/* TimeTraveler: NeurIPS 2026 project page
   Theme: the two institutions behind the paper.
   - Illini Blue / Kyung Hee Blue (nearly the same navy) is the shared ink.
   - Kyung Hee Red (#A40F16) and Illini Orange (#FF5F05) are the two accents.
   They also carry the method's own semantics on the timeline:
   red = past, blue = current, orange = future. */

:root {
  --paper: #fafaf7;
  --card: #ffffff;
  --ink: #13294b;          /* Illini Blue */
  --soft: #4b586c;
  --faint: #8590a0;
  --line: #e2e1da;
  --wash: #f2f1ec;

  --khu: #a40f16;          /* Kyung Hee Red, PANTONE 201C */
  --illini: #ff5f05;       /* Illini Orange, PMS 1655 */
  --altgeld: #c84113;      /* UIUC accessible orange for text */
  --industrial: #1d58a7;   /* UIUC Industrial Blue */

  --past: var(--khu);
  --current: var(--industrial);
  --future: var(--illini);
  --future-text: var(--altgeld);

  --past-tint: #f8ebeb;
  --current-tint: #eaf0f8;
  --future-tint: #fff1e8;
  --ours-tint: #edf2f9;

  --duo: linear-gradient(90deg, var(--khu) 0%, var(--illini) 100%);
  --radius: 10px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Public Sans", -apple-system, "Segoe UI", sans-serif;
  font-size: 16.5px;
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
}

h1, h2, h3 { font-family: "Spectral", Georgia, serif; font-weight: 600; line-height: 1.15; margin: 0; }
a { color: inherit; }
.wrap { max-width: 1000px; margin: 0 auto; padding: 0 22px; }

/* two-tone wordmark: Kyung Hee red into Illini orange, past into future */
.duo-text {
  background: linear-gradient(90deg, var(--khu) 0%, #e2500b 100%);
  -webkit-background-clip: text; background-clip: text;
  color: transparent;
}

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 20;
  background: rgba(250, 250, 247, 0.93);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}
.nav::before { content: ""; display: block; height: 3px; background: var(--duo); }
.nav-inner { display: flex; align-items: center; gap: 20px; height: 54px; }
.wordmark {
  font-family: "Spectral", Georgia, serif;
  font-weight: 700; font-size: 20px; text-decoration: none; letter-spacing: 0.005em;
}
.nav-links { margin-left: auto; display: flex; gap: 18px; overflow-x: auto; scrollbar-width: none; }
.nav-links::-webkit-scrollbar { display: none; }
.nav-links a {
  font-size: 14px; font-weight: 500; color: var(--soft);
  text-decoration: none; white-space: nowrap; padding: 4px 0;
}
.nav-links a:hover { color: var(--ink); }

/* ---------- hero ---------- */
.hero { padding: 58px 0 30px; text-align: center; }

.venue {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--ink); border-radius: 999px;
  padding: 3px 14px; font-size: 13.5px; font-weight: 500;
}

.venue-row { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.venue-logo { height: 46px; width: auto; display: block; }
.hero h1 { margin: 20px auto 6px; max-width: 880px; }
.hero h1 .name { display: block; font-size: clamp(40px, 6.4vw, 68px); font-weight: 700; letter-spacing: -0.005em; line-height: 1.08; padding-bottom: 4px; }
.hero h1 .title { display: block; margin-top: 10px; font-size: clamp(22px, 3.1vw, 32px); font-weight: 600; line-height: 1.22; }

.hero .subline { margin: 16px auto 0; max-width: 660px; color: var(--soft); font-size: 17px; }

/* timeline diagram */
.tline { margin: 30px auto 4px; max-width: 760px; }
.tline svg { width: 100%; height: auto; display: block; overflow: visible; }
.tline-mobile { display: none; }

@media (prefers-reduced-motion: no-preference) {
  .tline .planner { opacity: 0; animation: rise 0.5s ease 0.05s forwards; }
  .tline .ent { opacity: 0; animation: rise 0.25s ease forwards; }
  .tline .axis { stroke-dasharray: 760; stroke-dashoffset: 760; animation: draw 1.1s ease 0.1s forwards; }
  .tline .arm { stroke-dasharray: 420; stroke-dashoffset: 420; animation: draw 0.6s ease forwards; }
  .tline .arm.a1 { animation-delay: 1.15s; }
  .tline .arm.a2 { animation-delay: 1.30s; }
  .tline .arm.a3 { animation-delay: 1.45s; }
  .tline .lbl { opacity: 0; animation: rise 0.5s ease 1.7s forwards; }
  .tline .now { opacity: 0; animation: rise 0.4s ease 0.95s forwards; }
}
@keyframes rise { to { opacity: 1; } }
@keyframes draw { to { stroke-dashoffset: 0; } }

/* authors */
.authors { margin-top: 30px; font-size: 17px; }
.authors .row { max-width: 760px; margin: 0 auto; }
.authors a { text-decoration: none; border-bottom: 1px solid var(--line); }
.authors a:hover { border-bottom-color: var(--ink); }
sup { font-size: 11px; color: var(--soft); }
sup.k { color: var(--khu); font-weight: 600; }
sup.u { color: var(--altgeld); font-weight: 600; }

.affils {
  margin-top: 12px; display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 14px;
  font-size: 14.5px; color: var(--soft);
}
.inst {
  display: inline-flex; align-items: center; gap: 8px;
  border: 1px solid var(--line); border-radius: 999px; background: var(--card);
  padding: 4px 14px 4px 6px;
}
.inst .dot { width: 18px; height: 18px; border-radius: 999px; flex: none; }
.inst.khu .dot { background: var(--khu); box-shadow: inset 0 0 0 3px #f1d9da; }
.inst.uiuc .dot { background: var(--illini); box-shadow: inset 0 0 0 3px var(--ink); }
.inst sup { margin-right: -2px; }
.marks { margin-top: 8px; font-size: 13px; color: var(--faint); }

/* buttons */
.btn-row { margin-top: 26px; display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--ink); color: #fff;
  border: 1.5px solid var(--ink); border-radius: 999px;
  padding: 9px 20px; font-size: 15px; font-weight: 500; text-decoration: none;
}
.btn:hover { background: #1e3a66; border-color: #1e3a66; }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { background: #eceae3; }
.btn.soon { background: transparent; color: var(--faint); border-color: var(--line); border-style: dashed; cursor: default; }
.btn.soon:hover { background: transparent; }
.btn .tag { font-size: 11.5px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; color: var(--faint); }

/* ---------- sections ---------- */
section { padding: 50px 0 10px; scroll-margin-top: 72px; }
section h2 { font-size: 29px; margin-bottom: 18px; text-align: center; }
section h2::after {
  content: ""; display: block; width: 44px; height: 3px; margin: 12px auto 0;
  border-radius: 2px; background: var(--duo);
}
h3.sub-title { font-size: 21px; max-width: 940px; margin: 34px auto 4px; text-align: center; }
p.sub-lead { max-width: 680px; margin: 0 auto 6px; text-align: center; color: var(--soft); font-size: 15.5px; }

.prose { max-width: 720px; margin: 0 auto; }
.prose p { margin: 0 0 16px; }
.prose b, .prose strong { font-weight: 600; }

.t-past { color: var(--past); font-weight: 600; }
.t-current { color: var(--current); font-weight: 600; }
.t-future { color: var(--future-text); font-weight: 600; }

ol.steps { max-width: 680px; margin: 22px auto; padding: 0; list-style: none; counter-reset: s; }
ol.steps li { counter-increment: s; position: relative; padding: 6px 0 6px 46px; margin-bottom: 8px; }
ol.steps li::before {
  content: counter(s);
  position: absolute; left: 0; top: 7px;
  width: 28px; height: 28px;
  border: 1.5px solid var(--ink); border-radius: 999px;
  display: flex; align-items: center; justify-content: center;
  font-family: "Spectral", Georgia, serif; font-weight: 600; font-size: 15px;
}
ol.steps li b { font-weight: 600; }

/* figures */
figure {
  margin: 26px auto; max-width: 940px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 10px;
}
figure img { display: block; width: 100%; border-radius: 6px; }
figcaption { padding: 10px 6px 4px; font-size: 14px; color: var(--soft); line-height: 1.55; }
figcaption b { color: var(--ink); font-weight: 600; }

/* ---------- headline numbers ---------- */
.headline { max-width: 940px; margin: 22px auto 0; display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.hl {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 18px;
}
.hl .bench { font-size: 13px; font-weight: 600; color: var(--soft); text-transform: uppercase; letter-spacing: 0.05em; }
.hl .line { display: flex; align-items: baseline; gap: 10px; margin-top: 8px; flex-wrap: wrap; }
.hl .bk { font-size: 14px; color: var(--soft); min-width: 118px; }
.hl .from { font-size: 15px; color: var(--faint); font-variant-numeric: tabular-nums; }
.hl .to { font-family: "Spectral", Georgia, serif; font-size: 27px; font-weight: 700; font-variant-numeric: tabular-nums; }
.hl .gain { font-size: 14px; font-weight: 600; color: var(--altgeld); font-variant-numeric: tabular-nums; }

/* ---------- Time Dictionary schema ---------- */
.schema {
  max-width: 940px; margin: 18px auto 0;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
}
.field {
  background: var(--card); border: 1px solid var(--line); border-radius: 8px;
  padding: 10px 12px;
}
.field .fn { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 13.5px; font-weight: 600; }
.field .fd { font-size: 13.5px; color: var(--soft); line-height: 1.45; margin-top: 2px; }
.note { max-width: 940px; margin: 10px auto 0; font-size: 13.5px; color: var(--soft); text-align: center; }

/* ---------- strategy cards ---------- */
.strategies { max-width: 940px; margin: 18px auto 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.strat {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  border-top: 4px solid var(--c); padding: 16px 18px 14px;
}
.strat.past { --c: var(--past); --tc: var(--past); --bg: var(--past-tint); }
.strat.current { --c: var(--current); --tc: var(--current); --bg: var(--current-tint); }
.strat.future { --c: var(--future); --tc: var(--future-text); --bg: var(--future-tint); }
.strat .kick { font-size: 12.5px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--tc); }
.strat h4 { margin: 2px 0 8px; font-family: "Spectral", Georgia, serif; font-size: 22px; font-weight: 600; }
.strat p { margin: 0; font-size: 14.5px; line-height: 1.55; color: var(--soft); }
.strat .eg { margin-top: 10px; font-size: 13.5px; color: var(--ink); background: var(--bg); border-radius: 6px; padding: 6px 10px; font-style: italic; }
.strat .formula { margin-top: 10px; font-size: 13px; color: var(--soft); font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; }

/* ---------- demo explorer ---------- */
.explorer {
  max-width: 940px; margin: 24px auto;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px;
}
.method-tabs { display: flex; gap: 8px; flex-wrap: wrap; margin: 0 0 18px; }
.mtab {
  border: 1.5px solid var(--line); border-radius: 999px; background: transparent;
  padding: 7px 18px; font-size: 14.5px; font-weight: 500; color: var(--soft);
  cursor: pointer; font-family: inherit;
}
.mtab:hover { border-color: var(--ink); color: var(--ink); }
.mtab.active { background: var(--ink); border-color: var(--ink); color: #fff; }

.qa-card .qk { font-size: 13px; font-weight: 600; color: var(--faint); }
.qa-card .q { font-family: "Spectral", Georgia, serif; font-size: 20px; font-weight: 600; line-height: 1.4; margin-top: 2px; }

.planner-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin: 16px 0 14px; font-size: 14px; color: var(--soft); }
.chip {
  border: 1.5px solid var(--line); border-radius: 999px; padding: 3px 12px;
  font-size: 13.5px; font-weight: 500; color: var(--faint);
}
.chip.on.past { border-color: var(--past); background: var(--past-tint); color: var(--past); font-weight: 600; }

.stream { display: flex; align-items: stretch; gap: 8px; overflow-x: auto; padding: 18px 2px 6px; }
.fr { flex: 1 0 96px; max-width: 150px; position: relative; }
.fr img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; display: block; border-radius: 5px; border: 1px solid var(--line); }
.fr .t { font-size: 12.5px; color: var(--soft); margin-top: 4px; text-align: center; font-variant-numeric: tabular-nums; }
.fr.unseen img { filter: grayscale(1); opacity: 0.32; }
.fr.unseen .t { color: var(--faint); }
.fr.hit img { outline: 3px solid var(--past); outline-offset: 1px; }
.fr.hit .tag {
  position: absolute; top: -18px; left: 50%; transform: translateX(-50%);
  font-size: 11px; font-weight: 600; letter-spacing: 0.05em; text-transform: uppercase;
  color: var(--past); white-space: nowrap;
}
.fr.hit .t { color: var(--past); font-weight: 600; }
.qline { flex: 0 0 auto; display: flex; flex-direction: column; align-items: center; width: 34px; }
.qline .bar { flex: 1; width: 0; border-left: 2px dashed var(--ink); min-height: 50px; }
.qline .t { font-size: 12.5px; font-weight: 600; margin-top: 4px; }
.unseen-note { font-size: 12.5px; color: var(--faint); text-align: right; margin-top: 2px; }

.entry {
  margin-top: 14px; border: 1px solid var(--line); border-left: 4px solid var(--past);
  border-radius: 8px; padding: 12px 16px; background: #fffdfc;
}
.entry .eh { font-size: 13.5px; font-weight: 600; margin-bottom: 6px; }
.entry .eh span { color: var(--past); }
.entry dl { display: grid; grid-template-columns: 96px 1fr; gap: 3px 12px; margin: 0; font-size: 14.5px; line-height: 1.5; }
.entry dt { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 13px; font-weight: 600; color: var(--soft); padding-top: 1px; }
.entry dd { margin: 0; }
.entry mark { background: var(--past-tint); color: var(--past); font-weight: 600; padding: 0 3px; border-radius: 3px; }
.entry .excerpt { margin-top: 6px; font-size: 12.5px; color: var(--faint); }
.verdict { margin-top: 14px; font-size: 15px; line-height: 1.6; }
.verdict .ans { font-weight: 600; }

/* ---------- results tables ---------- */
.tbl-head { max-width: 960px; margin: 34px auto 0; display: flex; align-items: flex-end; justify-content: space-between; gap: 12px; flex-wrap: wrap; padding: 0 2px; }
.tbl-head h3 { font-size: 21px; }
.toggle {
  border: 1.5px solid var(--line); border-radius: 999px; background: var(--card);
  padding: 5px 14px; font-size: 13.5px; font-weight: 500; color: var(--soft);
  cursor: pointer; font-family: inherit;
}
.toggle:hover { border-color: var(--ink); color: var(--ink); }
.tables-wrap {
  max-width: 960px; margin: 12px auto 0;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 8px 14px; overflow-x: auto;
}
table.res { border-collapse: collapse; width: 100%; font-size: 14px; font-variant-numeric: tabular-nums; }
.res th, .res td { padding: 6px 9px; text-align: right; white-space: nowrap; }
.res th:first-child, .res td:first-child, .res th:nth-child(2), .res td:nth-child(2) { text-align: left; }
.res thead th { font-weight: 600; font-size: 13px; color: var(--soft); border-bottom: 2px solid var(--ink); vertical-align: bottom; }
.res thead th.grp { text-align: center; border-bottom: 1px solid var(--line); color: var(--ink); }
.res thead tr:first-child th.grp { border-bottom: 1px solid var(--line); }
.res tbody td { border-bottom: 1px solid #ecebe4; }
.res tbody tr:last-child td { border-bottom: none; }
.res td.avg, .res td.ovr { font-weight: 400; }
table.res.full td.avg, table.res.full th.avg { background-image: linear-gradient(rgba(19,41,75,0.035), rgba(19,41,75,0.035)); }
.res tr.ref td { color: var(--faint); background: #f7f6f2; }
.res tr.ours td { background: var(--ours-tint); }
.res tr.ours td:first-child { font-weight: 600; color: var(--ink); padding-left: 22px; }
.res tr.group td { background: var(--wash); text-align: center; font-weight: 600; font-size: 12.5px; color: var(--soft); letter-spacing: 0.02em; }
.res b { font-weight: 700; }
.res u { text-decoration-thickness: 1.5px; text-underline-offset: 3px; }
.res .up, .res .dn { font-size: 10.5px; margin-left: 4px; font-weight: 600; }
.res .up { color: var(--altgeld); }
.res .dn { color: var(--faint); }
table.res.compact .sub { display: none; }
table.res.compact { min-width: 640px; }
table.res.full { min-width: 1240px; }
.tbl-note { max-width: 960px; margin: 8px auto 0; font-size: 13px; color: var(--faint); padding: 0 2px; }
.tbl-note .up-legend { color: var(--altgeld); font-weight: 600; }

/* ---------- analysis cards ---------- */
.cards { max-width: 960px; margin: 20px auto 0; display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 16px 18px 12px; min-width: 0;
}
.card h4 { margin: 0 0 4px; font-family: "Spectral", Georgia, serif; font-size: 19.5px; font-weight: 600; }
.card .take { margin: 0 0 10px; font-size: 14.5px; color: var(--soft); line-height: 1.5; }
.card .take b { color: var(--ink); font-weight: 600; }
.card .scroll { overflow-x: auto; }
table.mini { border-collapse: collapse; width: 100%; font-size: 13px; font-variant-numeric: tabular-nums; }
.mini th, .mini td { padding: 5px 5px; text-align: right; white-space: nowrap; }
.mini th:first-child, .mini td:first-child { padding-left: 2px; }
.mini th:first-child, .mini td:first-child { text-align: left; }
.mini thead th { font-size: 12px; font-weight: 600; color: var(--soft); border-bottom: 1.5px solid var(--ink); }
.mini tbody td { border-bottom: 1px solid #ecebe4; }
.mini tbody tr:last-child td { border-bottom: none; }
.mini tr.ours td { background: var(--ours-tint); font-weight: 600; }
.mini tr.base td { color: var(--soft); }
.mini tr.sep td { border-top: 1.5px solid var(--line); }
.card .src { margin-top: 8px; font-size: 12px; color: var(--faint); }

/* charts */
.chart-card { padding-bottom: 14px; }
.chart svg { width: 100%; height: auto; display: block; overflow: visible; }
.chart text { font-family: "Public Sans", sans-serif; }
.legend { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 12.5px; color: var(--soft); margin: 4px 0 2px; }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; vertical-align: -2px; margin-right: 6px; }
.legend i.ln { height: 0; border-top: 2px dashed var(--faint); border-radius: 0; vertical-align: 3px; }
.hit-target { cursor: default; }
.tip {
  position: fixed; z-index: 50; pointer-events: none;
  background: var(--ink); color: #fff; border-radius: 6px;
  padding: 6px 10px; font-size: 12.5px; line-height: 1.45; max-width: 260px;
  box-shadow: 0 4px 14px rgba(19, 41, 75, 0.18);
  opacity: 0; transition: opacity 0.1s;
}
.tip.show { opacity: 1; }
.tip b { font-weight: 600; }

/* bibtex */
.bib-soon { text-align: center; color: var(--soft); }
.bib {
  position: relative; max-width: 760px; margin: 22px auto;
  background: #f1f0ea; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px 22px;
}
.bib pre {
  margin: 0; overflow-x: auto;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 13.5px; line-height: 1.6; color: var(--ink);
}
.copy-btn {
  position: absolute; top: 12px; right: 12px;
  background: var(--card); border: 1px solid var(--line); border-radius: 8px;
  padding: 5px 12px; font-size: 13px; font-weight: 500; color: var(--soft); cursor: pointer; font-family: inherit;
}
.copy-btn:hover { color: var(--ink); border-color: var(--ink); }

/* footer */
footer { margin-top: 70px; border-top: 1px solid var(--line); padding: 0 0 44px; font-size: 14px; color: var(--soft); text-align: center; }
footer::before { content: ""; display: block; height: 3px; background: var(--duo); margin-bottom: 26px; }
footer a { color: var(--soft); }
footer a:hover { color: var(--ink); }
footer .insts { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 14px; margin-bottom: 14px; }

/* ---------- responsive ---------- */
@media (max-width: 820px) {
  .schema { grid-template-columns: repeat(2, 1fr); }
  .strategies { grid-template-columns: 1fr; }
  .cards { grid-template-columns: 1fr; }
  .headline { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .hero { padding-top: 40px; }
  .tline svg { display: none; }
  .tline-mobile { display: flex; flex-direction: column; align-items: center; gap: 8px; }
  .tline-mobile .q {
    font-family: "Spectral", Georgia, serif; font-weight: 600; font-size: 19px;
    border: 1.5px solid var(--ink); border-radius: 10px; padding: 7px 18px; background: var(--card);
  }
  .tline-mobile .down { color: var(--faint); font-size: 15px; }
  .tline-mobile .opts { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
  .tline-mobile .o { border: 1.5px solid; border-radius: 10px; padding: 6px 12px; background: var(--card); font-size: 14px; line-height: 1.3; }
  .tline-mobile .o b { display: block; font-family: "Spectral", Georgia, serif; font-size: 17px; }
  .tline-mobile .o.p { border-color: var(--past); color: var(--past); }
  .tline-mobile .o.c { border-color: var(--current); color: var(--current); }
  .tline-mobile .o.f { border-color: var(--future); color: var(--future-text); }
  section h2 { font-size: 25px; }
  .explorer { padding: 16px; }
  .entry dl { grid-template-columns: 1fr; gap: 0; }
  .entry dt { margin-top: 6px; }
  .fr { flex-basis: 110px; }
  .hl .line { flex-wrap: nowrap; gap: 8px; }
  .hl .bk { min-width: 0; flex: 1; font-size: 13px; }
  .hl .to { font-size: 23px; }
}