:root {
  --bg: #eff1ec;
  --card: #f7f8f5;
  --ink: #202521;
  --ink-soft: #5b6259;
  --ink-faint: #8b9188;
  --rule: #d9dcd3;
  --accent: #2f6e68;
  --accent-tint: #dce8e5;
  --focus: #2f6e68;
  --display: Optima, "Gill Sans", "Gill Sans MT", "Segoe UI", Corbel, sans-serif;
  --serif: Charter, "Iowan Old Style", Georgia, "Times New Roman", serif;
  --mono: ui-monospace, "SF Mono", Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141815; --card: #1a1f1b; --ink: #e7e9e2; --ink-soft: #9aa298; --ink-faint: #676e64;
    --rule: #2b312b; --accent: #63b0a6; --accent-tint: #1e2e2b; --focus: #63b0a6;
  }
}
:root[data-theme="dark"] {
  --bg: #141815; --card: #1a1f1b; --ink: #e7e9e2; --ink-soft: #9aa298; --ink-faint: #676e64;
  --rule: #2b312b; --accent: #63b0a6; --accent-tint: #1e2e2b; --focus: #63b0a6;
}
:root[data-theme="light"] {
  --bg: #eff1ec; --card: #f7f8f5; --ink: #202521; --ink-soft: #5b6259; --ink-faint: #8b9188;
  --rule: #d9dcd3; --accent: #2f6e68; --accent-tint: #dce8e5; --focus: #2f6e68;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg); color: var(--ink); font-family: var(--serif);
  line-height: 1.65; -webkit-font-smoothing: antialiased;
}
a { color: var(--ink); text-decoration-color: var(--ink-faint); text-underline-offset: 3px; }
a:hover { color: var(--accent); text-decoration-color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 2px; }
::selection { background: var(--accent-tint); }
img { max-width: 100%; }

.page { max-width: 48rem; margin: 0 auto; padding: 3.5rem 1.5rem 6rem; }

/* ---- masthead / nav ---- */
.masthead {
  display: flex; justify-content: space-between; align-items: baseline;
  border-bottom: 1px solid var(--rule); padding-bottom: 1.6rem; margin-bottom: 3rem;
  gap: 1rem; flex-wrap: wrap;
}
nav.top { display: flex; gap: 1.3rem; font-family: var(--display); flex-wrap: wrap; }
nav.top a { font-size: 0.82rem; color: var(--ink-soft); text-decoration: none; }
nav.top a:hover, nav.top a[aria-current] { color: var(--accent); }
.theme-toggle {
  font-family: var(--display); font-size: 0.7rem; background: none; border: 1px solid var(--rule);
  color: var(--ink-soft); padding: 0.3rem 0.65rem; border-radius: 999px; cursor: pointer;
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); }

/* ---- home hero ---- */
.hero {
  display: grid; grid-template-columns: 1fr auto; gap: 1.8rem; align-items: center;
  margin-bottom: 3.6rem;
}
.hero-copy .kicker {
  font-family: var(--display); font-size: 0.75rem; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent); margin: 0 0 0.8rem;
}
.hero-copy h1 {
  font-family: var(--display); font-weight: 500; font-size: clamp(2rem, 5vw, 2.7rem);
  margin: 0 0 0.7rem; letter-spacing: -0.01em; text-wrap: balance;
}
.hero-copy h1 .name-kr {
  display: inline-block; font-size: 0.42em; font-weight: 400; color: var(--ink-soft);
  margin-left: 0.65em; padding-left: 0.65em; border-left: 1px solid var(--rule);
  vertical-align: middle;
}
.hero-copy h1 .name-kr a { color: inherit; text-decoration-color: var(--ink-faint); }
.hero-copy h1 .name-kr a:hover { color: var(--accent); text-decoration-color: var(--accent); }
.hero-copy .lede { font-family: var(--serif); font-size: 1.1rem; max-width: 40rem; color: var(--ink); }
.hero-copy .contact-line { font-family: var(--display); font-size: 0.85rem; color: var(--ink-soft); margin: 0.9rem 0 0; }
.hero-copy .contact-line a { color: var(--ink-soft); }
.hero-copy .contact-line a:hover { color: var(--accent); }
.monogram {
  width: 4.6rem; height: 4.6rem; border-radius: 50%; background: var(--accent-tint);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--display); font-size: 1.3rem; color: var(--accent); border: 1px solid var(--rule);
  flex-shrink: 0;
}
@media (max-width: 30rem) { .hero { grid-template-columns: 1fr; } .monogram { display: none; } }

/* ---- section headers ---- */
section { margin-bottom: 3.2rem; }
.section-head {
  display: flex; align-items: baseline; justify-content: space-between; gap: 0.9rem;
  border-bottom: 1px solid var(--rule); padding-bottom: 0.55rem; margin-bottom: 1.4rem;
}
.section-head h2 {
  font-family: var(--display); font-size: 0.82rem; letter-spacing: 0.06em; text-transform: uppercase;
  font-weight: 600; margin: 0;
}
.section-head .sub { font-family: var(--mono); font-size: 0.72rem; color: var(--ink-faint); }
.section-head .more {
  font-family: var(--display); font-size: 0.78rem; color: var(--accent); text-decoration: none;
  white-space: nowrap;
}
.section-head .more:hover { text-decoration: underline; }

.pull {
  font-family: var(--serif); font-style: italic; font-size: 1.2rem; color: var(--ink);
  border-left: 2px solid var(--accent); padding-left: 1.1rem; max-width: 34rem; margin: 0 0 1.6rem;
  text-wrap: balance;
}

/* ---- research interest cards ---- */
.interest-cards {
  display: flex; flex-direction: column; gap: 0.8rem;
}
.interest-card {
  background: var(--card); border: 1px solid var(--rule); border-left: 3px solid var(--accent);
  border-radius: 0.35rem; padding: 1.1rem 1.25rem;
}
.interest-card h3 {
  font-family: var(--display); font-size: 1rem; font-weight: 700; color: var(--accent);
  margin: 0 0 0.5rem; text-wrap: balance;
}
.interest-card p { font-family: var(--serif); font-size: 0.92rem; color: var(--ink-soft); margin: 0; }

/* ---- tags ---- */
.tags { display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; }
.tags span {
  font-family: var(--display); font-size: 0.86rem; color: var(--ink-soft);
  padding-bottom: 1px; border-bottom: 1px dotted var(--ink-faint);
}

/* ---- publications list ---- */
ol.pubs { list-style: none; margin: 0; padding: 0; counter-reset: pub; }
ol.pubs li {
  counter-increment: pub; position: relative; padding-left: 2.2rem;
  margin-bottom: 1.4rem; padding-bottom: 1.4rem; border-bottom: 1px solid var(--rule);
}
ol.pubs li:last-child { border-bottom: none; margin-bottom: 0; }
ol.pubs li::before {
  content: counter(pub, decimal-leading-zero);
  position: absolute; left: 0; top: 0.2rem;
  font-family: var(--mono); font-size: 0.98rem; color: var(--accent);
}
.tag {
  display: inline-block; font-family: var(--display); font-size: 0.68rem; letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--accent); border: 1px solid var(--accent); border-radius: 999px; padding: 0.12rem 0.55rem; margin-bottom: 0.5rem;
}
.pub-title { font-family: var(--serif); font-size: 1.05rem; margin: 0 0 0.3rem; }
.pub-meta { font-family: var(--display); font-size: 0.82rem; color: var(--ink-soft); }
.pub-meta sup { font-size: 0.72em; }
.pub-note { font-family: var(--display); font-size: 0.74rem; color: var(--ink-faint); margin: 0.35rem 0 0; }
.pub-abstract { font-family: var(--serif); font-size: 0.95rem; color: var(--ink-soft); margin: 0.6rem 0 0; max-width: 34rem; }
.pub-links { display: flex; gap: 1rem; margin-top: 0.6rem; }
.pub-links a { font-family: var(--display); font-size: 0.78rem; color: var(--accent); border-bottom: 1px solid var(--accent); }

/* ---- CV rows ---- */
.cv-row { display: grid; grid-template-columns: 8.5rem 1fr; gap: 1rem; align-items: baseline; margin-bottom: 1rem; }
.cv-row .when { font-family: var(--mono); font-size: 0.78rem; color: var(--ink-faint); white-space: nowrap; }
.cv-row .what strong { font-family: var(--display); font-weight: 600; }
.cv-row .what span { color: var(--ink-soft); font-family: var(--display); font-size: 0.88rem; }
.cv-row .what p { margin: 0.3rem 0 0; font-family: var(--serif); font-size: 0.92rem; color: var(--ink-soft); max-width: 30rem; }
.cv-link, .btn {
  display: inline-block; margin-top: 0.4rem; font-family: var(--display); font-size: 0.82rem; color: var(--accent);
  border-bottom: 1px solid var(--accent); text-decoration: none;
}
@media (max-width: 26rem) { .cv-row { grid-template-columns: 1fr; gap: 0.15rem; } }

/* ---- news ---- */
.news { display: grid; gap: 1rem; }
.news-item { display: flex; gap: 1.1rem; align-items: baseline; }
.news-item time { font-family: var(--mono); font-size: 0.74rem; color: var(--ink-faint); white-space: nowrap; padding-top: 0.15rem; }
.news-item p { margin: 0; font-family: var(--serif); font-size: 1rem; }

.news-full { display: grid; gap: 2rem; }
.news-full article time {
  font-family: var(--mono); font-size: 0.74rem; color: var(--ink-faint); display: block; margin-bottom: 0.3rem;
}
.news-full article h3 { font-family: var(--display); font-size: 1.1rem; font-weight: 600; margin: 0 0 0.5rem; }
.news-full article p { font-family: var(--serif); font-size: 0.98rem; color: var(--ink-soft); margin: 0; max-width: 34rem; }
.news-full article { padding-bottom: 1.8rem; border-bottom: 1px solid var(--rule); }
.news-full article:last-child { border-bottom: none; padding-bottom: 0; }

/* ---- detail page article body ---- */
.intro-line { font-family: var(--serif); font-size: 1.05rem; color: var(--ink-soft); max-width: 50rem; margin: 0 0 2.4rem; }
.back-link { font-family: var(--display); font-size: 0.8rem; color: var(--ink-soft); text-decoration: none; display: inline-block; margin-bottom: 2rem; }
.back-link:hover { color: var(--accent); }
.topic { margin-bottom: 2.2rem; }
.topic h3 { font-family: var(--display); font-size: 1.05rem; font-weight: 600; margin: 0 0 0.5rem; color: var(--accent); }
.topic p { font-family: var(--serif); font-size: 0.98rem; color: var(--ink-soft); margin: 0; max-width: 50rem; }

/* ---- footer ---- */
footer {
  border-top: 1px solid var(--rule); padding-top: 1.4rem; margin-top: 3.6rem;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.7rem;
  font-family: var(--display); font-size: 0.8rem; color: var(--ink-soft);
}
footer a { color: var(--ink-soft); }
footer .links { display: flex; gap: 1.2rem; }

@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }