/* Shared theme for every unit's slides. Same palette and type as CURRICULUM.html.
   Loaded after reveal.min.css; no reveal theme file is used. */

:root {
  --ground: #f3f5f6;
  --surface: #ffffff;
  --surface-sunk: #eef1f2;
  --ink: #151a1d;
  --ink-soft: #59646a;
  --ink-faint: #8a949a;
  --rule: #d9dfe1;
  --accent: #1f4a54;
  --accent-soft: #e2ecee;
  --warn: #8a3a3a;
  --warn-soft: #f6e9e9;
  --good: #1f6b3f;
  --good-soft: #e5f1e9;

  --c-root: #151a1d; --c-lp: #1f4a54; --c-ip: #8c5e12; --c-comb: #1f6b3f;
  --c-cp: #63397a; --c-apx: #8a3a3a; --c-prac: #5d686e; --c-coda: #2a4a80;
  --unit: var(--c-root);

  --f-display: "Zilla Slab", "Bitter", Georgia, serif;
  --f-body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
  --f-mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;

  --r-background-color: var(--ground);
  --r-main-font: var(--f-body);
  --r-main-font-size: 30px;
  --r-main-color: var(--ink);
  --r-heading-font: var(--f-display);
  --r-heading-color: var(--ink);
  --r-heading-line-height: 1.12;
  --r-heading-letter-spacing: -0.005em;
  --r-heading-text-transform: none;
  --r-heading-font-weight: 600;
  --r-code-font: var(--f-mono);
  --r-link-color: var(--accent);
  --r-link-color-hover: var(--ink);
  --r-selection-background-color: var(--accent-soft);
  --r-selection-color: var(--ink);
  /* syntax colours; the highlight.js GitHub theme the decks load is light-only */
  --hl-keyword: #d73a49; --hl-title: #6f42c1; --hl-number: #005cc5; --hl-string: #032f62;
  --hl-builtin: #e36209; --hl-comment: #6a737d; --hl-name: #22863a; --hl-bullet: #735c0f;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ground: #101416; --surface: #181d20; --surface-sunk: #141a1c;
    --ink: #e4e9eb; --ink-soft: #939ea4; --ink-faint: #6d787e; --rule: #283034;
    --accent: #7fbdc9; --accent-soft: #1c2b30;
    --warn: #dd9090; --warn-soft: #2e1c1c; --good: #5cbb82; --good-soft: #17281e;
    --c-root: #e4e9eb; --c-lp: #7fbdc9; --c-ip: #d6a241; --c-comb: #5cbb82;
    --c-cp: #b98fd0; --c-apx: #dd9090; --c-prac: #97a2a8; --c-coda: #8fb0e8;
    --hl-keyword: #ff7b72; --hl-title: #d2a8ff; --hl-number: #79c0ff; --hl-string: #a5d6ff;
    --hl-builtin: #ffa657; --hl-comment: #8b949e; --hl-name: #7ee787; --hl-bullet: #f2cc60;
  }
}
:root[data-theme="dark"] {
  --ground: #101416; --surface: #181d20; --surface-sunk: #141a1c;
  --ink: #e4e9eb; --ink-soft: #939ea4; --ink-faint: #6d787e; --rule: #283034;
  --accent: #7fbdc9; --accent-soft: #1c2b30;
  --warn: #dd9090; --warn-soft: #2e1c1c; --good: #5cbb82; --good-soft: #17281e;
  --c-root: #e4e9eb; --c-lp: #7fbdc9; --c-ip: #d6a241; --c-comb: #5cbb82;
  --c-cp: #b98fd0; --c-apx: #dd9090; --c-prac: #97a2a8; --c-coda: #8fb0e8;
  --hl-keyword: #ff7b72; --hl-title: #d2a8ff; --hl-number: #79c0ff; --hl-string: #a5d6ff;
  --hl-builtin: #ffa657; --hl-comment: #8b949e; --hl-name: #7ee787; --hl-bullet: #f2cc60;
}

body[data-trunk="lp"] { --unit: var(--c-lp); }
body[data-trunk="ip"] { --unit: var(--c-ip); }
body[data-trunk="comb"] { --unit: var(--c-comb); }
body[data-trunk="cp"] { --unit: var(--c-cp); }
body[data-trunk="apx"] { --unit: var(--c-apx); }
body[data-trunk="prac"] { --unit: var(--c-prac); }
body[data-trunk="coda"] { --unit: var(--c-coda); }

html, body, .reveal-viewport { background: var(--ground); }

/* ------------------------------------------------------------ base type -- */

.reveal { font-family: var(--f-body); font-size: var(--r-main-font-size); color: var(--ink); line-height: 1.42; }
.reveal .slides { text-align: left; }
.reveal .slides section { padding: 0 8px; height: 100%; }
.reveal h1, .reveal h2, .reveal h3 { font-family: var(--f-display); color: var(--ink); text-wrap: balance; }
.reveal h1 { font-size: 2.3em; font-weight: 700; margin-bottom: .3em; }
.reveal h2 { font-size: 1.45em; margin: 0 0 .55em; padding-bottom: .25em; border-bottom: 2px solid var(--ink); }
.reveal h3 { font-size: 1.02em; margin: 0 0 .35em; }
.reveal p, .reveal li { font-size: .88em; }
.reveal li li, .reveal li p { font-size: 1em; }
.reveal p { margin: 0 0 .6em; text-wrap: pretty; }
.reveal ul, .reveal ol { margin: 0 0 .6em 1.1em; display: block; }
.reveal li { margin-bottom: .28em; }
.reveal strong { font-weight: 600; }
.reveal em { font-style: italic; }
.reveal a { color: var(--accent); }
.reveal code {
  font-family: var(--f-mono); font-size: .86em;
  background: var(--surface-sunk); padding: .05em .3em; border-radius: 3px;
}
.reveal pre {
  width: 100%; margin: .2em 0 .7em; box-shadow: none; font-size: .62em;
  background: var(--surface); border: 1px solid var(--rule); border-radius: 6px;
}
.reveal pre code { background: transparent; padding: .8em 1em; max-height: 560px; line-height: 1.45; }
.reveal pre, .reveal .hljs, .reveal .hljs-subst, .reveal .hljs-emphasis, .reveal .hljs-strong { color: var(--ink); }
.reveal .hljs-doctag, .reveal .hljs-keyword, .reveal .hljs-template-tag, .reveal .hljs-template-variable,
.reveal .hljs-type, .reveal .hljs-variable.language_ { color: var(--hl-keyword); }
.reveal .hljs-title, .reveal .hljs-title.class_.inherited__ { color: var(--hl-title); }
.reveal .hljs-attr, .reveal .hljs-attribute, .reveal .hljs-literal, .reveal .hljs-meta, .reveal .hljs-number,
.reveal .hljs-operator, .reveal .hljs-selector-attr, .reveal .hljs-selector-class, .reveal .hljs-selector-id,
.reveal .hljs-variable, .reveal .hljs-section { color: var(--hl-number); }
.reveal .hljs-string, .reveal .hljs-regexp, .reveal .hljs-meta .hljs-string { color: var(--hl-string); }
.reveal .hljs-built_in, .reveal .hljs-symbol { color: var(--hl-builtin); }
.reveal .hljs-code, .reveal .hljs-comment, .reveal .hljs-formula { color: var(--hl-comment); }
.reveal .hljs-name, .reveal .hljs-quote, .reveal .hljs-selector-pseudo, .reveal .hljs-selector-tag,
.reveal .hljs-addition { color: var(--hl-name); background: transparent; }
.reveal .hljs-bullet { color: var(--hl-bullet); }
.reveal .hljs-deletion { color: var(--warn); background: transparent; }
.reveal table { font-size: .72em; border-collapse: collapse; margin: .3em 0 .8em; }
.reveal table th, .reveal table td { padding: .32em .8em; border-bottom: 1px solid var(--rule); text-align: left; }
.reveal table th { font-weight: 600; border-bottom: 2px solid var(--ink); }
.reveal table td.num, .reveal table th.num { text-align: right; font-variant-numeric: tabular-nums; }
.reveal table.dense { font-size: .6em; }
.reveal table.dense th, .reveal table.dense td { padding: .25em .55em; }

/* ------------------------------------------------------------ slide furniture */

.reveal .eyebrow {
  font-family: var(--f-mono); font-size: .42em; letter-spacing: .14em;
  text-transform: uppercase; color: var(--unit); margin: 0 0 .5em !important;
}
.muted { color: var(--ink-soft); }
.reveal .small { font-size: .74em; }
.center { text-align: center; }
.reveal .lede { font-size: 1.02em; color: var(--ink-soft); max-width: 36em; }

.title-slide h1 { max-width: 15em; }
.title-slide .unit-no {
  font-family: var(--f-display); font-weight: 700; font-size: 4.2em; line-height: 1;
  color: var(--unit); margin-bottom: .1em;
}
.reveal .title-slide .meta { font-family: var(--f-mono); font-size: .48em; color: var(--ink-soft); margin-top: 2.2em; }
.title-slide .meta span + span::before { content: "·"; margin: 0 .7em; color: var(--ink-faint); }

.reveal .slides section.divider { padding-top: 210px !important; }
section.divider h2 { border: 0; font-size: 2em; margin-bottom: .2em; }
.reveal section.divider p { font-size: 1em; color: var(--ink-soft); max-width: 30em; }

.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 1.4em; align-items: start; }
.cols.wide-left { grid-template-columns: 3fr 2fr; }
.cols.wide-right { grid-template-columns: 2fr 3fr; }
.cols.three { grid-template-columns: repeat(3, 1fr); gap: .8em; }
.cols > * { min-width: 0; }   /* let wide children scroll instead of squeezing siblings */

/* boxes for definitions, theorems, proofs, warnings */
.box {
  background: var(--surface); border: 1px solid var(--rule); border-left: 5px solid var(--accent);
  border-radius: 4px; padding: .55em .9em .45em; margin: 0 0 .7em;
}
.box > .label {
  display: block; font-family: var(--f-mono); font-size: .44em; letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent); margin-bottom: .25em;
}
.box p:last-child, .box ul:last-child { margin-bottom: .1em; }
.box.def { border-left-color: var(--unit); }
.box.def > .label { color: var(--unit); }
.box.thm { border-left-color: var(--ink); background: var(--surface); }
.box.thm > .label { color: var(--ink); }
.box.proof { border-left-color: var(--rule); background: transparent; border-style: dashed; border-left-style: solid; }
.box.proof > .label { color: var(--ink-soft); }
.box.warn { border-left-color: var(--warn); background: var(--warn-soft); }
.box.warn > .label { color: var(--warn); }
.box.good { border-left-color: var(--good); background: var(--good-soft); }
.box.good > .label { color: var(--good); }

/* the lab callout */
.lab {
  background: var(--accent-soft); border-radius: 6px; padding: .7em 1em; margin-top: .4em;
}
.lab .label { font-family: var(--f-mono); font-size: .44em; letter-spacing: .12em; text-transform: uppercase; color: var(--accent); }
.lab ol { margin-bottom: .2em; }

/* nine-problem cards */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: .45em; }
.card {
  background: var(--surface); border: 1px solid var(--rule); border-top: 4px solid var(--k, var(--ink));
  border-radius: 4px; padding: .38em .6em .3em; font-size: .62em; line-height: 1.3;
}
.card b { font-family: var(--f-display); font-size: 1.22em; font-weight: 600; display: block; }
.card .space { font-family: var(--f-mono); font-size: .8em; color: var(--ink-soft); }
.card .use { color: var(--ink-soft); display: block; margin-top: .2em; }
.k-bin { --k: var(--c-lp); } .k-perm { --k: var(--c-ip); } .k-part { --k: var(--c-cp); } .k-sched { --k: var(--c-apx); }
.reveal .legend { font-family: var(--f-mono); font-size: .42em; color: var(--ink-soft); margin-top: .6em; }
.legend i { display: inline-block; width: .9em; height: .9em; vertical-align: -.1em; margin: 0 .35em 0 1.2em; border-radius: 2px; }
.legend i:first-child { margin-left: 0; }

/* figures */
.fig { display: flex; flex-direction: column; align-items: center; }
.fig svg { max-width: 100%; height: auto; }
.reveal .fig .cap { font-size: .5em; color: var(--ink-soft); margin-top: .4em; text-align: center; max-width: 30em; }
svg text { font-family: var(--f-body); fill: var(--ink); }
svg .mono { font-family: var(--f-mono); }
svg .soft { fill: var(--ink-soft); }
svg .ink { stroke: var(--ink); }
svg .rule { stroke: var(--rule); }
svg .accent { stroke: var(--accent); }
svg .unit { stroke: var(--unit); }
svg .fill-unit { fill: var(--unit); }
svg .fill-accent { fill: var(--accent); }
svg .fill-soft { fill: var(--accent-soft); }
svg .fill-ground { fill: var(--ground); }
svg .fill-ink { fill: var(--ink); }
svg .warn { stroke: var(--warn); }
svg .fill-warn { fill: var(--warn); }
svg .good { stroke: var(--good); }
svg .fill-good { fill: var(--good); }

/* fragments that highlight instead of appearing */
.reveal .fragment.hl { opacity: 1; visibility: inherit; }
.reveal .fragment.hl.visible { background: var(--accent-soft); border-radius: 3px; }

.katex { font-size: 1.02em; }
.katex-display { margin: .45em 0 !important; overflow-x: auto; overflow-y: hidden; }

/* ------------------------------------------------------------ notes -------- */

/* Inline notes panel (key N): reveal places .speaker-notes to the right of the slide. */
.reveal .speaker-notes {
  background: var(--surface); color: var(--ink); border-left: 1px solid var(--rule);
  font-family: var(--f-body); font-size: 17px; line-height: 1.55; padding: 18px 22px;
}
.reveal .speaker-notes::before {
  content: "notes"; font-family: var(--f-mono); font-size: 11px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--unit); opacity: 1; position: static; display: block; margin-bottom: 8px;
}
.reveal .speaker-notes p { font-size: 1em; margin: 0 0 .7em; }
.reveal .speaker-notes ul { margin: 0 0 .7em 1.1em; }
.reveal .speaker-notes li { font-size: 1em; }
.reveal .speaker-notes h4 { font-family: var(--f-display); font-size: 1.05em; margin: 1em 0 .3em; }
.reveal .speaker-notes code { font-size: .9em; }
.reveal .speaker-notes .katex { font-size: 1em; }

/* Scroll/reading view: give notes room under each slide. */
.reveal-viewport.reveal-scroll .speaker-notes { font-size: 16px; }

/* ------------------------------------------------------------ reading mode */
/* ?view=read (key R): reveal is not initialised; slides stack with notes beside. */

body.reading { overflow: auto !important; height: auto !important; }
.reading .reveal { position: static; height: auto; overflow: visible; font-size: 21px; }
.reading .reveal .slides {
  position: static !important; width: auto !important; height: auto !important; inset: auto !important;
  transform: none !important; zoom: 1 !important; pointer-events: auto; perspective: none;
  max-width: 1560px; margin: 0 auto; padding: 28px 20px 90px;
}
.reading .read-slide {
  display: grid; grid-template-columns: minmax(0, 11fr) minmax(0, 8fr); gap: 26px;
  margin-bottom: 30px; align-items: start;
}
.reading .read-frame {
  background: var(--ground); border: 1px solid var(--rule); border-radius: 8px;
  padding: 22px 26px 12px; box-shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 14px rgba(0,0,0,.04);
}
.reading .reveal .slides section {
  display: block !important; position: static !important; opacity: 1 !important; visibility: visible !important;
  transform: none !important; width: auto !important; height: auto !important; top: auto !important; left: auto !important;
  padding: 0 !important; pointer-events: auto;
}
.reading .reveal .slides section.divider { padding: 30px 0 !important; }
.reading .reveal .fragment { opacity: 1 !important; visibility: visible !important; }
.reading .reveal aside.notes { display: block !important; }
.reading .read-notes { font-size: 16px; line-height: 1.6; color: var(--ink); padding-top: 4px; }
/* KaTeX's hidden MathML copy does not wrap with the visible math, and on a narrow screen it
   widened the page past the device, which zoomed the page out and pushed the button bar off. */
.reading .read-notes { overflow-x: clip; }
.reading .read-notes p, .reading .read-notes li { font-size: 1em; margin: 0 0 .7em; }
.reading .read-notes ul { margin: 0 0 .7em 1.2em; }
.reading .read-notes h4 { font-family: var(--f-display); font-size: 1.1em; margin: 1em 0 .3em; }
.reading .read-notes h4:first-of-type { margin-top: .2em; }
.reading .read-notes code { font-family: var(--f-mono); font-size: .88em; background: var(--surface-sunk); padding: .05em .3em; border-radius: 3px; }
.reading .read-notes .katex-display { margin: .6em 0 !important; }
.reading .read-no {
  display: inline-block; font-family: var(--f-mono); font-size: 12px; color: var(--ink-faint);
  text-decoration: none; margin-bottom: 6px; border-bottom: 1px solid var(--rule);
}
@media (max-width: 1000px) {
  .reading .read-slide { grid-template-columns: minmax(0, 1fr); gap: 10px; }
  .reading .reveal { font-size: 16px; }
}

/* ------------------------------------------------------------ chrome ------- */

/* The bar of buttons deck.js puts bottom left: one per key, so touch screens reach them all. */
.deck-bar {
  position: fixed; left: 10px; bottom: 6px; z-index: 30; display: flex; flex-wrap: wrap; gap: 4px;
  max-width: calc(100vw - 150px);   /* clear of reveal's arrows and slide number, bottom right */
  font-family: var(--f-mono); font-size: 11px; letter-spacing: .02em;
}
/* Bordered even with a mouse: as bare text with key hints they read as the old hint strip,
   and nobody thought to click them. */
.deck-bar button, .gl-hint {
  font: inherit; letter-spacing: inherit; color: var(--ink-soft); background: var(--surface);
  border: 1px solid var(--rule); border-radius: 4px; padding: 2px 7px 2px 4px; cursor: pointer;
}
.deck-bar button:hover, .deck-bar button:focus-visible, .gl-hint:hover { color: var(--ink); border-color: var(--ink-faint); }
.deck-bar button[aria-pressed="true"] { color: var(--unit); border-color: var(--unit); }
.deck-bar kbd {
  font-family: inherit; border: 1px solid var(--rule); border-radius: 3px;
  padding: 0 .3em; background: var(--surface-sunk); color: var(--ink-faint);
}
/* A touch screen has no keys to hint at, and needs targets a finger can hit. */
@media (hover: none), (pointer: coarse) {
  .deck-bar { font-size: 13px; gap: 4px; bottom: 8px; }
  .deck-bar kbd, .gl-hint kbd { display: none; }
  .deck-bar button { min-height: 34px; padding: 4px 11px; }
  .gl-foot .gl-hint, .gl-index-head .gl-hint { min-height: 34px; padding: 4px 10px; font-size: 13px; }
}
.reveal .slide-number { background: transparent; color: var(--ink-faint); font-family: var(--f-mono); font-size: 12px; }
.reveal .progress { color: var(--unit); height: 3px; }
.reveal .controls { color: var(--unit); }
.reveal .speaker-notes { padding-bottom: 56px; }   /* last lines clear of the button bar */

@media print {
  .deck-bar { display: none; }
}

/* ------------------------------------------------------------ glossary ----- */
/* <span class="term"> on slides; the popover and the G index are built by deck.js. */

.reveal .term {
  cursor: help; text-decoration: underline dotted var(--unit); text-decoration-thickness: 2px;
  text-underline-offset: .18em;
}
.reveal .term:hover { background: var(--accent-soft); border-radius: 3px; }

/* <span class="ref">: a name for a piece of the running example; hover shows it.
   Solid, thin and in the accent colour, so it never reads as a glossary term. */
.reveal .ref {
  cursor: zoom-in; white-space: nowrap;
  border-bottom: 1px solid var(--accent);   /* a border, not text-decoration: it also underlines KaTeX */
  padding-bottom: .04em;
}
.reveal .ref:hover { background: var(--accent-soft); border-radius: 3px; }
.ref-card {
  position: fixed; z-index: 61; max-width: min(420px, calc(100vw - 24px)); padding: 8px 12px;
  background: var(--surface); color: var(--ink); border: 1px solid var(--rule);
  border-left: 5px solid var(--accent); border-radius: 6px; box-shadow: 0 6px 28px rgba(0,0,0,.16);
  font: 17px/1.45 var(--f-body);
}
.ref-card .ref-name {
  display: block; font: 12px var(--f-mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 2px;
}
.ref-card .ref-name .katex { text-transform: none; letter-spacing: 0; font-size: 1.3em; }  /* keep $c_3$ as c₃ */
.ref-card .ref-note { display: block; font-size: .82em; color: var(--ink-soft); }
.ref-card svg { display: block; margin-top: 6px; }

.gl-pop, .gl-index {
  position: fixed; z-index: 60; background: var(--surface); color: var(--ink);
  border: 1px solid var(--rule); border-left: 5px solid var(--unit); border-radius: 6px;
  box-shadow: 0 6px 28px rgba(0,0,0,.16); font-family: var(--f-body); line-height: 1.5;
}
.gl-pop { width: min(460px, calc(100vw - 24px)); padding: 12px 16px 10px; font-size: 16px; }
.gl-term { font-family: var(--f-display); font-weight: 600; font-size: 1.15em; color: var(--unit); margin-bottom: 4px; }
.gl-def code { font-family: var(--f-mono); font-size: .9em; background: var(--surface-sunk); padding: 0 .25em; border-radius: 3px; }
.gl-foot { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 10px; }
.gl-go {
  font: 13px var(--f-mono); color: var(--accent); background: none; border: 0; padding: 0;
  cursor: pointer; text-align: left;
}
.gl-go:hover { text-decoration: underline; }
.gl-hint { font: 11px var(--f-mono); color: var(--ink-faint); white-space: nowrap; }  /* buttons: see .deck-bar */
.gl-hint kbd, .gl-index kbd {
  font-family: inherit; border: 1px solid var(--rule); border-bottom-width: 2px; border-radius: 3px;
  padding: 0 .35em; background: var(--surface); color: var(--ink-soft);
}

.gl-index {
  inset: 40px max(24px, calc(50vw - 420px)); display: flex; flex-direction: column; font-size: 15px;
}
.gl-index-head { display: flex; gap: 12px; align-items: center; padding: 14px 18px; border-bottom: 1px solid var(--rule); }
.gl-index input {
  flex: 1; font: 16px var(--f-body); color: var(--ink); background: var(--surface-sunk);
  border: 1px solid var(--rule); border-radius: 4px; padding: 6px 10px;
}
.gl-list { overflow-y: auto; padding: 4px 18px 18px; }
.gl-list h4 {
  font: 12px var(--f-mono); letter-spacing: .12em; text-transform: uppercase; color: var(--unit);
  margin: 18px 0 6px;
}
.gl-item { padding: 8px 0; border-bottom: 1px solid var(--rule); }
.gl-item .gl-term { font-size: 1.05em; margin-bottom: 2px; }
.gl-list [hidden] { display: none !important; }

/* worked examples, and pointers to proofs kept in the notes */
.box.ex { border-left-color: var(--accent); background: var(--accent-soft); }
.box.ex > .label { color: var(--accent); }
.reveal .proof-pointer { font-family: var(--f-mono); font-size: .44em; color: var(--ink-faint); letter-spacing: .04em; }

@media print {
  .gl-pop, .gl-index, .ref-card { display: none; }
}

/* link to a unit's optional interactive figures (explore.html): small, muted, skippable */
.reveal a.viz-link {
  display: inline-block; font: 13px var(--f-mono); letter-spacing: .04em; color: var(--ink-soft);
  border: 1px solid var(--rule); border-radius: 12px; padding: 2px 10px; text-decoration: none;
  background: var(--surface);
}
.reveal a.viz-link::before { content: "▸ "; color: var(--accent); }
.reveal a.viz-link:hover { color: var(--accent); border-color: var(--accent); }
.reveal .viz-link-row { position: absolute; right: 8px; top: 2px; margin: 0; }