/* Spearhead pusher study, Arrow skin. Brand from arrowair.com (Arrow blue #0943bf, hatch #527bd2, ink #00030a,
   JetBrains Mono caps) and the superapp's tokens (Radix Slate + Indigo, Inter). Chart roles validated with the
   dataviz checks: series KDE = slot 1 blue, MAD = slot 2 orange; light on #ffffff, dark on #18191b. */
:root, [data-mode="light"] {
  --brand: #0943bf; --brand-hatch: #527bd2; --brand-ink: #00030a;
  --bg: #fcfcfd; --surface: #ffffff; --surface-2: #f0f0f3;
  --text: #1c2024; --text-muted: #60646c; --text-faint: #8b8d98;
  --border: #e0e1e6; --border-strong: #b9bbc6;
  --accent: #0943bf; --accent-text: #0943bf; --accent-soft: rgba(9,67,191,.05); --accent-line: rgba(9,67,191,.22); --focus: #3e63dd;
  --tip-bg: #1c2024; --tip-text: #edeef0;
  --ok: #18794e; --ok-bg: rgba(48,164,108,.10); --fail: #ce2c31; --fail-bg: rgba(229,72,77,.09); --warn: #ab6400; --warn-bg: rgba(255,197,61,.18);
  --s-kde: #2a78d6; --s-mad: #eb6834;
  --grid: #ececf0; --axis: #cdced6; --ref: #60646c; --heat-1: #60646c; --heat-2: #8b8d98; --band: rgba(206,44,49,.07);
  --body: #f0f0f3; --body-line: #1c2024; --flow: #0d8478;
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  color-scheme: light;
}
[data-mode="dark"] {
  --bg: #111113; --surface: #18191b; --surface-2: #212225;
  --text: #edeef0; --text-muted: #b0b4ba; --text-faint: #696e77;
  --border: #2e3135; --border-strong: #43484e;
  --accent: #3e63dd; --accent-text: #9eb1ff; --accent-soft: rgba(62,99,221,.10); --accent-line: rgba(84,114,228,.38); --focus: #5472e4;
  --tip-bg: #272a2d; --tip-text: #edeef0;
  --ok: #3dd68c; --ok-bg: rgba(61,214,140,.10); --fail: #ff9592; --fail-bg: rgba(255,149,146,.10); --warn: #ffca16; --warn-bg: rgba(255,202,22,.10);
  --s-kde: #3987e5; --s-mad: #d95926;
  --grid: #26282b; --axis: #43484e; --ref: #b0b4ba; --heat-1: #696e77; --heat-2: #b0b4ba; --band: rgba(255,149,146,.08);
  --body: #212225; --body-line: #edeef0; --flow: #12a594;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.6 var(--font-sans); -webkit-font-smoothing: antialiased;
}
.mono, code, .meta, .kicker, .tick, .axis-label, .ref-label, .end-label, .mark-label, .tip, .row-label, .bar-value, .seg-label,
.dim-label, .illus-note, .illus-title, .callout, .callout-strong, .tile-k, .tile-sub, table.data, .scen-body, .scen-toggle, .sec-num, .note-k, .legend, .small {
  font-family: var(--font-mono);
}
a { color: inherit; text-decoration-color: var(--accent); text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }
.small { font-size: 12px; color: var(--text-muted); }
b { font-weight: 600; }

/* top bar: arrowair.com's blue nav with its hatched lower edge */
.topbar { background: var(--brand); color: #fff; padding-bottom: 4px; }
.topbar-row { display: flex; align-items: center; gap: 18px; height: 56px; }
.lockup { display: flex; align-items: center; flex: none; }
.lockup img { display: block; height: 26px; width: auto; }
.crumb { font: 600 13px var(--font-mono); letter-spacing: .06em; text-transform: uppercase; color: rgba(255,255,255,.86); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.crumb .sep { color: rgba(255,255,255,.45); margin: 0 6px; }
.top-links { margin-left: auto; display: flex; align-items: center; gap: 10px; flex: none; }
.top-btn { display: inline-flex; align-items: center; gap: 6px; min-height: 32px; padding: 0 12px; border: 1px solid rgba(255,255,255,.32); border-radius: 6px;
  background: rgba(0,3,10,.12); color: #fff; font: 600 12px var(--font-mono); letter-spacing: .06em; text-transform: uppercase; text-decoration: none; cursor: pointer; }
.top-btn:hover { border-color: rgba(255,255,255,.7); background: rgba(0,3,10,.22); }
.top-btn:focus-visible { outline-color: #fff; }
.hatch { height: 8px;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='6' height='8'%3E%3Cpath d='M4 0h2L2 8H0z' fill='%23527bd2'/%3E%3C/svg%3E") repeat-x; }

/* hero: dark in both modes, as on arrowair.com */
.hero {
  background:
    radial-gradient(ellipse 55% 90% at 88% 0%, rgba(9,67,191,.42), transparent 70%),
    linear-gradient(rgba(82,123,210,.07) 1px, transparent 1px) 0 0 / 28px 28px,
    linear-gradient(90deg, rgba(82,123,210,.07) 1px, transparent 1px) 0 0 / 28px 28px,
    var(--brand-ink);
  color: #edeef0; padding: 52px 0 44px; border-bottom: 1px solid rgba(255,255,255,.08);
}
.kicker { font-size: 12px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--brand-hatch); margin-bottom: 16px; }
h1 { font-size: clamp(32px, 5.4vw, 54px); line-height: 1.04; font-weight: 800; letter-spacing: -.03em; margin: 0 0 18px; max-width: 920px; color: #fff; }
.lede { font-size: 18px; line-height: 1.6; max-width: 780px; margin: 0; color: #b0b4ba; }
.matchup { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px; margin: 26px 0 0; padding: 0; list-style: none; }
.mu { display: inline-flex; align-items: center; gap: 8px; padding: 7px 12px; border: 1px solid rgba(255,255,255,.16); border-radius: 8px;
  background: rgba(255,255,255,.04); font: 600 12px var(--font-mono); letter-spacing: .05em; text-transform: uppercase; color: #edeef0; }
.mu-vs { font: 12px var(--font-mono); color: #8b8d98; text-transform: uppercase; letter-spacing: .08em; }
.mu-ctx { font: 12px var(--font-mono); color: #8b8d98; margin-left: 6px; }
.meta { font-size: 12px; color: #8b8d98; margin: 22px 0 0; letter-spacing: .02em; }

.linkish { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; color: var(--text); padding: 4px 10px;
  font: 600 11px var(--font-mono); letter-spacing: .06em; text-transform: uppercase; cursor: pointer; min-height: 30px; }
.linkish:hover { border-color: var(--accent); color: var(--accent-text); }

/* sections */
.sec { padding: 48px 20px 12px; }
.sec-num { display: flex; align-items: center; gap: 10px; font-size: 12px; font-weight: 600; color: var(--accent-text); letter-spacing: .12em; border-top: 1px solid var(--border); padding-top: 12px; }
.sec-num::before { content: ''; width: 8px; height: 8px; background: var(--accent); border-radius: 1px; }
h2 { font-size: clamp(23px, 3vw, 31px); line-height: 1.18; letter-spacing: -.02em; margin: 8px 0 14px; font-weight: 700; }
h3 { font-size: 16px; margin: 22px 0 8px; font-weight: 700; letter-spacing: -.005em; }
p { max-width: 780px; }
.verdict { font-size: clamp(22px, 3vw, 29px); font-weight: 700; letter-spacing: -.015em; line-height: 1.25; margin: 6px 0 14px; max-width: 820px;
  border-left: 3px solid var(--accent); padding-left: 16px; }

/* stat tiles */
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 12px; margin: 22px 0; }
.tile { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px 16px; }
.tile-k { font-size: 11px; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 10px; }
.tile-v { display: flex; flex-direction: column; gap: 4px; }
.tile-line { display: flex; align-items: baseline; gap: 8px; }
.tile-line .key { flex: none; transform: translateY(-4px); }
.tile-num { font-size: 26px; font-weight: 700; line-height: 1.1; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.tile-unit { font-size: 14px; color: var(--text-muted); }
.tile-name { font-size: 13px; color: var(--text-muted); }
.tile-sub { font-size: 12px; color: var(--text-muted); margin-top: 10px; line-height: 1.5; }
.chip { white-space: nowrap; display: inline-flex; align-items: center; gap: 6px; font: 600 12px var(--font-mono); padding: 2px 8px; border-radius: 6px; border: 1px solid; }
.chip.ok { color: var(--ok); background: var(--ok-bg); border-color: var(--ok); }
.chip.fail { color: var(--fail); background: var(--fail-bg); border-color: var(--fail); }
.chip.warn { color: var(--warn); background: var(--warn-bg); border-color: var(--warn); }

.note { border: 1px solid var(--accent-line); border-left: 3px solid var(--accent); border-radius: 10px; padding: 12px 16px; margin: 18px 0 8px; background: var(--accent-soft); max-width: 860px; }
.note p { margin: 4px 0 0; }
.note-k { font-size: 11px; font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--accent-text); }

/* figures */
.fig { margin: 22px 0 26px; padding: 16px 18px 12px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; position: relative; }
.fig-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-start; gap: 8px 16px; margin-bottom: 10px; }
.fig-title { font-size: 14px; font-weight: 600; letter-spacing: -.005em; max-width: 560px; }
.fig-tools { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; }
.fig-plot { position: relative; width: 100%; }
.fig-cap { font-size: 13px; color: var(--text-muted); margin: 8px 0 2px; max-width: 860px; }
.fig-table { margin-top: 10px; }
.panels { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 8px 22px; }
.panel-title { font: 600 12px var(--font-mono); margin: 4px 0 2px; }
.panel-note { font: 12px var(--font-mono); color: var(--text-muted); margin: 0 0 4px; min-height: 18px; }
.legend { display: flex; flex-wrap: wrap; gap: 6px 14px; list-style: none; margin: 0; padding: 0; font-size: 12px; color: var(--text-muted); }
.legend li { display: inline-flex; align-items: center; gap: 6px; }
.key { display: inline-block; flex: none; }
.key-line { width: 16px; height: 0; border-top: 2px solid var(--c); }
.key-line.key-ref { border-top-style: dashed; }
.key-rect { width: 12px; height: 12px; border-radius: 3px; background: var(--c); }

svg.chart { display: block; width: 100%; height: auto; overflow: visible; }
.grid { stroke: var(--grid); stroke-width: 1; }
.axis { stroke: var(--axis); stroke-width: 1; }
.tick { fill: var(--text-muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.axis-label { fill: var(--text-muted); font-size: 11px; }
.line { fill: none; stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.line-ref { stroke-dasharray: 5 4; stroke-width: 1.5; }
.line-thin { stroke-width: 1.25; opacity: .85; }
.area { fill-opacity: .12; stroke: none; }
.dot { stroke: var(--surface); stroke-width: 2; }
.ref { stroke: var(--ref); stroke-width: 1.25; stroke-dasharray: 4 4; }
.ref-strong { stroke-dasharray: none; }
.ref-label, .mark-label { fill: var(--text-muted); font-size: 11px; }
.end-label { fill: var(--text); font-size: 11px; }
.band { fill: var(--band); }
.hair { stroke: var(--text-faint); stroke-width: 1; }
.hit { cursor: crosshair; outline: none; }
.seg { cursor: pointer; transition: opacity .12s; }
.seg:hover, .seg:focus { opacity: .82; outline: none; }
.seg-label { font-size: 11px; }
.seg-label.on-dark { fill: #ffffff; }
.seg-label.on-light { fill: #1c2024; }
.row-label { fill: var(--text); font-size: 12px; }
.bar-value { fill: var(--text); font-size: 12px; font-weight: 600; }
.tip { position: absolute; display: none; pointer-events: none; z-index: 5; background: var(--tip-bg); color: var(--tip-text); font-size: 12px; padding: 8px 10px;
  border: 1px solid rgba(255,255,255,.08); border-radius: 8px; box-shadow: 0 8px 24px rgba(0,0,0,.28); min-width: 150px; max-width: 260px; }
.tip-x { opacity: .7; margin-bottom: 4px; }
.tip-row { display: flex; align-items: center; gap: 8px; white-space: nowrap; }
.tip-row b { font-weight: 600; }
.tip-row span:last-child { opacity: .8; }
.tip .key-line { border-top-width: 2px; }

/* illustrations */
.illus-fig { padding: 12px 18px; }
svg.illus { display: block; width: 100%; height: auto; max-height: 360px; }
.ink-fill { fill: var(--surface-2); stroke: var(--text); stroke-width: 1.5; }
.ink-fill-2 { fill: var(--surface); stroke: var(--text); stroke-width: 1.5; }
.ink-thin { stroke: var(--text-muted); stroke-width: 1; }
.dim { stroke: var(--text-muted); stroke-width: 1; }
.dim-label, .illus-note { fill: var(--text-muted); font-size: 11px; }
.illus-title { fill: var(--text); font-size: 12px; font-weight: 600; }
.body { fill: var(--body); stroke: var(--body-line); stroke-width: 1.5; }
.body-2 { fill: var(--surface); stroke: var(--body-line); stroke-width: 1.2; }
.boom { stroke: var(--text-muted); stroke-width: 6; stroke-linecap: round; opacity: .5; }
.motor { fill: var(--s-mad); stroke: var(--text); stroke-width: 1.5; }
.motor-neutral { fill: var(--text-muted); stroke: var(--text); stroke-width: 1.5; }
.num-dot { fill: var(--surface); stroke: var(--accent); stroke-width: 1.5; }
.num-txt { fill: var(--text); font: 600 11px var(--font-mono); }
.prop { stroke: var(--text); stroke-width: 3; }
.prop-disc { fill: none; stroke: var(--text-faint); stroke-width: 1; stroke-dasharray: 3 3; }
.flow { fill: none; stroke: var(--flow); stroke-width: 1.6; }
.flow.faint { stroke: var(--text-faint); stroke-dasharray: 3 3; }
.flow-head { fill: var(--flow); }
.flow-head-faint { fill: var(--text-faint); }
.wake { fill: var(--band); stroke: none; }
.callout { fill: var(--text-muted); font-size: 11px; }
.callout-strong { fill: var(--text); font-size: 11px; font-weight: 600; }

/* scenario: full controls in the page, plus a fixed one-line bar once they have scrolled away. Never sticky: a sticky
   bar that changes height as it pins makes scroll anchoring bounce the page. */
.scenario { border-top: 2px solid var(--accent); border-bottom: 1px solid var(--border); }
.scen-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 10px; padding-top: 12px; font: 12px var(--font-mono); }
.scen-note { color: var(--text-muted); }
.scen-k { font-weight: 600; letter-spacing: .12em; text-transform: uppercase; color: var(--accent-text); }
.scen-pin { position: fixed; top: 0; left: 0; right: 0; z-index: 30; visibility: hidden; transform: translateY(-100%);
  transition: transform .18s ease, visibility 0s linear .18s;
  background: color-mix(in srgb, var(--bg) 94%, transparent); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  border-top: 2px solid var(--accent); border-bottom: 1px solid var(--border); }
.scen-pin.show { visibility: visible; transform: none; transition: transform .18s ease; }
.scen-pin.open { box-shadow: 0 12px 32px rgba(0,0,0,.18); }
.scen-toggle { display: flex; align-items: center; gap: 4px 10px; width: 100%; text-align: left; background: none; border: 0; color: var(--text); padding: 8px 0; font-size: 12px; cursor: pointer; min-height: 40px; }
.scen-toggle #scen-summary { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.scen-edit { flex: none; border: 1px solid var(--border); border-radius: 6px; padding: 2px 8px; text-transform: uppercase; letter-spacing: .06em; font-size: 11px; font-weight: 600; }
.scen-toggle:hover .scen-edit { border-color: var(--accent); color: var(--accent-text); }
.scen-pin:not(.open) .scen-pin-body { display: none; }
.scen-pin-body { max-height: calc(100vh - 52px); max-height: calc(100dvh - 52px); overflow-y: auto; overscroll-behavior: contain; }
.scen-body { display: flex; flex-wrap: wrap; gap: 8px 18px; padding: 10px 0 12px; font-size: 12px; align-items: flex-end; }
.ctl { display: flex; flex-direction: column; gap: 3px; min-width: 120px; }
.ctl label { color: var(--text-muted); font-size: 11px; letter-spacing: .04em; }
.ctl select, .ctl input[type=range] { font: 12px var(--font-mono); color: var(--text); background: var(--surface); border: 1px solid var(--border); border-radius: 6px; height: 32px; padding: 0 6px; }
.ctl select:hover { border-color: var(--border-strong); }
.ctl input[type=range] { padding: 0; accent-color: var(--accent); background: none; border: 0; width: 130px; }
.ctl .val { font-variant-numeric: tabular-nums; color: var(--text); }
.ctl-row { display: flex; align-items: center; gap: 8px; }

/* tables */
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 12px 0; }
table.data { border-collapse: collapse; font-size: 12px; min-width: 100%; font-variant-numeric: tabular-nums; }
table.data th, table.data td { padding: 8px 10px; border-bottom: 1px solid var(--border); text-align: right; white-space: nowrap; vertical-align: top; }
table.data thead th { font-weight: 600; color: var(--text-muted); border-bottom: 1px solid var(--border-strong); }
table.data th:first-child, table.data td:first-child { text-align: left; }
table.data tbody th { font-weight: 500; }
table.data td.best { font-weight: 700; }
table.data th .key { margin-right: 6px; }
table.data .sub { display: block; color: var(--text-muted); font-weight: 400; }
table.spec td, table.spec th { white-space: normal; }
table.spec td, table.spec thead th { text-align: left; }
table.spec td .key { margin-right: 6px; }

.readouts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 10px; margin: 0 0 12px; }
.readout { border: 1px solid var(--border); border-radius: 10px; padding: 10px 12px; background: var(--surface); font-size: 13px; }
.readout .tile-k { margin-bottom: 4px; }

ol.steps { padding-left: 24px; max-width: 860px; }
ol.steps li { margin: 0 0 14px; padding-left: 4px; }
ol.steps li::marker { color: var(--accent-text); font: 600 13px var(--font-mono); }
ol.steps li b { display: block; }
.cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 8px 32px; }
ol.qs, ul.method, ul.sources { padding-left: 20px; font-size: 14px; }
ol.qs li, ul.method li, ul.sources li { margin-bottom: 8px; }
ol.qs li::marker { color: var(--accent-text); font-family: var(--font-mono); }
ul.sources { font-size: 13px; }

/* footer: dark band with the logomark tile from arrowair.com */
.foot { margin-top: 48px; background:
    linear-gradient(rgba(82,123,210,.06) 1px, transparent 1px) 0 0 / 28px 28px,
    linear-gradient(90deg, rgba(82,123,210,.06) 1px, transparent 1px) 0 0 / 28px 28px,
    var(--brand-ink);
  color: #b0b4ba; font-size: 13px; }
.foot .hatch { background-color: var(--brand); height: 12px; background-position: 0 2px; }
.foot-row { display: flex; gap: 18px; align-items: flex-start; padding-top: 28px; padding-bottom: 44px; }
.foot-tile { flex: none; display: grid; place-items: center; width: 56px; height: 56px; border: 1px solid rgba(255,255,255,.16); border-radius: 10px; background: #00030a; }
.foot-tile img { display: block; width: 26px; height: auto; }
.foot-title { font: 600 12px var(--font-mono); letter-spacing: .1em; text-transform: uppercase; color: #fff; margin-bottom: 6px; }
.foot p { margin: 0 0 6px; max-width: 720px; }
.foot .small { color: #8b8d98; }
.foot-links { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 12px; }
.foot-links a { color: #fff; font: 600 12px var(--font-mono); letter-spacing: .06em; text-transform: uppercase; text-decoration: none; }
.foot-links a:hover { color: var(--brand-hatch); }

@media (max-width: 720px) {
  body { font-size: 15px; }
  .topbar-row { gap: 12px; }
  .crumb { display: none; }
  .hero { padding: 36px 0 32px; }
  .lede { font-size: 16px; }
  .mu-ctx { margin-left: 0; width: 100%; }
  .sec { padding-top: 36px; }
  .ctl { flex: 1 1 calc(50% - 9px); min-width: 0; }
  .ctl select { width: 100%; min-width: 0; }
  .ctl input[type=range] { width: 100%; }
  .fig { padding: 12px 10px 8px; margin-left: -6px; margin-right: -6px; }
}
@media (max-width: 380px) {
  .top-links .gh { display: none; }
}
@media print {
  .topbar, .scenario, .scen-pin, #theme, .fig-tools button, .foot .hatch { display: none; }
  body { background: #fff; }
  .hero, .foot { background: none; color: #000; border: 0; }
  .hero h1, .foot-title, .foot-links a { color: #000; }
  .lede, .meta, .mu, .mu-vs, .mu-ctx { color: #333; }
  .foot-tile { background: #0943bf; }
  .fig, .tile, .note { break-inside: avoid; }
}
@media (prefers-reduced-motion: reduce) {
  .scen-pin, .scen-pin.show { transition: none; }
}