/* ============================================================
   AVI-Bench Project Page  —  "Evolution" editorial theme
   Inspired by Nature / Cell paper landing pages.
   Ink-on-paper restraint, single oxblood accent, generous serif display.
   ============================================================ */

:root {
  --paper:      #f6f1e8;  /* warm ivory background  */
  --paper-dim:  #ece5d6;  /* slightly darker ivory  */
  --ink:        #1a1a1a;  /* near-black body text   */
  --ink-soft:   #4a4a4a;  /* secondary text         */
  --ink-fade:   #7a7268;  /* tertiary / captions    */
  --accent:     #8a2422;  /* deep oxblood signal    */
  --accent-soft:#c05a3f;  /* warm terra (hover/highlight) */
  --rule:       #c9bda5;  /* hairline rules         */
}

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'EB Garamond', 'Crimson Pro', Georgia, serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; transition: border-color .2s; }
a:hover { border-color: var(--accent); }

/* ---------- typography ---------- */
.display { font-family: 'Fraunces', 'EB Garamond', Georgia, serif; font-weight: 500; letter-spacing: -0.015em; }
.mono    { font-family: 'JetBrains Mono', 'IBM Plex Mono', monospace; }
.sans    { font-family: 'Inter', -apple-system, sans-serif; }
.caps    { text-transform: uppercase; letter-spacing: 0.12em; font-size: 0.78rem; font-weight: 600; }

h1.display { font-weight: 600; line-height: 1.05; }

.divider-rule {
  display: block;
  width: 60px;
  height: 1px;
  background: var(--ink);
  margin: 0 auto;
}

/* ---------- top strip ---------- */
.top-strip {
  border-bottom: 1px solid var(--rule);
  padding: 0.9rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: 'Inter', sans-serif;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
}
.top-strip .brand { font-family: 'Fraunces', serif; font-weight: 600; font-size: 1.05rem; letter-spacing: 0; }
.top-strip .brand .dot { color: var(--accent); margin: 0 0.25rem; }
.top-strip .meta { color: var(--ink-fade); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.14em; }

/* ---------- hero ---------- */
.hero {
  padding: 7vh 1.5rem 4vh;
  text-align: center;
  background: var(--paper);
  position: relative;
}
.hero .venue {
  font-family: 'Inter', sans-serif;
  font-size: 0.72rem;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.6rem;
}
.hero h1 {
  font-family: 'Fraunces', 'EB Garamond', serif;
  font-weight: 500;
  font-size: clamp(2.5rem, 5.5vw, 4.5rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
  max-width: 18ch;
  margin: 0 auto 1rem;
  color: var(--ink);
}
.hero h1 .accent { color: var(--accent); font-style: italic; font-weight: 500; }
.hero h1 .ampersand {
  font-style: italic;
  font-weight: 400;
  color: var(--ink-fade);
  display: inline-block;
  transform: translateY(0.04em);
}
.hero .subtitle {
  font-family: 'Fraunces', serif;
  font-style: italic;
  font-weight: 400;
  font-size: 1.25rem;
  color: var(--ink-soft);
  max-width: 50ch;
  margin: 0 auto 2.5rem;
}

.hero .authors {
  font-family: 'Inter', sans-serif;
  font-size: 0.95rem;
  color: var(--ink-soft);
  max-width: 65rem;
  margin: 0 auto 0.4rem;
  line-height: 1.6;
}
.hero .authors a { color: var(--ink); border-bottom: 1px solid var(--rule); }
.hero .authors a:hover { color: var(--accent); border-color: var(--accent); }
.hero .affiliation {
  font-family: 'Inter', sans-serif;
  font-size: 0.85rem;
  color: var(--ink-fade);
  margin-bottom: 2.2rem;
}

/* hero action buttons */
.action-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem; margin-bottom: 4vh; }
.action {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.7rem 1.2rem;
  background: transparent;
  border: 1.2px solid var(--ink);
  color: var(--ink);
  font-family: 'Inter', sans-serif;
  font-size: 0.88rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  border-radius: 0;
  cursor: pointer;
  transition: all 0.18s;
}
.action:hover {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}
.action.primary {
  background: var(--ink);
  color: var(--paper);
}
.action.primary:hover { background: var(--accent); border-color: var(--accent); }
.action i { font-size: 0.92rem; }

/* ---------- the evolution centerpiece ---------- */
.evolution-piece {
  max-width: 1280px;
  margin: 4vh auto 6vh;
  padding: 0 1.5rem;
}
.evolution-piece figure {
  margin: 0;
  position: relative;
}
.evolution-piece img {
  width: 100%;
  display: block;
  filter: contrast(1.02);
  mix-blend-mode: multiply;
}
.evolution-piece figcaption {
  margin-top: 1.2rem;
  font-family: 'Fraunces', serif;
  font-style: italic;
  font-size: 1.05rem;
  text-align: center;
  color: var(--ink-fade);
  max-width: 64ch;
  margin-left: auto;
  margin-right: auto;
}
.evolution-piece figcaption .marker {
  color: var(--accent);
  font-weight: 600;
  font-style: normal;
  text-transform: uppercase;
  font-size: 0.78rem;
  letter-spacing: 0.15em;
  margin-right: 0.55em;
}

/* ---------- generic section ---------- */
section.section {
  padding: 7vh 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
}
section.section.tight   { padding: 5vh 1.5rem; }
section.section.banded {
  max-width: none;
  background: var(--paper-dim);
  padding: 8vh 1.5rem;
}
section.section.banded > .container { max-width: 1100px; margin: 0 auto; }

.section-head { text-align: center; margin-bottom: 3rem; }
.section-head .eyebrow {
  font-family: 'Inter', sans-serif;
  font-size: 0.72rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.85rem;
}
.section-head h2 {
  font-family: 'Fraunces', serif;
  font-weight: 500;
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  letter-spacing: -0.012em;
  line-height: 1.15;
  margin: 0 auto 0.9rem;
  max-width: 22ch;
  color: var(--ink);
}
.section-head .lede {
  font-family: 'Fraunces', serif;
  font-style: italic;
  color: var(--ink-soft);
  font-size: 1.05rem;
  max-width: 60ch;
  margin: 0 auto;
}

/* ---------- abstract block ---------- */
.abstract-block {
  max-width: 720px;
  margin: 0 auto;
  font-size: 1.15rem;
  line-height: 1.8;
  color: var(--ink);
  text-align: left;
}
.abstract-block p { margin-bottom: 1.1rem; }
.abstract-block .dropcap::first-letter {
  font-family: 'Fraunces', serif;
  font-size: 3.6rem;
  font-weight: 500;
  float: left;
  line-height: 0.9;
  padding: 0.35rem 0.5rem 0 0;
  color: var(--accent);
}
.abstract-block em { color: var(--ink); font-style: italic; }
.abstract-block strong { font-weight: 700; color: var(--ink); }

/* ---------- benchmark overview row ---------- */
.overview-row {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 3rem;
  align-items: center;
}
.overview-row figure { margin: 0; }
.overview-row img { width: 100%; height: auto; mix-blend-mode: multiply; }
.overview-row .copy h3 {
  font-family: 'Fraunces', serif;
  font-weight: 500;
  font-size: 1.6rem;
  margin-bottom: 1rem;
  letter-spacing: -0.01em;
}
.overview-row .copy p { color: var(--ink-soft); }
.overview-row .stat-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.4rem;
  margin-top: 1.6rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--rule);
}
.overview-row .stat { line-height: 1.1; }
.overview-row .stat .num {
  font-family: 'Fraunces', serif;
  font-weight: 500;
  font-size: 2.1rem;
  color: var(--accent);
  display: block;
  margin-bottom: 0.25rem;
}
.overview-row .stat .label {
  font-family: 'Inter', sans-serif;
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--ink-fade);
}

/* ---------- four-level cards ---------- */
.levels-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  margin-top: 1rem;
}
.level-card {
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 1.4rem 1.4rem 1.6rem;
  position: relative;
}
.level-card .num {
  font-family: 'Fraunces', serif;
  font-style: italic;
  font-size: 2.4rem;
  font-weight: 500;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 0.6rem;
}
.level-card .name {
  font-family: 'Fraunces', serif;
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
}
.level-card .desc {
  font-size: 0.95rem;
  color: var(--ink-soft);
  line-height: 1.55;
}
.level-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 40px;
  height: 2px;
  background: var(--accent);
}

/* ---------- results tables ---------- */
.results-wrap { max-width: 920px; margin: 0 auto; }
.results-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 0.8rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--ink);
}
.results-head h3 {
  font-family: 'Fraunces', serif;
  font-weight: 500;
  font-size: 1.3rem;
  letter-spacing: -0.01em;
  margin: 0;
}
.results-head .meta { font-family: 'Inter', sans-serif; font-size: 0.78rem; color: var(--ink-fade); letter-spacing: 0.12em; text-transform: uppercase; }

table.r-table {
  width: 100%;
  border-collapse: collapse;
  font-family: 'Inter', sans-serif;
  font-size: 0.92rem;
  margin-bottom: 3rem;
}
table.r-table th {
  text-align: right;
  font-weight: 500;
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-fade);
  padding: 0.85rem 0.7rem;
  border-bottom: 1px solid var(--ink);
}
table.r-table th:first-child { text-align: left; }
table.r-table td {
  text-align: right;
  padding: 0.65rem 0.7rem;
  border-bottom: 1px solid var(--rule);
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}
table.r-table td:first-child { text-align: left; font-family: 'Fraunces', serif; font-size: 1rem; }
table.r-table tr.highlight td { background: rgba(138, 36, 34, 0.08); }
table.r-table tr.highlight td:first-child { color: var(--accent); font-weight: 600; }
table.r-table tr.human td { font-style: italic; color: var(--ink-fade); border-top: 1px solid var(--ink); }

.observations { margin-top: 2rem; }
.observations .obs {
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: 1rem;
  padding: 1rem 0;
  border-top: 1px solid var(--rule);
}
.observations .obs:last-child { border-bottom: 1px solid var(--rule); }
.observations .obs .label {
  font-family: 'Fraunces', serif;
  font-style: italic;
  color: var(--accent);
  font-size: 0.92rem;
  letter-spacing: 0.04em;
  padding-top: 0.05rem;
}
.observations .obs .text {
  font-family: 'EB Garamond', serif;
  font-size: 1.05rem;
  color: var(--ink-soft);
  line-height: 1.65;
}
.observations .obs .text strong { color: var(--ink); font-weight: 700; }

/* ---------- task samples (compact tabs) ---------- */
.samples-shell {
  border: 1px solid var(--rule);
  background: var(--paper);
  padding: 0;
}
.tabs {
  display: flex;
  border-bottom: 1px solid var(--rule);
  background: var(--paper-dim);
}
.tab-btn {
  flex: 1;
  padding: 1rem 0.6rem;
  background: none;
  border: none;
  font-family: 'Inter', sans-serif;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-fade);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all 0.18s;
}
.tab-btn:hover { color: var(--ink); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); background: var(--paper); }

.tab-panel { padding: 2.2rem 2rem; display: none; }
.tab-panel.active { display: block; animation: fade 0.35s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

.sample-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}
.sample {
  display: flex;
  flex-direction: column;
}
.sample .task-tag {
  font-family: 'Inter', sans-serif;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.4rem;
}
.sample .task-name {
  font-family: 'Fraunces', serif;
  font-size: 1.15rem;
  margin-bottom: 0.8rem;
  color: var(--ink);
}
.sample video,
.sample img {
  width: 100%;
  border-radius: 2px;
  margin-bottom: 0.6rem;
  background: #000;
}
.sample audio { width: 100%; margin-bottom: 0.6rem; }
.sample .qa {
  font-family: 'EB Garamond', serif;
  font-size: 1rem;
  color: var(--ink-soft);
  line-height: 1.55;
  margin-top: auto;
}
.sample .qa p { margin: 0.3rem 0; }
.sample .qa .qtag, .sample .qa .atag {
  font-family: 'Inter', sans-serif;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-fade);
  margin-right: 0.5em;
}
.sample .qa .atag { color: var(--accent); }
.sample .qa code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  background: var(--paper-dim);
  padding: 0.1em 0.35em;
  border-radius: 2px;
}

/* ---------- quickstart code ---------- */
.code-block {
  background: var(--ink);
  color: #e9e2d2;
  padding: 1.8rem 1.8rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.88rem;
  line-height: 1.65;
  overflow-x: auto;
  border-left: 3px solid var(--accent);
  white-space: pre;
}
.code-block .c { color: #8a8270; }   /* comment */
.code-block .k { color: var(--accent-soft); }

/* ---------- citation ---------- */
.cite-shell {
  max-width: 820px;
  margin: 0 auto;
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 2rem 2.2rem;
}
.cite-shell pre {
  margin: 0;
  white-space: pre;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.83rem;
  line-height: 1.65;
  color: var(--ink);
  overflow-x: auto;
}
.cite-shell pre .b { color: var(--accent); }

/* ---------- footer ---------- */
footer.foot {
  border-top: 1px solid var(--rule);
  padding: 2.2rem 1.5rem;
  text-align: center;
  font-family: 'Inter', sans-serif;
  font-size: 0.82rem;
  color: var(--ink-fade);
  background: var(--paper);
}
footer.foot a { color: var(--ink-soft); }
footer.foot a:hover { color: var(--accent); }

/* ---------- entrance animation ---------- */
.fade-up { opacity: 0; transform: translateY(18px); animation: fadeUp 0.9s ease forwards; }
.fade-up.d1 { animation-delay: 0.05s; }
.fade-up.d2 { animation-delay: 0.18s; }
.fade-up.d3 { animation-delay: 0.30s; }
.fade-up.d4 { animation-delay: 0.42s; }
.fade-up.d5 { animation-delay: 0.55s; }
@keyframes fadeUp { to { opacity: 1; transform: none; } }

/* ---------- responsive ---------- */
@media (max-width: 880px) {
  .overview-row { grid-template-columns: 1fr; gap: 1.5rem; }
  .levels-grid { grid-template-columns: 1fr 1fr; }
  .sample-grid { grid-template-columns: 1fr; }
  .tab-btn { font-size: 0.7rem; letter-spacing: 0.08em; }
  .top-strip .meta { display: none; }
}
@media (max-width: 540px) {
  .levels-grid { grid-template-columns: 1fr; }
  .hero { padding: 5vh 1.2rem 3vh; }
  .hero h1 { font-size: 2.2rem; }
}

/* ---------- corresponding author mail icon ---------- */
.authors .mail {
  margin-left: 0.15em;
  color: var(--accent);
  border-bottom: none !important;
  display: inline-block;
  vertical-align: super;
  font-size: 0.7em;
  opacity: 0.85;
  transition: opacity 0.18s;
}
.authors .mail:hover { opacity: 1; }
.authors .mail i { font-size: 0.85em; }

/* ---------- huggingface logo in dataset button ---------- */
.action .hf-logo {
  width: 1.05em;
  height: 1.05em;
  margin-right: 0.25em;
  vertical-align: -0.18em;
}

/* ---------- team section ---------- */
.team-row {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 3.5rem;
  margin-top: 1rem;
}
.team-card {
  text-align: center;
  border-bottom: none !important;
  color: inherit;
  display: block;
}
.team-card:hover .team-name { color: var(--accent); }
.team-photo {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  object-fit: cover;
  display: block;
  margin: 0 auto 0.85rem;
  box-shadow: 0 6px 22px rgba(0,0,0,0.10);
  filter: grayscale(0.10);
  transition: filter 0.25s, transform 0.25s;
}
.team-card:hover .team-photo {
  filter: grayscale(0);
  transform: translateY(-2px);
}
.team-name {
  font-family: 'Fraunces', serif;
  font-weight: 500;
  font-size: 1.15rem;
  color: var(--ink);
  transition: color 0.18s;
}
.team-role {
  font-family: 'Inter', sans-serif;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-fade);
  margin-top: 0.25rem;
}

/* ---------- inline SVG icon sizing in actions ---------- */
.action .ico {
  width: 1.1em;
  height: 1.1em;
  vertical-align: -0.18em;
  fill: currentColor;
}
.action .ico text { fill: currentColor; }

/* ---------- envelope SVG next to corresponding author ---------- */
.authors .mail svg {
  width: 0.85em;
  height: 0.85em;
  vertical-align: middle;
}

/* ---------- Usage Policy banner ---------- */
.policy-banner {
  background: #fff8ec;
  border-top: 1px solid #e4d9c1;
  border-bottom: 1px solid #e4d9c1;
}
.policy-banner .policy-card {
  max-width: 64rem;
  margin: 0 auto;
  padding: 1.25rem 0;
}
.policy-banner .eyebrow.accent { color: var(--accent, #8a2422); }
.policy-banner .policy-title {
  font-family: 'Fraunces', 'EB Garamond', serif;
  font-size: clamp(1.6rem, 2.2vw, 2.1rem);
  line-height: 1.15;
  margin: .25rem 0 .75rem;
  color: #2a1a05;
}
.policy-banner .policy-body { line-height: 1.55; margin: .35rem 0; }
.policy-banner .policy-body.small { font-size: .92em; color: #5a4a30; }
.policy-banner .policy-actions {
  margin-top: .9rem;
  display: flex;
  gap: .6rem;
  flex-wrap: wrap;
}
.policy-banner .btn {
  display: inline-block;
  padding: .45rem .9rem;
  border-radius: .375rem;
  background: var(--accent, #8a2422);
  color: #fffaf0;
  text-decoration: none;
  font-weight: 600;
}
.policy-banner .btn.ghost {
  background: transparent;
  color: var(--accent, #8a2422);
  border: 1px solid var(--accent, #8a2422);
}