/* ============================================================
   Ziteng Cui — academic site
   Palette derives from illuminant duality: tungsten (warm) and
   daylight (cool), the two light sources at the centre of the
   multi-illuminant white balance work.
   ============================================================ */

:root {
  --ink:        #16181c;
  --ink-soft:   #2c3138;
  --muted:      #6b737d;
  --muted-soft: #8b929a;
  --paper:      #ffffff;
  --paper-alt:  #f7f7f5;
  --rule:       #e4e6e9;
  --tungsten:   #c2703a;
  --daylight:   #2e6099;
  --warm-wash:  #fdf6f0;

  --sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --wrap: 1080px;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink-soft);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--daylight);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .15s ease, border-color .15s ease;
}
a:hover { color: var(--tungsten); border-bottom-color: currentColor; }
a:focus-visible {
  outline: 2px solid var(--tungsten);
  outline-offset: 2px;
  border-radius: 2px;
}

img { max-width: 100%; display: block; }

/* ---------- Navigation ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--ink);
}

.nav-inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 58px;
}

.nav-name {
  font-weight: 600;
  font-size: 1.06rem;
  letter-spacing: -0.01em;
  color: #fff;
  border-bottom: none;
  white-space: nowrap;
}
.nav-name:hover { color: #fff; border-bottom: none; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 22px;
  list-style: none;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-links a {
  color: #a8afb8;
  font-size: 0.92rem;
  font-weight: 450;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}
.nav-links a:hover { color: #fff; border-bottom-color: var(--tungsten); }
.nav-links a[aria-current="page"] { color: #fff; border-bottom-color: var(--tungsten); }

/* White-balance strip: tungsten to daylight. The signature element. */
.wb-strip {
  height: 3px;
  background: linear-gradient(90deg,
    var(--tungsten) 0%,
    #d9a06b 22%,
    #eeeae4 50%,
    #7fa3cb 78%,
    var(--daylight) 100%);
}

/* ---------- Layout ---------- */

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 28px;
}

main { padding: 46px 0 80px; }

section + section { margin-top: 52px; }

/* ---------- Section headings ---------- */

.sec-head {
  font-family: var(--mono);
  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 20px;
  padding-bottom: 9px;
  border-bottom: 1px solid var(--rule);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
}
.sec-head .count {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted-soft);
  font-weight: 400;
}

/* ---------- Hero / identity ---------- */

.hero {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr) 215px;
  gap: 38px;
  align-items: start;
}

.hero-photo {
  width: 100%;
  border-radius: 3px;
  border: 1px solid var(--rule);
}

.hero-name {
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.028em;
  line-height: 1.1;
  color: var(--ink);
  margin: -6px 0 3px;
}

.hero-name-cn {
  font-size: 1rem;
  color: var(--muted);
  font-weight: 400;
  margin: 0 0 16px;
}

.affil {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
  font-size: 0.94rem;
  line-height: 1.62;
}
.affil li { color: var(--ink-soft); }
.affil .role { font-weight: 550; color: var(--ink); }
.affil .incoming {
  margin-top: 9px;
  padding-top: 9px;
  border-top: 1px dashed var(--rule);
}
.affil .tag {
  font-family: var(--mono);
  font-size: 0.66rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--tungsten);
  background: var(--warm-wash);
  border: 1px solid #f0dcc9;
  border-radius: 2px;
  padding: 1px 6px;
  margin-right: 7px;
  vertical-align: 1px;
}

.mail {
  font-family: var(--mono);
  font-size: 0.87rem;
}

.social {
  display: flex;
  gap: 14px;
  margin-top: 14px;
  font-size: 0.87rem;
  flex-wrap: wrap;
}
.social a { color: var(--muted); }
.social a:hover { color: var(--tungsten); }

.interests-title {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 4px 0 11px;
  font-weight: 500;
}
.interests {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.91rem;
  line-height: 1.55;
}
.interests li {
  padding: 5px 0 5px 13px;
  border-left: 2px solid var(--rule);
  color: var(--ink-soft);
  transition: border-color .18s ease;
}
.interests li:hover { border-left-color: var(--tungsten); }

/* ---------- Prose ---------- */

.prose { font-size: 1rem; line-height: 1.78; }
.prose p { margin: 0 0 15px; }
.prose p:last-child { margin-bottom: 0; }
.prose strong { color: var(--ink); font-weight: 600; }
.prose em { color: var(--ink); font-style: italic; }

.bio { margin-top: 40px; }

/* ---------- Recruiting callout ---------- */

.callout {
  margin-top: 30px;
  background: var(--warm-wash);
  border: 1px solid #f2e2d3;
  border-left: 3px solid var(--tungsten);
  border-radius: 3px;
  padding: 20px 24px;
}
.callout-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--tungsten);
  font-weight: 550;
  margin: 0 0 9px;
}
.callout p { margin: 0 0 10px; font-size: 0.95rem; line-height: 1.72; }
.callout p:last-child { margin-bottom: 0; }
.callout .cn { color: var(--muted); font-size: 0.92rem; }

/* ---------- News ---------- */

.news { list-style: none; margin: 0; padding: 0; }

.news li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 16px;
  padding: 9px 0;
  border-bottom: 1px solid #f0f1f2;
  font-size: 0.94rem;
  align-items: baseline;
}
.news li:last-child { border-bottom: none; }

.news time {
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted-soft);
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.news .hidden-item { display: none; }
.news.expanded .hidden-item { display: grid; }

.more-btn {
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
  background: none;
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 6px 13px;
  cursor: pointer;
  transition: border-color .15s ease, color .15s ease;
}
.more-btn:hover { color: var(--tungsten); border-color: var(--tungsten); }
.more-btn:focus-visible { outline: 2px solid var(--tungsten); outline-offset: 2px; }

/* ---------- Publications ---------- */

.year-head {
  font-family: var(--mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin: 42px 0 4px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--ink);
}
.year-head:first-of-type { margin-top: 0; }

.pub {
  display: grid;
  grid-template-columns: 196px minmax(0, 1fr);
  gap: 26px;
  padding: 22px 0;
  border-bottom: 1px solid #f0f1f2;
  align-items: start;
}
.pub:last-child { border-bottom: none; }

/* Entry with no thumbnail: text takes the full width. */
.pub:not(:has(.pub-media)) { grid-template-columns: minmax(0, 1fr); }

.pub-media {
  align-self: start;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: #fff;
  overflow: hidden;
  line-height: 0;
}
.pub-media img,
.pub-media video {
  width: 100%;
  height: auto;
  max-height: 260px;
  object-fit: contain;
  display: block;
}

/* Hover to reveal the "after" result. The before image sets the box size;
   the after layer is absolutely positioned on top and fades in. */
.pub-media.swap { position: relative; }
.pub-media.swap .after {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity .28s ease;
}
.pub-media.swap .after img,
.pub-media.swap .after video {
  width: 100%;
  height: 100%;
  max-height: none;
  object-fit: cover;
}
.pub:hover .pub-media.swap .after,
.pub-media.swap:focus-within .after { opacity: 1; }

/* Small affordance so people know there is something to hover. */
.pub-media.swap::after {
  content: "hover";
  position: absolute;
  right: 6px;
  bottom: 6px;
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  line-height: 1;
  color: #fff;
  background: rgba(20, 22, 26, 0.62);
  border-radius: 2px;
  padding: 3px 5px;
  pointer-events: none;
  transition: opacity .28s ease;
}
.pub:hover .pub-media.swap::after { opacity: 0; }

.pub-title {
  font-size: 1.02rem;
  font-weight: 600;
  line-height: 1.42;
  color: var(--ink);
  margin: -3px 0 6px;
}
.pub-title a { color: var(--ink); }
.pub-title a:hover { color: var(--tungsten); }

.pub-authors {
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.6;
  margin: 0 0 8px;
}
.pub-authors .me { color: var(--ink); font-weight: 600; }

.pub-venue {
  font-family: var(--mono);
  font-size: 0.76rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--tungsten);
  font-weight: 500;
  margin: 0 0 9px;
}
.pub-venue .note {
  color: var(--muted-soft);
  text-transform: none;
  letter-spacing: 0.02em;
  font-weight: 400;
}

.pub-links {
  font-size: 0.85rem;
  color: var(--muted-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 4px 0;
  align-items: center;
}
.pub-links a { font-size: 0.85rem; }
.pub-links .sep { margin: 0 8px; color: var(--rule); }

.pub-badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  color: var(--tungsten);
  background: var(--warm-wash);
  border: 1px solid #f0dcc9;
  border-radius: 2px;
  padding: 1px 6px;
  margin-left: 7px;
  vertical-align: 1px;
  text-transform: none;
}

.note-line {
  font-size: 0.92rem;
  color: var(--muted);
  margin: 0 0 26px;
}

/* ---------- Generic entry lists (awards, service, talks) ---------- */

.entries { list-style: none; margin: 0; padding: 0; }

.entries li {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid #f0f1f2;
  font-size: 0.96rem;
  align-items: baseline;
}
.entries li:last-child { border-bottom: none; }

.entries .yr {
  font-family: var(--mono);
  font-size: 0.79rem;
  color: var(--muted-soft);
  white-space: nowrap;
}
.entries .what { color: var(--ink-soft); }
.entries .what strong { color: var(--ink); font-weight: 600; }
.entries .where { color: var(--muted); font-size: 0.9rem; display: block; margin-top: 1px; }

.plain-list { list-style: none; margin: 0; padding: 0; font-size: 0.96rem; }
.plain-list li {
  padding: 9px 0;
  border-bottom: 1px solid #f0f1f2;
}
.plain-list li:last-child { border-bottom: none; }
.plain-list .label {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted-soft);
  display: block;
  margin-bottom: 4px;
}

.reviewer-list {
  font-size: 0.93rem;
  color: var(--muted);
  line-height: 1.8;
}

/* ---------- Lab page ---------- */

.lab-hero {
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 32px 34px;
  background: linear-gradient(180deg, var(--paper-alt) 0%, var(--paper) 100%);
}
.lab-name {
  font-size: 1.9rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin: 0 0 4px;
  line-height: 1.2;
}
.lab-sub {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--tungsten);
  margin: 0 0 18px;
}

.topics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(330px, 1fr));
  gap: 18px;
  margin-top: 4px;
}

/* The three readings of RAW */
.triptych {
  margin-top: 26px;
  padding-top: 22px;
  border-top: 1px solid var(--rule);
}
.triptych-lead {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 16px;
}
.triptych dl {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
  margin: 0;
}
.triptych dt {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 6px;
  padding-bottom: 6px;
  border-bottom: 2px solid var(--tungsten);
  display: inline-block;
}
.triptych dd {
  margin: 0;
  font-size: 0.91rem;
  line-height: 1.62;
  color: var(--muted);
}
.topic {
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 18px 20px;
  transition: border-color .18s ease;
}
.topic:hover { border-color: var(--muted-soft); }
.topic h3 {
  font-size: 0.99rem;
  font-weight: 600;
  color: var(--ink);
  margin: 0 0 7px;
}
.topic p {
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.65;
  margin: 0;
}
.topic .kw {
  font-family: var(--mono);
  font-size: 0.71rem;
  letter-spacing: 0.02em;
  color: var(--muted-soft);
  line-height: 1.65;
  margin-top: 10px;
  padding-top: 9px;
  border-top: 1px solid var(--rule);
}

/* ---------- More page ---------- */

.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 34px;
}

/* ---------- Footer ---------- */

footer {
  border-top: 1px solid var(--rule);
  margin-top: 70px;
  padding: 26px 0 40px;
  font-size: 0.83rem;
  color: var(--muted-soft);
}
footer .wrap {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}
footer a { color: var(--muted); }

/* ---------- Responsive ---------- */

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 156px minmax(0, 1fr);
    gap: 26px;
  }
  .hero-interests {
    grid-column: 1 / -1;
    padding-top: 6px;
    border-top: 1px solid var(--rule);
  }
  .interests {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }
  .interests li {
    border-left: none;
    padding: 3px 10px;
    background: var(--paper-alt);
    border-radius: 2px;
    font-size: 0.87rem;
  }
  .interests li:hover { background: var(--warm-wash); }
}

@media (max-width: 640px) {
  body { font-size: 15px; }
  .wrap, .nav-inner { padding: 0 18px; }

  .nav-inner {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    min-height: 0;
    padding-top: 11px;
    padding-bottom: 0;
  }
  .nav-name { font-size: 1rem; }

  .nav-links {
    justify-content: flex-start;
    flex-wrap: nowrap;
    gap: 18px;
    margin-top: 9px;
    padding-bottom: 9px;
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
  }
  .nav-links::-webkit-scrollbar { display: none; }
  .nav-links li { flex: 0 0 auto; }
  .nav-links a { font-size: 0.87rem; white-space: nowrap; }

  .hero { grid-template-columns: 1fr; gap: 20px; }
  .hero-photo { width: 132px; }
  .hero-name { font-size: 2rem; }

  .pub { grid-template-columns: 1fr; gap: 14px; }
  .pub-media { max-width: 320px; }

  .news li, .entries li { grid-template-columns: 62px minmax(0, 1fr); gap: 12px; }

  .lab-hero { padding: 24px 20px; }
  .lab-name { font-size: 1.5rem; }
  .triptych dl { grid-template-columns: 1fr; gap: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}