/* ===========================================================
   Zeman Li — fancy minimalist academic stylesheet (v2)
   - Charter / Source Serif body, Fraunces display, Inter sans
   - Warm sienna accent, thin asterism dividers, drop cap
   - IntersectionObserver-driven reveals, gentle hover motion
   - Honors prefers-reduced-motion
   =========================================================== */

:root {
  --max: 760px;
  --text: #1c1c1c;
  --muted: #5a5a5a;
  --soft: #8a8a8a;
  --rule: #e5e1d8;
  --bg: #fbf8f3;
  --paper: #ffffff;
  --accent: #b85c38;        /* warm sienna */
  --accent-soft: color-mix(in srgb, var(--accent) 15%, transparent);
  --link: #1c4f8a;
  --serif: "Charter", "Source Serif Pro", "Iowan Old Style", "Apple Garamond",
    Georgia, "Times New Roman", serif;
  --display: "Fraunces", var(--serif);
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    Arial, sans-serif;
  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
}

* { box-sizing: border-box; }

html {
  background: var(--bg);
  scroll-behavior: smooth;
}

/* breathing room when anchor nav scrolls a section into view */
section[id] { scroll-margin-top: 1.5rem; }
/* subtle accent flash when the section is the current :target
   (i.e. the URL hash points at it). Reassures the user the link
   actually went where they expected. */
section[id]:target {
  animation: hash-flash 1.6s var(--ease);
}
@keyframes hash-flash {
  0% { background: var(--accent-soft); }
  100% { background: transparent; }
}
@media (prefers-reduced-motion: reduce) {
  section[id]:target { animation: none; }
}

body {
  font-family: var(--serif);
  font-size: 17.5px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  margin: 0;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* faint paper grain — pure SVG noise data URI */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.045;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/></filter><rect width='100%25' height='100%25' filter='url(%23n)' opacity='0.7'/></svg>");
}

main.page {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 4rem auto 4rem;
  padding: 0 1.5rem;
}

a {
  color: var(--link);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-position: 0 100%;
  background-repeat: no-repeat;
  background-size: 0% 1px;
  transition: background-size 0.32s var(--ease), color 0.2s var(--ease);
}
a:hover { background-size: 100% 1px; color: var(--accent); }

/* visually-hidden — for SR-only context (aria-describedby etc.) */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* keyboard-only skip link — slides in when focused */
.skip-link {
  position: absolute;
  left: 0.6rem;
  top: -40px;
  z-index: 999;
  background: var(--accent);
  color: #fff;
  padding: 0.55rem 0.9rem;
  border-radius: 4px;
  font-family: var(--sans);
  font-size: 0.85rem;
  font-weight: 600;
  background-image: none;
  transition: top 0.2s var(--ease);
}
.skip-link:hover { color: #fff; background-size: 0% 0; }
.skip-link:focus,
.skip-link:focus-visible {
  top: 0.6rem;
  outline: 2px solid #fff;
  outline-offset: 2px;
}

/* visible focus ring across all interactive elements */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}
/* skip-link targets <main>, but a 2px ring around the whole <main>
   looks like a layout glitch, so suppress it when <main> takes focus. */
main:focus,
main:focus-visible {
  outline: none;
}
a:focus-visible {
  background-size: 100% 1px;
  color: var(--accent);
}
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ---------- Header ---------- */
.site-header {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.4rem;
  align-items: center;
}

.profile {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  background: #eee;
  box-shadow: 0 0 0 1px rgba(0, 0, 0, 0.08), 0 8px 28px -16px rgba(0, 0, 0, 0.35);
  transition: transform 0.6s var(--ease), box-shadow 0.6s var(--ease);
  animation: photoIn 1s var(--ease) both;
}
.profile:hover {
  transform: scale(1.03) rotate(-1deg);
  box-shadow: 0 0 0 1px var(--accent), 0 0 0 8px var(--accent-soft),
              0 12px 32px -16px rgba(0, 0, 0, 0.4);
}

.display-name {
  font-family: var(--display);
  font-weight: 800;
  font-size: 2.1rem;
  letter-spacing: -0.015em;
  line-height: 1.05;
  margin: 0;
  font-variation-settings: "opsz" 144;
}
.display-name .ch {
  display: inline-block;
  opacity: 0;
  transform: translateY(0.4em);
  animation: chIn 0.6s var(--ease) forwards;
  animation-delay: calc(var(--i, 0) * 50ms);
}
.display-name .zh {
  display: inline-block;
  margin-left: 0.5rem;
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.5rem;
  color: var(--soft);
  vertical-align: 0.1em;
  opacity: 0;
  animation: chIn 0.7s var(--ease) forwards;
  animation-delay: calc(var(--i, 0) * 50ms);
}

.tagline {
  margin: 0.45rem 0 0;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 0.95rem;
  letter-spacing: 0.005em;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.55s forwards;
}
.tagline .sep { margin: 0 0.45rem; color: var(--soft); }

.anchor-nav {
  grid-column: 1 / -1;
  margin-top: 1.6rem;
  padding: 0.7rem 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  display: flex;
  flex-wrap: wrap;
  row-gap: 0.4rem;
  gap: 1.6rem;
  opacity: 0;
  animation: fadeUp 0.6s var(--ease) 0.7s forwards;
}
.anchor-nav a {
  color: var(--muted);
  background-image: linear-gradient(var(--accent), var(--accent));
  background-size: 0% 1.5px;
  padding-bottom: 2px;
}
.anchor-nav a:hover,
.anchor-nav a:focus-visible,
.anchor-nav a.active {
  color: var(--accent);
  background-size: 100% 1.5px;
}

/* ---------- Sections ---------- */
.content { margin-top: 2.5rem; }

section {
  margin-top: 3.5rem;
  position: relative;
}
section + section::before {
  content: "✦";
  display: block;
  text-align: center;
  color: var(--soft);
  margin: -1.5rem 0 2.5rem;
  font-size: 0.8rem;
  letter-spacing: 0.4em;
}

section h2 {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.45rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text);
  margin: 0 0 1.2rem;
  font-variation-settings: "opsz" 14;
}

section h3 {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.92rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 2rem 0 0.7rem;
}

p, li { font-feature-settings: "kern", "liga", "clig", "calt"; }

#bio .lede::first-letter {
  font-family: var(--display);
  font-weight: 800;
  font-size: 3.6em;
  float: left;
  line-height: 0.85;
  padding: 0.05em 0.12em 0 0;
  color: var(--accent);
  font-variation-settings: "opsz" 144;
}

ul { padding-left: 1.2rem; margin: 0.4rem 0; }
li { margin: 0.4rem 0; }

code {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: rgba(0, 0, 0, 0.05);
  padding: 0.1em 0.4em;
  border-radius: 3px;
}

/* ---------- CV-style two-column lists (news, vita, contact) ---------- */
.cv-list, .news-list, .contact-list {
  list-style: none;
  padding: 0;
  margin: 0.6rem 0;
}
.cv-list li, .news-list li, .contact-list li {
  display: grid;
  grid-template-columns: 8.5rem 1fr;
  gap: 1.1rem;
  padding: 0.6rem 0;
  border-bottom: 1px dashed var(--rule);
  align-items: baseline;
}
.cv-list li:last-child,
.news-list li:last-child,
.contact-list li:last-child { border-bottom: none; }
.cv-when {
  font-family: var(--sans);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--soft);
  white-space: nowrap;
}
.cv-what em { color: var(--muted); font-style: italic; }
.cv-sub { font-size: 0.93em; color: var(--muted); }

/* ---------- Publications ---------- */
.pub-fresh {
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--soft);
  margin: 0.4rem 0 0.2rem;
  letter-spacing: 0.02em;
}
.pub-fresh span { color: var(--accent); margin-right: 0.2em; }
.pub-fresh time { font-variant-numeric: tabular-nums; }
.pub-feed {
  margin-left: 0.7em;
  font-family: var(--sans);
  font-size: 0.74rem;
  color: var(--muted);
  background-image: none;
  padding: 0.05em 0.45em;
  border: 1px solid var(--rule);
  border-radius: 3px;
  letter-spacing: 0.04em;
}
.pub-feed:hover,
.pub-feed:focus-visible { color: var(--accent); border-color: var(--accent); background-size: 0% 0; }
.pubs {
  list-style: none;
  padding: 0;
  margin: 0.6rem 0 0;
  counter-reset: pub;
}
.pubs li {
  position: relative;
  padding: 1rem 0 1rem 2.4rem;
  border-bottom: 1px dashed var(--rule);
  counter-increment: pub;
  transition: transform 0.4s var(--ease), background-color 0.4s var(--ease);
}
.pubs li::before {
  content: counter(pub);
  position: absolute;
  left: 0;
  top: 1rem;
  width: 1.8rem;
  font-family: var(--display);
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--soft);
  text-align: right;
  font-variant-numeric: tabular-nums;
}
.pubs li:last-child { border-bottom: none; }
.pubs li:hover,
.pubs li:focus-within {
  transform: translateX(4px);
  background-color: rgba(184, 92, 56, 0.03);
}
.pub-title {
  font-family: var(--display);
  font-weight: 600;
  font-size: 1.05rem;
  line-height: 1.35;
  color: var(--text);
  margin-bottom: 0.2rem;
}
.pub-authors { font-family: var(--serif); color: var(--muted); font-size: 0.97rem; }
.pub-authors strong { color: var(--text); font-weight: 600; }
.pub-meta {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--soft);
  margin-top: 0.25rem;
  letter-spacing: 0.01em;
}
.pub-meta em {
  font-style: normal;
  color: var(--accent);
  font-weight: 500;
}

/* ---------- Visitor widget ---------- */
.visitor {
  margin-top: 4rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--rule);
  border-radius: 6px;
  background: var(--paper);
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
}
.visitor-line {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem 0.6rem;
}
.visitor .dot {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--accent);
  display: inline-block;
  margin-right: 0.3rem;
  animation: pulse 2.6s var(--ease) infinite;
}
.visitor .sep { color: var(--soft); }
.visitor [data-visitor-city],
.visitor [data-visitor-count],
.visitor [data-visitor-total] {
  color: var(--text);
  font-weight: 500;
}
.visitor-fine {
  margin: 0.5rem 0 0;
  font-size: 0.78rem;
  color: var(--soft);
  line-height: 1.5;
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.82rem;
  color: var(--soft);
}
.site-footer .disclaimer {
  margin: 0 0 0.6rem;
  color: var(--muted);
  font-size: 0.85rem;
  font-family: var(--serif);
  font-style: italic;
  line-height: 1.55;
}
.site-footer .meta { margin: 0; }
.site-footer .cipher {
  display: inline-block;
  color: var(--soft);
  text-decoration: none;
  background: none;
  padding: 0 0.2em;
  transition: color 0.4s var(--ease), transform 0.6s var(--ease);
}
.site-footer .cipher:hover,
.site-footer .cipher:focus-visible {
  color: var(--accent);
  transform: rotate(72deg) scale(1.2);
}

/* ---------- Reveal animations ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}
[data-reveal].in-view {
  opacity: 1;
  transform: translateY(0);
}
.pubs li[data-reveal].in-view {
  transition-delay: calc(var(--idx, 0) * 40ms);
}

/* ---------- Keyframes ---------- */
@keyframes chIn {
  to { opacity: 1; transform: translateY(0); }
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes photoIn {
  from { opacity: 0; transform: scale(0.94); }
  to { opacity: 1; transform: scale(1); }
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 var(--accent-soft); }
  50% { box-shadow: 0 0 0 6px transparent; }
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .display-name .ch, .display-name .zh,
  .tagline, .anchor-nav,
  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
  .profile { animation: none; }
  .visitor .dot { animation: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  body { font-size: 16.5px; }
  main.page { margin: 2rem auto 3rem; padding: 0 1.1rem; }
  .site-header { grid-template-columns: 84px 1fr; gap: 1rem; }
  .profile { width: 84px; height: 84px; }
  .display-name { font-size: 1.6rem; }
  .display-name .zh { font-size: 1.1rem; }
  .anchor-nav { gap: 1.1rem; font-size: 0.82rem; }
  .cv-list li, .news-list li, .contact-list li {
    grid-template-columns: 5.5rem 1fr;
    gap: 0.7rem;
  }
  .cv-when { font-size: 0.74rem; }
  .pubs li { padding-left: 1.8rem; }
  .pubs li::before { width: 1.4rem; font-size: 0.78rem; }
  #bio .lede::first-letter { font-size: 3em; }
}

/* ---------- Knowledge Base (homepage section) ---------- */
.kb-intro {
  color: var(--muted);
  margin: 0 0 1.1rem;
}
.kb-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 0.9rem;
}
.kb-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.9rem 1.1rem;
  align-items: start;
  padding: 1.1rem 1.1rem 1.2rem;
  border: 1px solid var(--rule);
  border-radius: 8px;
  background: var(--paper);
  color: var(--text);
  text-decoration: none;
  background-image: none;
  transition: transform 0.5s var(--ease),
              border-color 0.4s var(--ease),
              box-shadow 0.5s var(--ease);
}
.kb-card:hover,
.kb-card:focus-visible {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: 0 14px 32px -22px rgba(0, 0, 0, 0.45);
  color: var(--text);
}
.kb-glyph {
  font-size: 1.4rem;
  line-height: 1;
  padding-top: 0.15rem;
}
.kb-text {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-width: 0;
}
.kb-name {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.005em;
}
.kb-desc {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ---------- Playground (homepage section) ---------- */
.playground-intro {
  color: var(--muted);
  margin: 0 0 1.1rem;
}
.playground-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.9rem;
}
.play-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.1rem 1rem 1.2rem;
  border: 1px solid var(--rule);
  border-radius: 8px;
  background: var(--paper);
  color: var(--text);
  text-decoration: none;
  background-image: none;
  transition: transform 0.5s var(--ease),
              border-color 0.4s var(--ease),
              box-shadow 0.5s var(--ease);
}
.play-card:hover,
.play-card:focus-visible {
  transform: translateY(-3px);
  border-color: var(--accent);
  box-shadow: 0 14px 32px -22px rgba(0, 0, 0, 0.45);
  color: var(--text);
}
.play-glyph {
  font-size: 1.5rem;
  color: var(--accent);
  line-height: 1;
}
.play-name {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.005em;
}
.play-desc {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
}

@media (max-width: 600px) {
  .playground-grid { grid-template-columns: 1fr; }
}

/* ============== game pages share base typography ============== */
body.game {
  background: var(--bg);
}
body.game main.page { max-width: 760px; }
body.game .game-back {
  display: inline-block;
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 1.2rem;
}

/* ---------- Print stylesheet (CV-friendly) ---------- */
@media print {
  :root { --bg: #fff; --paper: #fff; --rule: #ccc; }
  html, body { background: #fff; color: #000; font-size: 11pt; }
  .grain, .skip-link, .anchor-nav, .visitor-line,
  #playground, .playground-grid, .play-card,
  #knowledge-base, .kb-list, .kb-card,
  .site-footer .disclaimer, .cipher, .pub-fresh,
  body.game .game-back { display: none !important; }
  main.page { max-width: 100%; margin: 0; padding: 0.5in 0.6in; }
  a { color: #000; background: none !important; text-decoration: none; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 9pt; color: #444; }
  a[href^="#"]::after, a[href^="mailto:"]::after { content: ""; }
  .pubs li, h2, h3 { break-inside: avoid; page-break-inside: avoid; }
  .site-header {
    display: block;
    border-bottom: 1px solid #999;
    padding-bottom: 0.4rem;
    margin-bottom: 1rem;
  }
  .profile { display: none; }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
}