/* Hong Qin Research — minimalist styles */

@import url('https://fonts.googleapis.com/css2?family=Kalam:wght@400;700&family=Caveat:wght@500;700&family=DM+Serif+Display:ital@0;1&display=swap');

:root {
  --ink: #1d1d1f;
  --muted: #4a4a4f;
  --rule: #d2d2d7;
  --accent: #0066cc;
  --bg: #ffffff;
  --max-width: 980px;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
               "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 19px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  font-weight: 400;
  letter-spacing: -0.003em;
}

a {
  color: var(--accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

img { max-width: 100%; height: auto; }

p { margin: 0 0 14px; }

ul, ol { padding-left: 1.3em; margin: 0 0 14px; }
li { margin-bottom: 8px; }

strong { font-weight: 600; }

em { color: var(--muted); }

/* ---------- Header / nav ---------- */
.site-header {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--rule);
  position: sticky;
  top: 0;
  z-index: 100;
}
.site-header .wrap {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.site-title {
  font-family: "DM Serif Display", "Playfair Display", Georgia, "Times New Roman", serif;
  font-size: 1.6rem;
  font-style: italic;
  font-weight: 400;
  letter-spacing: 0.005em;
  color: var(--ink);
  line-height: 1.1;
}
.site-title a { color: var(--ink); }
.site-title a:hover { color: var(--accent); text-decoration: none; }
.site-title .sub {
  display: block;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 0.82rem;
  font-style: normal;
  font-weight: 400;
  color: var(--muted);
  margin-top: 4px;
  letter-spacing: 0;
}

.nav {
  display: flex;
  gap: 30px;
  flex-wrap: wrap;
  align-items: baseline;
}
.nav a {
  color: var(--ink);
  font-family: "Kalam", "Caveat", "Marker Felt", "Comic Sans MS", cursive;
  font-size: 1.35rem;
  font-weight: 400;
  letter-spacing: 0;
  padding: 2px 4px 6px;
  position: relative;
  transition: color 0.15s ease;
  text-decoration: none;
}
.nav a:hover {
  color: var(--accent);
  text-decoration: none;
}
.nav a:hover::after,
.nav a.active::after {
  content: "";
  position: absolute;
  left: 2px;
  right: 2px;
  bottom: 0;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  opacity: 0.55;
  transform: skewY(-1.2deg);
}
.nav a.active {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- Hero ---------- */
.hero {
  background: var(--bg);
  padding: 96px 24px 64px;
  text-align: center;
  border-bottom: 1px solid var(--rule);
}
.hero .wrap {
  max-width: var(--max-width);
  margin: 0 auto;
}
.hero h1 {
  margin: 0 0 18px;
  font-size: 3.2rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.1;
  color: var(--ink);
}
.hero .role {
  font-size: 1.3rem;
  font-weight: 400;
  color: var(--muted);
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}
.hero .affiliation {
  font-size: 1.05rem;
  color: var(--muted);
  margin: 0 0 32px;
}
.hero .pill {
  display: inline-block;
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 8px 18px;
  margin: 0 4px 10px 0;
  font-size: 0.95rem;
  color: var(--ink);
  font-weight: 500;
  transition: border-color 0.15s ease, color 0.15s ease;
}
.hero .pill:hover {
  border-color: var(--ink);
}

/* ---------- Main / sections ---------- */
main { padding: 64px 24px 80px; }
.wrap { max-width: var(--max-width); margin: 0 auto; }

section {
  margin-bottom: 64px;
}

h2 {
  font-size: 2rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin: 0 0 24px;
  padding-bottom: 0;
  border: none;
  text-transform: none;
}

h3 {
  color: var(--ink);
  font-size: 1.3rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 32px 0 12px;
}

h4 {
  color: var(--ink);
  font-size: 1.1rem;
  font-weight: 600;
  margin: 20px 0 8px;
  letter-spacing: -0.005em;
  text-transform: none;
}

/* ---------- Theme cards (now minimal) ---------- */
.themes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 36px 32px;
  margin-top: 8px;
}
.theme-card {
  background: transparent;
  border: none;
  border-left: none;
  padding: 0;
  border-radius: 0;
}
.theme-card h3 {
  margin: 0 0 10px;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--ink);
}
.theme-card p {
  margin: 0;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.6;
}

/* ---------- Facts strip (minimal text) ---------- */
.facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 24px;
  margin: 24px 0 0;
  padding: 32px 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.fact {
  background: transparent;
  text-align: center;
  padding: 0;
}
.fact .num {
  display: block;
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}
.fact .label {
  font-size: 0.92rem;
  color: var(--muted);
  text-transform: none;
  letter-spacing: 0;
  font-weight: 400;
}

/* ---------- Student sections ---------- */
.student-section {
  background: transparent;
  padding: 0;
  border: none;
  border-left: none;
  border-radius: 0;
  margin-bottom: 36px;
}
.student-section h3 {
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}
.cohort {
  margin-bottom: 22px;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.65;
}
.cohort .year {
  font-weight: 600;
  color: var(--ink);
  margin-right: 4px;
}

/* ---------- Publication entries ---------- */
.pub-list {
  list-style: none;
  padding: 0;
  counter-reset: pubs;
}
.pub-list li {
  counter-increment: pubs;
  padding: 16px 0 16px 42px;
  border-bottom: 1px solid var(--rule);
  position: relative;
  font-size: 1.02rem;
  color: var(--ink);
  line-height: 1.55;
}
.pub-list li:last-child { border-bottom: none; }
.pub-list li::before {
  content: counter(pubs);
  position: absolute;
  left: 0;
  top: 16px;
  color: var(--muted);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  font-size: 0.95rem;
}
.pub-list em {
  color: var(--muted);
  font-style: italic;
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--bg);
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.92rem;
  padding: 32px 24px;
  text-align: center;
}
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--ink); }

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  body { font-size: 17px; }
  .hero { padding: 64px 20px 48px; }
  .hero h1 { font-size: 2.2rem; }
  .hero .role { font-size: 1.1rem; }
  .site-header .wrap {
    flex-direction: column;
    align-items: flex-start;
    padding: 14px 20px;
  }
  .nav { gap: 20px; }
  main { padding: 40px 20px 56px; }
  section { margin-bottom: 48px; }
  h2 { font-size: 1.6rem; }
}