@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,600;1,400;1,600&family=Inter:wght@300;400;500;600&display=swap');

/* ─── TOKENS ───────────────────────────────────────────────────── */
:root {
  --bg:       #f5f4f0;   /* warm off-white, paper-like          */
  --text:     #1c1917;   /* warm near-black                     */
  --body:     #57534e;   /* medium warm gray                    */
  --muted:    #a8a29e;   /* light warm gray                     */
  --line:     #e5e2de;   /* subtle warm divider                 */
  --line-mid: #ccc9c5;   /* slightly stronger                   */
  --blue:     #2d4a7a;   /* deep scholar blue — links           */
  --blue-hov: #1e3558;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ─── LINKS ─────────────────────────────────────────────────────── */
a                        { color: var(--blue); text-decoration: none; }
a:hover, a:focus-visible { color: var(--blue-hov); text-decoration: underline; }
.link-muted              { color: var(--muted); }

/* ─── SHELL ─────────────────────────────────────────────────────── */
.shell {
  width: min(780px, calc(100% - 48px));
  margin: 0 auto;
  padding: 0 0 120px;
}

/* ─── HEADER ────────────────────────────────────────────────────── */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 0 24px;
  border-bottom: 1px solid var(--line);
}

.brand {
  font-family: 'Lora', Georgia, serif;
  font-style: italic;
  font-weight: 600;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.01em;
  transition: color 150ms;
}
.brand:hover { color: var(--blue); text-decoration: none; }

.nav { display: flex; flex-wrap: wrap; gap: 2px; }
.nav a {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border-radius: 4px;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  transition: color 140ms, background 140ms;
}
.nav a.active, .nav a[aria-current="page"] {
  color: var(--text);
  font-weight: 600;
  background: rgba(0,0,0,0.05);
}
.nav a:hover, .nav a:focus-visible {
  color: var(--text);
  background: rgba(0,0,0,0.04);
  text-decoration: none;
}

/* ─── HERO SECTION ──────────────────────────────────────────────── */
.hero-section {
  display: grid;
  grid-template-columns: minmax(0, 1.65fr) minmax(180px, 0.5fr);
  gap: 72px;
  align-items: start;
  padding: 64px 0 60px;
  border-bottom: 1px solid var(--line);
}

/* ─── CONTENT SECTIONS ──────────────────────────────────────────── */
.content-section {
  padding: 48px 0;
  border-bottom: 1px solid var(--line);
}
.content-section:last-child { border-bottom: none; }

.content-two-up {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 64px;
  padding: 48px 0;
  border-bottom: 1px solid var(--line);
}

/* ─── PAGE HEADER ───────────────────────────────────────────────── */
.page-header {
  padding: 56px 0 48px;
  border-bottom: 1px solid var(--line);
}

/* ─── EYEBROW ───────────────────────────────────────────────────── */
.eyebrow {
  display: block;
  margin-bottom: 18px;
  font-size: 0.71rem;
  font-weight: 500;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ─── TYPOGRAPHY ────────────────────────────────────────────────── */
h1, h2, h3 { margin: 0; color: var(--text); }

/* The name — italic Lora, editorial signature */
h1 {
  font-family: 'Lora', Georgia, serif;
  font-style: italic;
  font-weight: 600;
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  line-height: 1.1;
  letter-spacing: -0.025em;
  margin-bottom: 20px;
}

/* Section labels — small, restrained, uppercase */
h2 {
  font-family: 'Inter', sans-serif;
  font-size: 0.69rem;
  font-weight: 600;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 18px;
}

h3 { font-size: 0.95rem; font-weight: 600; margin-bottom: 8px; }

p, ul, ol { margin: 0; }
p         { color: var(--body); }

.lede {
  font-size: 0.97rem;
  line-height: 1.85;
  color: var(--body);
  max-width: 44rem;
}
.lede + .lede { margin-top: 12px; }
.muted { color: var(--muted); }

/* ─── RESEARCH TAGS ─────────────────────────────────────────────── */
.chip-row {
  display: flex;
  flex-wrap: wrap;
  column-gap: 18px;
  row-gap: 8px;
  margin-top: 24px;
}
/* Each chip: plain text tag with a subtle underline — no pill, no bg */
.chip {
  font-size: 0.80rem;
  font-weight: 400;
  color: var(--body);
  border-bottom: 1px solid var(--line-mid);
  padding-bottom: 2px;
  line-height: 1;
}

/* ─── PROFILE PHOTO ─────────────────────────────────────────────── */
.profile-photo {
  display: block;
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background-image: url('figures/xiaodong.jpg');
  background-size: 300%;        /* lower % = more zoomed out */
  background-position: 70% 6%; /* x: slightly left of center; y: near top */
  background-repeat: no-repeat;
  margin-bottom: 28px;
  filter: saturate(0.92) contrast(1.02);
}

/* ─── META DL ────────────────────────────────────────────────────── */
.meta-dl { margin: 0; display: grid; gap: 24px; }
.meta-dl dt {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}
.meta-dl dd {
  margin: 0;
  font-size: 0.88rem;
  color: var(--body);
  line-height: 1.5;
}

/* ─── PLAIN LIST ─────────────────────────────────────────────────── */
.plain-list { padding: 0; list-style: none; }
.plain-list li + li { margin-top: 10px; }
.plain-list li {
  position: relative;
  padding-left: 16px;
  font-size: 0.92rem;
  color: var(--body);
}
.plain-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--muted);
}

/* ─── SERVICE LIST ───────────────────────────────────────────────── */
.service-list { padding: 0; margin: 0; list-style: none; }
.service-list li + li { margin-top: 14px; }
.service-list li { font-size: 0.92rem; color: var(--body); line-height: 1.65; }
.service-list strong { color: var(--text); font-weight: 600; }

/* ─── CTA — arrow text links, zero boxes ────────────────────────── */
.cta-grid { display: grid; margin-top: 4px; }
.cta-card {
  display: grid;
  grid-template-columns: 20px 1fr;
  align-items: baseline;
  gap: 10px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  color: var(--text);
  font-size: 0.93rem;
  transition: color 140ms;
  position: relative;
}
.cta-card:first-child { border-top: 1px solid var(--line); }
.cta-card::before {
  content: '→';
  font-size: 0.85rem;
  color: var(--muted);
  transition: color 140ms, transform 140ms;
  transform: translateX(0);
  display: inline-block;
}
.cta-card strong {
  display: inline;
  font-weight: 600;
  font-size: 0.93rem;
  color: var(--text);
  margin-right: 8px;
}
.cta-card, .cta-card p { color: var(--body); }
.cta-card:hover, .cta-card:focus-visible {
  text-decoration: none;
  color: var(--blue);
}
.cta-card:hover .cta-card strong,
.cta-card:hover::before {
  color: var(--blue);
}
.cta-card:hover::before { transform: translateX(3px); }

/* ─── PUBLICATION LIST ──────────────────────────────────────────── */
.pub-list { padding: 0; list-style: none; }
.pub-list li + li { margin-top: 2px; }

.pub-entry {
  padding: 9px 8px 9px 12px;
  border-left: 2px solid transparent;
  border-radius: 3px;
  font-size: 0.89rem;
  line-height: 1.58;
  color: var(--body);
  transition: border-left-color 130ms, color 130ms, background 130ms;
}
.pub-entry:hover {
  border-left-color: var(--blue);
  color: var(--text);
  background: rgba(0,0,0,0.025);
}

/* ─── CATEGORY HEADER ───────────────────────────────────────────── */
.cat-header {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 36px 0 10px;
  padding: 0;
}
.cat-header:first-child { margin-top: 0; }

/* ─── CONTACT LIST ──────────────────────────────────────────────── */
.contact-list { padding: 0; list-style: none; }
.contact-list li {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 16px;
  align-items: baseline;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
  font-size: 0.92rem;
  color: var(--body);
}
.contact-list li:first-child { border-top: 1px solid var(--line); }
.contact-list strong {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ─── FOOTER ────────────────────────────────────────────────────── */
.site-footer { display: flex; justify-content: flex-end; padding: 28px 0 0; }
.visitor-counter { font-size: 0.69rem; color: var(--muted); opacity: 0.5; letter-spacing: 0.04em; }
.visitor-counter.is-hidden { display: none; }
.footer-note { font-size: 0.88rem; color: var(--body); }

/* ─── RESPONSIVE ─────────────────────────────────────────────────── */
@media (max-width: 620px) {
  .shell { width: calc(100% - 36px); padding-bottom: 80px; }
  .site-header { padding: 20px 0 18px; flex-wrap: wrap; gap: 14px; }
  .hero-section, .content-two-up { grid-template-columns: 1fr; gap: 40px; }
  .hero-section { padding: 44px 0 40px; }
  .content-section, .content-two-up, .page-header { padding: 36px 0; }
  .cat-header { margin-top: 28px; }
  .contact-list li { grid-template-columns: 90px 1fr; }
}