/* ─────────────────────────────────────────────
   Design tokens. 换风格主要改这里。
   Layout idea: one calm academic page in a "pixel lab notebook" skin —
   pixel type for labels and headings, crisp sans for reading, hard pixel shadows,
   and a pixel seedling that rides the scrollbar.
   ───────────────────────────────────────────── */
:root {
  --bg: #eef1ea;
  --card: #ffffff;
  --ink: #16202a;
  --muted: #55606a;
  --line: #c9cfc4;
  --accent: #3a5cff;
  --leaf: #3faa5c;
  --leaf-dark: #257a3e;
  --sun: #ffc83d;
  --coral: #ff7a59;
  --soil: #8a5a3b;
  --on-accent: #ffffff;

  --font-pixel: "Pixelify Sans", "Silkscreen", ui-monospace, monospace;
  --font-micro: "Silkscreen", "Pixelify Sans", ui-monospace, monospace;
  --font-body: "IBM Plex Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;

  --px: 3px;            /* pixel border width */
  --shadow: 5px;        /* pixel shadow offset */
  --maxw: 1120px;
  --datecol: 120px;      /* width of the date column in news / papers / lists */
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #10151b; --card: #19212a; --ink: #e6ebe3; --muted: #9ba7b1; --line: #2c3742;
    --accent: #8197ff; --leaf: #5cc97a; --leaf-dark: #3b9d58; --sun: #ffd45c;
    --coral: #ff8e70; --soil: #a87454; --on-accent: #0d1220;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #10151b; --card: #19212a; --ink: #e6ebe3; --muted: #9ba7b1; --line: #2c3742;
  --accent: #8197ff; --leaf: #5cc97a; --leaf-dark: #3b9d58; --sun: #ffd45c;
  --coral: #ff8e70; --soil: #a87454; --on-accent: #0d1220;
  color-scheme: dark;
}

/* ── base ── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: var(--font-body); font-size: 17px; line-height: 1.65;
}
img, svg { max-width: 100%; }
a { color: var(--accent); text-underline-offset: 3px; text-decoration-thickness: 1.5px; }
a:hover { text-decoration-thickness: 3px; }
:focus-visible { outline: 3px solid var(--sun); outline-offset: 2px; }
h1, h2, h3 { text-wrap: balance; line-height: 1.15; margin: 0; }
p { margin: 0 0 1em; }
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }
.sprite { display: block; image-rendering: pixelated; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 16px; z-index: 10; background: var(--sun); color: #16202a; padding: 6px 10px; }

/* ── header ── */
.top { position: sticky; top: 0; z-index: 5; background: var(--bg); border-bottom: var(--px) solid var(--ink); }
.top .wrap { display: flex; align-items: center; gap: 18px; min-height: 62px; }
.logo {
  font-family: var(--font-pixel); font-weight: 700; font-size: 22px; color: var(--ink);
  text-decoration: none; white-space: nowrap; flex: none; display: inline-flex; align-items: center; gap: 10px;
}
.logo .bot { width: 32px; height: 32px; transition: transform .15s steps(2); }
.logo:hover .bot { transform: translateY(-3px); }
.logo .cursor { display: inline-block; width: .55em; height: .16em; background: var(--leaf); margin-left: 3px; animation: blink 1.1s steps(1) infinite; }
@keyframes blink { 50% { opacity: 0; } }
.nav { display: flex; gap: 2px; margin-left: auto; min-width: 0; overflow-x: auto; scrollbar-width: none; }
.nav::-webkit-scrollbar { display: none; }
.nav a {
  font-size: 14.5px; font-weight: 500; color: var(--ink); text-decoration: none;
  padding: 4px 8px; border: 2px solid transparent; white-space: nowrap; flex: none;
}
.nav a:hover { border-color: var(--ink); }
.nav a[aria-current] { background: var(--sun); color: #16202a; border-color: var(--ink); }
.tools { display: flex; gap: 8px; align-items: center; flex: none; }
.chipbtn {
  font-family: var(--font-micro); font-size: 12px; color: var(--ink); background: var(--card);
  border: 2px solid var(--ink); padding: 4px 8px; cursor: pointer; text-decoration: none;
  box-shadow: 2px 2px 0 var(--ink); line-height: 1.4;
}
.chipbtn:hover { transform: translate(-1px, -1px); box-shadow: 3px 3px 0 var(--ink); }
.chipbtn:active { transform: translate(2px, 2px); box-shadow: 0 0 0 var(--ink); }
@media (max-width: 1000px) {
  .top .wrap { flex-wrap: wrap; gap: 6px 12px; padding-top: 10px; padding-bottom: 6px; }
  .nav { order: 3; width: 100%; margin-left: 0; }
  .tools { margin-left: auto; }
}

/* ── seedling scrollbar (desktop with a mouse only) ── */
.vine { display: none; }
@media (min-width: 900px) and (pointer: fine) {
  html { scrollbar-width: none; }
  html::-webkit-scrollbar { display: none; }
  .vine { display: block; position: fixed; right: 6px; top: 80px; bottom: 14px; width: 32px; z-index: 6; cursor: pointer; }
  .vine.off { display: none; }
  .vine-track { position: absolute; left: 14px; width: 4px; top: 0; bottom: 0;
    background: repeating-linear-gradient(var(--line) 0 6px, transparent 6px 10px); }
  .vine-fill { width: 4px; background: var(--leaf-dark); }
  .vine-thumb { position: absolute; left: 0; top: 0; width: 32px; cursor: grab; touch-action: none; transition: filter .1s; }
  .vine-thumb:hover, .vine.drag .vine-thumb { filter: drop-shadow(2px 2px 0 var(--sun)); }
  .vine.drag .vine-thumb { cursor: grabbing; }
}

/* ── buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-micro); font-size: 13px; text-transform: uppercase; letter-spacing: .4px;
  color: var(--ink); background: var(--card); text-decoration: none;
  border: 2px solid var(--ink); padding: 7px 12px; box-shadow: 3px 3px 0 var(--ink);
  transition: transform .08s, box-shadow .08s;
}
.btn:hover { transform: translate(-1px, -1px); box-shadow: 4px 4px 0 var(--ink); text-decoration: none; }
.btn:active { transform: translate(3px, 3px); box-shadow: 0 0 0 var(--ink); }
.btn.primary { background: var(--accent); color: var(--on-accent); }
.btns { display: flex; flex-wrap: wrap; gap: 10px 12px; }

/* ── sections ── */
.sec { padding: 64px 0 0; scroll-margin-top: 72px; }
.sec-h { display: flex; align-items: baseline; gap: 14px; margin-bottom: 24px; flex-wrap: wrap; }
.sec-h h2 { font-family: var(--font-pixel); font-weight: 600; font-size: 30px; display: flex; align-items: center; gap: 12px; }
.sec-h h2::before { content: ""; width: 14px; height: 14px; background: var(--leaf); box-shadow: 4px 4px 0 var(--ink); flex: none; }
.more-link { margin-left: auto; font-size: 14.5px; }
h3.sub { font-size: 15px; font-weight: 600; text-transform: uppercase; letter-spacing: .8px; color: var(--muted); margin: 8px 0 4px; }
h3.sub ~ h3.sub { margin-top: 36px; }
.sub-row { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; margin: 48px 0 12px; }
.sub-row h3.sub { margin: 0; }
@media (max-width: 1000px) { .sec { scroll-margin-top: 110px; } }

/* ── hero ── */
.hero { display: grid; grid-template-columns: 260px 1fr; gap: 48px; align-items: center; padding: 52px 0 0; scroll-margin-top: 120px; }
.avatar { background: var(--card); border: var(--px) solid var(--ink); box-shadow: var(--shadow) var(--shadow) 0 var(--ink); aspect-ratio: 1; overflow: hidden; }
.avatar img { display: block; width: 100%; height: 100%; object-fit: cover; }
.avatar-cap { font-family: var(--font-micro); font-size: 12px; color: var(--muted); margin-top: 14px; text-transform: uppercase; display: flex; align-items: center; gap: 6px; }
.avatar-cap::before { content: ""; width: 8px; height: 8px; background: var(--coral); }
.eyebrow { font-family: var(--font-micro); font-size: 13px; text-transform: uppercase; letter-spacing: .6px; color: var(--muted); margin-bottom: 12px; white-space: nowrap; }
.hero h1 { display: flex; align-items: baseline; flex-wrap: wrap; gap: 0 .35em; font-family: var(--font-body); font-weight: 700; font-size: clamp(38px, 5.4vw, 56px); letter-spacing: -1px; }
.hero h1 .zh { font-weight: 600; font-size: .5em; color: var(--muted); letter-spacing: 0; }
.tagline { font-size: clamp(19px, 2.3vw, 25px); line-height: 1.35; margin: 14px 0 18px; font-weight: 500; white-space: nowrap; }
.tagline mark { background: none; color: var(--accent); font-weight: 600; text-decoration: underline 4px var(--sun); text-underline-offset: 7px; text-decoration-skip-ink: none; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 22px; padding: 0; list-style: none; }
.chips li { font-size: 14px; border: 2px solid var(--ink); padding: 2px 10px; background: var(--bg); }
.mail { font-size: 15px; color: var(--muted); margin: 14px 0 0; }
.mail code { font-family: ui-monospace, Menlo, monospace; color: var(--ink); }
@media (max-width: 760px) {
  .hero { grid-template-columns: 1fr; gap: 24px; padding-top: 28px; }
  .hero .avatar-col { max-width: 190px; }
  .eyebrow, .tagline { white-space: normal; }
}

/* ── green highlight for key phrases (About, featured paper) ── */
.bio strong, .feature p strong { font-weight: 600; color: var(--ink); padding: 0 1px;
  background: linear-gradient(transparent 76%, color-mix(in srgb, var(--leaf) 60%, transparent) 76%, color-mix(in srgb, var(--leaf) 60%, transparent) 94%, transparent 94%); }

/* ── about ── */
.about { display: grid; grid-template-columns: minmax(0, 2.1fr) minmax(0, 1fr); gap: 40px; align-items: start; }
.bio p:last-child { margin-bottom: 0; }
.bio .inline { display: inline-block; width: 32px; height: 32px; vertical-align: -9px; margin-left: 8px; }
.facts { background: var(--card); border: 2px solid var(--ink); box-shadow: 4px 4px 0 var(--ink); padding: 18px 20px 20px; }
.facts h3 { font-family: var(--font-pixel); font-weight: 600; font-size: 19px; margin-bottom: 14px; }
.facts ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.facts li { display: grid; grid-template-columns: 32px 1fr; gap: 14px; align-items: center; font-size: 15.5px; line-height: 1.45; word-break: keep-all; }
.facts .sprite { width: 32px; height: 32px; transition: transform .15s steps(2); }
.facts li:hover .sprite { transform: translateY(-3px); }
@media (max-width: 1000px) { .about { grid-template-columns: 1fr; gap: 28px; } .facts { max-width: 480px; } }

/* ── research cards ── */
.research { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.rcard { background: var(--card); border: 2px solid var(--ink); padding: 20px 22px; display: grid; grid-template-columns: 48px 1fr; gap: 18px; align-items: start; }
.rcard .sprite { width: 48px; height: 48px; transition: transform .15s steps(2); }
.rcard:hover .sprite { transform: translateY(-4px); }
.rcard h3 { font-family: var(--font-pixel); font-weight: 600; font-size: 21px; margin-bottom: 6px; text-wrap: wrap; }
.rcard p { font-size: 15px; color: var(--muted); margin: 0; }
.rcard:nth-child(1) { border-left: 8px solid var(--accent); }
.rcard:nth-child(2) { border-left: 8px solid var(--sun); }
.rcard:nth-child(3) { border-left: 8px solid var(--coral); }
.rcard:nth-child(4) { border-left: 8px solid var(--leaf); }
@media (max-width: 760px) { .research { grid-template-columns: 1fr; } }

/* ── featured paper ── */
.feature {
  display: grid; grid-template-columns: 1fr auto; gap: 28px; align-items: center;
  background: var(--card); border: var(--px) solid var(--ink); box-shadow: var(--shadow) var(--shadow) 0 var(--ink);
  padding: 26px 30px; margin-top: 30px;
}
.flag { display: inline-block; font-family: var(--font-micro); font-size: 12px; text-transform: uppercase; background: var(--sun); color: #16202a; border: 2px solid var(--ink); padding: 1px 8px; margin-bottom: 12px; }
.feature h3 { font-family: var(--font-pixel); font-weight: 600; font-size: clamp(22px, 3vw, 30px); margin-bottom: 6px; }
.feature .fv { font-weight: 600; margin-bottom: .6em; }
.feature p { color: var(--muted); max-width: 70ch; }
.feature .fv { color: var(--ink); font-weight: 400; }
.feature .fv b { font-weight: 600; }
.feature .fv .sep { color: var(--muted); margin: 0 .6em; }
.feature .sprite { width: 128px; height: auto; margin-right: 6px; }
@media (max-width: 640px) { .feature { grid-template-columns: 1fr; padding: 22px; } .feature .sprite { display: none; } }

/* ── news ── */
.news { list-style: none; margin: 0; padding: 0; }
.news li { display: grid; grid-template-columns: var(--datecol) 1fr; gap: 18px; padding: 12px 0; border-bottom: 2px dotted var(--line); }
.news > li:first-child { padding-top: 0; }
.news time { font-family: var(--font-micro); font-size: 13px; color: var(--muted); padding-top: 3px; text-transform: uppercase; }
.news p { margin: 0; }
details.more summary { cursor: pointer; list-style: none; font-size: 15px; font-weight: 600; color: var(--accent); padding: 14px 0 4px; display: inline-flex; align-items: center; gap: 8px; }
details.more summary::-webkit-details-marker { display: none; }
details.more summary::before { content: "+"; font-family: var(--font-micro); width: 20px; height: 20px; display: grid; place-items: center; border: 2px solid var(--ink); color: var(--ink); background: var(--card); line-height: 1; }
details.more[open] summary::before { content: "−"; }
details.more .news li:first-child { padding-top: 12px; }
@media (max-width: 520px) { .news li { grid-template-columns: 1fr; gap: 2px; } }

/* ── publications ── */
.filters { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 14px; }
.filters button { font-family: var(--font-body); font-size: 13.5px; font-weight: 500; }
.filters button[aria-pressed="true"] { background: var(--ink); color: var(--bg); }
.pubs { list-style: none; margin: 0; padding: 0; }
.pub { display: grid; grid-template-columns: var(--datecol) 1fr; gap: 18px; padding: 18px 0; border-bottom: 2px dotted var(--line); }
.pub[hidden] { display: none; }
.pub .yr { font-family: var(--font-micro); font-size: 13px; color: var(--muted); padding-top: 4px; }
.pub .t { font-weight: 600; font-size: 17.5px; line-height: 1.4; display: block; margin-bottom: 4px; }
.pub .t a { color: var(--ink); text-decoration: none; }
.pub .t a:hover { color: var(--accent); text-decoration: underline; }
.pub .au { font-size: 15px; color: var(--muted); margin: 0; }
.pub .au b { color: var(--ink); font-weight: 600; }
.pub .ve { font-size: 15px; margin: 3px 0 0; display: flex; flex-wrap: wrap; gap: 6px 10px; align-items: center; }
.pub .t .badge { margin-left: 10px; vertical-align: 2px; white-space: nowrap; }
.ptags { display: flex; flex-wrap: wrap; gap: 6px; margin: 4px 0 7px; }
.tag { font-size: 12.5px; line-height: 1.5; padding: 0 7px; border: 1.5px solid var(--line); color: var(--muted); background: var(--card); }
.badge { font-family: var(--font-micro); font-size: 11px; text-transform: uppercase; border: 2px solid var(--ink); padding: 0 6px; line-height: 1.6; background: var(--sun); color: #16202a; }
.plinks { display: inline-flex; flex-wrap: wrap; gap: 10px; margin-left: 4px; }
.plinks a { font-family: var(--font-micro); font-size: 12px; text-transform: uppercase; text-decoration: none; color: var(--accent); }
.plinks a::before { content: "["; color: var(--muted); }
.plinks a::after { content: "]"; color: var(--muted); }
.plinks a:hover { background: var(--accent); color: var(--on-accent); }
@media (max-width: 520px) { .pub { grid-template-columns: 1fr; gap: 2px; } .plinks { margin-left: 0; } }

/* ── generic rows (funding, teaching, students, talks, service, awards) ── */
.rows { list-style: none; margin: 0; padding: 0; }
.rows > li { display: grid; grid-template-columns: var(--datecol) 1fr; gap: 18px; padding: 13px 0; border-bottom: 2px dotted var(--line); }
.rows .when { font-family: var(--font-micro); font-size: 13px; color: var(--muted); text-transform: uppercase; padding-top: 3px; }
.rows .what { font-weight: 600; }
.rows .lvl { font-weight: 400; color: var(--muted); }
.rows .where { font-size: 15px; color: var(--muted); margin: 2px 0 0; }
.rows .win { font-size: 14.5px; margin: 4px 0 0; display: flex; gap: 8px; align-items: baseline; }
.rows .win::before { content: ""; width: 9px; height: 9px; background: var(--sun); border: 2px solid var(--ink); flex: none; transform: translateY(1px); }
.courses { margin: 6px 0 0; padding: 0; list-style: none; display: grid; gap: 3px; }
.courses li { font-size: 15px; display: flex; gap: 10px; align-items: baseline; }
.courses li::before { content: ""; width: 6px; height: 6px; background: var(--accent); flex: none; transform: translateY(-2px); }
@media (max-width: 520px) { .rows > li { grid-template-columns: 1fr; gap: 2px; } }

/* ── footer ── */
.foot { margin-top: 80px; border-top: var(--px) solid var(--ink); padding: 26px 0 40px; }
.foot .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center; }
.foot p { margin: 0; font-size: 14px; color: var(--muted); }
.foot .ground { flex-basis: 100%; height: 12px; background:
  repeating-linear-gradient(90deg, var(--soil) 0 12px, color-mix(in srgb, var(--soil) 75%, var(--ink)) 12px 16px); }
.foot nav { display: flex; gap: 14px; margin-left: auto; flex-wrap: wrap; }
.foot nav a { font-size: 14px; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}