/* ---------- tokens ---------- */
:root {
  color-scheme: light;
  --page: #f9f9f7;
  --surface: #fcfcfb;
  --surface-2: #f3f2ee;
  --ink: #0b0b0b;
  --ink-2: #52514e;
  --muted: #898781;
  --grid: #e1e0d9;
  --axis: #c3c2b7;
  --border: rgba(11, 11, 11, 0.1);
  --link: #1c5cab;
  --c1: #2a78d6; --c2: #eb6834; --c3: #1baf7a; --c4: #eda100;
  --c5: #e87ba4; --c6: #008300; --c7: #4a3aa7; --c8: #e34948;
  --wash-1: rgba(42, 120, 214, 0.12);
  --wash-2: rgba(235, 104, 52, 0.14);
  --bar-muted: #c3c2b7;
  --band: rgba(11, 11, 11, 0.05);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 4px 16px rgba(0, 0, 0, 0.04);
  --serif: "Fraunces", Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --page: #0d0d0d; --surface: #1a1a19; --surface-2: #232321;
    --ink: #ffffff; --ink-2: #c3c2b7; --muted: #898781;
    --grid: #2c2c2a; --axis: #383835; --border: rgba(255, 255, 255, 0.1);
    --link: #86b6ef;
    --c1: #3987e5; --c2: #d95926; --c3: #199e70; --c4: #c98500;
    --c5: #d55181; --c6: #008300; --c7: #9085e9; --c8: #e66767;
    --wash-1: rgba(57, 135, 229, 0.18); --wash-2: rgba(217, 89, 38, 0.2);
    --bar-muted: #4a4a47; --band: rgba(255, 255, 255, 0.05);
    --shadow: none;
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --page: #0d0d0d; --surface: #1a1a19; --surface-2: #232321;
  --ink: #ffffff; --ink-2: #c3c2b7; --muted: #898781;
  --grid: #2c2c2a; --axis: #383835; --border: rgba(255, 255, 255, 0.1);
  --link: #86b6ef;
  --c1: #3987e5; --c2: #d95926; --c3: #199e70; --c4: #c98500;
  --c5: #d55181; --c6: #008300; --c7: #9085e9; --c8: #e66767;
  --wash-1: rgba(57, 135, 229, 0.18); --wash-2: rgba(217, 89, 38, 0.2);
  --bar-muted: #4a4a47; --band: rgba(255, 255, 255, 0.05);
  --shadow: none;
}

/* ---------- base ---------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  font: 17px/1.65 var(--sans);
  overflow-x: hidden;
}
a { color: var(--link); text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 2px solid var(--c1); outline-offset: 2px; border-radius: 4px; }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 16px; }
.wrap-text { max-width: 700px; margin: 0 auto; padding: 0 16px; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 8px; background: var(--surface); padding: 8px 12px; z-index: 10; }
.dot { display: inline-block; width: 8px; height: 8px; border-radius: 50%; flex: none; }
.c1 { background: var(--c1); } .c2 { background: var(--c2); } .c3 { background: var(--c3); } .c4 { background: var(--c4); }
.c5 { background: var(--c5); } .c6 { background: var(--c6); } .c7 { background: var(--c7); } .c8 { background: var(--c8); }

/* ---------- header + tabs ---------- */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 5; }
.header-row { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand img { width: 34px; height: 34px; flex: none; }
.brand-text { display: flex; flex-direction: column; gap: 3px; }
.brand-name { font: 800 23px/1 var(--serif); letter-spacing: -0.02em; }
.brand-name em { font-style: italic; font-weight: 600; color: var(--c2); }
.brand-tag { font: 400 12px/1.2 var(--sans); color: var(--muted); letter-spacing: 0; }
@media (max-width: 640px) { .brand-tag { display: none; } }
.fresh { display: inline-block; padding: 2px 8px; border-radius: 999px; background: var(--c1); color: #fff; font-size: 11.5px; letter-spacing: 0.06em; }
.header-tools { display: flex; align-items: center; gap: 12px; }
.header-link { color: var(--ink-2); text-decoration: none; font-size: 15px; }
.header-link.is-active, .header-link:hover { color: var(--ink); }
.theme-toggle { width: 36px; height: 36px; border-radius: 50%; border: 1px solid var(--border); background: transparent; color: var(--ink-2); cursor: pointer; display: grid; place-items: center; }
.theme-toggle svg { width: 18px; height: 18px; fill: currentColor; }
.theme-toggle:hover { color: var(--ink); background: var(--surface-2); }

.tabs { border-top: 1px solid var(--border); }
.tabs-row { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; }
.tabs-row::-webkit-scrollbar { display: none; }
.tab {
  display: inline-flex; align-items: center; gap: 7px; white-space: nowrap;
  padding: 11px 12px 10px; font-size: 14.5px; color: var(--ink-2); text-decoration: none;
  border-bottom: 2px solid transparent;
}
.tab:hover { color: var(--ink); }
.tab.is-active { color: var(--ink); border-bottom-color: var(--ink); font-weight: 600; }

/* ---------- story ---------- */
.story { padding: 0 0 8px; }
.kicker { display: flex; align-items: center; gap: 8px; margin: 0 0 14px; font-size: 13px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-2); }
.meta { display: flex; align-items: center; flex-wrap: wrap; gap: 8px; margin: 0 0 12px; font-size: 14px; color: var(--ink-2); }
.meta-sep { color: var(--muted); }
.chip {
  display: inline-flex; align-items: center; gap: 7px; padding: 3px 10px 3px 9px;
  border: 1px solid var(--border); border-radius: 999px; background: var(--surface);
  color: var(--ink); text-decoration: none; font-size: 13px; line-height: 1.5;
}
a.chip:hover { background: var(--surface-2); }
.headline { font: 700 clamp(30px, 5.2vw, 46px)/1.12 var(--serif); letter-spacing: -0.015em; margin: 0 0 16px; text-wrap: balance; }
.dek { font-size: 20px; line-height: 1.5; color: var(--ink-2); margin: 0; text-wrap: pretty; }
.story-body { min-width: 0; }
.beat { margin: 0 0 28px; }
.beat-label { font: 600 13px/1.4 var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 8px; display: flex; align-items: center; gap: 10px; }
.beat-label::after { content: ""; flex: 1; height: 1px; background: var(--grid); }
.beat p { margin: 0 0 14px; text-wrap: pretty; }
.term { border-bottom: 1.5px dotted var(--ink-2); cursor: help; }
.term:hover, .term:focus-visible { background: var(--wash-1); }

/* ---------- figures ---------- */
.figures { margin: 20px auto 8px; }
.fig-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.viz {
  margin: 0; background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 18px 18px 14px; box-shadow: var(--shadow); display: flex; flex-direction: column;
}
.viz-title { font: 600 17px/1.3 var(--sans); margin: 0 0 3px; }
.viz-sub { font-size: 13.5px; line-height: 1.4; color: var(--ink-2); margin: 0 0 12px; }
.viz-body { flex: 1; display: flex; align-items: center; }
.chart { width: 100%; height: auto; display: block; overflow: visible; font-family: var(--sans); }
.viz figcaption { font-size: 12.5px; line-height: 1.45; color: var(--muted); margin-top: 12px; }
.legend { list-style: none; display: flex; flex-wrap: wrap; gap: 4px 14px; padding: 0; margin: 0 0 8px; font-size: 12.5px; color: var(--ink-2); }
.legend li { display: flex; align-items: center; gap: 6px; }
.sw { width: 12px; height: 10px; border-radius: 3px; display: inline-block; }
.sw.s1 { background: var(--c1); } .sw.s2 { background: var(--c2); }

/* chart marks */
.chart .t-label { font-size: 13px; fill: var(--ink); }
.chart .t-value { font-size: 13px; fill: var(--ink-2); font-variant-numeric: tabular-nums; }
.chart .t-tick { font-size: 11.5px; fill: var(--muted); font-variant-numeric: tabular-nums; }
.chart .grid { stroke: var(--grid); stroke-width: 1; }
.chart .axis { stroke: var(--axis); stroke-width: 1; }
.chart .ref-line { stroke: var(--ink-2); stroke-width: 1.5; }
.chart .band { fill: var(--band); }
.chart .s1 { fill: var(--c1); } .chart .s2 { fill: var(--c2); }
.chart .s-muted { fill: var(--bar-muted); }
.chart .line { fill: none; stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.chart .s1-stroke { stroke: var(--c1); }
.chart .hit { fill: transparent; }
.chart .mark { cursor: default; outline: none; }
.chart .mark:hover path, .chart .mark:hover rect:not(.hit), .chart .mark:focus-visible path, .chart .mark:focus-visible rect:not(.hit) { filter: brightness(1.12); }
.chart .mark:focus-visible .hit { stroke: var(--c1); stroke-width: 1.5; rx: 6; }
.chart .xhair { visibility: hidden; pointer-events: none; }
.chart .xhair.on { visibility: visible; }
.chart .xhair-line { stroke: var(--axis); stroke-width: 1; }
.chart .xhair-dot { stroke: var(--surface); stroke-width: 2; }
.chart .wave-hit { cursor: crosshair; outline: none; }

/* diagram classes (content/diagrams/*.svg) */
.diagram text { font-family: var(--sans); fill: var(--ink); }
.diagram .d-text-b { font-size: 14.5px; font-weight: 600; }
.diagram .d-text-sm { font-size: 13px; fill: var(--ink-2); }
.diagram .d-text-xs { font-size: 12px; fill: var(--muted); }
.diagram .d-num { font-size: 12px; font-weight: 700; fill: #fff; }
.diagram .d-card { fill: var(--surface-2); stroke: var(--border); }
.diagram .d-card-1 { fill: var(--wash-1); stroke: var(--c1); stroke-width: 1.2; }
.diagram .d-card-2 { fill: var(--wash-2); stroke: var(--c2); stroke-width: 1.2; }
.diagram .d-tooth { fill: var(--surface); stroke: var(--ink-2); stroke-width: 1.5; stroke-linejoin: round; }
.diagram .d-ghost { stroke: var(--muted); stroke-width: 1.2; stroke-dasharray: 3 3; }
.diagram .d-bud { fill: var(--wash-2); stroke: var(--c2); stroke-width: 1.2; }
.diagram .d-bud-strong { fill: var(--wash-2); stroke: var(--c2); stroke-width: 2; stroke-linejoin: round; }
.diagram .d-dot-1 { fill: var(--c1); } .diagram .d-dot-2 { fill: var(--c2); }
.diagram .d-fill-1 { fill: var(--c1); } .diagram .d-fill-2 { fill: var(--c2); }
.diagram .d-fill-2-strong { fill: var(--c2); stroke: var(--surface); stroke-width: 1.5; }
.diagram .d-fill-ink2 { fill: var(--ink-2); }
.diagram .d-wash-2 { fill: var(--wash-2); }
.diagram .d-line-1 { stroke: var(--c1); stroke-width: 2; stroke-linecap: round; }
.diagram .d-line-2 { stroke: var(--c2); stroke-width: 2; stroke-linecap: round; }
.diagram .d-line-ink2 { stroke: var(--ink-2); stroke-width: 1.5; stroke-linecap: round; }
.diagram .d-line-muted { stroke: var(--muted); stroke-width: 1.2; stroke-linecap: round; }
.diagram .d-dash { stroke-dasharray: 4 4; }
.diagram .d-thick { stroke-width: 3; }
.diagram .d-robot { fill: var(--surface); stroke: var(--ink-2); stroke-width: 1.5; }
.diagram .d-chassis { fill: var(--ink-2); }
.diagram .d-wheel { fill: var(--ink-2); }
.diagram .d-hub { fill: var(--surface); }
.diagram .d-planet-1 { fill: var(--wash-1); stroke: var(--c1); stroke-width: 1.5; }
.diagram .d-planet-2 { fill: var(--wash-2); stroke: var(--c2); stroke-width: 1.5; }
.diagram .d-orbit { stroke: var(--axis); stroke-width: 1.2; }

/* stat tiles */
.stats { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; width: 100%; }
.stat { background: var(--surface-2); border-radius: 10px; padding: 18px 14px; }
.stat-value { font: 600 44px/1 var(--sans); letter-spacing: -0.02em; }
.stat-label { font-size: 13.5px; line-height: 1.35; color: var(--ink-2); margin-top: 10px; }

/* data tables */
.data { margin-top: 10px; font-size: 13px; }
.data summary { cursor: pointer; color: var(--ink-2); width: fit-content; }
.data summary:hover { color: var(--ink); }
.data table { width: 100%; border-collapse: collapse; margin-top: 8px; font-variant-numeric: tabular-nums; }
.data th, .data td { text-align: left; padding: 5px 6px; border-bottom: 1px solid var(--grid); vertical-align: top; }
.data thead th { color: var(--muted); font-weight: 600; }
.data tbody th { font-weight: 400; }

/* ---------- extras ---------- */
.extras { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 56px; align-items: start; }
.extra-card { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 18px 20px; box-shadow: var(--shadow); }
.extra-card h2 { font: 600 13px/1.4 var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 10px; }
.terms { margin: 0; font-size: 14.5px; line-height: 1.5; }
.terms div + div { margin-top: 10px; }
.terms dt { font-weight: 600; }
.terms dd { margin: 0; color: var(--ink-2); }
.fine { margin: 0; padding-left: 18px; font-size: 14.5px; line-height: 1.5; color: var(--ink-2); }
.fine li + li { margin-top: 8px; }
.think { background: var(--wash-1); border-color: transparent; }
.think p { margin: 0; font-size: 15.5px; line-height: 1.55; }

/* ---------- source ---------- */
.source { margin-top: 36px; padding-top: 24px; border-top: 1px solid var(--grid); }
.source h2 { font: 600 13px/1.4 var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin: 0 0 10px; }
.source-title { font: 600 20px/1.35 var(--serif); margin: 0 0 4px; }
.source-title a { color: var(--ink); }
.source-meta { margin: 0 0 12px; color: var(--ink-2); font-size: 15px; }
.badges { list-style: none; padding: 0; margin: 0 0 14px; display: flex; flex-wrap: wrap; gap: 8px; }
.badges li { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; padding: 3px 10px; border-radius: 999px; background: var(--surface-2); color: var(--ink-2); }
.badges svg { width: 14px; height: 14px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.badges a { color: inherit; }
.cite { display: flex; gap: 12px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; }
.cite-text { margin: 0; font-size: 14px; line-height: 1.55; color: var(--ink-2); flex: 1; overflow-wrap: anywhere; }
.copy { flex: none; font: 500 13px var(--sans); padding: 6px 10px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface-2); color: var(--ink); cursor: pointer; }
.copy:hover { filter: brightness(0.97); }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 36px; }
.pager a { display: block; padding: 14px 16px; border: 1px solid var(--border); border-radius: 12px; background: var(--surface); color: var(--ink); text-decoration: none; font-size: 15px; line-height: 1.4; }
.pager a span { display: block; font-size: 12.5px; color: var(--muted); margin-bottom: 4px; }
.pager-next { text-align: right; }
.pager a:hover { border-color: var(--axis); }

/* ---------- cards / lists ---------- */
.more { margin-top: 48px; }
.more-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 14px; }
.more-head h2 { font: 700 24px/1.2 var(--serif); margin: 0; }
.cards { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.card-link { display: flex; flex-direction: column; gap: 8px; height: 100%; padding: 18px; border-radius: 14px; border: 1px solid var(--border); background: var(--surface); color: var(--ink); text-decoration: none; box-shadow: var(--shadow); transition: border-color 0.15s; }
.card-link:hover { border-color: var(--axis); }
.card-meta { display: flex; align-items: center; justify-content: space-between; gap: 8px; font-size: 13px; color: var(--muted); }
.card-title { font: 600 19px/1.3 var(--serif); }
.card-dek { font-size: 14.5px; line-height: 1.5; color: var(--ink-2); }

.page-title { font: 700 clamp(30px, 5vw, 42px)/1.15 var(--serif); margin: 40px 0 8px; }
.page-lede { color: var(--ink-2); font-size: 18px; margin: 0 0 24px; }
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.filter { display: inline-flex; align-items: center; gap: 7px; font: 500 14px var(--sans); padding: 7px 12px; border-radius: 999px; border: 1px solid var(--border); background: var(--surface); color: var(--ink); cursor: pointer; }
.filter .count { color: var(--muted); font-variant-numeric: tabular-nums; }
.filter:hover:not(:disabled) { background: var(--surface-2); }
.filter.is-active { background: var(--ink); color: var(--page); border-color: var(--ink); }
.filter.is-active .count { color: inherit; opacity: 0.7; }
.filter:disabled { opacity: 0.45; cursor: not-allowed; }
.cards-archive .card[hidden] { display: none; }
.archive-empty { color: var(--ink-2); }

.empty { padding: 56px 16px 24px; }
.empty .kicker { text-transform: none; letter-spacing: 0; font-size: 15px; }

.about h2 { font: 700 22px/1.3 var(--serif); margin: 32px 0 8px; }
.about ul { padding-left: 20px; }
.about li { margin-bottom: 8px; }
.pool { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 24px; }
.pool h3 { display: flex; align-items: center; gap: 8px; font: 600 15px var(--sans); margin: 16px 0 4px; }
.pool ul { margin: 0; padding-left: 18px; font-size: 15px; }
.pool li { margin-bottom: 2px; }

/* ---------- footer + tooltip ---------- */
.site-footer { margin-top: 64px; border-top: 1px solid var(--border); background: var(--surface); padding: 20px 0 28px; }
.disclaimer { font-size: 12px; line-height: 1.55; color: var(--muted); max-width: 760px; margin: 0 0 8px; }
.footer-links { font-size: 13px; margin: 0; color: var(--muted); }
.footer-links a { color: var(--ink-2); }

.tip {
  position: fixed; z-index: 20; max-width: 280px; pointer-events: none;
  background: var(--ink); color: var(--page); font-size: 13px; line-height: 1.45;
  padding: 8px 10px; border-radius: 8px; box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}
.tip strong { font-weight: 700; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .fig-row, .extras, .cards { grid-template-columns: 1fr 1fr; }
  
}
@media (max-width: 640px) {
  body { font-size: 16.5px; }
  .fig-row, .extras, .cards, .pager, .pool { grid-template-columns: 1fr; }
  .story { padding-top: 28px; }
  .dek { font-size: 18px; }
  .cite { flex-direction: column; }
  .stat-value { font-size: 38px; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }
@media print {
  .site-header, .site-footer .footer-links, .copy, .data summary { display: none; }
  .data table { display: table; }
}


/* =================================================================
   Layout v2: hero, story rail, sections, tiles
   ================================================================= */
.progress { position: absolute; left: 0; right: 0; bottom: -1px; height: 3px; pointer-events: none; }
.progress span { display: block; height: 100%; background: linear-gradient(90deg, var(--c1), var(--c2)); transform-origin: left; transform: scaleX(0); }

.hero { position: relative; overflow: hidden; padding: 72px 0 56px; margin-bottom: 24px; border-bottom: 1px solid var(--border); isolation: isolate; }
.hero-aura { position: absolute; inset: -20% -10%; z-index: -1; opacity: 0.6; pointer-events: none; }
.hero-aura i { will-change: transform; }
.hero-aura i { position: absolute; width: 46vmax; height: 46vmax; border-radius: 50%; background: radial-gradient(circle, color-mix(in srgb, var(--subj, var(--c1)) 55%, transparent), transparent 65%); }
.hero-aura i:nth-child(1) { left: -8%; top: -30%; animation: drift1 22s ease-in-out infinite alternate; }
.hero-aura i:nth-child(2) { right: -12%; top: 10%; background: radial-gradient(circle, color-mix(in srgb, var(--c2) 35%, transparent), transparent 65%); animation: drift2 26s ease-in-out infinite alternate; }
.hero-aura i:nth-child(3) { left: 30%; bottom: -45%; background: radial-gradient(circle, color-mix(in srgb, var(--c1) 30%, transparent), transparent 65%); animation: drift3 30s ease-in-out infinite alternate; }
@keyframes drift1 { to { transform: translate(12%, 18%) scale(1.15); } }
@keyframes drift2 { to { transform: translate(-16%, -8%) scale(0.9); } }
@keyframes drift3 { to { transform: translate(-10%, -14%) scale(1.1); } }
.hero .headline { font-size: clamp(34px, 6vw, 60px); line-height: 1.05; letter-spacing: -0.02em; }
.hero .dek { font-size: clamp(18px, 2.2vw, 22px); }
.scroll-cue { display: inline-flex; align-items: center; gap: 8px; margin-top: 28px; font-size: 14px; font-weight: 600; color: var(--ink-2); text-decoration: none; }
.scroll-cue svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; animation: nudge 1.8s ease-in-out infinite; }
.scroll-cue:hover { color: var(--ink); }
@keyframes nudge { 50% { transform: translateY(4px); } }

.story-grid { display: grid; grid-template-columns: 200px minmax(0, 700px); gap: 56px; justify-content: center; }
.rail { position: relative; }
.rail ol { position: sticky; top: 130px; list-style: none; margin: 8px 0 0; padding: 0 0 0 14px; border-left: 2px solid var(--grid); }
.rail li { position: relative; }
.rail li + li { margin-top: 10px; }
.rail a { display: flex; gap: 10px; align-items: baseline; font-size: 13.5px; color: var(--muted); text-decoration: none; transition: color 0.25s, transform 0.25s; }
.rail a span { font-variant-numeric: tabular-nums; font-size: 11.5px; opacity: 0.8; }
.rail a:hover { color: var(--ink-2); }
.rail a.is-active { color: var(--ink); font-weight: 600; transform: translateX(4px); }
.rail a.is-active::before { content: ""; position: absolute; left: -16px; top: 1px; width: 2px; height: 18px; background: var(--subj, var(--c1)); border-radius: 2px; }
.beat { scroll-margin-top: 130px; }
.beat-num { font: 700 12px var(--sans); color: var(--subj, var(--c1)); letter-spacing: 0.04em; }

.section-head { margin: 0 0 18px; }
.eyebrow { margin: 0 0 4px; font-size: 12.5px; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: var(--subj, var(--c1)); }
.section-head h2 { margin: 0; font: 700 clamp(26px, 3.4vw, 34px)/1.15 var(--serif); letter-spacing: -0.01em; }
.figures, .extras, .source { scroll-margin-top: 120px; }
.figures { margin-top: 56px; }

.explore { margin-top: 64px; }
.tiles { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.tile a { position: relative; display: grid; grid-template-columns: auto 1fr auto; grid-template-rows: auto auto; column-gap: 12px; align-items: center; padding: 20px; border-radius: 16px; border: 1px solid var(--border); background: var(--surface); color: var(--ink); text-decoration: none; overflow: hidden; box-shadow: var(--shadow); transition: transform 0.35s cubic-bezier(.2,.7,.2,1), border-color 0.35s; }
.tile a::after { content: ""; position: absolute; inset: 0; pointer-events: none; background: radial-gradient(120% 100% at 0% 0%, color-mix(in srgb, var(--subj) 16%, transparent), transparent 60%); opacity: 0; transition: opacity 0.35s; }
.tile a:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--subj) 50%, var(--border)); }
.tile a:hover::after { opacity: 1; }
.tile-dot { grid-row: span 2; width: 14px; height: 14px; border-radius: 50%; background: var(--subj); box-shadow: 0 0 0 5px color-mix(in srgb, var(--subj) 18%, transparent); }
.tile-name { font: 700 19px/1.2 var(--serif); }
.tile-count { grid-column: 2; font-size: 13.5px; color: var(--muted); }
.tile-go { grid-row: 1 / span 2; grid-column: 3; font-size: 20px; color: var(--ink-2); transition: transform 0.35s; }
.tile a:hover .tile-go { transform: translateX(4px); }

.card-link { transition: transform 0.35s cubic-bezier(.2,.7,.2,1), border-color 0.35s; }
.card-link:hover { transform: translateY(-4px); }
.diagram .d-band-1 { fill: var(--wash-1); }

/* =================================================================
   Motion: scroll reveals and chart draw-ins (only when JS is running)
   ================================================================= */
.js .reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.8s cubic-bezier(.2,.7,.2,1), transform 0.8s cubic-bezier(.2,.7,.2,1); transition-delay: calc(var(--i, 0) * 90ms); }
.js .reveal.in { opacity: 1; transform: none; }
/* the hero animates on first paint (no waiting for scroll or script) */
.js .hero .reveal { opacity: 1; transform: none; transition: none; animation: heroIn 0.8s cubic-bezier(.2,.7,.2,1) both; animation-delay: calc(var(--i, 0) * 90ms); }
@keyframes heroIn { from { opacity: 0; transform: translateY(16px); filter: blur(5px); } to { opacity: 1; transform: none; filter: none; } }

.js .viz .grow { transform: scaleX(0); transform-box: fill-box; transform-origin: left center; transition: transform 1s cubic-bezier(.2,.7,.2,1); transition-delay: calc(var(--i, 0) * 120ms + 250ms); }
.js .viz.in .grow { transform: scaleX(1); }
.js .viz .draw { stroke-dasharray: 1; stroke-dashoffset: 1; transition: stroke-dashoffset 1.8s cubic-bezier(.4,.1,.2,1) 0.3s; }
.js .viz.in .draw { stroke-dashoffset: 0; }
.js .viz .t-value { opacity: 0; transition: opacity 0.5s ease 1.1s; }
.js .viz.in .t-value { opacity: 1; }
.js .viz .diagram { opacity: 0; transform: scale(0.97); transition: opacity 0.9s ease 0.2s, transform 0.9s cubic-bezier(.2,.7,.2,1) 0.2s; }
.js .viz.in .diagram { opacity: 1; transform: none; }

@media (max-width: 1000px) {
  .story-grid { grid-template-columns: minmax(0, 700px); }
  .rail, .rail-spacer { display: none; }
  .tiles { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .hero { padding: 44px 0 36px; }
  .tiles { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }
@media (prefers-reduced-motion: reduce) {
  .hero-aura i, .scroll-cue svg, .js .hero .reveal { animation: none; }
  .js .reveal, .js .hero .reveal, .js .viz .grow, .js .viz .draw, .js .viz .t-value, .js .viz .diagram { opacity: 1; transform: none; filter: none; stroke-dashoffset: 0; transition: none; }
}


/* =================================================================
   Figures v3: editorial panels (copy column + tinted stage)
   ================================================================= */
.fig-list { display: flex; flex-direction: column; gap: 72px; }
.viz {
  display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 48px; align-items: center;
  margin: 0; padding: 0; background: none; border: 0; box-shadow: none; border-radius: 0;
}
.viz:nth-child(even) { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.viz:nth-child(even) .viz-copy { order: 2; }
.viz-copy { max-width: 420px; }
.viz:nth-child(even) .viz-copy { justify-self: end; }
.viz-num { margin: 0 0 6px; font: 800 64px/0.9 var(--serif); letter-spacing: -0.04em; color: color-mix(in srgb, var(--subj, var(--c1)) 70%, transparent); }
.viz-title { margin: 0 0 12px; font: 700 clamp(24px, 2.6vw, 30px)/1.15 var(--serif); letter-spacing: -0.01em; }
.viz-take { margin: 0 0 16px; font-size: 18px; line-height: 1.55; color: var(--ink); }
.viz-copy figcaption { margin: 0; font-size: 13.5px; line-height: 1.5; color: var(--muted); padding-left: 12px; border-left: 2px solid color-mix(in srgb, var(--subj, var(--c1)) 45%, transparent); }
.viz-copy .data { margin-top: 14px; }

.viz-stage {
  position: relative; padding: 28px 30px 26px; border-radius: 24px;
  background-color: color-mix(in srgb, var(--subj, var(--c1)) 7%, var(--surface));
  background-image: radial-gradient(color-mix(in srgb, var(--subj, var(--c1)) 20%, transparent) 1px, transparent 1.3px);
  background-size: 18px 18px;
  border: 1px solid color-mix(in srgb, var(--subj, var(--c1)) 18%, var(--border));
  box-shadow: 0 1px 2px rgba(0,0,0,.03), 0 18px 40px -24px color-mix(in srgb, var(--subj, var(--c1)) 45%, transparent);
}
.viz-stage .viz-sub { margin: 0 0 14px; font-size: 13px; font-weight: 600; letter-spacing: 0.02em; color: var(--ink-2); }
.viz-stage .legend { margin-bottom: 10px; }
.viz-stage .viz-body { max-width: 480px; margin: 0; }
.viz-stage .viz-body .diagram { max-width: 420px; margin: 0 auto; }
.viz-stage .chart { background: none; }

/* marks */
.chart .s-subj { fill: var(--subj, var(--c1)); }
.chart .s-subj-stroke { stroke: var(--subj, var(--c1)); stroke-width: 3; }
.chart .dot-subj { fill: var(--subj, var(--c1)); stroke: var(--surface); stroke-width: 2.5; }
.chart .area { fill: color-mix(in srgb, var(--subj, var(--c1)) 16%, transparent); }
.chart .track { fill: color-mix(in srgb, var(--ink) 7%, transparent); }
.chart .s-muted { fill: color-mix(in srgb, var(--ink) 28%, transparent); }
.chart .t-label { font-size: 14px; font-weight: 500; }
.chart .t-value { font-size: 15px; font-weight: 600; fill: var(--ink-2); }
.chart .t-value.is-strong, .chart .t-label.is-strong { fill: var(--ink); font-weight: 700; }
.chart .t-tick { font-size: 12.5px; }
.chart .t-tick.is-strong { fill: var(--ink-2); font-weight: 600; }
.chart .band { fill: color-mix(in srgb, var(--ink) 6%, transparent); }
.chart .ref-line { stroke: var(--ink); stroke-width: 2; stroke-linecap: round; }

/* diagrams sit on the stage: lift their cards off the dotted background */
.diagram .d-card { fill: var(--surface); stroke: color-mix(in srgb, var(--ink) 10%, transparent); }
.diagram rect.d-card, .diagram rect.d-card-1, .diagram rect.d-card-2 { filter: drop-shadow(0 2px 3px rgba(0,0,0,.06)); }
.diagram .d-text-b { font-size: 15px; }

/* stat tiles */
.viz-stats .stats { gap: 14px; }
.viz-stats .stat { background: var(--surface); border: 1px solid color-mix(in srgb, var(--subj, var(--c1)) 18%, var(--border)); border-radius: 18px; padding: 22px 18px; }
.viz-stats .stat-value { font: 800 clamp(40px, 5vw, 56px)/1 var(--serif); letter-spacing: -0.03em; color: var(--subj, var(--c1)); }

/* animation extras for the new marks */
.js .viz .fade-in { opacity: 0; transition: opacity 0.8s ease 1.2s; }
.js .viz.in .fade-in { opacity: 1; }

/* "Think about it" callout */
.think-band { margin-top: 32px; }
.think-inner {
  position: relative; overflow: hidden; padding: 36px 40px 38px; border-radius: 24px;
  background: linear-gradient(135deg, color-mix(in srgb, var(--subj, var(--c1)) 16%, var(--surface)), color-mix(in srgb, var(--c2) 8%, var(--surface)));
  border: 1px solid color-mix(in srgb, var(--subj, var(--c1)) 22%, var(--border));
}
.think-inner .eyebrow { margin: 0 0 10px; }
.think-q { position: relative; margin: 0; max-width: 820px; font: 600 clamp(21px, 2.4vw, 27px)/1.4 var(--serif); letter-spacing: -0.005em; }
.think-mark { position: absolute; right: 28px; top: -18px; font: 800 180px/1 var(--serif); color: color-mix(in srgb, var(--subj, var(--c1)) 22%, transparent); pointer-events: none; }

@media (max-width: 900px) {
  .viz, .viz:nth-child(even) { grid-template-columns: 1fr; gap: 20px; }
  .viz:nth-child(even) .viz-copy { order: 0; justify-self: start; }
  .viz-copy { max-width: none; }
  .viz-num { font-size: 48px; }
  .extras { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .viz-stage { padding: 20px 16px; border-radius: 18px; }
  .think-inner { padding: 26px 22px 28px; }
  .think-mark { font-size: 120px; right: 14px; }
  .fig-list { gap: 52px; }
}
@media (prefers-reduced-motion: reduce) { .js .viz .fade-in { opacity: 1; transition: none; } }


/* =================================================================
   v4: icons, subject hero art, glance, evidence, big number, map, next
   ================================================================= */
.icon { width: 1em; height: 1em; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; overflow: visible; flex: none; }

/* icons in tabs, chips, tiles */
.tab-ico, .chip-ico { display: inline-flex; color: var(--subj); }
.tab-ico .icon { width: 17px; height: 17px; }
.chip-ico .icon { width: 15px; height: 15px; }
.tab-ico .icon path, .tile-ico .icon path, .next-eyebrow .icon path { stroke-dasharray: 1; stroke-dashoffset: 0; }
.tab:hover .tab-ico .icon path, .tile a:hover .tile-ico .icon path { animation: iconDraw 0.9s ease both; }
@keyframes iconDraw { from { stroke-dashoffset: 1; } to { stroke-dashoffset: 0; } }
.tile-ico { grid-row: span 2; display: grid; place-items: center; width: 44px; height: 44px; border-radius: 12px; color: var(--subj); background: color-mix(in srgb, var(--subj) 13%, transparent); }
.tile-ico .icon { width: 24px; height: 24px; }
.filter .chip-ico .icon { width: 15px; height: 15px; }
.filter.is-active .chip-ico { color: inherit; }
.pool h3 .chip-ico .icon { width: 17px; height: 17px; }

/* subject hero art */
.hero-art { position: absolute; inset: 0; width: 100%; height: 100%; z-index: -1; color: var(--subj); pointer-events: none;
  -webkit-mask-image: linear-gradient(to right, transparent 0%, rgba(0,0,0,.18) 35%, rgba(0,0,0,.35) 60%, #000 85%); mask-image: linear-gradient(to right, transparent 0%, rgba(0,0,0,.18) 35%, rgba(0,0,0,.35) 60%, #000 85%); }
.hero-art * { vector-effect: non-scaling-stroke; }
/* space */
.hero-art .star { fill: currentColor; opacity: .5; animation: twinkle var(--t, 4s) ease-in-out var(--d, 0s) infinite alternate; }
@keyframes twinkle { from { opacity: .12; } to { opacity: .8; } }
.hero-art .planet { fill: color-mix(in srgb, currentColor 18%, transparent); stroke: currentColor; stroke-width: 1.5; opacity: .7; }
.hero-art .ring { fill: none; stroke: currentColor; stroke-width: 1.5; opacity: .6; }
.hero-art .float-slow { animation: floatY 14s ease-in-out infinite alternate; }
@keyframes floatY { to { transform: translateY(16px); } }
/* earth */
.hero-art .contour { fill: none; stroke: currentColor; stroke-width: 1.1; opacity: .38; }
.hero-art .contour.major { stroke-width: 1.8; opacity: .55; }
.hero-art .drift { animation: drift 28s ease-in-out infinite alternate; }
@keyframes drift { to { transform: translate(-26px, 12px) scale(1.03); } }
/* life */
.hero-art .membrane { fill: color-mix(in srgb, currentColor 8%, transparent); stroke: currentColor; stroke-width: 1.4; opacity: .55; }
.hero-art .nucleus { fill: currentColor; opacity: .22; }
.hero-art .cell { animation: cellFloat var(--t, 14s) ease-in-out var(--d, 0s) infinite alternate; }
@keyframes cellFloat { to { transform: translate(14px, -22px); } }
/* health */
.hero-art .grid-line { fill: none; stroke: currentColor; stroke-width: .6; opacity: .14; }
.hero-art .beat-trace { fill: none; stroke: currentColor; stroke-width: 2; stroke-linejoin: miter; stroke-miterlimit: 10; opacity: .6; stroke-dasharray: .22 .78; animation: sweep 5.5s linear var(--d, 0s) infinite; }
@keyframes sweep { from { stroke-dashoffset: 1; } to { stroke-dashoffset: 0; } }
/* technology */
.hero-art .trace { fill: none; stroke: currentColor; stroke-width: 1.2; opacity: .28; }
.hero-art .current { fill: none; stroke: currentColor; stroke-width: 2.4; opacity: .8; stroke-dasharray: .08 .92; animation: sweep var(--t, 4s) linear var(--d, 0s) infinite; }
.hero-art .pad { fill: var(--page); stroke: currentColor; stroke-width: 1.5; opacity: .6; }
/* physics & chemistry */
.hero-art .bond { fill: none; stroke: currentColor; stroke-width: 1.2; opacity: .35; }
.hero-art .atom { fill: currentColor; opacity: .45; animation: pulse 3.6s ease-in-out var(--d, 0s) infinite alternate; }
@keyframes pulse { to { opacity: .85; } }
.hero-art .spin { animation: spin 120s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.hero-art-physics-chemistry .spin { transform-box: view-box; }

/* at a glance */
.glance { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin: 8px 0 14px; }
.g-item { position: relative; margin: 0; padding: 14px 14px 13px; border-radius: 14px; background: var(--surface); border: 1px solid var(--border); }
.g-ico { width: 22px; height: 22px; color: var(--subj); margin-bottom: 8px; }
.g-item dt { font-size: 11.5px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.g-item dd { margin: 3px 0 0; font-size: 14.5px; line-height: 1.35; font-weight: 600; }

/* evidence meter */
.evidence { margin: 0 0 40px; padding: 18px 18px 16px; border-radius: 16px; background: var(--surface); border: 1px solid var(--border); }
.ev-head { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 10px; margin-bottom: 12px; }
.ev-ico { width: 22px; height: 22px; color: var(--subj); }
.ev-title { font: 700 17px/1.2 var(--serif); }
.ev-type { margin-left: auto; font-size: 12.5px; padding: 3px 10px; border-radius: 999px; background: color-mix(in srgb, var(--subj) 12%, transparent); color: var(--ink-2); font-weight: 600; }
.ev-scale { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px; }
.ev-seg { position: relative; padding-top: 12px; }
.ev-seg::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 8px; border-radius: 4px; background: color-mix(in srgb, var(--ink) 9%, transparent); }
.ev-seg.on::before { background: var(--subj); }
.ev-seg b { display: block; font-size: 12px; font-weight: 500; color: var(--muted); }
.ev-seg.here b { color: var(--ink); font-weight: 700; }
.ev-seg.here::after { content: ""; position: absolute; right: -2px; top: -4px; width: 16px; height: 16px; border-radius: 50%; background: var(--subj); border: 3px solid var(--surface); box-shadow: 0 0 0 1px color-mix(in srgb, var(--subj) 40%, transparent); }
.ev-note { margin: 12px 0 0; font-size: 14.5px; line-height: 1.5; color: var(--ink-2); }
.ev-own { display: block; margin-top: 4px; font-size: 12px; color: var(--muted); }
.js .evidence .ev-seg.on::before { transform: scaleX(0); transform-origin: left; transition: transform .6s cubic-bezier(.2,.7,.2,1); transition-delay: calc(var(--i) * 160ms + 300ms); }
.js .evidence.in .ev-seg.on::before { transform: none; }
.js .evidence .ev-seg.here::after { transform: scale(0); transition: transform .4s cubic-bezier(.3,1.6,.5,1) 1s; }
.js .evidence.in .ev-seg.here::after { transform: none; }

/* section icons draw in */
.beat-label { gap: 10px; }
.beat-ico { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 10px; color: var(--subj); background: color-mix(in srgb, var(--subj) 12%, transparent); }
.beat-ico .icon { width: 20px; height: 20px; }
.js .beat-label .beat-ico path { stroke-dasharray: 1; stroke-dashoffset: 1; transition: stroke-dashoffset 1.1s ease .15s; }
.js .beat-label.in .beat-ico path { stroke-dashoffset: 0; }

/* big number interlude */
.bignum { position: relative; margin: 8px 0 40px; padding: 30px 28px 28px; border-radius: 22px; overflow: hidden; text-align: left;
  background: radial-gradient(120% 140% at 100% 0%, color-mix(in srgb, var(--subj) 22%, transparent), transparent 60%), color-mix(in srgb, var(--subj) 7%, var(--surface));
  border: 1px solid color-mix(in srgb, var(--subj) 25%, var(--border)); }
.bignum-value { font: 800 clamp(56px, 9vw, 96px)/.95 var(--serif); letter-spacing: -.04em; color: var(--subj); }
.bignum-label { margin: 10px 0 0; max-width: 460px; font-size: 18px; line-height: 1.45; color: var(--ink); }

/* world map */
.where { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: 40px; align-items: center; margin-top: 64px; }
.where h2 { margin: 0 0 14px; font: 700 clamp(24px, 2.8vw, 30px)/1.15 var(--serif); }
.where-list { margin: 0; padding: 0; list-style: none; counter-reset: pin; }
.where-list li { counter-increment: pin; display: flex; gap: 10px; align-items: baseline; margin-bottom: 8px; font-size: 15px; line-height: 1.4; }
.where-list li::before { content: counter(pin); flex: none; display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; background: var(--subj); color: #fff; font-size: 12px; font-weight: 700; }
.where-map { padding: 18px; border-radius: 22px; background: var(--surface); border: 1px solid var(--border); }
.where-map svg { width: 100%; height: auto; display: block; }
.where-map .land { fill: none; stroke: color-mix(in srgb, var(--ink) 24%, transparent); stroke-width: 4; stroke-linecap: round; }
.where-map .pin-dot { fill: var(--subj); stroke: var(--surface); stroke-width: 2.5; }
.where-map .pin-num { fill: #fff; font: 700 10px var(--sans); }
.where-map .pin-pulse { fill: var(--subj); opacity: .25; transform-box: fill-box; transform-origin: center; animation: pinPulse 2.4s ease-out infinite; animation-delay: calc(var(--i) * .4s); }
@keyframes pinPulse { from { transform: scale(.6); opacity: .45; } to { transform: scale(2.2); opacity: 0; } }
.js .where .pin { opacity: 0; transform: translateY(-14px); transform-box: fill-box; transition: opacity .5s ease, transform .6s cubic-bezier(.3,1.5,.5,1); transition-delay: calc(var(--i) * 180ms + 400ms); }
.js .where.in .pin { opacity: 1; transform: none; }

/* keep reading */
.next-card { position: relative; display: grid; gap: 8px; margin-top: 48px; padding: 28px 90px 28px 30px; border-radius: 22px; text-decoration: none; color: var(--ink); overflow: hidden;
  background: linear-gradient(120deg, color-mix(in srgb, var(--subj) 14%, var(--surface)), var(--surface) 70%); border: 1px solid color-mix(in srgb, var(--subj) 25%, var(--border)); transition: transform .35s cubic-bezier(.2,.7,.2,1); }
.next-card:hover { transform: translateY(-4px); }
.next-eyebrow { display: flex; align-items: center; gap: 8px; font-size: 12.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--subj); }
.next-eyebrow .icon { width: 18px; height: 18px; }
.next-title { font: 700 clamp(22px, 2.6vw, 30px)/1.2 var(--serif); }
.next-dek { font-size: 15.5px; line-height: 1.5; color: var(--ink-2); max-width: 720px; }
.next-go { position: absolute; right: 28px; top: 50%; translate: 0 -50%; display: grid; place-items: center; width: 48px; height: 48px; border-radius: 50%; background: var(--subj); color: #fff; transition: transform .35s; }
.next-go .icon { width: 22px; height: 22px; }
.next-card:hover .next-go { transform: translateX(6px); }

/* mobile section bar (phones/tablets, where the side rail is hidden) */
.mbar { display: none; }
@media (max-width: 1000px) {
  .mbar { display: flex; align-items: center; gap: 8px; height: 0; overflow: hidden; padding: 0 16px; font-size: 13px; font-weight: 600; color: var(--ink-2); background: var(--surface); border-top: 1px solid transparent; transition: height .3s ease, border-color .3s; }
  .mbar.show { height: 34px; border-top-color: var(--border); }
  .mbar-num { color: var(--subj, var(--c1)); font-variant-numeric: tabular-nums; }
}

@media (max-width: 900px) {
  .where { grid-template-columns: 1fr; gap: 18px; }
}
@media (max-width: 640px) {
  .glance { grid-template-columns: 1fr 1fr; }
  .ev-type { margin-left: 0; }
  .ev-seg b { font-size: 10.5px; }
  .bignum { padding: 24px 20px; }
  .next-card { padding: 22px 22px 80px; }
  .next-go { top: auto; bottom: 20px; right: 20px; translate: none; }
}
@media (prefers-reduced-motion: reduce) {
  .hero-art *, .where-map .pin-pulse { animation: none !important; }
  .hero-art .beat-trace, .hero-art .current { stroke-dasharray: none; opacity: .35; }
  .js .beat-label .beat-ico path { stroke-dashoffset: 0; transition: none; }
  .js .evidence .ev-seg.on::before, .js .evidence .ev-seg.here::after, .js .where .pin { transform: none; opacity: 1; transition: none; }
}