/* Layout: a ~66ch reading column; figures break out wide onto dark "darkroom" stages; every control is an engraved lens ring */
:root {
  --paper: #eef1f5;
  --paper-2: #e2e7ee;
  --ink: #121720;
  --ink-2: #4b5567;
  --rule: #c8d0dc;
  --accent: #a35f00;
  --index: #d8323a;
  --chip-on-bg: #121720;
  --chip-on-fg: #f3f5f8;
  --stage: #090c12;
  --stage-edge: #1b2230;
  --stage-text: #8c98ad;
  --stage-hi: #e8ecf4;
  --light: #ffc35a;
  --glass: #7cc6ff;
  --font-display: "Unbounded", "Arial Black", "Helvetica Neue", sans-serif;
  --font-body: "Literata", "Iowan Old Style", Georgia, "Times New Roman", serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --wide: 74rem;
  --measure: var(--wide);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0b0e14;
    --paper-2: #151a24;
    --ink: #e6eaf1;
    --ink-2: #97a2b4;
    --rule: #252d3c;
    --accent: #ffbe55;
    --index: #ff5a5f;
    --chip-on-bg: #e6eaf1;
    --chip-on-fg: #0b0e14;
    --stage-edge: #232c3d;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0b0e14;
  --paper-2: #151a24;
  --ink: #e6eaf1;
  --ink-2: #97a2b4;
  --rule: #252d3c;
  --accent: #ffbe55;
  --index: #ff5a5f;
  --chip-on-bg: #e6eaf1;
  --chip-on-fg: #0b0e14;
  --stage-edge: #232c3d;
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.1875rem;
  line-height: 1.62;
  font-optical-sizing: auto;
  -webkit-font-smoothing: antialiased;
}
main { padding-inline: 20px; padding-block: 0 6rem; }

/* ---------- type ---------- */
h1, h2, h3 { font-family: var(--font-display); text-wrap: balance; margin: 0; }
h2 {
  font-weight: 600;
  font-size: clamp(1.55rem, 1.1rem + 1.6vw, 2.15rem);
  line-height: 1.12;
  letter-spacing: -0.015em;
}
p { margin: 0; }
.prose { max-width: var(--measure); margin-inline: auto; display: grid; gap: 1.05em; }
.prose em { font-style: italic; }
.prose strong { font-weight: 650; }
.prose .formula {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--paper-2);
  border-radius: 6px;
  padding: 0.08em 0.4em;
  white-space: nowrap;
}
.prose .note { font-size: 0.88em; color: var(--ink-2); }
.k { /* key term */
  font-weight: 650;
  background-image: linear-gradient(transparent 62%, color-mix(in srgb, var(--accent) 22%, transparent) 62%);
}

/* ---------- hero ---------- */
.hero { max-width: var(--wide); margin-inline: auto; padding-block: clamp(2.5rem, 6vw, 5rem) 1.5rem; display: grid; gap: 1.4rem; }
.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-2);
  display: flex; gap: 0.9em; align-items: center; flex-wrap: wrap;
}
.lang-switch {
  margin-left: auto; text-transform: none; letter-spacing: 0.02em; color: var(--ink); text-decoration: none;
  border: 1px solid var(--rule); border-radius: 999px; padding: 0.35em 0.9em;
}
.lang-switch:hover { border-color: var(--accent); }
.lang-switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.eyebrow .dot { width: 0.55em; height: 0.55em; border-radius: 50%; background: var(--index); display: inline-block; }
.hero h1 {
  font-weight: 700;
  font-size: clamp(2.5rem, 1.2rem + 6vw, 5.4rem);
  line-height: 0.98;
  letter-spacing: -0.035em;
  max-width: 12ch;
}
.hero .lede { font-size: 1.22rem; color: var(--ink-2); }
.cover { margin: 0.6rem 0 0; display: grid; gap: 10px; }
.cover-frame { overflow: hidden; border-radius: 16px; border: 1px solid var(--stage-edge); background: var(--stage); }
.cover img { display: block; width: 100%; max-width: 100%; height: auto; aspect-ratio: 2400 / 1018; transform-origin: 50% 45%; }
.cover figcaption { font-size: 0.86rem; line-height: 1.45; color: var(--ink-2); }
.hero-stage { aspect-ratio: 21 / 8; min-height: 240px; }

/* ---------- chapters ---------- */
.chapter { padding-top: clamp(3rem, 7vw, 5.5rem); }
#inside { padding-top: clamp(1.5rem, 3vw, 2.5rem); }
.chapter-head { max-width: var(--measure); margin-inline: auto; display: grid; gap: 0.7rem; margin-bottom: 1.4rem; }
.stop {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 0.86rem;
  letter-spacing: 0.04em;
  color: var(--accent);
  display: flex; align-items: center; gap: 0.7rem;
}
.stop::after { content: ""; height: 1px; flex: 1; background: var(--rule); }

/* ---------- figures ---------- */
.fig { width: 100%; max-width: var(--wide); margin: 2.2rem auto 2.6rem; display: grid; gap: 14px; }
.stage {
  position: relative;
  background:
    radial-gradient(120% 90% at 50% 40%, #111725 0%, var(--stage) 70%);
  border: 1px solid var(--stage-edge);
  border-radius: 16px;
  overflow: hidden;
  color: var(--stage-text);
  isolation: isolate;
}
.stage > canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; touch-action: pan-y pinch-zoom; }
.ar-3-1 { aspect-ratio: 3 / 1; }
.ar-2-1 { aspect-ratio: 2 / 1; }
.ar-3-2 { aspect-ratio: 3 / 2; }
.ar-21-9 { aspect-ratio: 21 / 9; }
.ar-16-9 { aspect-ratio: 16 / 9; }
.ar-16-10 { aspect-ratio: 16 / 10; }
.ar-4-3 { aspect-ratio: 4 / 3; }
.ar-1-1 { aspect-ratio: 1 / 1; }
@media (max-width: 640px) {
  .ar-2-1, .ar-21-9, .ar-16-9, .ar-16-10 { aspect-ratio: 4 / 3; }
  .ar-3-1 { aspect-ratio: 16 / 10; }
}
.stage-tag {
  position: absolute; left: 14px; top: 12px; z-index: 2;
  font: 500 11px/1.3 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--stage-text); pointer-events: none;
}
.stage-hint {
  position: absolute; right: 14px; top: 12px; z-index: 2;
  font: 500 11px/1.3 var(--font-mono); letter-spacing: 0.06em;
  color: #6f7b90; pointer-events: none;
}
.fig figcaption {
  max-width: var(--measure); margin-inline: auto; width: 100%;
  font-size: 0.92rem; line-height: 1.5; color: var(--ink-2);
}
.fig figcaption b { font-family: var(--font-mono); font-weight: 600; font-size: 0.8rem; letter-spacing: 0.06em; color: var(--ink); margin-right: 0.5em; text-transform: uppercase; }

.panel-row { display: grid; gap: 14px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 900px) {
  .panel-row.split-2-1 { grid-template-columns: minmax(0, 1.75fr) minmax(0, 1fr); }
  .panel-row.split-1-1 { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .panel-row.split-1-2 { grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.6fr); }
}

/* ---------- controls ---------- */
.controls { display: grid; gap: 14px 18px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 15.5rem), 1fr)); align-items: end; }
.ring { display: grid; gap: 7px; min-width: 0; }
.ring-head { display: flex; justify-content: space-between; align-items: baseline; gap: 10px; }
.ring-label {
  font: 500 0.72rem/1.2 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2);
}
.ring-value {
  font: 600 0.98rem/1.2 var(--font-mono); color: var(--ink); font-variant-numeric: tabular-nums; white-space: nowrap;
}
.ring-body {
  position: relative; height: 58px; border-radius: 11px;
  background: #15191f;
  box-shadow: 0 1px 0 rgba(255,255,255,0.05) inset, 0 6px 14px -8px rgba(0,0,0,0.55);
  cursor: grab; touch-action: pan-y; user-select: none; -webkit-user-select: none;
  outline: none;
}
.ring-body.grabbing { cursor: grabbing; }
.ring-body canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; border-radius: inherit; }
.ring-body:focus-visible { box-shadow: 0 0 0 2px var(--paper), 0 0 0 4px var(--accent); }

.chips-wrap { display: grid; gap: 7px; min-width: 0; }
.chips { display: flex; flex-wrap: wrap; gap: 4px; padding: 4px; border-radius: 12px; background: var(--paper-2); width: fit-content; max-width: 100%; }
.chip {
  font: 500 0.8rem/1 var(--font-mono); letter-spacing: 0.02em;
  padding: 0.62em 0.85em; border-radius: 8px; border: 0;
  background: transparent; color: var(--ink-2); cursor: pointer;
  transition: background-color 0.15s, color 0.15s;
}
.chip:hover { color: var(--ink); }
.chip[aria-pressed="true"] { background: var(--chip-on-bg); color: var(--chip-on-fg); }
.chip:focus-visible, .btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn {
  font: 600 0.8rem/1 var(--font-mono); letter-spacing: 0.06em; text-transform: uppercase;
  display: inline-flex; align-items: center; gap: 0.6em;
  padding: 0.85em 1.1em; border-radius: 10px; border: 1px solid var(--rule);
  background: var(--paper); color: var(--ink); cursor: pointer;
}
.btn:hover { border-color: var(--ink-2); }
.btn .led { width: 0.6em; height: 0.6em; border-radius: 50%; background: var(--index); box-shadow: 0 0 0 3px color-mix(in srgb, var(--index) 25%, transparent); }
.btn.shutter { background: var(--chip-on-bg); color: var(--chip-on-fg); border-color: transparent; }

/* ---------- readouts ---------- */
.readouts { display: flex; flex-wrap: wrap; gap: 6px 22px; font-family: var(--font-mono); font-size: 0.82rem; color: var(--ink-2); font-variant-numeric: tabular-nums; }
.readouts span b { color: var(--ink); font-weight: 600; }
.formula-live {
  font-family: var(--font-mono); font-size: 0.95rem; color: var(--ink);
  background: var(--paper-2); border-radius: 10px; padding: 0.7em 1em;
  font-variant-numeric: tabular-nums; display: flex; flex-wrap: wrap; gap: 0.3em 1.4em;
}
.formula-live > span { white-space: nowrap; }
@media (max-width: 640px) { .formula-live { font-size: 0.82rem; } .formula-live > span { white-space: normal; } }
.legend { display: flex; flex-wrap: wrap; gap: 6px 18px; font: 0.8rem/1.4 var(--font-mono); color: var(--ink-2); }
.legend i { display: inline-block; width: 18px; height: 3px; border-radius: 2px; vertical-align: middle; margin-right: 6px; }

/* ---------- 3D lens ---------- */
.hotspots { position: absolute; inset: 0; pointer-events: none; z-index: 3; }
.hotspot {
  position: absolute; width: 24px; height: 24px; margin: -12px 0 0 -12px; padding: 0;
  border-radius: 50%; border: 1.5px solid rgba(255,255,255,0.88); background: rgba(9,12,18,0.72);
  color: #fff; font: 600 11px/21px var(--font-mono); text-align: center;
  pointer-events: auto; cursor: pointer; box-shadow: 0 2px 8px rgba(0,0,0,0.45);
  transition: transform 0.15s, background-color 0.15s, color 0.15s;
}
.hotspot:hover, .hotspot.on { background: var(--light); border-color: var(--light); color: #14110a; transform: scale(1.18); }
.hotspot:focus-visible { outline: 2px solid var(--light); outline-offset: 3px; }
.parts { list-style: none; margin: 0; padding: 0; display: grid; gap: 1px; }
.parts button {
  width: 100%; display: flex; gap: 10px; align-items: baseline; text-align: left;
  background: none; border: 0; border-radius: 8px; padding: 0.42em 0.6em; cursor: pointer;
  font: 500 0.8rem/1.25 var(--font-mono); color: var(--ink-2);
}
.parts button b { min-width: 1.7em; color: var(--accent); font-weight: 600; }
.parts button:hover { color: var(--ink); background: var(--paper-2); }
.parts button[aria-pressed="true"] { background: var(--chip-on-bg); color: var(--chip-on-fg); }
.parts button[aria-pressed="true"] b { color: inherit; }
.parts button:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.part-card { background: var(--paper-2); border-radius: 12px; padding: 0.9rem 1rem; display: grid; gap: 0.4rem; }
.part-card h3 { font: 600 0.98rem/1.25 var(--font-display); display: flex; gap: 0.6em; align-items: baseline; }
.part-card h3 b { font: 600 0.8rem/1 var(--font-mono); color: var(--accent); }
.part-card p { font-size: 0.9rem; line-height: 1.5; color: var(--ink); }
.part-card a { color: var(--accent); }
@media (max-width: 899px) {
  .parts { grid-template-columns: repeat(auto-fill, minmax(min(100%, 9.6rem), 1fr)); }
}

/* ---------- narrated tour ---------- */
.tour-launch {
  justify-self: start; display: inline-flex; align-items: center; gap: 12px; margin-top: 0.3rem;
  padding: 0.55rem 1.1rem 0.55rem 0.55rem; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--rule); background: var(--paper-2); color: var(--ink); text-align: left;
}
.tour-launch:hover { border-color: var(--accent); }
.tour-launch:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.tour-launch-icon { width: 38px; height: 38px; border-radius: 50%; background: var(--accent); display: grid; place-items: center; flex: none; }
.tour-launch-icon svg { width: 18px; height: 18px; fill: var(--paper); margin-left: 2px; }
.tour-launch b { display: block; font: 600 0.92rem/1.2 var(--font-display); }
.tour-launch small { display: block; font: 500 0.76rem/1.3 var(--font-mono); color: var(--ink-2); }
.tour-from {
  justify-self: start; display: inline-flex; align-items: center; gap: 8px; padding: 0.4rem 0.8rem 0.4rem 0.6rem;
  border-radius: 999px; border: 1px solid var(--rule); background: transparent; color: var(--ink-2); cursor: pointer;
  font: 500 0.78rem/1.2 var(--font-mono);
}
.tour-from svg { width: 14px; height: 14px; fill: var(--accent); }
.tour-from:hover { color: var(--ink); border-color: var(--accent); }
.tour-from:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.tour-main > .cover { margin: 0; display: grid; gap: 8px; }
.tour-main > .cover figcaption { font-size: 0.8rem; color: var(--ink-2); }
body.touring { overflow: hidden; }
body.touring main { display: none; }
.tour {
  --paper: #0b0e14; --paper-2: #161b26; --ink: #e6eaf1; --ink-2: #97a2b4; --rule: #252d3c;
  --accent: #ffbe55; --index: #ff5a5f; --chip-on-bg: #e6eaf1; --chip-on-fg: #0b0e14; --stage-edge: #232c3d;
  color-scheme: dark;
  position: fixed; inset: 0; z-index: 50;
  display: grid; grid-template-rows: auto minmax(0, 1fr) auto auto; gap: 12px;
  padding: calc(16px + env(safe-area-inset-top, 0px)) clamp(16px, 3vw, 48px) calc(12px + env(safe-area-inset-bottom, 0px));
  background: radial-gradient(120% 100% at 50% 25%, #121828 0%, #07090e 72%);
  color: var(--ink);
}
.tour-head { display: flex; align-items: baseline; gap: 14px; min-width: 0; }
.tour-stop { font: 500 0.95rem/1 var(--font-display); color: var(--accent); }
.tour-title { font: 600 clamp(1.15rem, 2vw, 1.9rem)/1.1 var(--font-display); letter-spacing: -0.01em; }
.tour-count { font: 500 0.78rem/1 var(--font-mono); color: var(--ink-2); }
.tour-brand { margin-left: auto; font: 500 0.72rem/1 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); white-space: nowrap; }
.tour-main { position: relative; min-height: 0; display: grid; place-items: center; overflow: hidden; }
.tour-main > .fig { margin: 0; max-width: none; }
.tour-main > .fig > figcaption { display: none; }
.tour-sub { min-height: 3.1em; display: grid; place-items: center; text-align: center; font-size: clamp(1rem, 1.75vw, 1.6rem); }
.tour-sub p { max-width: 60rem; font-family: var(--font-body); line-height: 1.38; text-wrap: balance; text-shadow: 0 2px 10px rgba(0,0,0,0.6); }
.tour-bar { display: flex; align-items: center; gap: 10px; min-width: 0; }
.tour-btn {
  width: 40px; height: 40px; flex: none; display: grid; place-items: center; padding: 0;
  border-radius: 50%; border: 1px solid var(--rule); background: var(--paper-2); color: var(--ink); cursor: pointer;
}
.tour-btn svg { width: 18px; height: 18px; fill: currentColor; }
.tour-btn.tour-play { width: 48px; height: 48px; background: var(--accent); border-color: transparent; color: #14110a; }
.tour-btn:hover { border-color: var(--ink-2); }
.tour-btn:focus-visible, .tour-prog:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.tour-prog { flex: 1; min-width: 60px; height: 8px; border-radius: 4px; background: var(--paper-2); cursor: pointer; position: relative; }
.tour-prog i { position: absolute; left: 0; top: 0; bottom: 0; width: 0; background: var(--accent); border-radius: inherit; }
.tour-time { font: 500 0.8rem/1 var(--font-mono); color: var(--ink-2); font-variant-numeric: tabular-nums; white-space: nowrap; }
.tour-note { font: 500 0.75rem/1.2 var(--font-mono); color: var(--accent); }
.tour-note:empty { display: none; }
.tour-spot { outline: 3px solid var(--accent); outline-offset: 5px; border-radius: 14px; animation: tour-spot 1.4s ease-in-out infinite; }
@keyframes tour-spot { 50% { outline-color: color-mix(in srgb, var(--accent) 30%, transparent); } }
.recording *, .recording *::before, .recording *::after { transition: none !important; animation: none !important; }
.recording .tour-bar { display: none; }
.recording .tour { padding-bottom: 28px; }
@media (max-width: 640px) {
  .tour { gap: 8px; }
  .tour-main { overflow-y: auto; place-items: start center; }
  .tour-brand, .tour-time { display: none; }
}
@media (prefers-reduced-motion: reduce) { .tour-spot { animation: none; } }

/* ---------- photo ---------- */
.photo {
  position: relative; aspect-ratio: 3 / 2; max-width: 100%;
  border-radius: 12px; overflow: hidden; background: #05070b;
  border: 1px solid var(--stage-edge); isolation: isolate;
}
.photo .layers { position: absolute; inset: 0; }
.photo .layers canvas { position: absolute; display: block; pointer-events: none; }
.photo .layers canvas.light { mix-blend-mode: screen; }
.photo .vignette { position: absolute; inset: 0; pointer-events: none; background: radial-gradient(120% 120% at 50% 50%, transparent 45%, rgba(0,0,0,0.85) 100%); opacity: 0; }
.photo .flash { position: absolute; inset: 0; background: #fff; opacity: 0; pointer-events: none; }
.photo .hud {
  position: absolute; left: 10px; right: 10px; bottom: 9px; display: flex; justify-content: space-between; gap: 10px;
  font: 500 11px/1.2 var(--font-mono); letter-spacing: 0.04em; color: rgba(255,255,255,0.82);
  text-shadow: 0 1px 3px rgba(0,0,0,0.8); pointer-events: none;
}
.photo .af {
  position: absolute; width: 46px; height: 34px; margin: -17px 0 0 -23px; pointer-events: none;
  border: 1.5px solid rgba(255,255,255,0.9); border-radius: 3px; opacity: 0; transition: opacity 0.4s;
  box-shadow: 0 0 0 1px rgba(0,0,0,0.25);
}
.photo .af.on { opacity: 1; }
.photo .af.ok { border-color: #63e6a1; }
.photo.clickable { cursor: crosshair; }

.filmstrip { display: flex; gap: 10px; overflow-x: auto; padding-bottom: 4px; min-height: 0; }
.filmstrip:empty::before { content: attr(data-empty); font: 0.8rem/1.4 var(--font-mono); color: var(--ink-2); }
.shot { flex: 0 0 auto; width: 168px; display: grid; gap: 4px; font: 0.72rem/1.35 var(--font-mono); color: var(--ink-2); }
.shot canvas { width: 168px; height: 112px; border-radius: 6px; display: block; border: 1px solid var(--rule); }

.side { display: grid; gap: 12px; align-content: start; min-width: 0; }
.mini-title { font: 500 0.72rem/1.2 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }

.toc { max-width: var(--measure); margin: 0 auto; display: flex; flex-wrap: wrap; gap: 6px 8px; padding: 0; list-style: none; }
.toc a {
  display: inline-flex; gap: 0.5em; align-items: baseline; text-decoration: none; color: var(--ink-2);
  font: 0.8rem/1 var(--font-mono); padding: 0.55em 0.75em; border-radius: 8px; background: var(--paper-2);
}
.toc a span { color: var(--accent); }
.toc a:hover { color: var(--ink); }
.toc a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

footer.end { max-width: var(--measure); margin: 4rem auto 0; padding-top: 1.4rem; border-top: 1px solid var(--rule); font-size: 0.9rem; color: var(--ink-2); display: grid; gap: 0.6em; }

@media (max-width: 640px) {
  body { font-size: 1.06rem; }
  main { padding-inline: 16px; }
  .hero-stage { aspect-ratio: 4 / 3; }
  .ring-body { height: 54px; }
  .stage-hint { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
  .chip { transition: none; }
}

/* Site chrome shared by every page of raycat.org (explainers included): top bar, footer,
   buttons and banner slots. Colours and fonts come from the explainer tokens
   (camera-lens/src/style.css); every class is prefixed so explainers' own styles stay untouched. */
:root { --rc-head: #121720; --rc-dark: #090c12; --rc-dark-2: #111622; --rc-dark-edge: #1d2534; --rc-dark-text: #8c98ad; --rc-dark-hi: #e8ecf4; --rc-amber: #ffc35a; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) { --rc-head: #2b3447; }
}
:root[data-theme="dark"] { --rc-head: #2b3447; }

.rc-sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.rc-mark { display: block; flex: none; overflow: visible; }

/* ---------- top bar ---------- */
.rc-bar { padding-inline: 20px; border-bottom: 1px solid var(--rule); background: var(--paper); }
.rc-bar-in {
  max-width: var(--wide); margin-inline: auto;
  display: flex; align-items: center; flex-wrap: wrap; gap: 10px 26px;
  padding-block: 12px;
}
.rc-home {
  display: inline-flex; align-items: center; gap: 0.3em;
  font: 600 1.32rem/1 var(--font-display); letter-spacing: -0.03em;
  color: var(--ink); text-decoration: none;
}
.rc-home .rc-mark { width: 1.2em; height: 1.2em; }
.rc-home b { font-weight: inherit; color: var(--accent); }
.rc-nav { display: flex; flex-wrap: wrap; gap: 4px 22px; font: 500 0.76rem/1.2 var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; }
.rc-nav a { color: var(--ink-2); text-decoration: none; padding-block: 6px; }
.rc-nav a:hover { color: var(--ink); }
.rc-tools { margin-left: auto; display: flex; align-items: center; gap: 8px; }
.rc-ask, .rc-lang {
  font: 600 0.78rem/1 var(--font-mono); letter-spacing: 0.02em; text-decoration: none; white-space: nowrap;
  border-radius: 999px; padding: 0.62em 1em; border: 1px solid var(--rule); color: var(--ink);
}
.rc-ask { border-color: var(--accent); color: var(--accent); }
.rc-ask:hover { background: var(--accent); color: var(--paper); }
.rc-lang:hover { border-color: var(--ink-2); }
.rc-home:focus-visible, .rc-nav a:focus-visible, .rc-ask:focus-visible, .rc-lang:focus-visible,
.rc-foot a:focus-visible, .rc-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

@media (max-width: 720px) {
  .rc-nav { order: 3; width: 100%; gap: 4px 18px; }
  .rc-ask { padding: 0.62em 0.8em; }
}
@media (max-width: 400px) {
  .rc-home { font-size: 1.15rem; }
  .rc-ask { font-size: 0.72rem; }
}

/* ---------- buttons ---------- */
.rc-btn {
  display: inline-flex; align-items: center; gap: 0.55em;
  font: 600 0.9rem/1 var(--font-mono); letter-spacing: 0.01em; text-decoration: none; cursor: pointer;
  padding: 0.95em 1.25em; border-radius: 12px; border: 1px solid var(--ink); background: transparent; color: var(--ink);
}
.rc-btn:hover { border-color: var(--accent); color: var(--accent); }
.rc-btn.primary { background: var(--ink); color: var(--paper); }
.rc-btn.primary:hover { background: var(--accent); border-color: var(--accent); color: var(--paper); }
.rc-btn[disabled] { opacity: 0.6; cursor: progress; }
.on-dark .rc-btn { border-color: rgba(232, 236, 244, 0.35); color: var(--rc-dark-hi); }
.on-dark .rc-btn:hover { border-color: var(--rc-amber); color: var(--rc-amber); }
.on-dark .rc-btn.primary { background: var(--rc-amber); border-color: var(--rc-amber); color: var(--rc-dark); }
.on-dark .rc-btn.primary:hover { background: #ffd789; border-color: #ffd789; color: var(--rc-dark); }
.on-dark .rc-btn:focus-visible { outline-color: var(--rc-amber); }

/* ---------- footer: always dark, like the stages ---------- */
.rc-foot { padding-inline: 20px; background: var(--rc-dark); color: var(--rc-dark-text); --rc-head: #2b3447; }
.rc-foot-in {
  max-width: var(--wide); margin-inline: auto;
  display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 2fr); gap: 32px 48px;
  padding-block: 44px 28px; font-size: 0.95rem; line-height: 1.5;
}
.rc-foot .rc-home { color: var(--rc-dark-hi); font-size: 1.25rem; }
.rc-foot .rc-home b { color: var(--rc-amber); }
.rc-foot-brand { display: grid; gap: 12px; align-content: start; }
.rc-foot-brand p { margin: 0; max-width: 28ch; }
.rc-foot-cols { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.rc-foot-h { margin: 0 0 10px; font: 500 0.72rem/1.3 var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--rc-dark-text); }
.rc-foot ul { margin: 0; padding: 0; list-style: none; display: grid; gap: 8px; }
.rc-foot a { color: var(--rc-dark-hi); text-decoration: none; }
.rc-foot a:hover { color: var(--rc-amber); }
.rc-foot a:focus-visible { outline-color: var(--rc-amber); }
.rc-foot-base {
  grid-column: 1 / -1; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px;
  padding-top: 20px; border-top: 1px solid var(--rc-dark-edge);
  font: 500 0.78rem/1.4 var(--font-mono); letter-spacing: 0.04em;
}
@media (max-width: 760px) {
  .rc-foot-in { grid-template-columns: minmax(0, 1fr); }
  .rc-foot-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- banner slots ---------- */
.ad { max-width: var(--wide); margin: clamp(2.2rem, 5vw, 3.6rem) auto 0; display: grid; gap: 6px; justify-items: center; }
.ad-label { justify-self: center; font: 500 0.64rem/1 var(--font-mono); letter-spacing: 0.16em; text-transform: uppercase; color: var(--ink-2); }
.ad a { display: block; width: 100%; max-width: 970px; }
.ad img { display: block; width: 100%; height: auto; border-radius: 10px; }
.ad-erid { font: 400 0.62rem/1 var(--font-mono); color: var(--ink-2); }
.ad-demo .ad-box {
  width: 100%; max-width: 970px; aspect-ratio: 970 / 250; display: grid; place-content: center; gap: 6px; text-align: center;
  border: 1.5px dashed var(--rule); border-radius: 10px; font: 500 0.8rem/1.3 var(--font-mono); color: var(--ink-2);
}
@media (max-width: 640px) { .ad-demo .ad-box { aspect-ratio: 320 / 100; } }

/* ---------- cookie notice (only when Google Analytics is configured) ---------- */
.rc-consent {
  position: fixed; z-index: 1000; left: 16px; right: 16px; bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  max-width: 44rem; margin-inline: auto; display: grid; gap: 14px; padding: 18px 20px;
  border-radius: 16px; border: 1px solid var(--rc-dark-edge); background: var(--rc-dark); color: var(--rc-dark-hi);
  box-shadow: 0 20px 50px -18px rgba(0, 0, 0, 0.65); font: 400 0.95rem/1.5 var(--font-body);
}
.rc-consent p { margin: 0; color: var(--rc-dark-hi); }
.rc-consent a { color: var(--rc-amber); }
.rc-consent-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.rc-consent .rc-btn { border-color: rgba(232, 236, 244, 0.4); color: var(--rc-dark-hi); padding: 0.8em 1.2em; }
.rc-consent .rc-btn:hover { border-color: var(--rc-amber); color: var(--rc-amber); }
.rc-consent .rc-btn:focus-visible { outline-color: var(--rc-amber); }
.rc-foot-base .rc-foot-links { display: flex; flex-wrap: wrap; gap: 6px 18px; }


/* Pages of raycat.org itself: home, contact, legal, root and 404.
   Builds on the explainer stylesheet (tokens, stages, rings, chips) and chrome.css. */
main.page { padding: 0; }
.wrap { max-width: var(--wide); margin-inline: auto; }
.pad { padding-inline: 20px; }

/* ---------- dark bands: the darkroom ---------- */
.on-dark {
  position: relative; isolation: isolate; overflow: hidden;
  background: var(--rc-dark); color: var(--rc-dark-hi);
}
.on-dark::before {
  content: ""; position: absolute; inset: 0; z-index: -1; pointer-events: none;
  background-image: linear-gradient(rgba(140, 160, 200, 0.055) 1px, transparent 1px), linear-gradient(90deg, rgba(140, 160, 200, 0.055) 1px, transparent 1px);
  background-size: 34px 34px; background-position: center;
}
.on-dark::after {
  content: ""; position: absolute; z-index: -1; pointer-events: none;
  left: -15%; top: -35%; width: 75%; height: 150%;
  background: radial-gradient(closest-side, rgba(255, 195, 90, 0.11), transparent);
}
.on-dark .eyebrow { color: var(--rc-dark-text); }

/* ---------- home: hero ---------- */
.home-hero .wrap { display: grid; gap: 1.3rem; padding-block: clamp(2.6rem, 6vw, 4.4rem) clamp(2.2rem, 4vw, 3rem); }
.home-hero h1 {
  font: 700 clamp(2.4rem, 1.15rem + 5vw, 5rem)/0.98 var(--font-display); letter-spacing: -0.035em;
  max-width: 15ch; color: var(--rc-dark-hi);
}
.home-hero .lede { font-size: 1.2rem; line-height: 1.55; color: var(--rc-dark-text); max-width: 44rem; margin: 0; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; padding-top: 0.2rem; }
.home-fig { margin: 1.4rem 0 0; }
.home-fig .stage { border-color: var(--rc-dark-edge); }
.home-fig figcaption { color: var(--rc-dark-text); }
.home-fig figcaption b { color: var(--rc-dark-hi); }
.home-fig .ring-label { color: var(--rc-dark-text); }
.home-fig .ring-value { color: var(--rc-dark-hi); }
.home-fig .ring-body:focus-visible { box-shadow: 0 0 0 2px var(--rc-dark), 0 0 0 4px var(--rc-amber); }
.home-fig .chips { background: var(--rc-dark-2); border: 1px solid var(--rc-dark-edge); }
.home-fig .chip { color: var(--rc-dark-hi); }
.home-fig .chip:hover { color: var(--rc-amber); }
.home-fig .controls { align-items: end; }
.readout { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; }
.readout output {
  font: 600 0.92rem/1.2 var(--font-mono); font-variant-numeric: tabular-nums;
  padding: 9px 12px; border-radius: 10px; background: var(--rc-dark-2); border: 1px solid var(--rc-dark-edge); color: var(--rc-dark-hi);
}
.readout output[data-sharp="yes"] { background: var(--rc-amber); border-color: var(--rc-amber); color: var(--rc-dark); }

/* ---------- home: sections ---------- */
.sec { padding-top: clamp(3.4rem, 8vw, 5.6rem); display: grid; gap: 1.6rem; }
section[id] { scroll-margin-top: 0.5rem; }
.sec-title {
  display: flex; align-items: center; gap: 0.8rem; margin: 0;
  font: 600 clamp(1.45rem, 1.1rem + 1.2vw, 2.05rem)/1.1 var(--font-display); letter-spacing: -0.02em;
}
.sec-title::after { content: ""; height: 1px; flex: 1; background: var(--rule); }

.cards { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; align-items: stretch; }
.cards > .feature:first-child { grid-column: span 2; }
.card {
  display: grid; grid-template-rows: auto 1fr; min-width: 0;
  border-radius: 18px; overflow: hidden; background: var(--paper-2); color: inherit; text-decoration: none;
}
.card-pic { position: relative; margin: 0; background: var(--rc-dark); }
.card-pic img { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; object-fit: cover; transition: transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1); }
.card:hover .card-pic img { transform: scale(1.025); }
.card-pic figcaption {
  position: absolute; left: 10px; bottom: 10px; font: 500 0.66rem/1 var(--font-mono); letter-spacing: 0.04em;
  color: #e8ecf4; background: rgba(9, 12, 18, 0.7); padding: 5px 7px; border-radius: 6px;
}
.card-body { display: grid; gap: 0.75rem; align-content: start; padding: 20px 22px 24px; }
.card-scale { font: 600 0.78rem/1.3 var(--font-mono); letter-spacing: 0.05em; color: var(--accent); }
.card-body h3 { margin: 0; font: 600 clamp(1.45rem, 1.1rem + 1.3vw, 2.1rem)/1.08 var(--font-display); letter-spacing: -0.025em; }
.card-body h3 a { color: inherit; text-decoration: none; }
.card-body h3 a::after { content: ""; position: absolute; inset: 0; }
.card.feature { position: relative; }
.card.feature .rc-btn { position: relative; z-index: 1; }
.card-body p { margin: 0; color: var(--ink-2); }
.card-meta { font: 500 0.8rem/1.5 var(--font-mono); color: var(--ink-2); }
.card-body .actions { display: flex; flex-wrap: wrap; gap: 10px; padding-top: 0.2rem; }
.card-body h3 a:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

.card.next {
  background: transparent; border: 1.5px dashed var(--rule); grid-template-rows: 1fr;
  align-content: center; transition: border-color 0.2s;
}
.card.next:hover { border-color: var(--accent); }
.card.next .card-body { align-content: center; gap: 0.9rem; }
.card.next .card-scale { color: var(--ink-2); }
.card.next h3 { font-size: clamp(1.35rem, 1.05rem + 1vw, 1.8rem); }
.card.next .more { font: 600 0.9rem/1 var(--font-mono); color: var(--accent); }
.card.next:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.next-cat { width: 72px; height: 72px; }

.video-wrap { margin: 0; display: grid; gap: 10px; }
.video-frame { border-radius: 16px; overflow: hidden; border: 1px solid var(--stage-edge); background: var(--rc-dark); }
.yt-facade { position: relative; display: block; aspect-ratio: 16 / 9; }
.yt-facade img { display: block; width: 100%; height: 100%; object-fit: cover; }
.yt-facade::after { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 50% 50%, rgba(9, 12, 18, 0.1), rgba(9, 12, 18, 0.55)); }
.yt-play {
  position: absolute; z-index: 1; left: 50%; top: 50%; width: 86px; height: 86px; margin: -43px 0 0 -43px;
  display: grid; place-items: center; border-radius: 50%;
  background: rgba(9, 12, 18, 0.72); border: 2px solid var(--rc-amber); transition: transform 0.2s ease;
}
.yt-play svg { width: 38px; height: 38px; margin-left: 4px; fill: var(--rc-amber); }
.yt-facade:hover .yt-play { transform: scale(1.07); }
.yt-facade:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.yt-dur { position: absolute; z-index: 1; right: 12px; bottom: 12px; font: 600 0.8rem/1 var(--font-mono); color: #fff; background: rgba(0, 0, 0, 0.75); padding: 5px 7px; border-radius: 6px; }
.yt-frame { display: block; width: 100%; aspect-ratio: 16 / 9; border: 0; }
.video-wrap figcaption { font-size: 0.92rem; line-height: 1.5; color: var(--ink-2); max-width: 70ch; }

.about-lead { margin: 0; font-size: clamp(1.2rem, 1.05rem + 0.5vw, 1.45rem); line-height: 1.5; max-width: 52rem; }
.pillars { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.pillar { display: grid; grid-template-rows: auto 1fr; border-radius: 18px; overflow: hidden; background: var(--paper-2); }
.pillar-pic { height: 132px; display: grid; place-items: center; background: var(--rc-dark); }
.pillar-pic svg { width: 100%; height: 100%; }
.pillar-pic .photons { animation: rc-photons 1.6s linear infinite; }
@keyframes rc-photons { to { stroke-dashoffset: -48; } }
@media (prefers-reduced-motion: reduce) { .pillar-pic .photons { animation: none; } }
.pillar-text { display: grid; gap: 0.45rem; align-content: start; padding: 18px 20px 22px; }
.pillar-text h3 { margin: 0; font: 600 1.15rem/1.2 var(--font-display); letter-spacing: -0.01em; }
.pillar-text p { margin: 0; font-size: 1rem; line-height: 1.5; color: var(--ink-2); }
.facts { margin: 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.facts li { padding-top: 0.8rem; border-top: 1px solid var(--rule); font-size: 0.98rem; line-height: 1.45; }
.facts b { display: block; margin-bottom: 0.25rem; font: 600 0.72rem/1.3 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); }

.cta { margin-top: clamp(3.6rem, 8vw, 5.6rem); }
.cta .wrap { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 1.4rem 3rem; align-items: center; padding-block: clamp(2.6rem, 5vw, 3.6rem); }
.cta h2 { margin: 0; font: 700 clamp(1.7rem, 1.2rem + 2vw, 2.7rem)/1.05 var(--font-display); letter-spacing: -0.03em; color: var(--rc-dark-hi); }
.cta p { margin: 0.7rem 0 0; color: var(--rc-dark-text); max-width: 46ch; }

@media (max-width: 880px) {
  .cards, .pillars, .facts { grid-template-columns: minmax(0, 1fr); }
  .cards > .feature:first-child { grid-column: auto; }
  .cta .wrap { grid-template-columns: minmax(0, 1fr); }
  .pillar { grid-template-columns: 120px minmax(0, 1fr); grid-template-rows: none; }
  .pillar-pic { height: auto; min-height: 110px; }
}

/* ---------- contact ---------- */
.page-head .wrap { display: grid; gap: 1rem; padding-block: clamp(2.4rem, 5vw, 3.6rem) clamp(1.6rem, 3vw, 2.2rem); }
.page-head h1 { margin: 0; font: 700 clamp(2.1rem, 1.2rem + 3.4vw, 3.8rem)/1 var(--font-display); letter-spacing: -0.035em; color: var(--rc-dark-hi); max-width: 18ch; }
.page-head .lede { margin: 0; font-size: 1.15rem; line-height: 1.55; color: var(--rc-dark-text); max-width: 46rem; }
.contact { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 32px 48px; align-items: start; padding-top: clamp(2rem, 4vw, 3rem); }
.form { display: grid; gap: 1.2rem; margin: 0; }
.field { display: grid; gap: 0.45rem; align-content: start; margin: 0; padding: 0; border: 0; min-width: 0; }
.field > label, .field legend { font: 600 0.78rem/1.3 var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink); padding: 0; }
.field small { font: 400 0.82rem/1.4 var(--font-body); letter-spacing: 0; text-transform: none; color: var(--ink-2); margin-left: 0.4em; }
.field input, .field textarea {
  font: 400 1.05rem/1.5 var(--font-body); color: var(--ink); background: var(--paper);
  border: 1px solid var(--rule); border-radius: 12px; padding: 0.8em 0.95em; width: 100%;
}
.field textarea { min-height: 9.5rem; resize: vertical; }
.field input:focus, .field textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.field .hint { font-size: 0.85rem; color: var(--ink-2); }
.kinds { display: flex; flex-wrap: wrap; gap: 6px; }
.kinds label { position: relative; }
.kinds input { position: absolute; opacity: 0; inset: 0; margin: 0; cursor: pointer; }
.kinds span {
  display: inline-block; font: 500 0.85rem/1 var(--font-mono); padding: 0.7em 0.95em; border-radius: 999px;
  border: 1px solid var(--rule); color: var(--ink-2); cursor: pointer;
}
.kinds input:checked + span { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.kinds input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.two { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.2rem; }
.trap { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form-note { margin: 0; font-size: 0.88rem; line-height: 1.5; color: var(--ink-2); }
.form-note a, .legal a, .aside-card a { color: var(--accent); }
.form-end { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 18px; }
.status { margin: 0; font-size: 0.98rem; line-height: 1.45; }
.status[data-state="ok"] { color: var(--ink); font-weight: 600; }
.status[data-state="fail"] { color: var(--index); }
.aside-card { display: grid; gap: 0.6rem; padding: 22px; border-radius: 18px; background: var(--paper-2); }
.aside-card h2 { margin: 0; font: 600 0.78rem/1.3 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-2); }
.aside-card .mail { font: 600 1.15rem/1.3 var(--font-mono); color: var(--ink); word-break: break-all; }
.aside-card p { margin: 0; color: var(--ink-2); font-size: 0.98rem; }
.copy { justify-self: start; font: 600 0.78rem/1 var(--font-mono); padding: 0.6em 0.9em; border-radius: 999px; border: 1px solid var(--rule); background: none; color: var(--ink); cursor: pointer; }
.copy:hover { border-color: var(--accent); }
.copy:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
@media (max-width: 880px) {
  .contact, .two { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- legal ---------- */
.legal { max-width: 46rem; padding-block: clamp(2rem, 4vw, 3rem) 1rem; display: grid; gap: 0.9rem; font-size: 1.05rem; line-height: 1.65; }
.legal h2 { margin: 1.2rem 0 0; font: 600 1.25rem/1.25 var(--font-display); letter-spacing: -0.01em; }
.legal p, .legal ul { margin: 0; }
.legal ul { padding-left: 1.2em; display: grid; gap: 0.4rem; }
.legal .updated { font: 500 0.82rem/1.4 var(--font-mono); color: var(--ink-2); }

/* ---------- root page and 404 ---------- */
.gate { min-height: 62vh; display: grid; place-items: center; padding: 48px 20px; }
.gate-in { display: grid; gap: 1.3rem; justify-items: start; max-width: 36rem; }
.gate .rc-home { font-size: 2rem; color: var(--rc-dark-hi); }
.gate .rc-home b { color: var(--rc-amber); }
.gate h1 { margin: 0; font: 700 clamp(1.6rem, 1.2rem + 2vw, 2.5rem)/1.1 var(--font-display); letter-spacing: -0.02em; color: var(--rc-dark-hi); }
.gate p { margin: 0; color: var(--rc-dark-text); }
.gate .actions { display: flex; flex-wrap: wrap; gap: 10px; }
.end-gap { height: clamp(3rem, 7vw, 5rem); }