:root {
  --paper: #f3f0e8;
  --paper-deep: #e7e1d5;
  --white: #fffdf8;
  --ink: #142126;
  --ink-soft: #34454b;
  --teal: #0c6b6d;
  --teal-deep: #074b4d;
  --rust: #a84a31;
  --line: #cfc8bb;
  --max: 1180px;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, "Segoe UI", Arial, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
img { max-width: 100%; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { line-height: 1.12; }
h1, h2 { font-family: var(--serif); font-weight: 500; letter-spacing: -0.035em; }
h1 { font-size: clamp(2.8rem, 7vw, 5.8rem); }
h2 { font-size: clamp(2.1rem, 4vw, 3.6rem); }
h3 { font-size: 1.22rem; }

.wrap { width: min(calc(100% - 40px), var(--max)); margin-inline: auto; }
.section { padding-block: clamp(72px, 9vw, 128px); }
.section--soft { background: var(--paper-deep); }
.section--ink { color: var(--white); background: var(--ink); }
.skip-link { position: fixed; left: 20px; top: -80px; z-index: 20; padding: 10px 16px; background: var(--white); }
.skip-link:focus { top: 12px; }
.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; }

.site-header { position: relative; z-index: 10; border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--paper) 94%, transparent); }
.header-inner { min-height: 92px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; line-height: 1.1; }
.brand-mark { width: 42px; height: 42px; display: grid; place-items: center; color: var(--white); background: var(--teal-deep); font: 700 0.82rem/1 var(--sans); letter-spacing: 0.06em; }
.brand strong { display: block; font-size: 0.98rem; }
.brand small { display: block; margin-top: 5px; color: var(--ink-soft); font-size: 0.72rem; }
.site-nav { display: flex; align-items: center; gap: clamp(14px, 1.8vw, 26px); }
.site-nav a { position: relative; padding-block: 7px; color: var(--ink-soft); font-size: 0.82rem; font-weight: 650; text-decoration: none; }
.site-nav a::after { content: ""; position: absolute; inset: auto 0 0; height: 2px; background: var(--rust); transform: scaleX(0); transform-origin: left; transition: transform 180ms ease; }
.site-nav a:hover::after, .site-nav a[aria-current="page"]::after { transform: scaleX(1); }
.site-nav a[aria-current="page"] { color: var(--ink); }
.nav-toggle { display: none; width: 44px; height: 44px; padding: 10px; border: 1px solid var(--line); background: transparent; }
.nav-toggle > span:not(.sr-only) { display: block; height: 2px; margin: 4px 0; background: var(--ink); }

.eyebrow { margin-bottom: 18px; color: var(--rust); font-size: 0.74rem; font-weight: 750; letter-spacing: 0.16em; text-transform: uppercase; }
.home-hero { min-height: 670px; display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(300px, 0.8fr); align-items: stretch; gap: clamp(48px, 8vw, 110px); padding-block: clamp(80px, 10vw, 142px); }
.hero-copy { align-self: center; }
.hero-copy h1 { max-width: 820px; margin-bottom: 30px; }
.hero-copy > p:not(.eyebrow):not(.hero-appointment) { max-width: 680px; color: var(--ink-soft); font-size: clamp(1.05rem, 1.8vw, 1.28rem); }
.hero-appointment { max-width: 720px; margin: 28px 0 0; padding-left: 16px; border-left: 3px solid var(--rust); color: var(--ink-soft); font-size: 0.88rem; font-weight: 650; }
.hero-actions { display: flex; align-items: center; gap: 28px; margin-top: 36px; }
.hero-profiles { display: flex; flex-wrap: wrap; gap: 10px 24px; margin: 30px 0 0; padding: 22px 0 0; border-top: 1px solid var(--line); list-style: none; font-size: 0.8rem; }
.button { display: inline-block; padding: 14px 20px; color: var(--white); background: var(--teal-deep); font-weight: 700; text-decoration: none; transition: transform 160ms ease, background 160ms ease; }
.button:hover { background: var(--teal); transform: translateY(-2px); }
.text-link, .light-link, .doi-link, .evidence-link, .news-title-link, .profile-link { text-underline-offset: 4px; text-decoration-thickness: 1px; }
.text-link { color: var(--teal-deep); font-weight: 700; }
.light-link { color: var(--white); font-weight: 700; }
.hero-aside { position: relative; align-self: center; padding: 34px 0 34px 34px; border-left: 1px solid var(--line); }
.hero-aside-label { color: var(--teal-deep); font-size: 0.78rem; font-weight: 750; letter-spacing: 0.13em; text-transform: uppercase; }
.hero-aside ol { margin: 28px 0 36px; padding: 0; list-style: none; }
.hero-aside li { display: grid; grid-template-columns: 34px 1fr; gap: 10px; padding-block: 15px; border-top: 1px solid var(--line); font: 500 1rem/1.35 var(--serif); }
.hero-aside li:last-child { border-bottom: 1px solid var(--line); }
.hero-aside li span { color: var(--rust); font: 700 0.68rem/1.6 var(--sans); }
.hero-aside-note { color: var(--ink-soft); font-size: 0.9rem; }

.page-intro { padding-block: clamp(82px, 11vw, 150px); border-bottom: 1px solid var(--line); }
.page-intro h1 { max-width: 980px; margin-bottom: 32px; font-size: clamp(2.8rem, 6vw, 5.2rem); }
.page-lead { max-width: 780px; color: var(--ink-soft); font-size: clamp(1.08rem, 2vw, 1.34rem); }
.section-heading { display: grid; grid-template-columns: 90px 1fr; gap: 28px; align-items: end; margin-bottom: 52px; }
.section-heading h2 { margin-bottom: 8px; }
.section-heading p { margin-bottom: 0; color: var(--ink-soft); }
.section-index { color: var(--rust) !important; font-size: 0.78rem; font-weight: 750; letter-spacing: 0.12em; }
.split-heading { grid-template-columns: 1fr auto; }
.split-heading > .text-link { align-self: end; margin-bottom: 9px; }

.research-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); }
.research-card { display: grid; grid-template-columns: minmax(220px, 0.75fr) 1fr; gap: 54px; padding-block: 54px; border-top: 1px solid var(--line); }
.research-card:first-child { border-top: 0; }
.research-card--compact { display: block; padding: 34px 30px; border-top: 0; border-right: 1px solid var(--line); }
.research-card--compact:first-child { padding-left: 0; }
.research-card--compact:last-child { padding-right: 0; border-right: 0; }
.research-card h3 { margin-bottom: 16px; font-family: var(--serif); font-size: clamp(1.35rem, 2.3vw, 2rem); font-weight: 500; }
.theme-korean, .project-korean, .person-korean, .course-korean { margin-bottom: 10px; color: var(--teal-deep); font-size: 0.78rem; font-weight: 700; letter-spacing: 0.04em; }
.research-card > p { color: var(--ink-soft); }
.method-list { grid-column: 2; display: flex; flex-wrap: wrap; gap: 7px 20px; margin: 8px 0 0; padding: 0; list-style: none; color: var(--teal-deep); font-size: 0.78rem; font-weight: 700; }
.method-list li::before { content: "—"; margin-right: 8px; color: var(--rust); }
.research-stack { border-bottom: 1px solid var(--line); }

.statement-grid { display: grid; grid-template-columns: 1.25fr 0.75fr; gap: clamp(50px, 10vw, 130px); align-items: end; }
.statement-grid .eyebrow { color: #e99b7f; }
.statement-grid h2 { margin-bottom: 0; }
.statement-grid p { color: #d5dddc; font-size: 1.08rem; }
.principles-layout { display: grid; grid-template-columns: 0.8fr 1.2fr; gap: clamp(50px, 10vw, 140px); }
.principles-layout > div > p:last-child { color: var(--ink-soft); }
.principles-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.principles-list li { display: grid; grid-template-columns: 44px 1fr; gap: 22px; padding: 25px 0; border-bottom: 1px solid var(--line); }
.principles-list li > span { color: var(--rust); font-size: 0.74rem; font-weight: 750; }
.principles-list h3 { margin-bottom: 6px; }
.principles-list p { margin-bottom: 0; color: var(--ink-soft); }

.project-list { border-top: 1px solid var(--line); }
.project-block { padding: clamp(36px, 5vw, 64px) 0; border-bottom: 1px solid var(--line); }
.project-block h3 { max-width: 880px; margin-bottom: 20px; font: 500 clamp(1.65rem, 3vw, 2.7rem)/1.15 var(--serif); }
.project-block > p:not(.project-korean) { max-width: 780px; color: var(--ink-soft); }
.project-official-title { max-width: 900px; margin-top: 30px; padding: 20px 24px; border-left: 2px solid var(--rust); background: color-mix(in srgb, var(--paper-deep) 64%, transparent); }
.project-official-title p { margin-bottom: 8px; color: var(--ink-soft); }
.project-official-title p:last-child { margin-bottom: 0; }
.project-official-label { color: var(--rust) !important; font-size: 0.7rem; font-weight: 750; letter-spacing: 0.12em; text-transform: uppercase; }
.project-meta { display: flex; justify-content: space-between; gap: 20px; margin-bottom: 32px; color: var(--teal-deep); font-size: 0.76rem; font-weight: 750; letter-spacing: 0.05em; text-transform: uppercase; }
.project-facts { display: flex; gap: 60px; margin: 28px 0 0; }
.project-facts div { display: grid; gap: 3px; }
.project-facts dt { color: var(--rust); font-size: 0.7rem; font-weight: 750; letter-spacing: 0.12em; text-transform: uppercase; }
.project-facts dd { margin: 0; }

.publication-list, .patent-list, .course-list, .news-list { border-top: 1px solid var(--line); }
.summary-grid { display: grid; grid-template-columns: repeat(4, 1fr); margin: 0; border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.summary-stat { min-height: 148px; display: flex; flex-direction: column-reverse; justify-content: space-between; gap: 24px; padding: 24px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.summary-stat dt { color: var(--ink-soft); font-size: 0.78rem; font-weight: 700; letter-spacing: 0.04em; }
.summary-stat dd { margin: 0; color: var(--teal-deep); font: 500 2.8rem/1 var(--serif); }
.publication-row, .patent-row, .course-row, .news-item { display: grid; grid-template-columns: 120px 1fr; gap: 34px; padding: 30px 0; border-bottom: 1px solid var(--line); }
.publication-row h3, .patent-row h3, .course-row h3, .news-item h3 { margin-bottom: 8px; font-family: var(--serif); font-size: clamp(1.15rem, 2vw, 1.55rem); font-weight: 500; }
.publication-year, .course-term { color: var(--rust); font-size: 0.78rem; font-weight: 750; }
.publication-authors { margin-bottom: 5px; color: var(--ink-soft); }
.publication-venue, .patent-row p, .course-row div > p:last-child, .news-item div > p { margin-bottom: 0; color: var(--ink-soft); }
.metric-line, .manuscript-meta { margin: 8px 0 0; color: var(--ink-soft); font-size: 0.78rem; font-weight: 650; letter-spacing: 0.015em; }
.metric-line { padding-left: 12px; border-left: 2px solid var(--rust); }
.manuscript-row > .publication-year { max-width: 95px; }
.invited-talk-list--profile { margin-bottom: 32px; }
.invited-talk-list--profile .publication-row { grid-template-columns: 110px 1fr; padding-block: 22px; }
.invited-talk-list--profile .publication-row h3 { font-size: 1.18rem; }
.doi-link, .evidence-link { color: var(--teal-deep); font-style: normal; }
.evidence-link { font-size: 0.82rem; font-weight: 700; }
.course-row { grid-template-columns: 150px 1fr; }
.course-korean { margin-bottom: 5px; }

.pi-profile { display: grid; grid-template-columns: minmax(240px, 0.6fr) 1.4fr; gap: clamp(50px, 10vw, 130px); align-items: start; }
.pi-photo { aspect-ratio: 4 / 5; margin: 0; overflow: hidden; background: var(--paper-deep); }
.pi-photo img { width: 100%; height: 100%; display: block; object-fit: cover; }
.pi-profile h2 { margin-bottom: 10px; }
.pi-role { color: var(--teal-deep); font-weight: 700; }
.pi-bio { max-width: 760px; margin: 30px 0 40px; color: var(--ink-soft); font-size: 1.08rem; }
.subheading { margin: 0 0 18px; font-size: 0.78rem; letter-spacing: 0.12em; text-transform: uppercase; }
.education-list { margin: 0 0 32px; padding: 0; list-style: none; }
.education-list li { display: grid; gap: 3px; padding: 13px 0; border-top: 1px solid var(--line); }
.education-list li:last-child { border-bottom: 1px solid var(--line); }
.education-list span { color: var(--ink-soft); }
.people-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.person-card { padding: 28px 0; border-top: 2px solid var(--teal-deep); }
.person-card h3 { margin-bottom: 6px; font-family: var(--serif); font-size: 1.55rem; font-weight: 500; }
.person-card p:last-child { color: var(--ink-soft); }

.news-date { display: flex; flex-direction: column; gap: 4px; color: var(--rust); font-size: 0.75rem; font-weight: 750; }
.news-date span { color: var(--teal-deep); text-transform: uppercase; }
.news-title-link { text-decoration-color: var(--line); }
.news-list--full .news-item { padding-block: 42px; }

.contact-layout { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: clamp(50px, 10vw, 130px); }
.contact-email { display: inline-block; margin-bottom: 30px; color: var(--teal-deep); font: 500 clamp(1.8rem, 4vw, 3.5rem)/1.1 var(--serif); text-underline-offset: 8px; }
.contact-phone { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-bottom: 22px; }
.contact-phone span { color: var(--rust); font-size: 0.74rem; font-weight: 750; letter-spacing: 0.12em; text-transform: uppercase; }
.contact-phone a { color: var(--teal-deep); font-weight: 700; text-underline-offset: 4px; }
.contact-primary > p:last-child { color: var(--ink-soft); }
.contact-profiles h2 { font-size: 2rem; }
.contact-profiles ul { margin: 25px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.contact-profiles li { display: flex; justify-content: space-between; gap: 25px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.contact-profiles li span { color: var(--ink-soft); font-size: 0.86rem; }
.profile-link { color: var(--teal-deep); font-weight: 700; }

.site-footer { padding-block: 55px; color: #cbd5d4; background: #0d191d; }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr auto; gap: 50px; align-items: end; }
.site-footer p { margin-bottom: 5px; }
.footer-brand { color: var(--white); font-family: var(--serif); font-size: 1.2rem; }
.site-footer a { color: var(--white); text-underline-offset: 4px; }
.footer-meta { color: #819092; font-size: 0.75rem; }

@media (max-width: 900px) {
  .nav-toggle { display: block; margin-left: auto; }
  .site-nav { position: absolute; inset: 92px 0 auto; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 14px 20px 24px; border-bottom: 1px solid var(--line); background: var(--paper); }
  .site-nav--open { display: flex; }
  .site-nav a { padding: 12px 0; border-bottom: 1px solid var(--line); }
  .home-hero { min-height: auto; grid-template-columns: 1fr; }
  .hero-aside { max-width: 620px; }
  .research-grid { grid-template-columns: 1fr; }
  .research-card--compact, .research-card--compact:first-child, .research-card--compact:last-child { padding: 34px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .research-card, .statement-grid, .principles-layout, .pi-profile, .contact-layout { grid-template-columns: 1fr; }
  .method-list { grid-column: 1; }
  .pi-photo { width: min(100%, 420px); }
  .people-grid { grid-template-columns: 1fr 1fr; }
  .summary-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-meta { grid-column: 1 / -1; }
}

@media (max-width: 620px) {
  .wrap { width: min(calc(100% - 28px), var(--max)); }
  .header-inner { min-height: 78px; }
  .site-nav { top: 78px; }
  .brand strong { font-size: 0.86rem; }
  .brand small { display: none; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 18px; }
  .hero-aside { padding-left: 22px; }
  .split-heading, .section-heading { grid-template-columns: 1fr; gap: 14px; }
  .split-heading > .text-link { justify-self: start; }
  .publication-row, .patent-row, .course-row, .news-item { grid-template-columns: 1fr; gap: 5px; }
  .project-meta { align-items: flex-start; flex-direction: column; gap: 5px; }
  .project-facts { flex-direction: column; gap: 20px; }
  .people-grid { grid-template-columns: 1fr; }
  .summary-grid { grid-template-columns: 1fr; }
  .contact-profiles li { align-items: flex-start; flex-direction: column; gap: 3px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-meta { grid-column: auto; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}