: center; justify-content: center;
  transition: box-shadow 0.3s;
}
.fig:hover { box-shadow: var(--shadow-sm); }
.fig img { border-radius: 6px; }

.pn-nav { border-top: 1px solid var(--line); padding: 36px 0 100px; }
.pn-grid { display: grid; grid-template-columns: 1fr auto 1fr; gap: 20px; align-items: center; }
.pn { display: flex; flex-direction: column; gap: 2px; transition: color 0.2s; }
.pn:hover { color: var(--amber-deep); }
.pn span { font-size: 12.5px; color: var(--ink-3); text-transform: uppercase; letter-spacing: 0.08em; }
.pn strong { font-family: var(--font-display); font-size: 17px; }
.pn.next { text-align: right; align-items: flex-end; }
.pn.all { text-align: center; padding: 10px 22px; border: 1.5px solid var(--line); border-radius: 999px; font-size: 14px; }
.pn.all:hover { border-color: var(--amber); }

/* ---------- people ---------- */
.prof-card {
  display: grid; grid-template-columns: 320px 1fr; gap: 52px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 46px; box-shadow: var(--shadow-sm);
}
.prof-photo img { border-radius: var(--radius-sm); width: 100%; object-fit: cover; aspect-ratio: 3/4; }
.prof-body h2 { font-size: 32px; margin-bottom: 6px; }
.prof-contact { color: var(--ink-3); margin-bottom: 30px; }
.prof-contact a { color: var(--amber-deep); font-weight: 600; }
/* 경력 쪽 문구(영문 학과명)가 길어 약간 더 넓게 배분 */
.prof-cols { display: grid; grid-template-columns: 1fr 1.08fr; gap: 28px; }
.prof-cols h4 {
  font-family: var(--font-display); font-size: 13px; text-transform: uppercase;
  letter-spacing: 0.14em; color: var(--ink-3); margin-bottom: 16px;
}
.timeline { list-style: none; }
/* 배지 열을 고정폭으로 두어 모든 줄의 텍스트 시작점(세로줄)을 맞춘다.
   줄바꿈이 일어나도 이어지는 줄이 같은 위치에서 시작(행잉 인덴트)된다. */
.timeline li {
  display: grid;
  grid-template-columns: var(--tl-w, 58px) 1fr;
  column-gap: 14px;
  align-items: start;
  margin-bottom: 15px;
}
.tl-badge {
  display: block; width: 100%; text-align: center;
  font-family: var(--font-display); font-size: 11.5px; font-weight: 600;
  background: var(--amber-soft); color: var(--amber-deep);
  padding: 3px 6px; border-radius: 999px; margin-top: 3px; white-space: nowrap;
}
.timeline strong { display: block; font-size: 14.5px; font-weight: 600; line-height: 1.45; }
.timeline em {
  display: block; font-style: normal; font-size: 13px;
  color: var(--ink-3); line-height: 1.55; margin-top: 1px;
}
/* 경력 열은 연도 범위(2022 – present)가 들어가므로 배지 폭을 더 넓게 */
.prof-cols > div:nth-child(2) .timeline { --tl-w: 100px; }

.members-section .container + .container { margin-top: 72px; }
.group-title { font-size: clamp(24px, 3vw, 30px); margin-bottom: 30px; }
.group-title::after { content: ""; display: block; width: 44px; height: 4px; background: var(--amber); border-radius: 2px; margin-top: 10px; }
.member-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(255px, 1fr)); gap: 24px; }
.member-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: transform 0.3s, box-shadow 0.3s;
  display: flex; flex-direction: column;
}
.member-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.member-photo { aspect-ratio: 1 / 1.06; overflow: hidden; background: var(--paper-2); }
.member-photo img { width: 100%; height: 100%; object-fit: cover; object-position: top; }
.member-body { padding: 20px 22px 22px; flex: 1; display: flex; flex-direction: column; gap: 8px; }
.member-body h3 { font-size: 18px; font-weight: 700; }
.member-mail { font-size: 13px; color: var(--ink-3); word-break: break-all; }
.member-mail:hover { color: var(--amber-deep); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 2px; }
.chip {
  font-size: 12px; font-weight: 600; background: var(--amber-soft); color: var(--amber-deep);
  padding: 4px 11px; border-radius: 999px;
}
.member-research summary {
  cursor: pointer; font-size: 13.5px; font-weight: 600; color: var(--ink-2);
  margin-top: 6px; list-style: none; display: flex; align-items: center; gap: 6px;
}
.member-research summary::-webkit-details-marker { display: none; }
.member-research summary::after { content: "+"; font-family: var(--font-display); color: var(--amber-deep); font-size: 15px; transition: transform 0.2s; }
.member-research[open] summary::after { transform: rotate(45deg); }
.member-research .dot-list { margin-top: 10px; }
.member-research .dot-list li { font-size: 13px; margin-bottom: 6px; }

.alum-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 22px; }
.alum-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 26px 28px; transition: box-shadow 0.3s; }
.alum-card:hover { box-shadow: var(--shadow-sm); }
.alum-card h3 { font-size: 18px; }
.alum-deg { font-size: 12px; font-weight: 600; color: var(--amber-deep); background: var(--amber-soft); padding: 3px 10px; border-radius: 999px; margin-left: 6px; vertical-align: middle; }
.alum-grad { font-size: 13px; color: var(--ink-3); margin-top: 6px; }
.alum-now { font-size: 14px; font-weight: 500; margin-top: 8px; }

/* ---------- publications ---------- */
.filter-bar { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 44px; }
.filter-btn {
  padding: 9px 22px; border-radius: 999px; border: 1.5px solid var(--line);
  font-size: 14px; font-weight: 600; color: var(--ink-2); background: #fff;
  transition: all 0.2s;
}
.filter-btn:hover { border-color: var(--amber); color: var(--amber-deep); }
.filter-btn.active { background: var(--ink); border-color: var(--ink); color: #fff; }
.pub-list { display: flex; flex-direction: column; gap: 18px; }
.pub-item {
  display: grid; grid-template-columns: 128px 1fr auto; gap: 26px; align-items: center;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 28px 22px 22px; transition: transform 0.25s, box-shadow 0.25s;
}
.pub-item:hover { transform: translateX(4px); box-shadow: var(--shadow-sm); }
.pub-item.hide { display: none; }
.pub-thumb { width: 128px; height: 92px; border-radius: var(--radius-sm); overflow: hidden; background: var(--paper-2); border: 1px solid var(--line); }
.pub-thumb img { width: 100%; height: 100%; object-fit: cover; }
.pub-thumb-empty { background: repeating-linear-gradient(45deg, var(--paper-2), var(--paper-2) 6px, #edeae1 6px, #edeae1 12px); }
.pub-meta { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-bottom: 7px; }
.pub-journal {
  font-size: 12px; font-weight: 700; color: var(--amber-deep);
  background: var(--amber-soft); padding: 3px 12px; border-radius: 999px;
}
.pub-vol { font-size: 12.5px; color: var(--ink-3); }
.pub-body h3 { font-size: 16.5px; font-weight: 600; line-height: 1.45; font-family: var(--font-body); letter-spacing: 0; }
.pub-authors { font-size: 13px; color: var(--ink-3); margin-top: 6px; }
.pub-authors strong { color: var(--ink); font-weight: 700; }
.pub-year { font-family: var(--font-display); font-size: 15px; font-weight: 700; color: var(--line); font-size: 26px; }

/* ---------- gallery ---------- */
.gal-panel { display: none; }
.gal-panel.active { display: block; }
.gal-event { margin-bottom: 54px; }
.gal-event h3 { font-family: var(--font-body); font-size: 17.5px; font-weight: 700; margin-bottom: 16px; padding-left: 14px; border-left: 4px solid var(--amber); }
.gal-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 14px; }
.gal-item {
  border-radius: var(--radius-sm); overflow: hidden; aspect-ratio: 4 / 3;
  background: var(--paper-2); padding: 0; display: block;
}
.gal-item img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease, filter 0.4s; }
.gal-item:hover img { transform: scale(1.06); filter: brightness(1.04); }

.lightbox {
  position: fixed; inset: 0; z-index: 200; background: rgba(12, 13, 16, 0.93);
  display: flex; align-items: center; justify-content: center; padding: 4vmin;
}
.lightbox[hidden] { display: none; }
.lightbox img { max-width: 92vw; max-height: 88vh; border-radius: 10px; object-fit: contain; }
.lb-close {
  position: absolute; top: 18px; right: 26px; font-size: 40px; color: #fff;
  opacity: 0.7; transition: opacity 0.2s; line-height: 1;
}
.lb-close:hover { opacity: 1; }

/* ---------- home: mini publications ---------- */
.pub-mini-list { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.pub-mini {
  display: flex; gap: 20px; background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px 26px;
  transition: transform 0.25s, box-shadow 0.25s;
}
.pub-mini:hover { transform: translateY(-3px); box-shadow: var(--shadow-sm); }
.pub-mini-year { font-family: var(--font-display); font-weight: 700; color: var(--amber-deep); font-size: 15px; }
.pub-mini h4 { font-size: 15px; font-weight: 600; line-height: 1.5; }
.pub-mini p { font-size: 13px; color: var(--ink-3); margin-top: 6px; }
.pub-mini em { font-style: normal; font-weight: 600; }

/* ---------- contact ---------- */
.section-contact { background: var(--paper-2); }
.contact-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 60px; align-items: start; }
.contact-grid h2 { margin-bottom: 26px; }
.contact-list { list-style: none; margin-bottom: 32px; }
.contact-list li { display: grid; grid-template-columns: 90px 1fr; gap: 14px; padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
.contact-list span { font-family: var(--font-display); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-3); padding-top: 3px; }
.contact-list a { color: var(--amber-deep); font-weight: 600; }
.contact-card {
  background: var(--dark); color: #fff; border-radius: var(--radius); padding: 40px;
}
.contact-card h3 { font-size: 24px; margin-bottom: 14px; }
.contact-card h3::after { content: ""; display: block; width: 36px; height: 3px; background: var(--amber); margin-top: 12px; border-radius: 2px; }
.contact-card p { color: rgba(255, 255, 255, 0.72); font-size: 14.5px; margin-bottom: 20px; }
.contact-card .text-link { color: var(--amber); border-color: var(--amber); }

/* ---------- footer ---------- */
.footer { background: var(--dark); color: rgba(255, 255, 255, 0.72); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 0.7fr 1.3fr; gap: 48px; padding: 68px 24px 52px; }
.footer-logo { display: flex; align-items: center; gap: 10px; font-family: var(--font-display); font-weight: 700; font-size: 19px; color: #fff; margin-bottom: 16px; }
.footer-logo img { width: 32px; }
.footer-logo em { font-style: normal; color: var(--amber); }
.footer-brand p, .footer-col p { font-size: 13.5px; line-height: 1.8; }
.footer-col h4 { font-family: var(--font-display); color: #fff; font-size: 13px; text-transform: uppercase; letter-spacing: 0.14em; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; margin-bottom: 9px; opacity: 0.75; transition: opacity 0.2s, color 0.2s; }
.footer-col a:hover { opacity: 1; color: var(--amber); }
.footer-col p a { display: inline; color: var(--amber); }
.footer-bottom { border-top: 1px solid var(--dark-line); padding: 20px 0; font-size: 12.5px; opacity: 0.55; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .about-grid, .contact-grid { grid-template-columns: 1fr; gap: 44px; }
  .rrow, .rrow-flip { grid-template-columns: 1fr; }
  .rrow-flip .rrow-img { order: 0; }
  .rrow-img { min-height: 220px; max-height: 300px; }
  .prof-card { grid-template-columns: 1fr; padding: 30px; }
  .prof-photo { max-width: 300px; }
  .footer-grid { grid-template-columns: 1fr; gap: 36px; }
  .pub-mini-list { grid-template-columns: 1fr; }
  .fig-grid.cols-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
  .menu {
    position: fixed; inset: 0; background: var(--paper);
    flex-direction: column; justify-content: center; gap: 26px;
    font-size: 19px; color: var(--ink);
    opacity: 0; visibility: hidden; transition: opacity 0.3s, visibility 0.3s;
  }
  .menu.open { opacity: 1; visibility: visible; }
  .hamburger { display: flex; }
  .dropdown { display: flex; flex-direction: column; align-items: center; }
  .dropdown-panel {
    position: static; opacity: 1; visibility: visible; transform: none;
    box-shadow: none; border: none; background: none; text-align: center;
    display: none; padding: 4px 0 0;
  }
  .dropdown.open-active .dropdown-panel, .dropdown:focus-within .dropdown-panel { display: block; }
  .dropdown-panel a { padding: 7px 14px; font-size: 15.5px; color: var(--ink-3); }
  .section { padding: 72px 0; }
  .page-hero { padding: 130px 0 60px; }
  .hero-stats { gap: 34px; }
  .prof-cols { grid-template-columns: 1fr; }
  .pub-item { grid-template-columns: 1fr; padding: 22px; }
  .pub-thumb { width: 100%; height: 150px; }
  .pub-year { display: none; }
  .fig-grid.cols-2, .fig-grid.cols-3 { grid-template-columns: 1fr; }
  .pn-grid { grid-template-columns: 1fr; }
  .pn.next { text-align: left; align-items: flex-start; }
  .rrow-body { padding: 30px 26px; }
}

/* ---------- i18n / new components ---------- */
.rcard-en, .rcard-body h3 .rcard-en {
  display: block; font-family: var(--font-body); font-weight: 500;
  font-size: 13px; color: var(--ink-3); letter-spacing: 0; margin-top: 2px;
}
.chip-link { cursor: pointer; text-decoration: none; display: inline-flex; align-items: center; gap: 3px; transition: background 0.18s, color 0.18s; }
.chip-link:hover { background: var(--amber); color: var(--ink); }
.chip-arr { font-size: 10px; opacity: 0.7; }

/* research detail: intro block */
.intro-section { padding-bottom: 72px; }
.intro-grid { display: grid; grid-template-columns: 1.35fr 1fr; gap: 56px; align-items: start; }
.intro-lead p { font-size: 17px; line-height: 1.75; color: var(--ink); }
.related-link { display: inline-block; margin-top: 20px; font-weight: 600; color: var(--amber-deep); border-bottom: 2px solid var(--amber); padding-bottom: 2px; }
.intro-points { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 30px 32px; }
.intro-points h3 { font-size: 15px; font-family: var(--font-display); text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-3); margin-bottom: 18px; }

/* topic sub-caption */
.topic-head > div { display: flex; flex-direction: column; gap: 4px; }
.topic-sub { font-family: var(--font-body); font-size: 14.5px; font-weight: 400; color: var(--ink-3); line-height: 1.6; letter-spacing: 0; }

@media (max-width: 960px) {
  .intro-grid { grid-template-columns: 1fr; gap: 32px; }
}
@media (max-width: 760px) {
  .lang-btn { margin-left: 12px; margin-right: 8px; }
}

/* ---------- hero news rail + section peek ---------- */
.hero { min-height: calc(100svh - 84px); }
.hero-inner {
  display: grid; grid-template-columns: 1.2fr 0.8fr; gap: 64px;
  align-items: center; width: 100%;
}
.hero h1 { font-size: clamp(38px, 4.9vw, 66px); }
.hero-news {
  background: rgba(255, 255, 255, 0.045);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius); padding: 26px 28px;
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}
.hero-news-title {
  font-family: var(--font-display); font-size: 12px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.18em; color: var(--amber);
  padding-bottom: 14px; border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}
.hero-news-item {
  display: flex; align-items: flex-start; gap: 12px; width: 100%;
  padding: 13px 0; text-align: left; color: inherit;
  transition: background 0.2s;
}
.hero-news-item + .hero-news-item { border-top: 1px solid rgba(255, 255, 255, 0.08); }
.news-ico {
  flex-shrink: 0; width: 34px; height: 34px; border-radius: 10px;
  background: rgba(232, 184, 32, 0.14); border: 1px solid rgba(232, 184, 32, 0.25);
  display: flex; align-items: center; justify-content: center; font-size: 16px;
}
.news-body { flex: 1; min-width: 0; }
.news-top { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.hero-news-item h3 { font-size: 14.5px; font-weight: 700; line-height: 1.35; }
.news-date {
  font-family: var(--font-display); font-size: 10.5px; font-weight: 600;
  letter-spacing: 0.06em; color: rgba(232, 184, 32, 0.85); white-space: nowrap;
}
.hero-news-item p {
  font-size: 12px; color: rgba(255, 255, 255, 0.45); line-height: 1.55; margin-top: 3px;
  display: -webkit-box; -webkit-line-clamp: 1; -webkit-box-orient: vertical; overflow: hidden;
  transition: color 0.25s;
}
.hero-news-item.open p { -webkit-line-clamp: unset; color: rgba(255, 255, 255, 0.78); }
.news-chev {
  flex-shrink: 0; margin-top: 8px; color: rgba(255, 255, 255, 0.35);
  transition: transform 0.25s, color 0.2s;
}
.hero-news-item:hover .news-chev { color: var(--amber); }
.hero-news-item:hover h3 { color: var(--amber); }
.hero-news-item.open .news-chev { transform: rotate(180deg); }

/* hero join banner */
.hero-join {
  grid-column: 1 / -1;
  display: flex; align-items: center; justify-content: space-between; gap: 18px;
  margin-top: 34px; padding: 14px 26px;
  border: 1px solid rgba(232, 184, 32, 0.35); border-radius: 999px;
  background: rgba(232, 184, 32, 0.07);
  transition: background 0.25s, transform 0.25s, border-color 0.25s;
}
.hero-join:hover { background: rgba(232, 184, 32, 0.15); transform: translateY(-2px); border-color: var(--amber); }
.hero-join-msg { font-size: 14.5px; color: rgba(255, 255, 255, 0.92); }
.hero-join-msg strong { font-weight: 700; }
.hero-join-sub { color: rgba(255, 255, 255, 0.55); font-size: 13.5px; margin-left: 6px; }
.hero-join-cta {
  font-family: var(--font-display); font-size: 13.5px; font-weight: 600;
  color: var(--amber); white-space: nowrap;
}

@media (max-width: 1080px) {
  .hero { min-height: auto; }
  .hero-inner { grid-template-columns: 1fr; gap: 44px; padding-top: 120px; padding-bottom: 70px; }
  .hero-news { max-width: 560px; }
  .hero-join { flex-direction: column; align-items: flex-start; gap: 6px; border-radius: 22px; }
}
.hero-main .hero-lead { margin-bottom: 36px; max-width: 520px; }
.hero-main .hero-stats { gap: 40px; }
/* tighten hero so the next section peeks below the join banner */
@media (min-width: 1081px) {
  .hero-inner { padding-top: 92px; padding-bottom: 46px; }
  .hero h1 { margin-bottom: 20px; }
  .hero-main .hero-lead { margin-bottom: 28px; }
  .hero-actions { margin-bottom: 40px; }
  .hero-join { margin-top: 30px; }
}

/* news frame slightly lower */
@media (min-width: 1081px) {
  .hero-news { margin-top: 52px; }
}

/* ---------- global scroll cue ---------- */
.scroll-cue {
  position: fixed; right: 30px; bottom: 26px; z-index: 90;
  display: flex; flex-direction: column; align-items: center; gap: 10px;
  color: #fff; mix-blend-mode: difference;
  opacity: 0.85; transition: opacity 0.5s ease, transform 0.5s ease;
  pointer-events: none;
}
.scroll-cue.hide { opacity: 0; transform: translateY(10px); }
.cue-text {
  font-family: var(--font-display); font-size: 9.5px; font-weight: 600;
  letter-spacing: 0.32em; writing-mode: vertical-rl;
}
.cue-line { width: 1.5px; height: 46px; background: rgba(255, 255, 255, 0.28); position: relative; overflow: hidden; border-radius: 2px; }
.cue-line::after {
  content: ""; position: absolute; left: 0; top: -14px; width: 100%; height: 14px;
  background: #fff; border-radius: 2px;
  animation: cuedrop 2.2s cubic-bezier(0.45, 0, 0.55, 1) infinite;
}
@keyframes cuedrop {
  0% { top: -14px; opacity: 0; }
  25% { opacity: 1; }
  70% { top: 46px; opacity: 1; }
  100% { top: 46px; opacity: 0; }
}
@media (prefers-reduced-motion: reduce) { .cue-line::after { animation: none; top: 16px; opacity: 1; } }
@media (max-width: 760px) { .scroll-cue { right: 18px; bottom: 18px; } .cue-line { height: 36px; } }

/* contact map */
.contact-map {
  border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--line); box-shadow: var(--shadow-sm);
  min-height: 340px; background: var(--paper-2);
}
.contact-map iframe { width: 100%; height: 100%; min-height: 340px; border: 0; display: block; filter: grayscale(0.15); }
@media (max-width: 960px) { .contact-map { min-height: 280px; } .contact-map iframe { min-height: 280px; } }
.contact-map { position: relative; display: block; }
.contact-map iframe { pointer-events: none; }
.contact-map-pin {
  position: absolute; left: 14px; bottom: 14px; z-index: 2;
  background: var(--ink); color: #fff; font-size: 13px; font-weight: 600;
  padding: 7px 14px; border-radius: 999px; box-shadow: var(--shadow-md);
}
.contact-map:hover { border-color: var(--amber); }

/* 논문 제목에 DOI 링크가 걸린 경우 */
.pub-body h3 a { transition: color 0.2s; }
.pub-body h3 a:hover { color: var(--amber-deep); }

/* ============================================================
   타이포그래피 정련 (Paperlogy 단일 서체)
   - 큰 제목: 굵게 + 자간 좁게 → 시선을 끈다
   - 작은 설명/메뉴: 굵기를 낮추고 자간·행간을 살짝 넓혀 또렷하게
   ============================================================ */

/* 본문 기본: 한글 가독성을 위해 행간을 넉넉히 */
body { line-height: 1.72; letter-spacing: -0.004em; }

/* 제목 위계: 크기가 클수록 자간을 더 좁혀 단단하게 보이도록 */
.hero h1 { font-weight: 800; letter-spacing: -0.035em; }
.page-hero h1 { font-weight: 800; letter-spacing: -0.03em; }
.section-head h2, .about-text h2, .contact-grid h2,
.news-head h2, .group-title { letter-spacing: -0.028em; }

/* 작은 글씨(설명·메타)는 400 굵기 + 자간을 살짝 벌려 답답함을 없앰 */
.hero-lead, .hero-lead-en, .section-sub, .rcard-body p, .rrow-desc,
.topic-sub, .intro-lead p, .about-text p, .pub-authors, .pub-vol,
.alum-grad, .alum-now, .member-mail, .hero-news-item p, .contact-list,
.footer-brand p, .footer-col p, .dot-list li, .timeline em {
  font-weight: 400;
  letter-spacing: 0.005em;
}

/* 메뉴·라벨류: 500~600으로 또렷하게, 자간은 아주 살짝 */
.menu { font-weight: 500; letter-spacing: 0.005em; }
.dropdown-panel a { font-weight: 500; }
.nav-cta, .btn { letter-spacing: 0.005em; }
.filter-btn { font-weight: 500; }

/* 강조 텍스트는 600 이상으로 확실히 구분 */
.timeline strong, .rcard-link, .member-body h3,
.pub-body h3, .hero-news-item h3 { font-weight: 600; }
.pub-authors strong { font-weight: 700; }

/* 대문자 라벨(eyebrow, SCROLL 등)은 자간을 넓혀 장식적으로 */
.eyebrow, .prof-cols h4, .hero-stats span, .rrow-tagline, .pn span {
  font-weight: 600;
}

/* ---------- 히어로 배경 연구 시뮬레이션 장면 ---------- */
#hero-canvas { position: absolute; inset: 0; width: 100%; height: 100%; z-index: 0; }
/* 텍스트 가독성용 그림자: 왼쪽(제목)과 하단을 더 어둡게 */
.hero-shade {
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background:
    linear-gradient(90deg, rgba(16,18,22,0.64) 0%, rgba(16,18,22,0.34) 45%, rgba(16,18,22,0.16) 100%),
    linear-gradient(180deg, rgba(16,18,22,0.26) 0%, rgba(16,18,22,0) 35%, rgba(16,18,22,0.40) 100%);
}
.hero-inner { z-index: 2; }
.hero-scene-cap {
  position: absolute; left: 24px; bottom: 16px; z-index: 2;
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-display); font-size: 11.5px; font-weight: 500; letter-spacing: 0.04em;
  color: rgba(255,255,255,0.7); pointer-events: none;
}
.hero-scene-cap .cap-dot { width: 6px; height: 6px; border-radius: 50%; background: var(--amber); box-shadow: 0 0 8px var(--amber); }
.hero-scene-cap.swap #hero-scene-name { animation: capIn 0.7s ease both; }
@keyframes capIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }
@media (max-width: 760px) { .hero-scene-cap { left: 16px; bottom: 12px; font-size: 10.5px; } }
.hero-video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; z-index: 0; opacity: 0; filter: saturate(1.05) brightness(1.02); }

/* 서브페이지 히어로: 장면 위 텍스트 가독성 */
.page-hero .hero-shade { background: linear-gradient(90deg, rgba(16,18,22,0.72) 0%, rgba(16,18,22,0.42) 50%, rgba(16,18,22,0.22) 100%), linear-gradient(180deg, rgba(16,18,22,0.30) 0%, rgba(16,18,22,0) 40%, rgba(16,18,22,0.35) 100%); }
.page-hero .hero-scene-cap { bottom: 14px; }