:root {
  --ink: #0f172a;
  --text: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-soft: #f6f8fc;
  --blue: #2f5ee0;
  --teal: #3fb6d0;
  --orange: #e8742a;
  --grad: linear-gradient(100deg, #2f5ee0 0%, #3a86e0 45%, #3fb6d0 100%);
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 12px 32px rgba(15, 23, 42, 0.07);
  --radius: 18px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  font-family: 'Inter', system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, .brand, .stat-num, .step-num, .kicker, .eyebrow {
  font-family: 'Plus Jakarta Sans', 'Inter', sans-serif;
  color: var(--ink);
}

a { color: var(--blue); text-decoration: none; }
img { max-width: 100%; display: block; }

.grad {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
.wrap.narrow { max-width: 860px; }
.center { text-align: center; }
.narrow-text { max-width: 760px; margin-left: auto; margin-right: auto; }

/* ---------- nav ---------- */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  height: 60px; display: flex; align-items: center; justify-content: space-between;
}
.brand { font-weight: 800; font-size: 1.3rem; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav-links { display: flex; gap: 28px; }
.nav-links a { color: var(--ink); font-weight: 600; font-size: 0.98rem; font-family: 'Plus Jakarta Sans', sans-serif; }
.nav-links a:hover { color: var(--blue); }
.nav-cite { color: var(--blue) !important; }

/* ---------- hero ---------- */
.hero {
  padding: 56px 0 56px;
  text-align: center;
  background:
    radial-gradient(900px 380px at 15% -10%, rgba(47, 94, 224, 0.08), transparent 60%),
    radial-gradient(800px 380px at 90% 0%, rgba(63, 182, 208, 0.10), transparent 60%),
    var(--bg-soft);
  border-bottom: 1px solid var(--line);
}
.eyebrow {
  display: inline-block; margin: 0 0 18px; padding: 5px 14px;
  border-radius: 999px; background: rgba(47, 94, 224, 0.08);
  color: var(--blue); font-weight: 700; font-size: 0.82rem; letter-spacing: 0.08em; text-transform: uppercase;
}
.title {
  margin: 0 auto 30px; max-width: 960px;
  font-size: clamp(2rem, 5vw, 3.9rem); font-weight: 800; line-height: 1.1; letter-spacing: -0.02em;
}
.authors { margin: 0; font-family: 'Plus Jakarta Sans', sans-serif; font-weight: 700; font-size: clamp(1.15rem, 2vw, 1.5rem); color: var(--ink); }
.affil { margin: 10px 0 0; color: var(--muted); font-size: 1rem; display: inline-flex; align-items: flex-start; gap: 2px; }
.affil sup { margin-top: 12px; }
.affil-logo { height: 72px; width: auto; }
.footer-logo { height: 40px; width: auto; margin: 0 auto 12px; }
sup { font-size: 0.62em; margin-left: 1px; }

.buttons { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin: 26px 0 36px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 26px; border-radius: 999px;
  background: var(--ink); color: #fff; font-weight: 600; font-size: 1.08rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 8px 20px rgba(15, 23, 42, 0.18); color: #fff; }
.btn small { font-weight: 500; opacity: 0.7; }
.btn.is-soon { background: #cbd5e1; color: #475569; pointer-events: none; }
.btn-accent { background: var(--grad); }

.pitch {
  max-width: 700px; margin: 0 auto 26px;
  font-size: 1.08rem; line-height: 1.6; color: var(--text);
}
.pitch em { font-style: normal; color: var(--blue); font-weight: 600; }

.stats {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px;
  max-width: 920px; margin: 0 auto;
}
.stat {
  padding: 12px 10px; border-radius: 12px;
  background: rgba(255, 255, 255, 0.7); border: 1px solid var(--line);
}
.stat-num { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.01em; line-height: 1.2; }
.stat-num .arrow { color: var(--muted); font-weight: 600; margin: 0 4px; }
.stat-label { margin-top: 4px; color: var(--muted); font-size: 0.78rem; line-height: 1.4; }

/* ---------- cards & figures ---------- */
.card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.figure { margin: 28px 0 0; padding: 22px; }
.figure figcaption { margin-top: 14px; color: var(--muted); font-size: 0.95rem; line-height: 1.6; text-align: left; }
.hero-figure { max-width: 820px; margin: 0 auto; }
.summary { margin-top: 40px; }

/* ---------- sections ---------- */
.section { padding: 84px 0; }
.section.alt { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.kicker { margin: 0 0 8px; color: var(--blue); font-weight: 700; font-size: 0.86rem; letter-spacing: 0.1em; text-transform: uppercase; }
h2 { margin: 0 0 18px; font-size: clamp(1.7rem, 3vw, 2.4rem); font-weight: 800; letter-spacing: -0.02em; line-height: 1.2; }
h3 { font-size: 1.1rem; font-weight: 700; margin: 0 0 8px; }
.lead { font-size: 1.1rem; color: var(--text); }

.versus { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin: 30px 0 22px; }
.vs-card { padding: 24px; border-radius: var(--radius); border: 1px solid var(--line); background: #fff; }
.vs-tag { margin: 0 0 8px; font-weight: 700; font-size: 0.8rem; letter-spacing: 0.1em; text-transform: uppercase; }
.vs-q { margin: 0 0 10px; font-family: 'Plus Jakarta Sans', sans-serif; font-size: 1.22rem; font-weight: 700; line-height: 1.4; color: var(--ink); }
.vs-a { margin: 0; color: var(--muted); font-size: 0.97rem; }
.vs-old .vs-tag { color: #94a3b8; }
.vs-old .vs-q em { font-style: normal; color: #64748b; text-decoration: underline wavy #cbd5e1; }
.vs-new { border: 2px solid transparent; background: linear-gradient(#fff, #fff) padding-box, var(--grad) border-box; }
.vs-new .vs-tag { color: var(--blue); }
.vs-new .vs-q em { font-style: normal; color: var(--blue); }

.callout {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 18px 22px; border-radius: 14px;
  background: rgba(47, 94, 224, 0.06); border: 1px solid rgba(47, 94, 224, 0.15);
}
.callout i { color: var(--blue); margin-top: 6px; }
.callout p { margin: 0; color: var(--ink); }

.steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-top: 28px; }
.step { padding: 24px; border-radius: var(--radius); background: #fff; border: 1px solid var(--line); }
.step p { margin: 0; font-size: 0.95rem; color: var(--text); }
.steps { align-items: start; }
.step summary { list-style: none; cursor: pointer; }
.step summary::-webkit-details-marker { display: none; }
.step .step-brief { margin: 0 0 10px; color: var(--muted); }
.step-more { font-size: 0.85rem; font-weight: 600; color: var(--blue); }
.step-more i { font-size: 0.7rem; margin-left: 4px; transition: transform 0.2s ease; }
.step[open] .step-more i { transform: rotate(180deg); }
.step[open] summary { margin-bottom: 12px; padding-bottom: 12px; border-bottom: 1px solid var(--line); }
.step > p + p, .step > .eq + p { margin-top: 8px; }
.step .eq { margin: 10px 0; font-size: 0.9rem; overflow-x: auto; max-width: 100%; }
mjx-container[display="true"] { max-width: 100%; overflow-x: auto; overflow-y: hidden; }
.step-num {
  width: 36px; height: 36px; border-radius: 10px; margin-bottom: 14px;
  display: grid; place-items: center; color: #fff; font-weight: 800; background: var(--grad);
}

.chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 28px; }
.chip {
  display: inline-flex; align-items: center; gap: 8px; padding: 8px 16px; border-radius: 999px;
  background: #fff; border: 1px solid var(--line); font-size: 0.92rem; font-weight: 500; color: var(--ink);
}
.chip i { color: var(--blue); }

/* ---------- results explorer ---------- */
.explorer { margin-top: 30px; padding: 26px; }
.explorer-controls { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.seg { display: inline-flex; padding: 4px; border-radius: 12px; background: #f1f5f9; }
.seg-groups { display: flex; flex-direction: column; align-items: flex-start; gap: 10px; }
.seg-tabs { display: flex; flex-wrap: wrap; gap: 22px; border-bottom: 1px solid var(--line); width: 100%; }
.seg-tabs button { border: 0; background: none; cursor: pointer; padding: 6px 0 9px; margin-bottom: -1px;
  font: 700 0.78rem 'Plus Jakarta Sans', sans-serif; letter-spacing: 0.06em; text-transform: uppercase; color: var(--muted);
  border-bottom: 2px solid transparent; }
.seg-tabs button.on { color: var(--ink); border-bottom-color: #2a78d6; }
.seg button {
  border: 0; background: transparent; cursor: pointer;
  padding: 8px 16px; border-radius: 9px;
  font: 600 0.92rem 'Plus Jakarta Sans', sans-serif; color: var(--muted);
}
.seg button.on { background: #fff; color: var(--ink); box-shadow: 0 1px 3px rgba(15, 23, 42, 0.12); }
.legend { display: flex; flex-wrap: wrap; align-items: center; gap: 18px; margin-bottom: 14px; font-size: 0.9rem; color: var(--muted); }
.legend > span { display: inline-flex; align-items: center; gap: 7px; }
.sw { display: inline-block; width: 14px; height: 10px; border-radius: 3px; }
.sw-flat { background: #cbd5e1; }
.sw-ours { background: var(--grad); }
.legend-gain { margin-left: auto; color: var(--ink); }
.legend-gain b { color: var(--blue); }

.row { display: grid; grid-template-columns: 170px 1fr 64px; align-items: center; gap: 14px; padding: 7px 0; border-top: 1px solid #f1f5f9; }
.env { font-weight: 600; font-size: 0.93rem; color: var(--ink); }
.track { display: grid; gap: 4px; }
.bar { position: relative; height: 15px; border-radius: 0 6px 6px 0; min-width: 2px; transition: width 0.5s ease; }
.bar span { position: absolute; left: calc(100% + 6px); top: -2px; font-size: 0.78rem; color: var(--muted); white-space: nowrap; font-variant-numeric: tabular-nums; }
.bar.flat { background: #cbd5e1; }
.bar.ours { background: var(--grad); }
.bar.ours span { color: var(--ink); font-weight: 600; }
.delta { text-align: right; font-weight: 700; font-family: 'Plus Jakarta Sans', sans-serif; font-variant-numeric: tabular-nums; }
.delta.up { color: var(--blue); }
.delta.down { color: #b45309; }
.fine { margin: 14px 0 0; color: var(--muted); font-size: 0.85rem; }

/* ---------- full tables ---------- */
.tables { margin-top: 28px; padding: 6px 22px; }
.tables summary { cursor: pointer; padding: 14px 0; font-weight: 600; color: var(--ink); list-style: none; }
.tables summary::-webkit-details-marker { display: none; }
.tables summary i { color: var(--blue); margin-right: 8px; }
.tables h3 { margin-top: 18px; }
.table-wrapper { overflow-x: auto; margin-bottom: 18px; }
.results-table { width: 100%; min-width: 720px; border-collapse: collapse; font-size: 0.88rem; font-variant-numeric: tabular-nums; }
.results-table th, .results-table td { padding: 7px 10px; text-align: center; white-space: nowrap; border-bottom: 1px solid #f1f5f9; }
.results-table th:first-child, .results-table td:first-child { text-align: left; }
.results-table thead th { background: #f8fafc; font-family: 'Plus Jakarta Sans', sans-serif; color: var(--ink); }
.results-table .group-row td { font-weight: 700; color: var(--ink); background: #f8fafc; }
.results-table .ours-row td { background: rgba(47, 94, 224, 0.05); }
.results-table .ours-row td:first-child { padding-left: 22px; font-weight: 600; }

/* ---------- generalisation & takeaways ---------- */
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 22px; }
.mini-card { padding: 22px; border-radius: var(--radius); background: #fff; border: 1px solid var(--line); }
.mini-card p { margin: 0; font-size: 0.95rem; }

.takeaways { list-style: none; padding: 0; margin: 10px 0 0; }
.takeaways li { position: relative; padding: 14px 0 14px 34px; border-top: 1px solid var(--line); }
.takeaways li::before {
  content: ""; position: absolute; left: 4px; top: 24px; width: 12px; height: 12px; border-radius: 50%; background: var(--grad);
}

/* ---------- citation ---------- */
.cite { background: var(--bg-soft); border-top: 1px solid var(--line); padding: 56px 0; }
.cite-title { font-size: 1.35rem; margin-bottom: 14px; }
.bib { position: relative; }
.bib pre {
  margin: 0; padding: 22px 24px; border-radius: 14px; overflow-x: auto;
  background: #0f172a; color: #e2e8f0; font: 0.88rem/1.6 'JetBrains Mono', monospace;
}
.copy {
  position: absolute; top: 12px; right: 12px; display: inline-flex; gap: 6px; align-items: center;
  border: 1px solid rgba(255, 255, 255, 0.2); background: rgba(255, 255, 255, 0.08); color: #e2e8f0;
  padding: 6px 12px; border-radius: 8px; cursor: pointer; font: 500 0.82rem 'Inter', sans-serif;
}
.copy:hover { background: rgba(255, 255, 255, 0.16); }

.footer { padding: 30px 24px 40px; text-align: center; color: var(--muted); font-size: 0.88rem; }

/* ---------- small screens ---------- */
@media (max-width: 860px) {
  .nav-links { gap: 16px; }
  .nav-links a:not(.nav-cite):nth-child(n+3) { display: none; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .versus, .steps, .grid3 { grid-template-columns: minmax(0, 1fr); }
  .row { grid-template-columns: 110px 1fr 52px; gap: 10px; }
  .section { padding: 60px 0; }
  .wrap { padding: 0 16px; }
  .legend-gain { margin-left: 0; }
}


/* ---------- problem: collapse strip ---------- */
.collapse-strip { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; max-width: 760px; margin: 30px auto 26px; }
.collapse-card { padding: 20px 22px; border-radius: var(--radius); background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.collapse-env { margin: 0 0 4px; font-family: 'Plus Jakarta Sans', sans-serif; font-weight: 700; color: var(--muted); font-size: 0.9rem; letter-spacing: 0.06em; text-transform: uppercase; }
.collapse-nums { font-family: 'Plus Jakarta Sans', sans-serif; font-weight: 800; font-size: 2.4rem; line-height: 1.1; color: var(--ink); }
.c-arrow { color: #cbd5e1; margin: 0 8px; font-weight: 600; }
.c-to { color: var(--muted); }
.c-bar { height: 10px; margin: 12px 0 8px; border-radius: 99px; background: #f1f5f9; overflow: hidden; }
.c-fill { height: 100%; border-radius: 99px; background: #94a3b8; transition: width 1.6s cubic-bezier(.2,.7,.2,1) 0.2s; }
.collapse-label { margin: 0; color: var(--muted); font-size: 0.84rem; }

/* ---------- problem: wall/door demo ---------- */

.demo-head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.demo-q { margin: 0; font-family: 'Plus Jakarta Sans', sans-serif; font-weight: 700; color: var(--ink); }
.demo-svg { width: 100%; height: auto; display: block; }
.demo-svg .room { fill: #f8fafc; stroke: #cbd5e1; stroke-width: 2; }
.demo-svg .wall { fill: #475569; }
.demo-svg .door-label { fill: #64748b; font: 600 13px 'Inter', sans-serif; }
.demo-svg .ghost { fill: none; stroke: #e2e8f0; stroke-width: 2; stroke-dasharray: 5 6; }
.demo-svg .trail { fill: none; stroke-width: 4; stroke-linecap: round; }
.demo-svg .trail.latent { stroke: #94a3b8; }
.demo-svg .trail.tempo { stroke: #2f5ee0; }
.demo-svg .goal polygon { fill: #16a34a; }
.demo-svg .agent { fill: #2f5ee0; stroke: #fff; stroke-width: 3; }
.demo-svg .g-label, .demo-svg .a-label { fill: #64748b; font: 600 13px 'Inter', sans-serif; }
.demo-svg .bump circle { fill: rgba(220, 38, 38, 0.12); stroke: #dc2626; stroke-width: 2; stroke-dasharray: 4 4; }
.demo-svg .bump text { fill: #dc2626; font: 700 13px 'Inter', sans-serif; }
.demo-svg .bump { transition: opacity 0.3s ease; }
.demo-status { margin: 10px 0 0; min-height: 1.6em; font-weight: 600; font-size: 0.97rem; }
.demo-status.bad { color: #dc2626; }
.demo-status.good { color: var(--blue); }
#problem .versus { max-width: 860px; margin-left: auto; margin-right: auto; }
@media (max-width: 860px) { .collapse-strip { grid-template-columns: 1fr; } .collapse-nums { font-size: 2rem; } }

/* ---------- hero: demo + success curve ---------- */
.hero-duo { max-width: 1000px; }
.duo { display: grid; grid-template-columns: 1.35fr 1fr; gap: 26px; align-items: center; }
.duo-demo .demo-head { margin-bottom: 10px; }
.duo-demo .demo-status { text-align: left; font-size: 0.92rem; }
.duo-curve img { width: 100%; height: auto; }
@media (max-width: 860px) { .duo { grid-template-columns: minmax(0, 1fr); } }


/* ---------- method: rollout video ---------- */
.video-figure { max-width: 860px; margin-left: auto; margin-right: auto; }
.video-figure video { width: 100%; max-width: 700px; height: auto; display: block; margin: 0 auto; border-radius: 10px; background: #fff; }
.pipeline-more { margin-top: 16px; border-top: 1px solid var(--line); padding-top: 12px; }
.pipeline-more summary { cursor: pointer; font-weight: 600; color: var(--ink); list-style: none; }
.pipeline-more summary::-webkit-details-marker { display: none; }
.pipeline-more summary i { color: var(--blue); margin-right: 8px; }
.pipeline-more img { margin-top: 14px; }

.video-head { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }

/* ---------- teaser video (top of page) ---------- */
.teaser-video { max-width: 960px; margin: 0 auto; padding: 10px; }
.teaser-video video { max-width: 100%; border-radius: 12px; background: #f6f8fc; }

/* ---------- problem: teaser success curve ---------- */
.problem-curve { max-width: 600px; margin: 24px auto 8px; padding: 14px 16px 12px; }
.problem-curve img { width: 100%; height: auto; display: block; }
.problem-curve figcaption { margin-top: 10px; text-align: center; }