/* =========================================================
   Yong Hoon Chung — personal academic site
   One shared stylesheet for every page. Edit colors, fonts,
   and spacing here and the change applies site-wide.
   ========================================================= */

:root {
  --paper:       #f4f5f7;  /* cool page background      */
  --surface:     #ffffff;  /* cards / hero panel        */
  --ink:         #1b2531;  /* primary text (deep slate) */
  --muted:       #59636f;  /* secondary text            */
  --line:        #e2e5ea;  /* hairline borders          */
  --accent:      #0f5d6b;  /* petrol teal               */
  --accent-deep: #0a454f;  /* hover / active            */
  --accent-soft: #e7f0f1;  /* tint background           */

  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --sans:  "Public Sans", system-ui, -apple-system, "Segoe UI", sans-serif;

  --wrap: 940px;   /* hero / wide sections */
  --read: 730px;   /* comfortable reading measure */
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ---------- Links ---------- */
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-deep); text-decoration: underline; text-underline-offset: 2px; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

/* ---------- Navigation ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(244, 245, 247, 0.88);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
  height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.nav-name {
  font-family: var(--serif);
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--ink);
  letter-spacing: 0.01em;
  white-space: nowrap;
}
.nav-name:hover { text-decoration: none; color: var(--accent-deep); }
.nav-links {
  display: flex;
  gap: 22px;
  flex-wrap: wrap;
  justify-content: flex-end;
}
.nav-links a {
  color: var(--muted);
  font-size: 0.98rem;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.nav-links a:hover { color: var(--ink); text-decoration: none; border-bottom-color: var(--line); }
.nav-links a.active { color: var(--ink); border-bottom-color: var(--accent); }

/* ---------- Layout containers ---------- */
main { padding: 0 24px; }
.wrap { max-width: var(--wrap); margin: 0 auto; }
.read { max-width: var(--read); margin: 0 auto; }

section { padding: 56px 0; }
section + section { border-top: 1px solid var(--line); }

/* ---------- Headings ---------- */
h1, h2, h3 { font-family: var(--serif); font-weight: 500; color: var(--ink); }
h2 {
  font-size: 1.7rem;
  line-height: 1.2;
  margin: 0 0 4px;
}
.section-rule {
  width: 34px;
  height: 2px;
  background: var(--accent);
  border: 0;
  margin: 0 0 26px;
}
h3 { font-family: var(--sans); font-weight: 600; font-size: 1.02rem; margin: 0 0 6px; }

p { margin: 0 0 1rem; }
.muted { color: var(--muted); }

/* ---------- Hero ---------- */
.hero { padding: 66px 0 58px; }
.hero-grid {
  display: grid;
  grid-template-columns: 230px 1fr;
  gap: 44px;
  align-items: start;
}
.headshot {
  width: 230px;
  height: 288px;
  object-fit: cover;
  object-position: 50% 35%;
  border-radius: 8px;
  border: 1px solid var(--line);
  box-shadow: 0 1px 0 rgba(27, 37, 49, 0.04);
  background: var(--surface);
}
.hero h1 {
  font-size: clamp(2.3rem, 5vw, 3.3rem);
  line-height: 1.05;
  margin: 2px 0 10px;
  letter-spacing: -0.01em;
}
.hero .role {
  font-size: 1.12rem;
  color: var(--ink);
  margin: 0 0 4px;
}
.hero .affil { color: var(--muted); margin: 0 0 20px; }
.hero .lede {
  font-size: 1.08rem;
  max-width: 52ch;
  margin: 0 0 22px;
}

/* ---------- Contact / inline link row ---------- */
.linkrow {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  list-style: none;
  padding: 0;
  margin: 0;
}
.linkrow a {
  display: inline-block;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink);
  font-size: 0.94rem;
}
.linkrow a:hover {
  border-color: var(--accent);
  color: var(--accent-deep);
  text-decoration: none;
  background: var(--accent-soft);
}

/* ---------- Reference lists (publications / talks) ---------- */
.reflist { list-style: none; margin: 0; padding: 0; }
.reflist li {
  padding: 0 0 18px 1.6em;
  text-indent: -1.6em;   /* hanging indent */
  margin: 0 0 4px;
  line-height: 1.55;
}
.reflist .me { font-weight: 700; }          /* author's own name */
.reflist.nobold .me { font-weight: 400; }    /* opt out of bolding */
.reflist .venue { font-style: italic; }      /* journal / meeting  */
.reflist .yr { color: var(--muted); }

/* inline "Paper Link" / "Talk Link" resource links */
.reslink {
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 2px;
  white-space: nowrap;
}

/* research topic: image on the left, heading + papers on the right */
.topic-grid {
  max-width: 900px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 34px;
  align-items: start;
}
.topic-figure { margin: 0; }
.topic-img,
.topic-ph {
  display: block;
  width: 100%;
  border-radius: 8px;
  border: 1px solid var(--line);
}
.topic-img { height: auto; background: #fff; padding: 8px; margin-top: 18px; }
.topic-ph {
  aspect-ratio: 4 / 3;
  background: var(--accent-soft);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 10px;
  color: var(--muted);
  font-size: 0.72rem;
  line-height: 1.4;
}
.topic-body h2 { margin-top: 0; }
.topic-lead { max-width: 60ch; }
@media (max-width: 620px) {
  .topic-grid { grid-template-columns: 1fr; gap: 16px; }
  .topic-ph { max-width: 220px; }
}

.subhead {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 34px 0 16px;
}
.subhead:first-of-type { margin-top: 0; }

/* the two note lines at the top of the publications page */
.pub-meta { margin-bottom: 28px; }
.pub-meta p { font-size: 0.85rem; line-height: 1.45; margin: 0 0 4px; }

.note {
  font-size: 0.9rem;
  color: var(--muted);
  margin: 22px 0 0;
}

/* ---------- CV blocks ---------- */
.cv-entry { margin: 0 0 22px; }
.cv-entry .top {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: baseline;
}
.cv-entry .title { font-weight: 600; }
.cv-entry .when { color: var(--muted); font-size: 0.92rem; white-space: nowrap; }
.cv-entry .sub { color: var(--muted); margin: 2px 0 0; }
.cv-entry ul { margin: 8px 0 0; padding-left: 1.1em; }
.cv-entry ul li { margin: 0 0 4px; }

.plainlist { margin: 0; padding-left: 1.1em; }
.plainlist li { margin: 0 0 7px; }

.btn {
  display: inline-block;
  padding: 9px 18px;
  background: var(--accent);
  color: #fff;
  border-radius: 7px;
  font-weight: 600;
  font-size: 0.96rem;
}
.btn:hover { background: var(--accent-deep); color: #fff; text-decoration: none; }

.awards { list-style: none; margin: 0; padding: 0; }
.awards li {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
}
.awards li:last-child { border-bottom: 0; }
.awards .yr { color: var(--muted); white-space: nowrap; font-size: 0.92rem; }

/* ---------- Embedded PDF (CV page) ---------- */
.pdf-frame {
  display: block;
  width: 100%;
  height: 82vh;
  min-height: 520px;
  margin-top: 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

/* ---------- Footer ---------- */
.foot {
  border-top: 1px solid var(--line);
  padding: 30px 0 46px;
  color: var(--muted);
  font-size: 0.9rem;
}
.foot .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.foot a { color: var(--muted); }
.foot a:hover { color: var(--accent-deep); }

/* ---------- Responsive ---------- */
@media (max-width: 620px) {
  body { font-size: 16px; }
  .hero-grid { grid-template-columns: 1fr; gap: 22px; }
  .headshot { width: 172px; height: 215px; }
  .nav-inner { height: auto; padding: 12px 20px; flex-direction: column; align-items: flex-start; gap: 8px; }
  .nav-links { justify-content: flex-start; gap: 16px; }
  section { padding: 42px 0; }
  .cv-entry .top { flex-direction: column; }
  .cv-entry .when { white-space: normal; }
}

@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
}