/* landing.css — shared styling for QUANTHEON Lab's static SEO pages (guides, tools,
   the /learn library, conversion landings). Premium + modern to match the app: ink/neon
   palette, layered gradient ("aurora") background, glass cards with neon glow, Inter type.
   Standalone (no build step). The generator content-hashes the URL (/landing.css?v=…),
   so edits here always bust the CDN cache. */
:root {
  --ink-950: #0b0f1a; --ink-900: #0f1424; --ink-800: #151b2e;
  --cyan: #22d3ee; --blue: #60a5fa; --violet: #a855f7; --green: #34d399; --amber: #fbbf24; --pink: #fb7185;
  --slate-100: #e2e8f0; --slate-200: #cbd5e1; --slate-300: #b6c2d4; --slate-400: #94a3b8; --slate-500: #64748b; --slate-600: #475569;
  --line: rgba(255, 255, 255, 0.08); --glass: rgba(255, 255, 255, 0.035);
  --grad: linear-gradient(100deg, var(--cyan), var(--blue), var(--violet));
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; min-height: 100vh; position: relative; color: var(--slate-300); background: var(--ink-950);
  font-family: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.65; -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility;
}

/* Ambient gradient background (fixed): layered neon glows + a soft aurora mesh + a faint,
   masked grid. Static (no animation) — rich but calm for reading and good for Core Web Vitals. */
.bg { position: fixed; inset: 0; z-index: -1; pointer-events: none; overflow: hidden;
  background:
    radial-gradient(900px 540px at 10% -10%, rgba(34, 211, 238, 0.16), transparent 60%),
    radial-gradient(820px 500px at 100% -6%, rgba(168, 85, 247, 0.15), transparent 58%),
    radial-gradient(760px 620px at 50% 118%, rgba(52, 211, 153, 0.10), transparent 60%),
    var(--ink-950);
}
.bg::before { content: ""; position: absolute; inset: -25%;
  background: conic-gradient(from 200deg at 60% 30%, rgba(34, 211, 238, 0.12), rgba(96, 165, 250, 0.10), rgba(168, 85, 247, 0.12), rgba(52, 211, 153, 0.08), rgba(34, 211, 238, 0.12));
  filter: blur(130px); opacity: 0.5;
}
.bg::after { content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.022) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, 0.022) 1px, transparent 1px);
  background-size: 52px 52px;
  -webkit-mask-image: radial-gradient(ellipse 85% 55% at 50% 0%, #000 35%, transparent 80%);
  mask-image: radial-gradient(ellipse 85% 55% at 50% 0%, #000 35%, transparent 80%);
}

.wrap { max-width: 880px; margin: 0 auto; padding: 0 24px; }
.wrap-wide { max-width: 1180px; }
a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }

/* Header / footer */
.site-head { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid var(--line); background: rgba(11, 15, 26, 0.6); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); }
.site-foot { border-top: 1px solid var(--line); margin-top: 72px; }
.site-head .wrap, .site-foot .wrap { display: flex; align-items: center; gap: 16px; padding: 15px 24px; flex-wrap: wrap; max-width: 1180px; }
.brand { display: flex; align-items: center; gap: 7px; font-weight: 800; letter-spacing: -0.02em; font-size: 18px; color: var(--slate-100); }
.brand .q { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.brand .dot { color: var(--green); font-size: 11px; }
.nav { margin-left: auto; display: flex; gap: 20px; font-size: 14px; font-weight: 600; flex-wrap: wrap; }
.nav a { color: var(--slate-400); }
.nav a:hover { color: var(--cyan); text-decoration: none; }
.site-foot .wrap { color: var(--slate-500); font-size: 13px; }

/* Hero / headings */
.eyebrow { display: inline-block; text-transform: uppercase; letter-spacing: 0.2em; font-weight: 700; font-size: 12.5px; color: var(--violet); padding: 6px 13px; border: 1px solid var(--line); border-radius: 999px; background: var(--glass); }
h1 { color: var(--slate-100); font-size: clamp(34px, 5.2vw, 52px); line-height: 1.05; letter-spacing: -0.025em; font-weight: 800; margin: 20px 0 16px; }
h2 { color: var(--slate-100); font-size: clamp(23px, 3vw, 30px); letter-spacing: -0.01em; font-weight: 800; margin: 50px 0 14px; }
h3 { color: var(--slate-100); font-size: 18.5px; font-weight: 700; margin: 28px 0 8px; }
.lead { font-size: 20px; line-height: 1.6; color: var(--slate-200); max-width: 730px; }
main { padding: 56px 0 24px; }
p, li { font-size: 16.5px; }
li { margin-bottom: 6px; }
strong { color: var(--slate-100); }
em { color: var(--slate-200); }
hr { border: 0; border-top: 1px solid var(--line); margin: 48px 0; }
.muted { color: var(--slate-500); font-size: 13px; }

/* Cards / callouts */
.card { background: var(--glass); border: 1px solid var(--line); border-radius: 18px; padding: 24px; backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }
.grid { display: grid; gap: 16px; }
@media (min-width: 640px) { .grid.cols-2 { grid-template-columns: 1fr 1fr; } }

/* Buttons */
.btn { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; font-size: 15px; border-radius: 13px; padding: 13px 22px; cursor: pointer; border: 1px solid transparent; transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease; }
.btn-primary { color: #04121a; background: var(--grad); box-shadow: 0 10px 32px -12px rgba(34, 211, 238, 0.55); }
.btn-primary:hover { text-decoration: none; transform: translateY(-1px); filter: brightness(1.06); box-shadow: 0 14px 40px -12px rgba(34, 211, 238, 0.65); }
.btn-ghost { color: var(--slate-100); background: var(--glass); border-color: var(--line); }
.btn-ghost:hover { text-decoration: none; border-color: rgba(34, 211, 238, 0.4); color: #fff; }
.cta { margin-top: 30px; display: flex; gap: 12px; flex-wrap: wrap; }

/* Calculator widgets */
.calc { margin: 30px 0; }
.calc label { display: block; font-size: 13px; font-weight: 600; color: var(--slate-400); margin-bottom: 7px; }
.calc .row { margin-bottom: 18px; }
.calc input {
  width: 100%; background: rgba(8, 11, 20, 0.7); border: 1px solid var(--line); border-radius: 11px;
  color: var(--slate-100); font-size: 16px; padding: 12px 14px; font-variant-numeric: tabular-nums;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.calc input:focus { outline: none; border-color: rgba(34, 211, 238, 0.55); box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.12); }
.result { margin-top: 10px; display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; }
.result .big { font-size: 42px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }
.result .verdict { font-weight: 700; }
.v-good { color: var(--green); }
.v-mid { color: var(--amber); }
.v-bad { color: var(--pink); }

/* FAQ */
.faq details { border: 1px solid var(--line); border-radius: 13px; padding: 4px 18px; margin-bottom: 11px; background: var(--glass); transition: border-color 0.15s ease; }
.faq details[open] { border-color: rgba(34, 211, 238, 0.25); }
.faq summary { cursor: pointer; font-weight: 700; color: var(--slate-100); padding: 13px 0; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before { content: "+"; color: var(--cyan); font-weight: 800; display: inline-block; width: 18px; }
.faq details[open] summary::before { content: "–"; }
.faq p { margin: 0 0 15px; }

/* Library / hub cards (/learn, /guides, /tools) */
.lib-section-title { display: flex; align-items: center; gap: 12px; color: var(--slate-200); font-size: 12.5px; font-weight: 800; text-transform: uppercase; letter-spacing: 0.2em; margin: 46px 0 18px; }
.lib-section-title::after { content: ""; flex: 1; height: 1px; background: linear-gradient(90deg, var(--line), transparent); }
.lib-grid { display: grid; gap: 16px; grid-template-columns: 1fr; }
@media (min-width: 560px) { .lib-grid { grid-template-columns: repeat(auto-fill, minmax(310px, 1fr)); } }
.lib-card {
  position: relative; display: flex; gap: 15px; align-items: flex-start; padding: 20px;
  border: 1px solid var(--line); border-radius: 18px; background: var(--glass);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}
.lib-card:hover {
  transform: translateY(-4px); text-decoration: none;
  background: rgba(255, 255, 255, 0.05);
  border-color: color-mix(in srgb, var(--ic, var(--cyan)) 50%, transparent);
  box-shadow: 0 18px 50px -18px color-mix(in srgb, var(--ic, var(--cyan)) 60%, transparent);
}
.lib-ico {
  flex: 0 0 auto; width: 46px; height: 46px; display: grid; place-items: center; border-radius: 13px;
  color: var(--ic, var(--cyan));
  background: linear-gradient(150deg, color-mix(in srgb, var(--ic, var(--cyan)) 22%, transparent), color-mix(in srgb, var(--ic, var(--cyan)) 7%, transparent));
  border: 1px solid color-mix(in srgb, var(--ic, var(--cyan)) 34%, transparent);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.08);
}
.lib-ico svg { width: 22px; height: 22px; }
.lib-card-body { display: flex; flex-direction: column; gap: 5px; min-width: 0; }
.lib-card-title { color: var(--slate-100); font-weight: 700; font-size: 16.5px; }
.lib-card-desc { color: var(--slate-400); font-size: 14px; line-height: 1.55; }
.lib-card-meta { color: var(--slate-500); font-size: 11.5px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.07em; margin-top: 3px; }

/* =========================================================================
   Product-shot figures — crafted, on-brand "screenshots" for the end-to-end
   walkthroughs. Pure CSS/SVG (no raster assets): crisp at any size, weightless
   for Core Web Vitals, and always in-sync with the app's real look.
   ========================================================================= */
.fig { margin: 30px 0; }
.cap { color: var(--slate-500); font-size: 13px; text-align: center; margin-top: 12px; line-height: 1.5; }
.cap b { color: var(--slate-300); font-weight: 700; }

/* Numbered step marker (used inline + in legends) */
.mark { flex: 0 0 auto; display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 999px;
  font-size: 12px; font-weight: 800; color: #04121a; background: var(--grad);
  box-shadow: 0 4px 14px -4px rgba(34, 211, 238, 0.6); font-variant-numeric: tabular-nums; }
.legend { list-style: none; padding: 0; margin: 16px 0 0; display: grid; gap: 10px; }
@media (min-width: 640px) { .legend { grid-template-columns: 1fr 1fr; } }
.legend li { display: flex; gap: 11px; align-items: flex-start; font-size: 14.5px; color: var(--slate-300); margin: 0; }
.legend li b { color: var(--slate-100); }

/* The app window */
.shot { --sg: var(--cyan); border: 1px solid var(--line); border-radius: 18px; overflow: hidden;
  background: linear-gradient(180deg, var(--ink-900), var(--ink-950));
  box-shadow: 0 30px 80px -40px color-mix(in srgb, var(--sg) 55%, transparent), inset 0 1px 0 rgba(255, 255, 255, 0.05); }
.shot-top { display: flex; align-items: center; gap: 12px; padding: 11px 15px; border-bottom: 1px solid var(--line); background: rgba(255, 255, 255, 0.02); }
.shot-dots { display: flex; gap: 6px; }
.shot-dots i { width: 10px; height: 10px; border-radius: 999px; background: var(--slate-600); }
.shot-dots i:nth-child(1) { background: #fb7185; } .shot-dots i:nth-child(2) { background: #fbbf24; } .shot-dots i:nth-child(3) { background: #34d399; }
.shot-url { font-size: 12px; color: var(--slate-500); font-family: "JetBrains Mono", ui-monospace, monospace;
  background: rgba(8, 11, 20, 0.6); border: 1px solid var(--line); border-radius: 999px; padding: 4px 12px; }

/* Tab strip */
.shot-tabs { display: flex; gap: 4px; padding: 8px 10px 0; border-bottom: 1px solid var(--line); overflow-x: auto; }
.shot-tab { flex: 0 0 auto; font-size: 12.5px; font-weight: 700; color: var(--slate-400); padding: 8px 14px 10px;
  border-bottom: 2px solid transparent; white-space: nowrap; display: flex; align-items: center; gap: 7px; }
.shot-tab i { color: var(--slate-600); font-style: normal; font-weight: 800; font-size: 11px; }
.shot-tab.on { color: var(--slate-100); border-bottom-color: var(--sg); }
.shot-tab.on i { color: var(--sg); }

/* Two-pane body: research desk + artifact */
.shot-main { display: grid; grid-template-columns: 1fr; }
@media (min-width: 620px) { .shot-main.split { grid-template-columns: 215px 1fr; } }
.shot-desk { padding: 15px; display: flex; flex-direction: column; gap: 10px; border-bottom: 1px solid var(--line); background: rgba(8, 11, 20, 0.35); }
@media (min-width: 620px) { .shot-desk { border-bottom: 0; border-right: 1px solid var(--line); } }
.shot-desk-h { font-size: 11px; font-weight: 800; text-transform: uppercase; letter-spacing: 0.16em; color: var(--slate-500); display: flex; align-items: center; gap: 7px; }
.shot-desk-h::before { content: ""; width: 7px; height: 7px; border-radius: 999px; background: var(--green); box-shadow: 0 0 10px var(--green); }
.shot-art { padding: 18px; min-width: 0; }

/* Chat bubbles (WhatsApp green/grey, matching the app) */
.bub { max-width: 88%; font-size: 12.5px; line-height: 1.5; padding: 9px 12px; border-radius: 13px; color: var(--slate-200); }
.bub.me { margin-left: auto; background: rgba(52, 211, 153, 0.14); border: 1px solid rgba(52, 211, 153, 0.3); border-bottom-right-radius: 4px; color: var(--slate-100); }
.bub.ai { background: rgba(255, 255, 255, 0.06); border: 1px solid var(--line); border-bottom-left-radius: 4px; }
.receipt { display: flex; align-items: center; gap: 9px; font-size: 12px; color: var(--green); background: rgba(52, 211, 153, 0.1);
  border: 1px solid rgba(52, 211, 153, 0.28); border-radius: 10px; padding: 8px 11px; }
.receipt b { color: var(--slate-100); font-weight: 700; }
.receipt .undo { margin-left: auto; color: var(--slate-400); font-weight: 700; }
.chips { display: flex; flex-wrap: wrap; gap: 7px; }
.chip { font-size: 11.5px; font-weight: 600; color: var(--slate-200); background: var(--glass); border: 1px solid var(--line); border-radius: 999px; padding: 5px 11px; }
.chip.on { color: var(--cyan); border-color: rgba(34, 211, 238, 0.4); }

/* Node graph */
.flow { position: relative; border: 1px solid var(--line); border-radius: 14px; padding: 20px 16px;
  background-color: rgba(8, 11, 20, 0.5);
  background-image: linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px), linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 22px 22px; }
.node-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 8px; }
.node-row + .node-row { margin-top: 14px; }
.node { --nc: var(--cyan); display: inline-flex; flex-direction: column; gap: 1px; padding: 8px 13px; border-radius: 11px;
  background: linear-gradient(160deg, color-mix(in srgb, var(--nc) 18%, transparent), color-mix(in srgb, var(--nc) 6%, transparent));
  border: 1px solid color-mix(in srgb, var(--nc) 42%, transparent); box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06); }
.node b { color: var(--slate-100); font-size: 13px; font-weight: 700; }
.node span { color: var(--slate-400); font-size: 11px; font-variant-numeric: tabular-nums; }
.node.entry { --nc: var(--green); } .node.exit { --nc: var(--pink); } .node.ind { --nc: var(--cyan); }
.node.cond { --nc: var(--violet); } .node.risk { --nc: var(--amber); }
.arrow { color: var(--slate-600); font-weight: 800; }
.readback { margin-top: 14px; font-size: 13px; color: var(--slate-300); font-style: italic;
  border-left: 2px solid rgba(34, 211, 238, 0.5); padding: 4px 0 4px 12px; }
.readback b { color: var(--cyan); font-style: normal; }

/* Metric tiles */
.tiles { display: grid; grid-template-columns: repeat(auto-fit, minmax(96px, 1fr)); gap: 10px; }
.tile { background: rgba(8, 11, 20, 0.5); border: 1px solid var(--line); border-radius: 12px; padding: 11px 13px; }
.tile .k { font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em; color: var(--slate-500); }
.tile .v { font-size: 20px; font-weight: 800; color: var(--slate-100); font-variant-numeric: tabular-nums; letter-spacing: -0.01em; margin-top: 3px; }
.tile .v.pos { color: var(--green); } .tile .v.neg { color: var(--pink); }

/* Overfitting Polygraph: three checks + a verdict */
.checks { display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr)); gap: 10px; }
.check { background: rgba(8, 11, 20, 0.5); border: 1px solid var(--line); border-radius: 12px; padding: 12px 13px; }
.check .k { font-size: 11px; font-weight: 700; color: var(--slate-300); }
.check .s { font-size: 12px; color: var(--slate-500); margin-top: 4px; display: flex; align-items: center; gap: 6px; }
.check .s::before { content: ""; width: 7px; height: 7px; border-radius: 999px; background: currentColor; }
.check.ok .s { color: var(--green); } .check.warn .s { color: var(--amber); } .check.bad .s { color: var(--pink); }
.verdict-pill { --vc: var(--amber); display: flex; align-items: center; gap: 14px; margin-top: 12px; padding: 14px 18px; border-radius: 14px;
  background: linear-gradient(120deg, color-mix(in srgb, var(--vc) 16%, transparent), transparent);
  border: 1px solid color-mix(in srgb, var(--vc) 45%, transparent); }
.verdict-pill .badge { font-size: 12px; font-weight: 800; text-transform: uppercase; letter-spacing: 0.14em; color: var(--vc);
  border: 1px solid color-mix(in srgb, var(--vc) 55%, transparent); border-radius: 999px; padding: 6px 13px; white-space: nowrap; }
.verdict-pill .txt { font-size: 13px; color: var(--slate-300); }
.verdict-pill .txt b { color: var(--slate-100); }
.verdict-pill.trust { --vc: var(--green); } .verdict-pill.fragile { --vc: var(--amber); } .verdict-pill.curve { --vc: var(--pink); }

/* Portfolio: holdings, attribution, allocation band */
.holds { display: grid; gap: 9px; }
.hold { display: grid; grid-template-columns: 58px 1fr 46px; align-items: center; gap: 11px; }
.hold .tkr { font-weight: 800; font-size: 13px; color: var(--slate-100); font-family: "JetBrains Mono", ui-monospace, monospace; }
.hold .track { display: block; height: 9px; border-radius: 999px; background: rgba(255, 255, 255, 0.06); overflow: hidden; }
.hold .fill { display: block; height: 100%; border-radius: 999px; background: var(--grad); }
.hold .pct { text-align: right; font-size: 12.5px; font-weight: 700; color: var(--slate-300); font-variant-numeric: tabular-nums; }
.alloc { display: flex; height: 46px; border-radius: 12px; overflow: hidden; border: 1px solid var(--line); }
.lane { display: grid; place-items: center; font-size: 11px; font-weight: 800; color: #04121a; min-width: 0; }
.lane span { padding: 0 4px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

/* Bottom stepper dock */
.dock { display: flex; align-items: center; gap: 10px; padding: 12px 15px; border-top: 1px solid var(--line); background: rgba(255, 255, 255, 0.02); }
.dock .d-btn { font-size: 12.5px; font-weight: 700; color: var(--slate-300); border: 1px solid var(--line); border-radius: 10px; padding: 8px 14px; background: var(--glass); }
.dock .d-btn.ghosted { color: var(--slate-600); }
.dock .d-cta { margin: 0 auto; font-size: 12.5px; font-weight: 800; color: #04121a; background: var(--grad); border-radius: 10px; padding: 9px 20px;
  box-shadow: 0 8px 24px -10px rgba(34, 211, 238, 0.6); }
.shot.violet { --sg: var(--violet); } .shot.green { --sg: var(--green); }

/* Real product screenshots (the two walkthrough guides): a real WebP dropped
   inside the SAME browser-frame chrome as the CSS mockups above, so the whole
   Learn library still reads as one system. Captured from the live app by
   seo/screenshots/capture.mjs — re-run it whenever the workbench UI changes. */
.shot-img { display: block; width: 100%; height: auto; border: 0; background: var(--ink-950); }
.fig.tight { max-width: 480px; margin-left: auto; margin-right: auto; }

/* "Keep reading" — the related-pages block generated at the foot of every content page
   (build.mjs renderRelated). Reuses .lib-grid/.lib-card so the library reads as one system;
   the rule here is only the separation from the article above it. */
.rel-h { margin: 52px 0 18px; padding-top: 26px; border-top: 1px solid var(--line);
  font-size: 12.5px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.2em;
  color: var(--slate-500); }

/* ---------------------------------------------------------------------------
   Legal pages (/privacy, /terms). They used to be hand-written HTML carrying their
   OWN copy of the brand tokens inline, linked from every footer and drifting from
   the design system in silence. They are generated pages now; these are the few
   element styles their bodies need that the library did not already have.
   --------------------------------------------------------------------------- */
.updated { color: var(--slate-500); font-size: 13px; margin-top: -6px; }
.pagenav { margin: 14px 0 26px; }
.pagenav a { color: var(--cyan); font-weight: 600; font-size: 14px; }
.lede { color: var(--slate-200); font-size: 17px; line-height: 1.7; }
main table { width: 100%; border-collapse: collapse; margin: 18px 0 26px; font-size: 14.5px; }
main table th { text-align: left; color: var(--slate-400); font-size: 11.5px; text-transform: uppercase;
  letter-spacing: 0.12em; padding: 0 12px 8px 0; border-bottom: 1px solid var(--line); }
main table td { padding: 11px 12px 11px 0; border-bottom: 1px solid var(--line);
  color: var(--slate-300); vertical-align: top; }
main table td.key { color: var(--slate-100); font-weight: 600; white-space: nowrap; }
.alert { border: 1px solid var(--line); border-left: 3px solid var(--amber); background: var(--glass);
  border-radius: 10px; padding: 14px 16px; margin: 18px 0; color: var(--slate-200); }
.alert .h { display: block; color: var(--amber); font-weight: 700; margin-bottom: 4px; }

/* ---------------------------------------------------------------------------
   CONCEPTUAL SCHEMATICS — a shared visual language for "how the mechanism works".

   The rule, borrowed from the in-app #vibecoded page which settled it first: a
   schematic is LAID OUT, never hand-drawn. No counted box characters, no absolute
   pixel positions, no SVG whose text a screen reader cannot reach. Flow direction
   is horizontal on a wide screen and vertical on a narrow one, and the arrow glyph
   follows automatically — so a diagram cannot go crooked, cannot overflow, and reads
   as prose when styling is unavailable.

   Two primitives cover every case so far:
     .schema        a flow of nodes, left to right (or top to bottom on mobile)
     .schema-vs     two panels contrasting the wrong way with the right one
   Both accept an optional .schema-cap caption. Reuse them — a page that invents its
   own diagram markup is how the library stops looking like one system.
   --------------------------------------------------------------------------- */
.schema { margin: 22px 0 26px; }
.schema-flow { display: flex; align-items: stretch; gap: 8px; flex-wrap: nowrap; }
.schema-node { flex: 1 1 0; min-width: 0; border: 1px solid var(--line); background: var(--glass);
  border-radius: 12px; padding: 12px 12px 11px; text-align: center; }
.schema-node .k { display: block; color: var(--slate-100); font-weight: 700; font-size: 13.5px; line-height: 1.3; }
.schema-node .v { display: block; margin-top: 4px; color: var(--slate-400); font-size: 12px; line-height: 1.4; }
.schema-node .t { display: block; margin-bottom: 3px; color: var(--cyan); font-size: 9.5px;
  font-weight: 700; text-transform: uppercase; letter-spacing: 0.14em; }
/* The one node that matters most on the page carries the accent. */
.schema-node.hot { border-color: rgba(34, 211, 238, 0.45); background: rgba(34, 211, 238, 0.06);
  box-shadow: 0 0 26px -10px rgba(34, 211, 238, 0.55); }
.schema-node.soft { border-style: dashed; background: transparent; }
.schema-node.out { border-color: rgba(52, 211, 153, 0.45); background: rgba(52, 211, 153, 0.06); }
.schema-node.out .t { color: var(--green); }
/* Arrows are generated, so the markup carries meaning and never punctuation. */
/* A node may be a link — then it doubles as the page's table of contents. */
a.schema-node { text-decoration: none; transition: border-color 0.15s ease, transform 0.15s ease; }
a.schema-node:hover { text-decoration: none; border-color: rgba(34, 211, 238, 0.5); transform: translateY(-1px); }
.schema-arrow { flex: 0 0 auto; align-self: center; color: rgba(34, 211, 238, 0.55); font-size: 15px; line-height: 1; }
.schema-arrow::before { content: "\2192"; }
.schema-cap { margin-top: 10px; color: var(--slate-500); font-size: 12.5px; line-height: 1.55; }
.schema-cap b { color: var(--slate-300); font-weight: 600; }

.schema-vs { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.schema-vs > div { border: 1px solid var(--line); background: var(--glass); border-radius: 14px; padding: 15px 16px; }
.schema-vs .h { display: block; font-weight: 700; font-size: 13.5px; margin-bottom: 8px; }
.schema-vs ul { margin: 0; padding-left: 18px; }
.schema-vs li { font-size: 13.5px; line-height: 1.6; color: var(--slate-300); }
.schema-vs .no { border-left: 3px solid var(--amber); }
.schema-vs .no .h { color: var(--amber); }
.schema-vs .yes { border-left: 3px solid var(--green); }
.schema-vs .yes .h { color: var(--green); }

/* Narrow screens: the flow turns vertical and the arrow turns with it. Nothing to
   re-author per page — the same markup serves both. */
@media (max-width: 720px) {
  .schema-flow { flex-direction: column; }
  .schema-arrow { align-self: center; }
  .schema-arrow::before { content: "\2193"; }
  .schema-vs { grid-template-columns: 1fr; }
}