:root {
  --bg: #fdfdfd;
  --fg: #1a1a1a;
  --muted: #666;
  --accent: #0a7a6b;
  --border: #e5e5e5;
  --card: #fafafa;
  --link: #0a7a6b;
  --link-hover: #065d51;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Source Serif Pro", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --max: 960px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --fg: #e8e8e8;
    --muted: #999;
    --accent: #4dc0b0;
    --border: #2a2a2a;
    --card: #1a1a1a;
    --link: #4dc0b0;
    --link-hover: #6dd4c4;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.15s;
}
a:hover { color: var(--link-hover); text-decoration: underline; }

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.25; letter-spacing: -0.01em; }
h1 { font-size: 2.4rem; margin: 0 0 0.5rem; }
h2 { font-size: 1.7rem; margin: 2.5rem 0 1rem; }
h3 { font-size: 1.2rem; margin: 1.5rem 0 0.5rem; font-family: var(--sans); letter-spacing: 0; }

p { margin: 0 0 1rem; }

/* ---------- Layout ---------- */
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 1.5rem; }

header.site {
  border-bottom: 1px solid var(--border);
  padding: 1.25rem 0;
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 10;
  backdrop-filter: saturate(180%) blur(8px);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
}
header.site .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
.brand { font-family: var(--serif); font-size: 1.15rem; font-weight: 600; color: var(--fg); }
.brand:hover { text-decoration: none; color: var(--accent); }
nav.primary { display: flex; gap: 1.25rem; flex-wrap: wrap; }
nav.primary a { color: var(--muted); font-size: 0.95rem; }
nav.primary a:hover, nav.primary a.active { color: var(--fg); text-decoration: none; }
nav.primary a.active { font-weight: 600; color: var(--accent); }

main { padding: 3rem 0 4rem; }

/* ---------- Home hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 3rem;
  align-items: center;
}
.hero .text h1 { font-size: clamp(2rem, 5vw, 3.2rem); }
.hero .text .subtitle { color: var(--muted); font-size: 1.05rem; text-transform: uppercase; letter-spacing: 0.08em; margin: 0 0 1.5rem; }
.hero .text .intro { font-size: 1.1rem; max-width: 56ch; }
.hero img.avatar { width: 260px; height: 260px; border-radius: 50%; object-fit: cover; box-shadow: 0 10px 40px rgba(0,0,0,0.12); }

@media (max-width: 720px) {
  .hero { grid-template-columns: 1fr; gap: 2rem; text-align: center; }
  .hero img.avatar { width: 180px; height: 180px; margin: 0 auto; }
  .hero .text .intro { margin-left: auto; margin-right: auto; }
}

/* ---------- Cards / list items ---------- */
.section-intro { color: var(--muted); max-width: 60ch; margin-bottom: 2rem; }

.list { display: grid; gap: 1rem; }
.list.grid-2 { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.5rem;
  transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,0.06); }
.card h3 { margin: 0 0 0.4rem; }
.card h3 a { color: var(--fg); }
.card h3 a:hover { color: var(--accent); text-decoration: none; }
.card .meta { color: var(--muted); font-size: 0.9rem; margin: 0.25rem 0; }
.card .summary { margin: 0.5rem 0; color: var(--fg); }
.card .tags { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.75rem; }
.tag {
  font-size: 0.75rem;
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  font-weight: 500;
}
.links-inline { margin-top: 0.5rem; display: flex; gap: 1rem; flex-wrap: wrap; font-size: 0.9rem; }

.note {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.1rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--muted);
  margin-left: 0.5rem;
  vertical-align: middle;
}

/* Publication section headers */
.pub-group { margin-top: 2.5rem; }
.pub-group h2 { border-bottom: 1px solid var(--border); padding-bottom: 0.5rem; }

/* ---------- Travel ---------- */
.travel-entry { margin: 2.5rem 0; padding-bottom: 2rem; border-bottom: 1px solid var(--border); }
.travel-entry:last-child { border-bottom: none; }
.travel-entry h3 { font-family: var(--serif); font-size: 1.5rem; }
.travel-entry .date { color: var(--muted); font-size: 0.9rem; }
.travel-entry .quote { font-style: italic; color: var(--fg); margin: 0.75rem 0 1rem; }
.travel-entry iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: none;
  border-radius: 8px;
  max-width: 720px;
  display: block;
}

/* ---------- About ---------- */
.about-body { display: grid; grid-template-columns: auto 1fr; gap: 2rem; align-items: start; }
.about-body img.avatar { width: 160px; height: 160px; border-radius: 50%; object-fit: cover; }
@media (max-width: 720px) {
  .about-body { grid-template-columns: 1fr; text-align: center; }
  .about-body img.avatar { margin: 0 auto; }
}
.about-body .lang { margin-top: 2rem; }

/* ---------- Footer ---------- */
footer.site {
  border-top: 1px solid var(--border);
  padding: 2.5rem 0;
  color: var(--muted);
  font-size: 0.9rem;
}
footer.site .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 1rem; align-items: center; }
.social { display: flex; gap: 1rem; }
.social a { color: var(--muted); display: inline-flex; align-items: center; }
.social a:hover { color: var(--accent); }
.social svg { width: 20px; height: 20px; fill: currentColor; }

/* ---------- World map (jsvectormap) ---------- */
.hero-map {
  position: relative;
  width: 100%;
  height: calc(100svh - 68px); /* 68px ≈ sticky header */
  min-height: 520px;
  background: var(--card);
  overflow: hidden;
  margin-top: -3rem; /* cancel main padding-top */
}
.hero-map #world-map {
  width: 100%;
  height: 100%;
}
.hero-map .overlay {
  position: absolute;
  top: clamp(1.5rem, 5vh, 3.5rem);
  left: clamp(1.5rem, 5vw, 4rem);
  z-index: 5;
  pointer-events: none;
  max-width: min(520px, 85vw);
}
.hero-map .overlay h1 {
  font-size: clamp(2.6rem, 7vw, 5rem);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
  color: var(--fg);
  text-shadow: 0 1px 2px color-mix(in srgb, var(--bg) 70%, transparent);
}
.hero-map .overlay p {
  color: var(--muted);
  font-size: 1.05rem;
  margin: 0;
}
.scroll-hint {
  position: absolute;
  bottom: 1.25rem;
  left: 50%;
  transform: translateX(-50%);
  color: var(--muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  animation: bob 2.2s ease-in-out infinite;
}
.scroll-hint svg { width: 18px; height: 18px; fill: currentColor; }
@keyframes bob {
  0%, 100% { transform: translate(-50%, 0); }
  50%      { transform: translate(-50%, 8px); }
}
#world-map {
  width: 100%;
  height: 100%;
}
.jvm-tooltip {
  background: var(--fg) !important;
  color: var(--bg) !important;
  border-radius: 6px !important;
  font-family: var(--sans) !important;
  font-size: 0.85rem !important;
  padding: 0.4rem 0.7rem !important;
  border: none !important;
}
.jvm-zoom-btn {
  background: var(--bg) !important;
  color: var(--fg) !important;
  border: 1px solid var(--border) !important;
}

/* ---------- Section dividers on hub pages ---------- */
.hub-section { margin-top: 3.5rem; }
.hub-section:first-of-type { margin-top: 2rem; }
.hub-section > h2 {
  font-family: var(--serif);
  font-size: 1.8rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4rem;
}

/* ---------- Utilities ---------- */
.loading { color: var(--muted); font-style: italic; }