/* Jiaqi Gan — personal site
   Terminal-inspired dark theme. Mono (JetBrains Mono) for structure, labels and data;
   sans (Inter) for reading. One accent: soft terminal green, used sparingly. */

@font-face {
  font-family: "JetBrains Mono";
  src: url("../fonts/jetbrains-mono-latin-wght.woff2") format("woff2");
  font-weight: 100 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Inter";
  src: url("../fonts/inter-latin-wght.woff2") format("woff2");
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

:root {
  --bg: #0a0b0d;
  --surface: #101216;
  --surface-2: #15181d;
  --text: #e6e8eb;
  --text-strong: #ffffff;
  --text-soft: #c4c9d0;
  --muted: #8f96a1;
  --faint: #5d6570;       /* decorative glyphs only */
  --rule: #1d2127;
  --rule-strong: #2d333b;
  --accent: #7ee787;
  --accent-hover: #9af0a1;
  --accent-dim: #2f6f3a;
  --accent-soft: #0f2416;
  --on-accent: #06130a;
  
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --wrap: 70rem;
  --measure: 42rem;
  --gutter: 16px;
  --label-col: 10.5rem;
  --radius: 6px;
  color-scheme: dark;
}
@media (min-width: 640px) { :root { --gutter: 24px; } }
@media (min-width: 1024px) { :root { --gutter: 32px; } }

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scrollbar-color: var(--rule-strong) transparent; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.65;
  font-feature-settings: "cv11", "ss03";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-wrap: break-word;
}
::selection { background: rgba(126, 231, 135, 0.28); color: var(--text-strong); }
img { max-width: 100%; height: auto; display: block; }

h1, h2 {
  font-family: var(--font-mono);
  font-weight: 650;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 0.5em;
  text-wrap: balance;
}
h3, h4 {
  font-family: var(--font-sans);
  font-weight: 600;
  line-height: 1.3;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
  text-wrap: balance;
}
h1 { font-size: clamp(1.9rem, 1.45rem + 1.8vw, 2.6rem); color: var(--text-strong); }
h2 { font-size: 1.2rem; color: var(--text-strong); }
h3 { font-size: 1.08rem; }
h4 { font-size: 1rem; }
p, ul, ol, dl { margin: 0 0 1rem; }
ul, ol { padding-left: 1.2rem; }
li + li { margin-top: 0.35rem; }
li::marker { color: var(--faint); }
a {
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: var(--rule-strong);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
}
a:hover { color: var(--accent); text-decoration-color: currentColor; }
strong { font-weight: 600; color: var(--text-strong); }
em, cite { font-style: italic; }
code, pre, kbd { font-family: var(--font-mono); font-variant-ligatures: none; }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 3px; }
main:focus { outline: none; }

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px; margin: -1px; padding: 0; border: 0;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}
.skip-link {
  position: absolute; left: var(--gutter); top: -3rem; z-index: 10;
  background: var(--accent); color: var(--on-accent);
  font-family: var(--font-mono); font-size: 0.85rem;
  padding: 0.5rem 0.9rem; border-radius: var(--radius); text-decoration: none;
}
.skip-link:focus { top: 0.75rem; color: var(--on-accent); }

.wrap { width: 100%; max-width: calc(var(--wrap) + 2 * var(--gutter)); margin-inline: auto; padding-inline: var(--gutter); }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.label { font-family: var(--font-mono); font-size: 0.75rem; color: var(--muted); margin-right: 0.45rem; text-transform: lowercase; }
.label::after { content: ":"; }
.lede { font-size: 1.05rem; color: var(--text-soft); max-width: var(--measure); }

/* ---------- Header / footer ---------- */
.site-header { border-bottom: 1px solid var(--rule); }
.header-inner {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  column-gap: 2rem; padding-block: 0.8rem 0.3rem;
}
@media (min-width: 640px) { .header-inner { padding-block: 0.5rem; } }
.site-name {
  display: inline-flex; align-items: center; gap: 0.6rem;
  font-family: var(--font-mono); font-size: 0.95rem; font-weight: 650;
  color: var(--text-strong); text-decoration: none; padding-block: 0.5rem;
}
.site-name::before {
  content: ""; width: 0.55rem; height: 0.55rem; border-radius: 2px;
  background: var(--accent); box-shadow: 0 0 10px rgba(126, 231, 135, 0.55);
}
.site-name:hover { color: var(--accent); }
.site-nav ul { display: flex; flex-wrap: wrap; gap: 0 1.5rem; list-style: none; margin: 0; padding: 0; }
.site-nav li + li { margin-top: 0; }
.site-nav a {
  display: inline-block; padding-block: 0.6rem;
  font-family: var(--font-mono); font-size: 0.85rem; text-transform: lowercase;
  color: var(--muted); text-decoration: none; border-bottom: 1px solid transparent;
}
.site-nav a:hover { color: var(--text-strong); }
.site-nav a[aria-current] { color: var(--accent); border-bottom-color: var(--accent); }

.site-footer { border-top: 1px solid var(--rule); margin-top: 5rem; }
.footer-inner { padding-block: 1.75rem 2.75rem; font-family: var(--font-mono); font-size: 0.78rem; color: var(--muted); }
.footer-inner p { margin: 0 0 0.35rem; }
.footer-inner a { color: var(--muted); }
.footer-inner a:hover { color: var(--accent); }

.draft-banner {
  background: var(--accent); color: var(--on-accent);
  padding: 0.5rem var(--gutter); font-family: var(--font-mono); font-size: 0.85rem; text-align: center;
}

/* ---------- Buttons and link chips ---------- */
.actions { display: flex; flex-wrap: wrap; gap: 0.6rem; list-style: none; padding: 0; margin: 1.75rem 0 0.7rem; }
.actions li + li { margin-top: 0; }
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem; min-height: 44px;
  padding: 0.55rem 1.05rem;
  font-family: var(--font-mono); font-size: 0.85rem; font-weight: 600;
  color: var(--text); background: var(--surface);
  border: 1px solid var(--rule-strong); border-radius: var(--radius);
  text-decoration: none;
}
.btn:hover { color: var(--accent); border-color: var(--accent-dim); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: var(--on-accent); }
.actions-note { font-family: var(--font-mono); font-size: 0.8rem; color: var(--muted); margin: 0; }
.actions-note a { color: var(--muted); }

.link-row { display: flex; flex-wrap: wrap; gap: 0.4rem; list-style: none; padding: 0; margin: 0.65rem 0 0; }
.link-row li + li { margin-top: 0; }
.tag-link {
  display: inline-flex; align-items: center; min-height: 30px;
  padding: 0.15rem 0.6rem;
  font-family: var(--font-mono); font-size: 0.75rem; text-transform: lowercase;
  color: var(--text); background: transparent;
  border: 1px solid var(--rule-strong); border-radius: 4px;
  text-decoration: none; cursor: pointer;
}
.tag-link:hover { border-color: var(--accent-dim); color: var(--accent); }
button.tag-link[aria-expanded="true"] { border-color: var(--accent-dim); color: var(--accent); background: var(--accent-soft); }
@media (pointer: coarse) { .tag-link { min-height: 40px; padding-inline: 0.8rem; } }

/* ---------- Sections ---------- */
.section { padding-block: 3.25rem 0.5rem; }
.section-head {
  display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 0.25rem 1.5rem;
  margin-bottom: 1.5rem;
}
.section-head h2 { margin: 0; }
.section-head h2::before, .facet-section > h2::before {
  content: "## "; content: "## " / "";
  color: var(--accent); font-weight: 400;
}
.more { font-family: var(--font-mono); font-size: 0.8rem; white-space: nowrap; color: var(--muted); text-decoration: none; }
.more:hover { color: var(--accent); }
.page-head { padding-top: 3rem; }
.page-head h1 { margin-bottom: 0.7rem; }
.page-head h1::before { content: "~/"; content: "~/" / ""; color: var(--faint); font-weight: 400; }
.page-head h1 { text-transform: lowercase; }
.project-page .page-head h1 { text-transform: none; }
.project-page .page-head h1::before { content: none; }

/* ---------- Home ---------- */
.intro {
  display: grid; gap: 1.25rem 2.5rem; align-items: center;
  padding-block: 3rem 1rem;
}
@media (min-width: 720px) {
  .intro { grid-template-columns: 9.5rem minmax(0, 1fr); padding-block: 5rem 1.5rem; }
}
.portrait {
  width: 6.5rem; aspect-ratio: 1 / 1; object-fit: cover;
  border-radius: 50%; border: 1px solid var(--rule-strong); background: var(--surface);
}
@media (min-width: 720px) { .portrait { width: 9.5rem; } }
.intro h1 { font-size: clamp(2.2rem, 1.6rem + 2.4vw, 3.2rem); font-weight: 700; letter-spacing: -0.04em; margin-bottom: 0.75rem; }
.cursor {
  display: inline-block; width: 0.4em; height: 0.8em; margin-left: 0.14em;
  background: var(--accent); vertical-align: -0.05em;
}
.headline { font-size: clamp(1.08rem, 1rem + 0.4vw, 1.25rem); line-height: 1.5; color: var(--text-strong); max-width: 40rem; margin-bottom: 0.6rem; }
.bio { color: var(--text-soft); max-width: 40rem; margin-bottom: 0.25rem; }
.seeking { font-family: var(--font-mono); font-size: 0.82rem; color: var(--muted); margin: 0; }
.seeking::before { content: "→ "; content: "→ " / ""; color: var(--accent); }
.intro .actions { margin-top: 1.4rem; }

/* Compact, clickable rows (home and research lists) */
.rows { list-style: none; padding: 0; margin: 0; border-top: 1px solid var(--rule); }
.rows > li { margin: 0; border-bottom: 1px solid var(--rule); }
.row {
  display: grid; grid-template-columns: minmax(0, 1fr); gap: 0.15rem 1.5rem;
  padding: 0.95rem 0.25rem; text-decoration: none; color: var(--text);
}
@media (min-width: 720px) {
  .row { grid-template-columns: minmax(0, 1fr) auto; }
  .row-meta { grid-column: 2; grid-row: 1; text-align: right; }
}
.row-title { font-weight: 600; color: var(--text-strong); }
.row-meta { font-family: var(--font-mono); font-size: 0.75rem; color: var(--muted); white-space: nowrap; padding-top: 0.2rem; }
.row-text, .row-role { grid-column: 1; }
.row-text { color: var(--text-soft); font-size: 0.93rem; }
.row-role { font-size: 0.85rem; color: var(--muted); }
.row-title::after { content: " →"; content: " →" / ""; color: var(--faint); transition: color 120ms ease; }
.row:hover .row-title { color: var(--accent); }
.row:hover .row-title::after { color: var(--accent); }
.row:hover { background: var(--surface); }

/* ---------- Publications ---------- */
.pub-list { display: grid; }
.pub { display: grid; gap: 0.35rem 1.5rem; padding-block: 1.3rem; border-top: 1px solid var(--rule); }
.pub:first-child { border-top: 0; padding-top: 0.25rem; }
@media (min-width: 680px) { .pub { grid-template-columns: 6.5rem minmax(0, 1fr); } }
.pub-body, .pub-meta { min-width: 0; } /* let long BibTeX lines scroll inside their box */
.pub-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 0.5rem; align-content: start; }
@media (min-width: 680px) { .pub-meta { flex-direction: column; align-items: flex-start; padding-top: 0.2rem; } }
.pub-year { font-family: var(--font-mono); font-size: 0.8rem; color: var(--muted); }
.status {
  display: inline-block; font-family: var(--font-mono); font-size: 0.7rem; text-transform: lowercase;
  padding: 0.05rem 0.5rem; border-radius: 999px; border: 1px solid var(--rule-strong); color: var(--muted);
}
.status-published { background: var(--accent-soft); border-color: var(--accent-dim); color: var(--accent); }
.pub-title { font-size: 1.03rem; line-height: 1.4; margin-bottom: 0.35rem; }
.pub-title a { color: var(--text-strong); text-decoration: none; }
.pub-title a:hover { color: var(--accent); }
.pub-authors { font-size: 0.9rem; color: #b9bfc7; margin-bottom: 0.2rem; }
.me { color: var(--accent); font-weight: 600; }
.mark { color: var(--accent); font-size: 0.72em; margin-left: 0.05em; }
.mark-inline { color: var(--accent); font-family: var(--font-mono); }
.pub-venue { font-family: var(--font-mono); font-size: 0.78rem; color: var(--muted); margin-bottom: 0.3rem; }
.pub-venue .venue { color: var(--text); }
.pub-venue a { color: var(--muted); }
.pub-notes { font-size: 0.8rem; color: var(--muted); margin-bottom: 0.3rem; }
.pub-notes span + span { margin-left: 0.6rem; }

.bibtex { margin-top: 0.7rem; }
.bibtex pre {
  margin: 0; padding: 0.9rem 1rem;
  background: var(--surface); border: 1px solid var(--rule-strong); border-radius: var(--radius);
  font-size: 0.75rem; line-height: 1.55; color: var(--text-soft);
  overflow-x: auto; max-width: 100%; white-space: pre;
}
.bibtex-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem; margin-top: 0.5rem; }
.bib-status { font-family: var(--font-mono); font-size: 0.75rem; color: var(--accent); }

.pub-year-group { padding-top: 1.5rem; }
.pub-year-group .pub-year { display: none; } /* the group heading already shows the year */
.year-heading {
  font-family: var(--font-mono); font-weight: 600; font-size: 0.85rem; letter-spacing: 0;
  color: var(--accent); border-bottom: 1px solid var(--rule); padding-bottom: 0.45rem; margin-bottom: 0.9rem;
}

/* ---------- Research ---------- */
.evidence { list-style: none; padding: 0; margin: 0 0 0.5rem; }
.evidence li + li { margin-top: 0.8rem; }
.stat { display: grid; gap: 0.1rem 1.25rem; align-items: baseline; }
@media (min-width: 560px) { .stat { grid-template-columns: 10.5rem minmax(0, 1fr); } }
.stat-value {
  font-family: var(--font-mono); font-size: 1.3rem; font-weight: 650; line-height: 1.2; letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums; color: var(--accent); white-space: nowrap;
}
.stat-label { font-size: 0.92rem; color: var(--text-soft); }
.evidence-note { font-size: 0.85rem; color: var(--muted); border-left: 2px solid var(--accent-dim); padding-left: 0.85rem; margin-top: 0.8rem; }

/* Project detail page */
.work-context { font-family: var(--font-mono); font-size: 0.78rem; color: var(--muted); margin-bottom: 0.9rem; }
.breadcrumb ol { display: flex; flex-wrap: wrap; list-style: none; padding: 0; margin: 0 0 1.25rem; font-family: var(--font-mono); font-size: 0.8rem; color: var(--muted); }
.breadcrumb li + li { margin-top: 0; }
.breadcrumb li + li::before { content: "/"; color: var(--faint); margin-inline: 0.45rem; }
.breadcrumb a { color: var(--muted); }
.facet-section { display: grid; gap: 0.25rem 2rem; }
@media (min-width: 860px) { .facet-section { grid-template-columns: var(--label-col) minmax(0, 1fr); } }
.facet-section > h2 { font-size: 0.95rem; padding-top: 1rem; margin: 0; border-top: 1px solid var(--rule-strong); }
.facet-body { border-top: 1px solid var(--rule); padding-top: 1rem; min-width: 0; }
@media (max-width: 859px) { .facet-body { border-top: 0; padding-top: 0.5rem; } }
.facet-body > ul, .facet-body > p, .facet-body > .evidence { max-width: var(--measure); }
.facet-body .pub { padding-top: 0; }
.approach { margin: 0; max-width: var(--measure); }
.approach > div + div { margin-top: 1.1rem; }
.approach dt { font-family: var(--font-mono); font-size: 0.88rem; font-weight: 600; color: var(--text-strong); }
.approach dd { margin: 0.2rem 0 0; color: var(--text-soft); }
.findings { margin-top: 1rem; color: var(--text-soft); }
.pager {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 1rem;
  margin-top: 3.5rem; padding-top: 1rem; border-top: 1px solid var(--rule);
  font-family: var(--font-mono); font-size: 0.85rem;
}

/* Data-construction diagram */
.flow { margin: 0 0 1.9rem; max-width: 54rem; }
.flow-authors { list-style: none; padding: 0; margin: 0; display: grid; gap: 1.6rem; counter-reset: flow; }
@media (min-width: 760px) { .flow-authors { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.flow-authors li + li { margin-top: 0; }
.flow-step {
  position: relative; counter-increment: flow;
  background: var(--surface); border: 1px solid var(--rule-strong); border-radius: var(--radius);
  padding: 0.85rem 0.95rem;
}
.flow-step p { margin: 0 0 0.45rem; font-size: 0.88rem; line-height: 1.45; }
.flow-step p:last-child { margin-bottom: 0; }
.flow-role { font-family: var(--font-mono); font-weight: 650; font-size: 0.88rem !important; color: var(--text-strong); }
.flow-role::before { content: counter(flow) ". "; color: var(--accent); }
.flow-step:not(:last-child)::after {
  content: "↓"; position: absolute; left: 50%; bottom: -1.45rem; transform: translateX(-50%);
  color: var(--accent); font-family: var(--font-mono);
}
@media (min-width: 760px) {
  .flow-step:not(:last-child)::after { content: "→"; left: auto; right: -1.3rem; bottom: auto; top: 42%; transform: none; }
}
.flow-gate {
  margin-top: 0.9rem; padding: 0.5rem 0.85rem;
  border-left: 2px solid var(--accent); background: var(--surface);
  border-radius: 0 var(--radius) var(--radius) 0; font-size: 0.88rem;
}
.flow-gate p { margin: 0; }
.flow-out { display: flex; flex-wrap: wrap; gap: 0.4rem 1.75rem; margin-top: 0.9rem; padding-left: 0.85rem; }
.flow-out p { margin: 0; font-family: var(--font-mono); font-size: 0.78rem; color: var(--muted); }
.flow-num { font-size: 1.15rem; font-weight: 650; color: var(--accent); font-variant-numeric: tabular-nums; margin-right: 0.3rem; }
.flow > figcaption { font-size: 0.82rem; color: var(--muted); margin-top: 1rem; }

/* ---------- CV ---------- */
.cv-head .actions { margin-top: 0.5rem; }
.edu { width: 100%; border-collapse: collapse; max-width: var(--measure); }
.edu th, .edu td { text-align: left; vertical-align: baseline; padding: 0.5rem 1rem 0.5rem 0; font-size: 0.95rem; }
.edu th { font-weight: 600; color: var(--text-strong); }
.edu .date { white-space: nowrap; color: var(--muted); text-align: right; padding-right: 0; font-family: var(--font-mono); font-size: 0.8rem; }
@media (max-width: 599px) {
  .edu, .edu tbody, .edu tr, .edu th, .edu td { display: block; text-align: left; }
  .edu tr { padding-block: 0.55rem; border-bottom: 1px dashed var(--rule); }
  .edu th, .edu td { padding: 0; }
  .edu .date { text-align: left; }
}
.role + .role { margin-top: 2rem; }
.role-head { display: grid; gap: 0 1rem; margin-bottom: 0.75rem; }
@media (min-width: 600px) { .role-head { grid-template-columns: 1fr auto; } .role-date { grid-column: 2; grid-row: 1; } }
.role-head h3 { margin: 0; }
.role-head h3 a { color: var(--text-strong); }
.role-title { margin: 0; color: var(--muted); font-size: 0.92rem; }
.role-date { margin: 0; font-family: var(--font-mono); font-size: 0.78rem; color: var(--accent); white-space: nowrap; }
.role-project { margin-top: 1.1rem; max-width: var(--measure); }
.role-project h4 { margin-bottom: 0.4rem; font-family: var(--font-mono); font-size: 0.88rem; }
.role-project h4 a { color: var(--text-strong); }
.role-project h4 a:hover { color: var(--accent); }
.role-project li { font-size: 0.93rem; color: var(--text-soft); }
.skills { margin: 0; max-width: var(--measure); }
.skills > div { display: grid; gap: 0 1rem; padding-block: 0.45rem; }
.skills > div + div { border-top: 1px dashed var(--rule); }
@media (min-width: 600px) { .skills > div { grid-template-columns: 9.5rem 1fr; } }
.skills dt { font-family: var(--font-mono); font-size: 0.8rem; color: var(--accent); padding-top: 0.15rem; text-transform: lowercase; }
.skills dd { margin: 0; font-size: 0.93rem; }

/* ---------- Contact ---------- */
.contact-email { font-family: var(--font-mono); font-size: 1.15rem; }
.contact-email a { color: var(--accent); text-decoration-color: var(--accent-dim); }
.profile-links { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; font-family: var(--font-mono); font-size: 0.85rem; }
.profile-links li + li { margin-top: 0; }
.profile-links a::after { content: " ↗"; content: " ↗" / ""; color: var(--faint); }

/* ---------- Motion and print ---------- */
@media (prefers-reduced-motion: no-preference) {
  a, .btn, .tag-link, .site-nav a, .row { transition: color 120ms ease, background-color 120ms ease, border-color 120ms ease; }
}
@media print {
  .site-nav, .skip-link, .actions, .link-row, .bibtex, .pager, .site-footer { display: none !important; }
  body, .flow-step, .flow-gate { background: #fff !important; color: #000 !important; }
  a, .me, h1, h2, h3, strong { color: #000 !important; }
}