:root {
  --bg: #ffffff;
  --text: #1d1d1f;
  --muted: #5f6368;
  --faint: #8a8f98;
  --line: #e6e8eb;
  --panel: #f7f8fa;
  --accent: #1a73e8;
  --ours: #eaf2fe;
  --good: #188038;
  --bad: #c5221f;
  --eyebrow: #188038;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 56px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* ---------- nav ---------- */
.topnav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: center;
  gap: 1.6rem;
  padding: 0.7rem 16px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  font-size: 0.88rem;
  font-weight: 500;
}
.topnav a { color: var(--muted); }
.topnav a:hover { color: var(--text); text-decoration: none; }

/* ---------- hero ---------- */
.hero {
  max-width: 900px;
  margin: 0 auto;
  padding: 3.5rem 16px 1rem;
  text-align: center;
}

.title {
  font-size: 2.6rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 1.2rem;
}

.authors {
  font-size: 1.05rem;
  margin: 0 0 0.3rem;
}
.authors a { margin: 0 0.45rem; white-space: nowrap; }
.authors sup { color: var(--muted); font-size: 0.7em; }

.affiliations {
  color: var(--muted);
  font-size: 0.88rem;
  margin: 0.2rem 0 1.2rem;
}
.small { font-size: 0.8rem; }

.links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 1rem;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 500;
  border: 1px solid transparent;
}
.pill.dark { background: #202124; color: #fff; }
.pill.dark:hover { background: #3c4043; text-decoration: none; }
.pill.muted { background: var(--panel); color: var(--faint); border-color: var(--line); cursor: default; }
.soon { font-size: 0.75rem; }

/* ---------- sections ---------- */
.section {
  max-width: 900px;
  margin: 0 auto;
  padding: 2.5rem 16px;
}
.section.wide { max-width: 1100px; }

h2 {
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-align: center;
  margin: 0 0 1.4rem;
}

h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 2.6rem 0 1rem;
}

#abstract p { text-align: justify; hyphens: auto; }

/* ---------- motivation ---------- */
.eyebrow {
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--eyebrow);
  margin: 0 0 0.4rem;
}

.headline {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin: 0 0 1rem;
}
.headline em { font-style: italic; color: var(--accent); }

.lead {
  max-width: 680px;
  margin: 0 auto 2rem;
  text-align: center;
  font-size: 1.08rem;
  color: #3c4043;
}

.prompt-label {
  text-align: center;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--faint);
  margin: 0;
}
.prompt {
  text-align: center;
  font-style: italic;
  font-size: 1.05rem;
  margin: 0.2rem auto 1.4rem;
  max-width: 640px;
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.2rem;
}

.card {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: var(--bg);
  display: flex;
  flex-direction: column;
}
.card.ours { border: 2px solid var(--accent); }

.card-img {
  height: 280px;
  background: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}
.card-img img { max-width: 100%; max-height: 100%; width: auto; height: auto; object-fit: contain; }

.card figcaption { padding: 0.9rem 1rem 1.1rem; font-size: 0.9rem; color: #3c4043; }
.card h3 { margin: 0; font-size: 1.05rem; color: var(--text); }
.card .examples { margin: 0 0 0.6rem; color: var(--faint); font-size: 0.8rem; }
.card p { margin: 0.5rem 0 0; }
.card .credit { color: var(--faint); font-size: 0.75rem; }

.checks { list-style: none; margin: 0; padding: 0; font-weight: 600; font-size: 0.88rem; }
.checks li { padding-left: 1.5rem; position: relative; }
.checks li::before {
  font-family: 'Font Awesome 6 Free';
  font-weight: 900;
  position: absolute;
  left: 0;
}
.checks .yes { color: var(--good); }
.checks .yes::before { content: '\f00c'; }
.checks .no { color: var(--bad); }
.checks .no::before { content: '\f00d'; }

/* intuition animation under the motivation cards (driven by static/js/index.js) */
.intuition { margin: 2.2rem auto 0; max-width: 760px; }
.anim-fig { margin: 0; text-align: center; }
#prior-anim { width: 100%; height: auto; display: block; background: #fbfcfd;
  border: 1px solid var(--line); border-radius: 12px; }
#prior-anim .a-prior { transition: opacity 0.8s ease; }
#prior-anim .a-goal { opacity: 0; transition: opacity 0.9s ease; }
#prior-anim.s1 .a-goal, #prior-anim.s2 .a-goal { opacity: 1; }
#prior-anim .a-dot { fill: #8a8f98; stroke: #fff; stroke-width: 1.2; opacity: 1;
  transition: transform 1.8s cubic-bezier(.45,.05,.25,1), fill 0.6s ease, opacity 0.6s ease; }
#prior-anim.pre .a-dot, #prior-anim.pre .a-prior { opacity: 0; transition: none; }
#prior-anim.s1 .a-dot { opacity: 0.35; }
#prior-anim.s1 .a-dot.a-hit { opacity: 1; fill: var(--good); }
#prior-anim.s2 .a-dot { opacity: 1; fill: var(--accent); }
.anim-steps { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.8rem;
  margin: 0.9rem 0 0.6rem; padding: 0; text-align: left; }
.anim-steps li { font-size: 0.84rem; color: var(--faint); line-height: 1.4; display: flex; gap: 0.5rem;
  transition: color 0.4s ease; }
.anim-steps li span { flex: none; width: 1.4rem; height: 1.4rem; border-radius: 50%; display: inline-grid;
  place-items: center; font-size: 0.75rem; font-weight: 700; background: var(--panel); border: 1px solid var(--line);
  transition: background 0.4s ease, color 0.4s ease; }
.anim-steps li.active { color: var(--text); }
.anim-steps li.active span { background: var(--accent); border-color: var(--accent); color: #fff; }
.anim-replay { margin-top: 0.2rem; }
.sw-dot.sw-base { background: #8a8f98; }
@media (max-width: 640px) { .anim-steps { grid-template-columns: 1fr; } }
@media (prefers-reduced-motion: reduce) {
  #prior-anim .a-dot, #prior-anim .a-goal, #prior-anim .a-prior, .anim-steps li, .anim-steps li span { transition: none; }
}

.d-prior { fill: #e6e9ee; stroke: #b9bec7; stroke-width: 1.5; }
.d-prior-ghost { fill: none; stroke: #b9bec7; stroke-width: 1.5; stroke-dasharray: 5 5; }
.d-goal { fill: rgba(24, 128, 56, 0.16); stroke: var(--good); stroke-width: 1.5; stroke-dasharray: 4 3; }
.d-dot { stroke: #fff; stroke-width: 1; }
.d-data { fill: #8a8f98; }
.d-hit { fill: var(--good); }
.d-ours { fill: var(--accent); }
.d-llm { fill: #e37400; }
.d-trail { fill: none; stroke: #e37400; stroke-width: 1.3; stroke-dasharray: 2 3; opacity: 0.8; }

.legend {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.4rem 1.4rem;
  margin: 0 0 1rem;
  padding: 0;
  font-size: 0.82rem;
  color: var(--muted);
}
.legend li { display: inline-flex; align-items: center; gap: 0.45rem; }
.sw { display: inline-block; width: 18px; height: 12px; border-radius: 6px; }
.sw-prior { background: #e6e9ee; border: 1.5px solid #b9bec7; }
.sw-goal { background: rgba(24, 128, 56, 0.16); border: 1.5px dashed var(--good); }
.sw-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); }

.statement {
  max-width: 720px;
  margin: 2.4rem auto 2rem;
  text-align: center;
  font-size: 1.08rem;
}

/* ---------- figures ---------- */
.figure { margin: 1.4rem 0; }
.figure img { width: 100%; border-radius: 8px; }
.figure.narrow { max-width: 680px; margin-left: auto; margin-right: auto; }
.figure.small { max-width: 520px; margin-left: auto; margin-right: auto; }
.figure figcaption, .note {
  font-size: 0.88rem;
  color: var(--muted);
  text-align: center;
  margin-top: 0.7rem;
  line-height: 1.5;
}
.note { margin-top: 0.5rem; }

.two-up {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.2rem;
  align-items: start;
}

/* ---------- method ---------- */
.phases {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin: 1.8rem 0;
}
.phase {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1rem 1.1rem;
  font-size: 0.9rem;
}
.phase h3 { margin: 0 0 0.4rem; font-size: 1rem; }
.phase p { margin: 0; color: #3c4043; }
.phase .phase-tag {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.3rem;
}

/* ---------- results ---------- */
.setup {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.9rem 1.1rem;
  font-size: 0.9rem;
}
.setup p { margin: 0; }

.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }

.results {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  font-variant-numeric: tabular-nums;
}
.results th, .results td {
  padding: 0.5rem 0.6rem;
  text-align: center;
  border-bottom: 1px solid var(--line);
  white-space: nowrap;
}
.results th { font-weight: 600; border-bottom: 2px solid #c9ccd1; }
.results td:first-child, .results th:first-child { text-align: left; }
.results tr.gt td { color: var(--muted); font-style: italic; }
.results tr.ours td { background: var(--ours); }
.results tr td.task {
  white-space: normal;
  min-width: 190px;
  font-style: normal;
  color: var(--text);
  background: var(--bg) !important;
  vertical-align: middle;
}

.results tr.sep td { border-top: 2px solid #c9ccd1; }

.breakdown { margin: 0.8rem 0 0.4rem; }
.breakdown summary {
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  text-align: center;
  list-style-position: inside;
}
.breakdown[open] summary { margin-bottom: 0.6rem; }

/* ---------- bibtex ---------- */
.bib-head { display: flex; align-items: center; justify-content: space-between; }
.bib-head h2 { margin: 0; text-align: left; }
.copy-btn {
  font: inherit;
  font-size: 0.85rem;
  padding: 0.35rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
}
.copy-btn:hover { background: var(--line); }

pre {
  margin: 1rem 0 0;
  padding: 1rem 1.2rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'JetBrains Mono', ui-monospace, Menlo, monospace;
  font-size: 0.82rem;
  line-height: 1.5;
}

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--line);
  margin-top: 2rem;
  padding: 2rem 16px 2.5rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--muted);
}
.footer p { margin: 0.3rem 0; }
.footer .ai, .footer .fab { font-size: 1.4rem; color: var(--muted); margin: 0 0.4rem; }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .cards, .phases { grid-template-columns: 1fr; }
  .card-img { height: 240px; }
}

@media (max-width: 640px) {
  .title { font-size: 1.8rem; }
  .title br { display: none; }
  .headline { font-size: 2.2rem; }
  .two-up { grid-template-columns: 1fr; }
  .topnav { gap: 1rem; }
  .results { font-size: 0.78rem; }
}