/* ==========================================================================
   Orrery — shared stylesheet
   One file for every page: site shell, gallery, prose pages and exhibits.
   Class reference: the comments below, and models/_template/ for a working example.
   No web fonts, no remote anything. Light and dark themes via tokens.
   ========================================================================== */

/* ---------- 1. Tokens ---------------------------------------------------- */

:root {
  /* Type */
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua",
           "URW Palladio L", P052, Georgia, Cambria, "Times New Roman", serif;
  --sans:  system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
           "Noto Sans", "DejaVu Sans", Arial, sans-serif;
  --mono:  ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas,
           "DejaVu Sans Mono", "Liberation Mono", monospace;

  /* Colour — light ("paper and brass") */
  --paper:      #f6f2e9;   /* page */
  --paper-2:    #eee7d8;   /* panels, figures */
  --paper-3:    #e4dac6;   /* tracks, hover */
  --ink:        #1f1b15;   /* body text        (15.3:1 on paper, 13.9 on paper-2) */
  --ink-2:      #4b4439;   /* secondary text   ( 8.6:1) */
  --ink-3:      #675e50;   /* captions, meta   ( 5.7:1; 5.2 on paper-2) */
  --rule:       #d6cbb6;   /* hairlines */
  --brass:      #8a5712;   /* accent, links    ( 5.4:1; 4.9 on paper-2) */
  --brass-deep: #6d430a;   /* link hover       ( 7.6:1) */
  --brass-lit:  #c1913a;   /* decorative fills only, never text */
  --verdigris:  #2c6764;   /* second accent    ( 5.8:1; 5.3 on paper-2) */
  --verdigris-lit: #5f9d97;/* decorative */
  --alarm:      #9b2c1f;   /* errors, "needs work" (6.8:1) */
  --focus:      #1f5fbf;   /* focus ring */
  --shadow:     0 1px 2px rgb(60 40 10 / 0.08), 0 4px 16px rgb(60 40 10 / 0.06);

  /* Space and measure */
  --measure: 38rem;        /* reading column (~68 characters) */
  --wide:    60rem;        /* figures, gallery */
  --gutter:  clamp(1rem, 4vw, 2rem);
  --radius:  6px;

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:      #15161a;
    --paper-2:    #1d1f24;
    --paper-3:    #2a2d33;
    --ink:        #ece6d9;   /* 14.5:1 on paper */
    --ink-2:      #c9c1b2;   /* 10.1:1 */
    --ink-3:      #a39b8d;   /*  6.6:1 */
    --rule:       #35383f;
    --brass:      #e2b46a;   /*  9.4:1 */
    --brass-deep: #f0cb8c;
    --brass-lit:  #c99a4c;
    --verdigris:  #86c6be;   /*  9.3:1 */
    --verdigris-lit: #4f8f88;
    --alarm:      #f0907f;
    --focus:      #8ab4ff;
    --shadow:     0 1px 2px rgb(0 0 0 / 0.4), 0 4px 16px rgb(0 0 0 / 0.25);
  }
}

/* ---------- 2. Base ------------------------------------------------------ */

*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 1rem;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: clamp(1.0625rem, 0.98rem + 0.35vw, 1.1875rem);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  font-kerning: normal;
  font-variant-numeric: oldstyle-nums proportional-nums;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.005em;
  text-wrap: balance;
  margin: 2.2em 0 0.6em;
}
h1 { font-size: clamp(2.1rem, 1.6rem + 2.4vw, 3.1rem); font-weight: 500; margin-top: 0; letter-spacing: -0.015em; }
h2 { font-size: clamp(1.45rem, 1.3rem + 0.8vw, 1.8rem); font-weight: 500; }
h3 { font-size: 1.2rem; }
h4 { font-size: 1rem; }

p, ul, ol, dl, blockquote, pre, table, figure { margin: 0 0 1.1em; }
p { text-wrap: pretty; hyphens: auto; }
ul, ol { padding-left: 1.4em; }
li + li { margin-top: 0.3em; }

a {
  color: var(--brass);
  text-decoration-line: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  text-decoration-color: color-mix(in srgb, var(--brass) 45%, transparent);
}
a:hover { color: var(--brass-deep); text-decoration-color: currentColor; }

strong, b { font-weight: 650; }
small { font-size: 0.85em; }

hr {
  border: 0;
  height: 1px;
  background: var(--rule);
  margin: 2.5rem 0;
}

code, kbd, samp, pre { font-family: var(--mono); font-size: 0.86em; font-variant-numeric: normal; }
code { background: var(--paper-2); padding: 0.08em 0.3em; border-radius: 3px; }
pre {
  background: var(--paper-2);
  padding: 0.9rem 1rem;
  border-radius: var(--radius);
  overflow-x: auto;
  line-height: 1.45;
}
pre code { background: none; padding: 0; }
kbd {
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 3px;
  padding: 0 0.3em;
  background: var(--paper);
}

blockquote {
  margin-left: 0;
  padding-left: 1.1rem;
  border-left: 2px solid var(--brass-lit);
  color: var(--ink-2);
  font-style: italic;
}

table { border-collapse: collapse; width: 100%; font-size: 0.92em; }
th, td { text-align: left; padding: 0.4em 0.6em; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-family: var(--sans); font-size: 0.85em; font-weight: 600; color: var(--ink-2); }
.table-scroll { overflow-x: auto; }

img, svg, canvas, video { max-width: 100%; }
img { height: auto; }

::selection { background: color-mix(in srgb, var(--brass-lit) 40%, transparent); }

/* Focus: always visible for keyboard users */
:focus { outline: none; }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: 2px;
}

.visually-hidden, .sr-only {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute;
  left: 0.75rem; top: -3rem;
  z-index: 10;
  background: var(--ink);
  color: var(--paper);
  padding: 0.5rem 0.8rem;
  border-radius: var(--radius);
  font-family: var(--sans);
  font-size: 0.9rem;
  text-decoration: none;
}
.skip-link:focus { top: 0.75rem; color: var(--paper); }

/* ---------- 3. Layout ---------------------------------------------------- */

/* A centred reading column. Children can break out with .wide or .full. */
.page {
  width: 100%;
  max-width: calc(var(--measure) + 2 * var(--gutter));
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.page > .wide, .wide-page {
  width: min(var(--wide), calc(100vw - 2 * var(--gutter)));
  margin-left: 50%;
  transform: translateX(-50%);
}
.wide-page { transform: none; margin: 0 auto; padding: 0 var(--gutter); width: 100%; max-width: calc(var(--wide) + 2 * var(--gutter)); }

.lede {
  font-size: 1.2em;
  line-height: 1.5;
  color: var(--ink-2);
  margin-bottom: 1.6em;
}

.kicker, .eyebrow {
  font-family: var(--sans);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--brass);
  margin: 0 0 0.9rem;
}

.muted { color: var(--ink-3); }
.sans { font-family: var(--sans); }
.num, .tabular { font-variant-numeric: lining-nums tabular-nums; }

/* ---------- 4. Site header, nav, footer ---------------------------------- */

.site-header {
  border-bottom: 1px solid var(--rule);
  font-family: var(--sans);
}
.site-header .bar {
  max-width: calc(var(--wide) + 2 * var(--gutter));
  margin: 0 auto;
  padding: 0.85rem var(--gutter);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink);
  text-decoration: none;
  font-family: var(--serif);
  font-size: 1.3rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}
.brand:hover { color: var(--ink); }
.brand svg { width: 1.6rem; height: 1.6rem; flex: none; }
.site-nav ul {
  list-style: none;
  display: flex;
  gap: 0.25rem 1.4rem;
  margin: 0;
  padding: 0;
  flex-wrap: wrap;
}
.site-nav li + li { margin-top: 0; }
.site-nav a {
  color: var(--ink-2);
  text-decoration: none;
  font-size: 0.95rem;
  padding: 0.35rem 0;
  border-bottom: 1px solid transparent;
}
.site-nav a:hover { color: var(--ink); border-bottom-color: var(--rule); }
.site-nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--brass-lit); }

.site-footer {
  margin-top: 5rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-3);
}
.site-footer .bar {
  max-width: calc(var(--wide) + 2 * var(--gutter));
  margin: 0 auto;
  padding: 1.6rem var(--gutter) 2.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem 2rem;
  justify-content: space-between;
}
.site-footer p { margin: 0; }
.site-footer a { color: var(--ink-2); }

/* ---------- 5. Front door ------------------------------------------------ */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1rem 3rem;
  align-items: center;
  padding: clamp(2.5rem, 7vw, 5rem) 0 clamp(2rem, 5vw, 3.5rem);
}
.hero h1 { margin-bottom: 0.3rem; font-size: clamp(2.8rem, 2rem + 4vw, 4.4rem); }
.hero .tagline {
  font-size: clamp(1.25rem, 1.1rem + 0.8vw, 1.6rem);
  font-style: italic;
  color: var(--ink-2);
  margin: 0 0 1.4rem;
}
.hero .intro { max-width: 34rem; color: var(--ink); }
.hero .emblem { width: clamp(15rem, 28vw, 20rem); }
@media (max-width: 720px) {
  .hero { grid-template-columns: 1fr; }
  .hero .emblem { width: min(19rem, 100%); justify-self: center; margin-top: 0.5rem; }
}

.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 0.5rem;
  margin: 3rem 0 1.5rem;
}
.section-head h2 { margin: 0; font-size: 1.35rem; }
.section-head .aside { font-family: var(--sans); font-size: 0.85rem; color: var(--ink-3); }

/* The emblem: a small orrery drawn in SVG by orrery-home.js */
.emblem { margin: 0; }
.emblem svg { display: block; width: 100%; height: auto; overflow: visible; }
.emblem figcaption { margin-top: 0.6rem; text-align: center; }
.emblem .crank {
  display: flex; align-items: center; gap: 0.6rem;
  font-family: var(--sans); font-size: 0.8rem; color: var(--ink-3);
  margin-top: 0.5rem;
}
.emblem .crank input { flex: 1; }

/* Latest note */
.latest-note {
  border-left: 2px solid var(--brass-lit);
  padding: 0.2rem 0 0.2rem 1.25rem;
}
.latest-note h3 { margin: 0 0 0.5rem; font-size: 1.1rem; }
.latest-teaser { font-family: var(--sans); font-size: 0.9rem; color: var(--ink-2); }
.latest-note .excerpt { color: var(--ink-2); }
.latest-note .excerpt p:last-child { margin-bottom: 0.6rem; }

/* ---------- 6. Gallery cards --------------------------------------------- */

.field-filter { margin: -0.5rem 0 1.25rem; gap: 0.4rem; }
.field-filter .btn { font-size: 0.8rem; font-weight: 500; min-height: 2rem; padding: 0.3em 0.85em; color: var(--ink-2); }
.field-filter .btn .n { color: var(--ink-3); font-variant-numeric: tabular-nums; margin-left: 0.15em; }
.field-filter .btn[aria-pressed="true"] { color: var(--ink); }

.gallery {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 16.5rem), 1fr));
  gap: 1.5rem;
}
.gallery > li { margin: 0; }
.card {
  position: relative;
  height: 100%;
  display: flex;
  flex-direction: column;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 150ms ease, transform 150ms ease, box-shadow 150ms ease;
}
.card:hover, .card:focus-within { border-color: var(--brass-lit); box-shadow: var(--shadow); }
.card .thumb {
  aspect-ratio: 8 / 5;
  background: var(--paper-3);
  border-bottom: 1px solid var(--rule);
  display: grid;
  place-items: center;
  overflow: hidden;
}
.card .thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }
@media (prefers-color-scheme: dark) {   /* thumbnails are light-theme pictures: soften them at night */
  .card .thumb img { filter: brightness(0.82) contrast(1.04); transition: filter 0.2s; }
  .card:hover .thumb img, .card:focus-within .thumb img { filter: none; }
}
@media (prefers-color-scheme: dark) and (prefers-reduced-motion: reduce) { .card .thumb img { transition: none; } }
.card .thumb svg { width: 30%; max-width: 7rem; height: auto; color: var(--brass-lit); opacity: 0.75; }
@media (max-width: 560px) { .card .thumb.placeholder { aspect-ratio: 16 / 6; } .card .thumb.placeholder svg { width: 22%; } }
.card .body { padding: 1rem 1.1rem 1.1rem; display: flex; flex-direction: column; flex: 1; }
.card .field {
  font-family: var(--sans); font-size: 0.72rem; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--verdigris);
  margin: 0 0 0.4rem;
}
.card h3 { margin: 0 0 0.4rem; font-size: 1.2rem; font-weight: 600; }
.card h3 a { color: var(--ink); text-decoration: none; }
.card h3 a::after { content: ""; position: absolute; inset: 0; } /* whole card clickable */
.card h3 a:focus-visible { outline: none; }
.card:has(h3 a:focus-visible) { outline: 2px solid var(--focus); outline-offset: 3px; }
.card .question { color: var(--ink-2); margin: 0 0 0.9rem; font-size: 0.98rem; line-height: 1.45; }
.card .meta {
  margin-top: auto;
  font-family: var(--sans); font-size: 0.78rem; color: var(--ink-3);
  display: flex; flex-wrap: wrap; gap: 0.3rem 0.8rem; align-items: center;
}
/* Phones: compact cards (picture beside the words), so 18+ exhibits don't bury the note below. */
@media (max-width: 600px) {
  .gallery { gap: 0.75rem; }
  .card { flex-direction: row; }
  .card .thumb, .card .thumb.placeholder {
    flex: 0 0 6.4rem; align-self: flex-start; aspect-ratio: 8 / 5;
    margin: 0.85rem 0 0 0.85rem;
    border: 1px solid var(--rule); border-radius: calc(var(--radius) / 2);
  }
  .card .thumb.placeholder svg { width: 45%; }
  .card .body { padding: 0.7rem 0.85rem 0.75rem; min-width: 0; }
  .card .field { margin-bottom: 0.2rem; }
  .card h3 { font-size: 1.05rem; margin-bottom: 0.25rem; }
  .card .question { font-size: 0.9rem; line-height: 1.4; margin-bottom: 0.45rem; }
  .card .meta { margin-bottom: 0; }
}


.empty-state {
  border: 1px dashed var(--rule);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  text-align: center;
  color: var(--ink-2);
}
.empty-state p { margin: 0 auto 0.5rem; max-width: 30rem; }
.empty-state p:last-child { margin-bottom: 0; }

/* ---------- 7. Exhibit parts --------------------------------------------- */

.exhibit-header { padding: clamp(2.5rem, 7vw, 4.5rem) 0 1rem; }
.exhibit-header h1 { margin-bottom: 0.8rem; }
.exhibit-header .lede { margin-bottom: 0.8rem; }
.byline { font-family: var(--sans); font-size: 0.85rem; color: var(--ink-3); margin: 0; }

/* Figures. <figure class="fig"> inside .page; add .wide to break out. */
.fig {
  margin: 2rem 0 2.2rem;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: clamp(0.75rem, 2.5vw, 1.25rem);
}
.fig .stage {             /* the drawing area: canvas or svg */
  position: relative;
  width: 100%;
  aspect-ratio: var(--aspect, 16 / 9);
  background: var(--paper);
  border-radius: calc(var(--radius) - 2px);
  overflow: hidden;
  touch-action: none;     /* so drags don't scroll; pages with scroll-only figures may override */
}
.fig .stage.scrollable { touch-action: pan-y; }
.fig .stage > canvas, .fig .stage > svg { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.fig figcaption {
  font-family: var(--sans);
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--ink-3);
  margin-top: 0.8rem;
}
.fig figcaption .fig-num { font-weight: 650; color: var(--ink-2); margin-right: 0.3em; }

/* Controls row */
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1.6rem;
  align-items: center;
  margin-top: 0.9rem;
  font-family: var(--sans);
  font-size: 0.9rem;
}
.control {
  display: grid;
  grid-template-columns: auto minmax(7rem, 1fr) auto;
  align-items: center;
  gap: 0.35rem 0.7rem;
  flex: 1 1 15rem;
  min-width: 0;
}
.control > label, .control > .label { color: var(--ink-2); white-space: nowrap; }
.control.stacked { grid-template-columns: 1fr auto; }
.control.stacked > input[type="range"] { grid-column: 1 / -1; }

.readout, output {
  font-family: var(--mono);
  font-size: 0.88rem;
  font-variant-numeric: tabular-nums lining-nums;
  color: var(--ink);
  min-width: 4.5ch;
  text-align: right;
  white-space: nowrap;
}
.readouts {                /* a row of labelled numeric values */
  display: flex; flex-wrap: wrap; gap: 0.5rem 1.6rem;
  margin: 0.8rem 0 0; padding: 0;
  font-family: var(--sans); font-size: 0.85rem; color: var(--ink-3);
}
.readouts > div { display: flex; flex-direction: column; margin: 0; }
.readouts dt { margin: 0; }
.readouts dd { margin: 0; font-family: var(--mono); font-size: 1.05rem; color: var(--ink); font-variant-numeric: tabular-nums lining-nums; }
/* Colour key inside readouts: <dt><span class="key" style="--key: var(--brass)" aria-hidden="true"></span>Label</dt>.
   A short line (for a line on the chart); .key.dot for points, .key.block for filled areas.
   The colour is decoration: the label text must name the series too. */
.readouts .key {
  display: inline-block; width: 0.9em; height: 0.2em; margin-right: 0.35em;
  vertical-align: middle; border-radius: 1px;
  background: var(--key, currentColor);
  forced-color-adjust: none;
}
.readouts .key.dot   { width: 0.6em; height: 0.6em; border-radius: 50%; }
.readouts .key.block { width: 0.75em; height: 0.75em; border-radius: 2px; }

/* Range sliders: a thin rule with a brass knob */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  min-width: 0;
  height: 1.75rem;              /* comfortable touch target */
  background: transparent;
  margin: 0;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px; border-radius: 2px;
  background: var(--paper-3);
  box-shadow: inset 0 0 0 1px var(--rule);
}
input[type="range"]::-moz-range-track {
  height: 4px; border-radius: 2px;
  background: var(--paper-3);
}
input[type="range"]::-moz-range-progress { height: 4px; border-radius: 2px; background: var(--brass-lit); }
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px; margin-top: -7px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #f1d9a0, var(--brass-lit) 55%, #7d5418);
  border: 1px solid #6a4510;
  box-shadow: 0 1px 2px rgb(0 0 0 / 0.25);
}
input[type="range"]::-moz-range-thumb {
  width: 16px; height: 16px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #f1d9a0, var(--brass-lit) 55%, #7d5418);
  border: 1px solid #6a4510;
}
input[type="range"]:focus-visible { outline-offset: 1px; }
input[type="range"]:disabled { opacity: 0.45; cursor: not-allowed; }

/* Buttons */
.btn, button.btn {
  font-family: var(--sans);
  font-size: 0.88rem;
  font-weight: 550;
  line-height: 1.2;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 0.5em 1.05em;
  min-height: 2.25rem;
  cursor: pointer;
  display: inline-flex; align-items: center; gap: 0.45em;
  text-decoration: none;
}
.btn:hover { border-color: var(--brass-lit); color: var(--ink); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn.primary:hover { background: var(--ink-2); color: var(--paper); }
/* Pressed (aria-pressed="true"), plain or primary: recessed paper-3 with ink text, so the text
   colour always follows the background (ink on paper-3: 12.4:1 light, 11.1:1 dark). */
.btn[aria-pressed="true"], .btn[aria-pressed="true"]:hover,
.btn.primary[aria-pressed="true"], .btn.primary[aria-pressed="true"]:hover {
  background: var(--paper-3); color: var(--ink); border-color: var(--brass-lit);
}
.btn.primary[aria-pressed="true"] { border-color: var(--ink-3); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-row { display: flex; flex-wrap: wrap; gap: 0.5rem; }

/* Radio group: <fieldset class="radio-row"><legend>Shape</legend>
     <label><input type="radio" name="shape" value="a" checked> A</label> …</fieldset> */
.radio-row {
  display: flex; flex-wrap: wrap; gap: 0.4rem 1rem;
  border: 0; padding: 0; margin: 0;
  font-family: var(--sans); font-size: 0.9rem;
}
.radio-row legend { font-weight: 600; margin-bottom: 0.3rem; padding: 0; }
.radio-row label { display: inline-flex; align-items: center; gap: 0.35rem; cursor: pointer; }
.radio-row input { accent-color: var(--brass); }

/* Toggle: <label class="toggle"><input type="checkbox"> Label</label> */
.toggle {
  display: inline-flex; align-items: center; gap: 0.55rem;
  cursor: pointer; color: var(--ink-2);
  font-family: var(--sans); font-size: 0.9rem;
  min-height: 2rem;
}
.toggle input {
  -webkit-appearance: none; appearance: none;
  position: relative;
  flex: none;
  width: 2.3rem; height: 1.3rem; margin: 0;
  border-radius: 999px;
  background: var(--paper-3);
  border: 1px solid var(--rule);
  cursor: pointer;
  transition: background-color 150ms ease;
}
.toggle input::after {
  content: ""; position: absolute; top: 2px; left: 2px;
  width: calc(1.3rem - 6px); height: calc(1.3rem - 6px);
  border-radius: 50%;
  background: var(--ink-3);
  transition: transform 150ms ease, background-color 150ms ease;
}
.toggle input:checked { background: var(--verdigris); border-color: var(--verdigris); }
.toggle input:checked::after { transform: translateX(1rem); background: var(--paper); }

select, input[type="number"], input[type="text"] {
  font: inherit; font-family: var(--sans); font-size: 0.9rem;
  color: var(--ink); background: var(--paper);
  border: 1px solid var(--rule); border-radius: 4px;
  padding: 0.3em 0.5em; min-height: 2rem;
}

/* Callouts: <aside class="callout"> … </aside>; variants .try, .note */
.callout {
  margin: 1.6rem 0;
  padding: 0.9rem 1.1rem;
  border-radius: var(--radius);
  background: var(--paper-2);
  border-left: 3px solid var(--brass-lit);
}
.callout > :last-child { margin-bottom: 0; }
.callout .callout-title {
  display: block;
  font-family: var(--sans); font-size: 0.75rem; font-weight: 650;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--brass);
  margin-bottom: 0.3rem;
}
.callout.try  { border-left-color: var(--verdigris-lit); }
.callout.try .callout-title { color: var(--verdigris); }
.callout.note { border-left-color: var(--rule); }
.callout.note .callout-title { color: var(--ink-3); }

/* Formula display */
.formula {
  font-family: var(--serif);
  font-style: italic;
  font-size: 1.12em;
  text-align: center;
  margin: 1.4rem 0;
  overflow-x: auto;
}

/* End matter: leaves-out, sources, colophon */
.end-matter {
  margin-top: 3.5rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--rule);
}
.leaves-out h2, .sources h2 { font-size: 1.3rem; margin-top: 2rem; }
.leaves-out ul { padding-left: 1.2em; }
.leaves-out li::marker { color: var(--brass-lit); }
.sources ol { padding-left: 1.4em; font-size: 0.95rem; }
.sources li { margin-bottom: 0.6em; }
.sources .note { display: block; color: var(--ink-3); font-size: 0.92em; }
.colophon {
  margin-top: 2.5rem;
  padding: 1rem 1.2rem;
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-3);
}
.colophon h2 { font-family: var(--sans); font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase; margin: 0 0 0.5rem; color: var(--ink-2); }
.colophon dl { display: grid; grid-template-columns: max-content 1fr; gap: 0.2rem 1rem; margin: 0; }
.colophon dl > div { display: contents; }   /* a <div> around a dt/dd pair (e.g. data-local-only) */
.colophon dt { color: var(--ink-3); }
.colophon dd { margin: 0; color: var(--ink-2); }
.colophon p { margin: 0.6rem 0 0; }

/* ---------- 8. Prose and record pages ----------------------------------- */

.page-header { padding: clamp(2.5rem, 7vw, 4rem) 0 0.5rem; }
.page-header h1 { margin-bottom: 0.6rem; }

.toc {
  font-family: var(--sans); font-size: 0.9rem;
  display: flex; flex-wrap: wrap; gap: 0.4rem 1.2rem;
  list-style: none; padding: 0; margin: 0 0 2rem;
}
.toc li + li { margin-top: 0; }
.section-nav {
  margin: 0; padding: 1.1rem 0 0;
  gap: 0.3rem 1.3rem;
  font-size: 0.85rem;
}
.section-nav a { color: var(--ink-3); text-decoration: none; }
.section-nav a:hover { color: var(--ink); }
.section-nav a[aria-current="page"] { color: var(--brass); font-weight: 600; }

.md h1 { font-size: 1.6rem; margin-top: 1.6rem; }
.md h2 { font-size: 1.3rem; margin-top: 1.8rem; }
.md h3 { font-size: 1.1rem; margin-top: 1.4rem; }
.md h4, .md h5, .md h6 { font-size: 1rem; margin-top: 1.2rem; }
.md > :first-child { margin-top: 0; }

details > summary { cursor: pointer; }
details.plain > summary { font-family: var(--sans); font-size: 0.9rem; color: var(--brass); margin-bottom: 0.6rem; }

/* ---------- 9. Motion and print ------------------------------------------ */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media print {
  .site-header, .site-footer, .controls, .skip-link { display: none; }
  body { background: #fff; color: #000; }
  .fig { break-inside: avoid; }
}