/* ==========================================================================
   Cinematography & Mise-en-Scène Cheat Sheets
   Shared stylesheet. No JavaScript anywhere in this project.
   --------------------------------------------------------------------------
   1. Tokens
   2. Reset & base
   3. Shell + sidebar
   4. Typography
   5. Components (cards, tables, callouts, chips, swatches)
   6. Diagrams (SVG theming)
   7. Pager + footer
   8. Responsive
   9. Print
   ========================================================================== */

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

:root {
  /* The two ends of the colour-temperature scale, used as the accent pair:
     tungsten 3200K (warm) and daylight 5600K (cool). */
  --tungsten: #e9b166;
  --tungsten-dim: #b98a4c;
  --daylight: #6fc9e0;
  --daylight-dim: #4b8fa3;

  --bg: #0a0b0d;
  --bg-grain: #0d0e12;
  --surface: #15171c;
  --surface-2: #1b1e24;
  --surface-3: #23272f;
  --line: #2b303a;
  --line-soft: #1f232b;

  --ink: #eceae6;
  --ink-dim: #a6a9b3;
  --ink-faint: #71757f;

  --good: #86c9a0;
  --bad: #e4735f;

  --radius: 14px;
  --radius-sm: 8px;
  --sidebar-w: 268px;

  --font-body:
    "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif;
  --font-display:
    "Instrument Serif", "Iowan Old Style", Georgia, "Times New Roman", serif;
  --font-mono:
    "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 8px 28px rgba(0, 0, 0, 0.35);

  /* Outbound-link marker, drawn as a mask so it inherits the link colour. */
  --ext-icon: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='%23000' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'><path d='M13 9.5V13H3V3h3.5'/><path d='M9.5 2.5h4v4'/><path d='M13.5 2.5 7.5 8.5'/></svg>");
}

/* 2. Reset & base -------------------------------------------------------- */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  /* Zoom is disabled via the viewport meta. iOS Safari ignores user-scalable=no
     by design, so this at least removes double-tap-to-zoom there. Panning and
     the horizontal scroll inside .dgm-scroll are unaffected. */
  touch-action: manipulation;
}

body {
  margin: 0;
  background: var(--bg);
  background-image:
    radial-gradient(
      1200px 600px at 12% -8%,
      rgba(233, 177, 102, 0.055),
      transparent 60%
    ),
    radial-gradient(
      900px 500px at 98% 4%,
      rgba(111, 201, 224, 0.045),
      transparent 62%
    );
  background-attachment: fixed;
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg {
  max-width: 100%;
}
svg {
  display: block;
}

a {
  color: var(--tungsten);
  text-decoration-color: rgba(233, 177, 102, 0.35);
  text-underline-offset: 3px;
}
a:hover {
  text-decoration-color: currentColor;
}

/* Links that leave the site open in a new tab, so they say so. The marker is a
   mask (never announced by screen readers); the spoken warning is the
   .visually-hidden "(opens in a new tab)" span in the markup. */
a[target="_blank"]::after {
  content: "";
  display: inline-block;
  width: 0.58em;
  height: 0.58em;
  margin-left: 0.3em;
  vertical-align: -0.01em;
  background-color: currentColor;
  opacity: 0.55;
  -webkit-mask: var(--ext-icon) no-repeat center / contain;
  mask: var(--ext-icon) no-repeat center / contain;
  transition: opacity 0.15s ease;
}
a[target="_blank"]:hover::after {
  opacity: 1;
}

:focus-visible {
  outline: 2px solid var(--daylight);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--tungsten);
  color: #10110f;
  padding: 0.6rem 1rem;
  z-index: 99;
  font-weight: 600;
  border-radius: 0 0 8px 0;
}
.skip:focus {
  left: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* 3. Shell + sidebar ----------------------------------------------------- */

.shell {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  overflow-y: auto;
  min-width: 0;
  padding: 1.6rem 1.1rem 2.5rem;
  border-right: 1px solid var(--line-soft);
  background: linear-gradient(
    180deg,
    rgba(21, 23, 28, 0.9),
    rgba(10, 11, 13, 0.9)
  );
  backdrop-filter: blur(6px);
  scrollbar-width: thin;
  scrollbar-color: var(--surface-3) transparent;
}
.sidebar::-webkit-scrollbar {
  width: 8px;
}
.sidebar::-webkit-scrollbar-thumb {
  background: var(--surface-3);
  border-radius: 8px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  color: var(--ink);
  padding: 0.35rem 0.4rem 1.1rem;
}
.brand-mark {
  width: 30px;
  height: 30px;
  flex: 0 0 auto;
  border-radius: 7px;
  background: radial-gradient(
    circle at 34% 32%,
    var(--tungsten),
    var(--tungsten-dim) 55%,
    #4a3418 100%
  );
  box-shadow:
    0 0 0 1px rgba(233, 177, 102, 0.35),
    0 0 22px rgba(233, 177, 102, 0.22);
  position: relative;
}
.brand-mark::after {
  content: "";
  position: absolute;
  inset: 9px;
  border-radius: 50%;
  background: rgba(10, 11, 13, 0.75);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.12);
}
.brand-text {
  display: grid;
  line-height: 1.25;
}
.brand-text strong {
  font-size: 0.95rem;
  letter-spacing: -0.01em;
}
.brand-text span {
  font-size: 0.74rem;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.nav-group {
  margin: 1.35rem 0 0.45rem;
  padding: 0 0.55rem;
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
}
.nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
}
.nav a {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  padding: 0.42rem 0.55rem;
  border-radius: var(--radius-sm);
  color: var(--ink-dim);
  text-decoration: none;
  font-size: 0.88rem;
  border-left: 2px solid transparent;
  transition:
    background 0.15s ease,
    color 0.15s ease;
}
.nav a .n {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--ink-faint);
  min-width: 1.35em;
}
.nav a:hover {
  background: var(--surface-2);
  color: var(--ink);
}

/* Active page is resolved purely in CSS from the body attribute, so every
   page can ship the identical nav markup. */
body[data-page="index"] .nav a[data-nav="index"],
body[data-page="shot-sizes"] .nav a[data-nav="shot-sizes"],
body[data-page="angles"] .nav a[data-nav="angles"],
body[data-page="focus"] .nav a[data-nav="focus"],
body[data-page="lenses"] .nav a[data-nav="lenses"],
body[data-page="movement"] .nav a[data-nav="movement"],
body[data-page="composition"] .nav a[data-nav="composition"],
body[data-page="continuity"] .nav a[data-nav="continuity"],
body[data-page="mise-en-scene"] .nav a[data-nav="mise-en-scene"],
body[data-page="lighting"] .nav a[data-nav="lighting"],
body[data-page="colour"] .nav a[data-nav="colour"],
body[data-page="time"] .nav a[data-nav="time"],
body[data-page="practice"] .nav a[data-nav="practice"],
body[data-page="resources"] .nav a[data-nav="resources"] {
  background: var(--surface-2);
  color: var(--ink);
  border-left-color: var(--tungsten);
  font-weight: 500;
}

/* 4. Typography ---------------------------------------------------------- */

main {
  padding: 3rem clamp(1.1rem, 3.5vw, 3.2rem) 4rem;
  max-width: 1120px;
  width: 100%;
  min-width: 0;
  /* Centre the column inside the content track, so wide screens get an even
     gutter on both sides instead of all the slack piling up on the right. */
  margin-inline: auto;
}

.page-head {
  margin-bottom: 2.6rem;
}
nav.eyebrow {
  margin-bottom: 0.75rem;
}

/* Breadcrumb. Shares the eyebrow's type treatment, and its visible text
   matches the BreadcrumbList in each page's JSON-LD. */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.crumbs li {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  max-width: none;
}
.crumbs li + li::before {
  content: "\203A";
  color: var(--ink-faint);
}
.crumbs a {
  color: var(--tungsten);
  text-decoration: none;
}
.crumbs a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}
.crumbs [aria-current="page"] {
  color: var(--ink-faint);
}

.section-intro {
  margin: -0.35rem 0 1.2rem;
  color: var(--ink-faint);
  font-size: 0.92rem;
}

h2[id] {
  scroll-margin-top: 1.2rem;
}

.eyebrow {
  margin: 0 0 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--tungsten);
}

h1 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(2.3rem, 1.5rem + 3.2vw, 3.6rem);
  line-height: 1.04;
  letter-spacing: -0.015em;
  margin: 0 0 0.7rem;
}

.standfirst {
  margin: 0;
  max-width: 62ch;
  font-size: clamp(1rem, 0.96rem + 0.3vw, 1.14rem);
  color: var(--ink-dim);
}

h2 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(1.5rem, 1.25rem + 0.9vw, 2rem);
  line-height: 1.18;
  letter-spacing: -0.01em;
  margin: 3.2rem 0 1rem;
  padding-top: 1.4rem;
  border-top: 1px solid var(--line-soft);
}
h2:first-of-type {
}

h3 {
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: -0.005em;
  margin: 2rem 0 0.6rem;
}

/* A small all-caps card heading. It is an <h3> so the document keeps a valid
   heading outline (h1 -> h2 -> h3); .label only carries the visual treatment. */
h3.label,
h4 {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 0.7rem;
}

p,
li {
  max-width: 74ch;
}
p {
  margin: 0 0 1rem;
}

strong {
  color: #fff;
  font-weight: 600;
}
em {
  color: var(--ink);
}

code,
.mono {
  font-family: var(--font-mono);
  font-size: 0.88em;
}

abbr[title] {
  text-decoration: none;
  border-bottom: 1px dotted var(--ink-faint);
  cursor: help;
}

/* 5. Components ---------------------------------------------------------- */

.card {
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}
.card > :last-child {
  margin-bottom: 0;
}
.card h3 {
  margin-top: 0;
}

.grid {
  display: grid;
  gap: 1rem;
}
.grid-2 {
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
}
.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(215px, 1fr));
}
.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(165px, 1fr));
}

/* Tables */
.table-wrap {
  overflow-x: auto;
  max-width: 100%;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: var(--surface);
  margin: 1.2rem 0 1.6rem;
  scrollbar-width: thin;
}
table.sheet {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  min-width: 520px;
}
table.sheet caption {
  text-align: left;
  padding: 0.9rem 1.1rem 0.2rem;
  color: var(--ink-faint);
  font-size: 0.8rem;
}
table.sheet th,
table.sheet td {
  text-align: left;
  padding: 0.7rem 0.95rem;
  border-bottom: 1px solid var(--line-soft);
  vertical-align: top;
  max-width: none;
}
table.sheet thead th {
  background: var(--surface-2);
  color: var(--ink);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-weight: 600;
  white-space: nowrap;
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
}
table.sheet tbody tr:last-child td {
  border-bottom: 0;
}
table.sheet tbody tr:hover {
  background: rgba(255, 255, 255, 0.022);
}
table.sheet td:first-child {
  color: #fff;
  font-weight: 500;
}

/* Abbreviation badge used in the shot-size table */
.abbr {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.12rem 0.45rem;
  border-radius: 5px;
  background: rgba(233, 177, 102, 0.11);
  border: 1px solid rgba(233, 177, 102, 0.25);
  color: var(--tungsten);
  white-space: nowrap;
}
.abbr.cool {
  background: rgba(111, 201, 224, 0.1);
  border-color: rgba(111, 201, 224, 0.24);
  color: var(--daylight);
}

/* Callouts */
.callout {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.2rem 0.85rem;
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--tungsten);
  background: var(--surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1rem 1.2rem;
  margin: 1.4rem 0;
}
.callout .ico {
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--tungsten);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  align-self: center;
  opacity: 0.85;
}
.callout > :last-child {
  margin-bottom: 0;
}
.callout.rule {
  border-left-color: var(--daylight);
}
.callout.rule .ico {
  color: var(--daylight);
}
.callout.watch {
  border-left-color: var(--ink-faint);
}
.callout.watch .ico {
  color: var(--ink-faint);
}

/* Illustrated term cards: a diagram beside each definition. Still a real <dl>,
   with each dt/dd pair wrapped in a div so the cards have something to lay out;
   the diagram lives inside the dd, which keeps the dl content model valid. */
.defcards {
  display: grid;
  gap: 0.9rem;
  margin: 1.3rem 0 1.7rem;
}
.defcards > div {
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 1rem 1.2rem 1.1rem;
}
.defcards dt {
  font-weight: 600;
  color: #fff;
  font-size: 0.95rem;
  margin-bottom: 0.6rem;
}
.defcards dd {
  margin: 0;
  display: grid;
  grid-template-columns: 152px minmax(0, 1fr);
  gap: 1.15rem;
  align-items: start;
}
.defcards dd svg {
  width: 100%;
  height: auto;
}
.defcards dd p {
  margin: 0;
  color: var(--ink-dim);
  font-size: 0.9rem;
  max-width: 68ch;
}

@media (max-width: 620px) {
  .defcards dd {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.8rem;
  }
  .defcards dd svg {
    max-width: 220px;
  }
}

/* Definition list */
.deflist {
  margin: 1.1rem 0 1.5rem;
  display: grid;
  gap: 0.85rem;
}
.deflist dt {
  font-weight: 600;
  color: #fff;
  font-size: 0.95rem;
}
.deflist dd {
  margin: 0.15rem 0 0;
  color: var(--ink-dim);
  max-width: 74ch;
}

/* Key/value stat row */
.keys {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0 0 1.2rem;
  padding: 0;
  list-style: none;
}
.keys li {
  font-size: 0.8rem;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--ink-dim);
}
.keys li b {
  color: var(--ink);
  font-weight: 600;
}

/* Do / Don't pair */
.verdict {
  border-left: 3px solid var(--good);
}
.verdict.no {
  border-left-color: var(--bad);
}
.verdict .label {
  color: var(--good);
}
.verdict.no .label {
  color: var(--bad);
}

/* Colour swatches */
.swatches {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 0.4rem 0 1rem;
  padding: 0;
  list-style: none;
}
.swatch {
  width: 74px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--line);
  font-size: 0.64rem;
  text-align: center;
}
.swatch i {
  display: block;
  height: 42px;
}
.swatch span {
  display: block;
  padding: 0.3rem 0.2rem;
  background: var(--surface-2);
  color: var(--ink-faint);
  font-style: normal;
  font-family: var(--font-mono);
}

/* Colour wheels (pure CSS) */
.wheels {
  display: flex;
  flex-wrap: wrap;
  gap: 1.6rem;
  margin: 1.2rem 0;
  padding: 0;
  list-style: none;
}
.wheel-fig {
  text-align: center;
  font-size: 0.8rem;
  color: var(--ink-dim);
}
.wheel {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  margin: 0 auto 0.55rem;
  position: relative;
  background: conic-gradient(
    from -90deg,
    #e14b4b 0deg,
    #e87b3a 30deg,
    #e8b04b 60deg,
    #d8d64b 90deg,
    #8cc94b 120deg,
    #4bc47a 150deg,
    #4bc4bc 180deg,
    #4b9ad8 210deg,
    #5a6fd8 240deg,
    #8a5ad8 270deg,
    #c44bc4 300deg,
    #e14b84 330deg,
    #e14b4b 360deg
  );
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.1);
}
.wheel::after {
  content: "";
  position: absolute;
  inset: 27%;
  border-radius: 50%;
  background: var(--bg);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}
.wheel b {
  position: absolute;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  border: 2px solid #fff;
  box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.55);
  top: 50%;
  left: 50%;
  margin: -7.5px;
  /* Each marker is placed by rotating out from the centre. */
  transform: rotate(var(--a)) translateY(-44px) rotate(calc(-1 * var(--a)));
}

/* 6. Diagrams ------------------------------------------------------------ */

figure.dgm {
  margin: 1.5rem 0 1.8rem;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 1.2rem 1.2rem 0.9rem;
}
/* SVG text is sized in user units, so it shrinks along with the viewBox. On a
   phone a 600-unit diagram scales to ~0.6 and 11px labels render at ~7px. Holding
   each diagram at its own viewBox width keeps the labels at their designed size
   and lets the diagram scroll instead: the same trade .table-wrap makes. */
.dgm-scroll {
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scrollbar-width: thin;
  scrollbar-color: var(--surface-3) transparent;
}
.dgm-scroll::-webkit-scrollbar {
  height: 8px;
}
.dgm-scroll::-webkit-scrollbar-thumb {
  background: var(--surface-3);
  border-radius: 8px;
}
figure.dgm svg {
  width: 100%;
  height: auto;
  min-width: var(--vb, 0);
}
figure.dgm figcaption {
  margin-top: 0.85rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--line-soft);
  font-size: 0.82rem;
  color: var(--ink-faint);
  max-width: 68ch;
}

/* SVG theming so diagrams follow the tokens above */
.dgm .stroke {
  stroke: var(--line);
  stroke-width: 1.5;
  fill: none;
}
.dgm .stroke-soft {
  stroke: var(--line-soft);
  stroke-width: 1;
  fill: none;
}
/* Mid-weight stroke: horizons, hills, set pieces, and any annotation that must
   actually be readable. Sits deliberately below .fig so the subject still owns
   the frame, but well clear of the panel background. */
.dgm .stroke-mid {
  stroke: var(--ink-faint);
  stroke-width: 1.3;
  fill: none;
  stroke-linejoin: round;
  stroke-linecap: round;
}
.dgm .dash {
  stroke: var(--ink-faint);
  stroke-width: 1.2;
  fill: none;
  stroke-dasharray: 5 5;
  opacity: 0.75;
}
.dgm .fig {
  fill: var(--ink-dim);
}
.dgm .fig-stroke {
  stroke: var(--ink-dim);
  fill: none;
  stroke-linecap: round;
}
/* Colour-only variants. The -s classes above pin stroke-width, which silently
   beats a stroke-width attribute; use these wherever the element sets its own. */
.dgm .warm-fill {
  fill: var(--tungsten);
}
.dgm .warm-stroke {
  stroke: var(--tungsten);
  fill: none;
  stroke-linecap: round;
}
.dgm .warm {
  fill: var(--tungsten);
}
.dgm .warm-s {
  stroke: var(--tungsten);
  fill: none;
  stroke-width: 1.6;
}
.dgm .cool {
  fill: var(--daylight);
}
.dgm .cool-s {
  stroke: var(--daylight);
  fill: none;
  stroke-width: 1.6;
}
.dgm .bad {
  fill: var(--bad);
}
.dgm .bad-s {
  stroke: var(--bad);
  fill: none;
  stroke-width: 1.6;
}
.dgm .good {
  fill: var(--good);
}
.dgm .good-s {
  stroke: var(--good);
  fill: none;
  stroke-width: 1.6;
}
.dgm .panel {
  fill: var(--surface-2);
}
.dgm text {
  font-family: var(--font-body);
  font-size: 11px;
  fill: var(--ink-dim);
}
.dgm text.lbl {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  fill: var(--ink-faint);
  text-transform: uppercase;
}
.dgm text.key {
  fill: var(--tungsten);
  font-weight: 600;
}
.dgm text.key2 {
  fill: var(--daylight);
  font-weight: 600;
}
.dgm text.no {
  fill: var(--bad);
  font-weight: 600;
}
.dgm text.yes {
  fill: var(--good);
  font-weight: 600;
}
.dgm text.big {
  font-size: 13px;
  fill: var(--ink);
  font-weight: 600;
}

/* Small icon grid used for movement / composition mini-diagrams */
.tiles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 0.9rem;
  margin: 1.3rem 0 1.6rem;
}
.tile {
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  padding: 0.9rem 0.9rem 1rem;
  text-align: center;
}
.tile svg {
  margin: 0 auto 0.6rem;
}
.tile b {
  display: block;
  font-size: 0.87rem;
  color: #fff;
}
.tile span {
  display: block;
  font-size: 0.76rem;
  color: var(--ink-faint);
  line-height: 1.45;
  margin-top: 0.15rem;
}

/* 7. Pager + footer ------------------------------------------------------ */

.pager {
  display: flex;
  gap: 1rem;
  justify-content: space-between;
  margin-top: 3.5rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--line-soft);
}
.pager a {
  flex: 1 1 0;
  display: grid;
  gap: 0.15rem;
  padding: 0.9rem 1.1rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: var(--surface);
  text-decoration: none;
  color: var(--ink);
  transition:
    border-color 0.15s ease,
    background 0.15s ease;
  max-width: 340px;
}
.pager a:hover {
  border-color: var(--line);
  background: var(--surface-2);
}
.pager a span {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
}
.pager a b {
  font-weight: 500;
  font-size: 0.95rem;
}
.pager .prev {
  text-align: left;
}
.pager .next {
  text-align: right;
}

.foot {
  margin-top: 2.6rem;
  font-size: 0.78rem;
  color: var(--ink-faint);
}

/* Index page ------------------------------------------------------------- */

.hero {
  padding: 1rem 0 2.4rem;
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 2.4rem;
}
.hero h1 {
  font-size: clamp(2.6rem, 1.5rem + 4.6vw, 4.6rem);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(236px, 1fr));
  gap: 1rem;
}
.cards a {
  display: grid;
  align-content: start;
  gap: 0.35rem;
  padding: 1.15rem 1.2rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--ink);
  transition:
    transform 0.16s ease,
    border-color 0.16s ease,
    background 0.16s ease;
}
.cards a:hover {
  transform: translateY(-2px);
  border-color: rgba(233, 177, 102, 0.4);
  background: var(--surface-2);
}
.cards a .num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--tungsten);
}
.cards a b {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.32rem;
  line-height: 1.15;
}
.cards a span {
  font-size: 0.84rem;
  color: var(--ink-faint);
  line-height: 1.5;
}

/* 8. Responsive ---------------------------------------------------------- */

@media (max-width: 900px) {
  .shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line-soft);
    padding: 1rem 0 1.1rem;
  }
  .brand {
    padding-bottom: 0.8rem;
    padding-left: 1.4rem;
    padding-right: 1.4rem;
  }
  .nav {
    display: flex;
    gap: 1.4rem;
    overflow-x: auto;
    padding-bottom: 0.4rem;
    padding-inline: 1rem;
    scrollbar-width: thin;
    max-width: 100%;
  }
  .nav > * {
    flex: 0 0 auto;
  }
  .nav-group {
    margin: 0 0 0.4rem;
    padding: 0 0.2rem;
  }
  .nav ul {
    grid-auto-flow: column;
    gap: 0.3rem;
  }
  .nav a {
    white-space: nowrap;
    border-left: 0;
    border-bottom: 2px solid transparent;
    border-radius: var(--radius-sm);
  }
  body[data-page] .nav a[data-nav] {
    border-left: 0;
  }
  main {
    padding-top: 2.2rem;
  }
  .pager {
    flex-direction: column;
  }
  .pager a {
    max-width: none;
  }
  .pager .next {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    scroll-behavior: auto !important;
  }
}

/* 9. Print --------------------------------------------------------------- */

@media print {
  :root {
    --bg: #fff;
    --surface: #fff;
    --surface-2: #f5f5f3;
    --surface-3: #ececea;
    --ink: #111;
    --ink-dim: #333;
    --ink-faint: #666;
    --line: #bbb;
    --line-soft: #ddd;
    --tungsten: #9a6b1f;
    --daylight: #1f6b80;
  }
  body {
    background: #fff;
    color: #111;
    font-size: 11pt;
  }
  .sidebar,
  .pager,
  .skip,
  .foot {
    display: none !important;
  }
  .shell {
    display: block;
  }
  main {
    padding: 0;
    max-width: none;
  }
  a {
    color: #111;
    text-decoration: none;
  }
  .card,
  .table-wrap,
  figure.dgm,
  .callout,
  .tile,
  .defcards > div {
    break-inside: avoid;
    box-shadow: none;
  }
  /* paper has no horizontal scroll, so let the diagram fit the page */
  .dgm-scroll {
    overflow: visible;
  }
  figure.dgm svg {
    min-width: 0;
  }
  table.sheet {
    min-width: 0;
    font-size: 9.5pt;
  }
  table.sheet thead th {
    position: static;
  }
  h2 {
    break-after: avoid;
  }
  figure.dgm figcaption {
    color: #444;
  }

  /* Elements that are hard-coded white for the dark theme need inverting,
     or they print as white-on-white. */
  strong,
  .deflist dt,
  .tile b,
  .cards a b,
  .pager a b,
  .keys li b,
  ol.drills li b,
  table.sheet td:first-child {
    color: #111;
  }
  a[target="_blank"]::after {
    display: none;
  }
  .crumbs a,
  .crumbs [aria-current="page"] {
    color: #444;
  }
  .section-intro {
    color: #555;
  }
  .defcards dd p {
    color: #333;
  }
  .swatch {
    border-color: #ccc;
  }
  .kelvin .bar {
    border-color: #999;
  }
}

/* 10. Page-specific components ------------------------------------------- */

/* Kelvin scale (sheet 09) */
.kelvin {
  margin: 1.3rem 0 1.7rem;
}
.kelvin .bar {
  height: 46px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: linear-gradient(
    90deg,
    #ff7a26 0%,
    #ffa14f 12%,
    #ffc489 24%,
    #ffe3c4 36%,
    #fff7ee 46%,
    #ffffff 53%,
    #e9f2ff 64%,
    #c6dcff 78%,
    #97bdff 92%,
    #7aa9ff 100%
  );
}
.kelvin .ticks {
  display: flex;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.67rem;
  color: var(--ink-faint);
}
.kelvin .ticks span {
  flex: 1 1 0;
  text-align: center;
}
.kelvin .ticks span:first-child {
  text-align: left;
}
.kelvin .ticks span:last-child {
  text-align: right;
}

/* Ratio ladder (sheet 09) */
.ratios {
  list-style: none;
  margin: 1rem 0 1.5rem;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}
.ratios li {
  display: grid;
  grid-template-columns: 82px 1fr;
  gap: 0.9rem;
  align-items: center;
  font-size: 0.88rem;
}
.ratios b {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--tungsten);
}
.ratios i {
  display: block;
  height: 10px;
  border-radius: 6px;
  font-style: normal;
  background: linear-gradient(90deg, var(--tungsten), var(--surface-3));
}

/* Numbered drill list (sheet 12) */
ol.drills {
  counter-reset: d;
  list-style: none;
  margin: 1.2rem 0 1.6rem;
  padding: 0;
  display: grid;
  gap: 1rem;
}
ol.drills li {
  counter-increment: d;
  position: relative;
  padding: 1.1rem 1.25rem 1.15rem 3.4rem;
  background: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  max-width: none;
}
ol.drills li::before {
  content: counter(d, decimal-leading-zero);
  position: absolute;
  left: 1.2rem;
  top: 1.15rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--tungsten);
}
ol.drills li b {
  display: block;
  color: #fff;
  margin-bottom: 0.2rem;
}

/* Resource lists (sheet 13) */
.links {
  list-style: none;
  margin: 0.8rem 0 1.5rem;
  padding: 0;
  display: grid;
  gap: 0.7rem;
}
.links li {
  padding-left: 1.1rem;
  position: relative;
}
.links li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--ink-faint);
}
.wheel-fig {
  margin: 0;
}
.wheel-fig b {
}