/* Single-page academic site: a heading column and plain prose, divided by thin rules. */
:root {
  --text: #25292e;
  --muted: #626870;
  --accent: #467f63;
  --accent-strong: #23362d;
  --heading: #2e5a45;
  --line: #e2e5e8;
  --paper: #fff;
  --photo-width: 200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, system-ui, "Segoe UI", Roboto, sans-serif;
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { margin: 0; line-height: 1.4; font-weight: 700; letter-spacing: -.015em; }
p { margin: 0; }
a { color: var(--accent); text-decoration: underline; text-decoration-color: #b8d0c3; text-underline-offset: 4px; text-decoration-thickness: 1px; }
a:hover { color: #2f5c46; text-decoration-color: currentColor; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
img { max-width: 100%; display: block; }
::selection { background: #dcebe2; }

.wrap { width: min(860px, calc(100% - 48px)); margin-inline: auto; }
.skip-link { position: fixed; top: 10px; left: 20px; transform: translateY(-180%); z-index: 200; padding: 8px 16px; color: #fff; background: var(--text); }
.skip-link:focus { transform: translateY(0); }

/* Masthead */
.navbar { position: relative; z-index: 100; border-bottom: 1px solid var(--line); background: var(--paper); }
.nav-inner { min-height: 68px; display: flex; justify-content: space-between; align-items: center; gap: 28px; }
.brand { font-size: 18px; font-weight: 600; color: var(--text); letter-spacing: -.02em; text-decoration: none; white-space: nowrap; }
.brand:hover { color: var(--text); }
.nav-links { display: flex; gap: 24px; padding: 0; margin: 0; list-style: none; }
.nav-links a { display: block; padding-block: 20px; font-size: 14.5px; font-weight: 450; color: var(--muted); text-decoration: none; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.menu-btn { display: none; padding: 10px 0 10px 14px; min-height: 44px; border: 0; background: none; color: var(--text); font: inherit; font-size: 15px; font-weight: 600; cursor: pointer; }

/* Portrait and identity */
.hero { padding: 64px 0 40px; }
.hero-grid { display: grid; grid-template-columns: var(--photo-width) minmax(0, 1fr); gap: 36px; align-items: center; }
.hero-photo img { width: 100%; height: auto; border-radius: 12px; }
.hero-text { min-width: 0; }
.hero-name { font-size: clamp(34px, 3.2vw, 46px); font-weight: 650; line-height: 1.15; letter-spacing: -.035em; margin: 0 0 16px; color: var(--accent-strong); }
.hero-name-ko { font-size: .5em; font-weight: 500; letter-spacing: 0; color: var(--muted); margin-left: 6px; white-space: nowrap; }
.hero-position { font-size: 18px; font-weight: 550; margin-bottom: 4px; }
.hero-affil a { color: var(--muted); text-decoration: none; }
.hero-affil a:hover { color: var(--accent); text-decoration: underline; }
.hero-social { display: flex; flex-wrap: wrap; column-gap: 20px; margin-top: 14px; }
.hero-social a { font-size: 15px; padding-block: 4px; color: var(--muted); text-decoration: none; }
.hero-social a:hover { color: var(--accent); text-decoration: underline; }

/* Sections */
.section-grid { padding-block: 30px; border-top: 1px solid var(--line); }
#about .section-grid { border-top-color: #b3c4ba; }
.section-title { margin-bottom: 14px; font-size: 21px; font-weight: 600; color: var(--heading); }
.section-body { min-width: 0; }

.about p + p { margin-top: 12px; }
.about p strong { font-weight: 600; color: var(--text); }
.about-lead { font-size: 19px; font-weight: 650; letter-spacing: -.015em; color: var(--accent-strong); margin-bottom: 4px; }
.sub-title { margin-top: 22px; font-size: 15px; font-weight: 600; letter-spacing: .01em; color: var(--muted); }
.interests { padding-left: 20px; margin: 6px 0 0; }
.interests li { margin-top: 3px; }
.interests strong { font-weight: 600; }
.interests li::marker, .pub-list li::marker { color: var(--accent); }

.timeline { display: grid; gap: 22px; }
.t-top { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 4px 20px; }
.t-title { font-size: 18px; font-weight: 650; letter-spacing: 0; }
.t-date { font-size: 15.5px; color: var(--muted); font-variant-numeric: tabular-nums; }
.t-sub { margin-top: 2px; color: var(--muted); }
.t-detail { margin-top: 4px; font-size: 16px; color: var(--muted); }
.t-label { font-weight: 600; color: var(--text); }

.pub-list { margin: 0; padding-left: 20px; }
.pub-list li { padding-left: 3px; }
.pub-list li + li { margin-top: 18px; }
.pub-title { font-size: 17.5px; font-weight: 600; line-height: 1.65; }
.pub-authors, .pub-venue { margin-top: 2px; color: var(--muted); font-size: 16px; }
.me { font-weight: 600; color: var(--text); }
.pub-status { margin-top: 4px; color: var(--accent); font-size: 15.5px; font-style: italic; }
.pub-links { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 4px; font-size: 15px; }

/* Footer */
.footer { margin-top: 12px; border-top: 1px solid var(--line); }
.footer-inner { padding-block: 18px; color: var(--muted); font-size: 14px; }

/* Narrow screens: single column, collapsible menu */
@media (max-width: 680px) {
  .wrap { width: calc(100% - 32px); }
  .menu-btn { display: block; }
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; flex-direction: column; gap: 0; padding: 4px 16px 10px; background: var(--paper); border-bottom: 1px solid var(--line); }
  .nav-links.open { display: flex; }
  .nav-links a { padding-block: 10px; font-size: 15.5px; }
  .hero { padding: 36px 0 24px; }
  .hero-grid { grid-template-columns: 1fr; gap: 22px; }
  .hero-photo { width: 168px; }
  .section-grid { padding-block: 24px; }
  body { font-size: 16.5px; }
}