@font-face { font-family: 'Maoken Assorted Sans'; src: url('../assets/fonts/MaokenAssortedSans.woff2') format('woff2'); font-weight: 400; font-display: block; }
@font-face { font-family: 'LXGW ZhenKai GB'; src: url('../assets/fonts/LXGWZhenKaiGB-Regular.woff2') format('woff2'); font-weight: 400; font-display: block; }
@font-face { font-family: 'Noto Sans SC'; src: url('../assets/fonts/NotoSansSC-VF.woff2') format('woff2'); font-weight: 100 900; font-display: block; }
@font-face { font-family: 'Paper Cuts 2'; src: url('../assets/fonts/papercuts-2.woff2') format('woff2'); font-weight: 400; unicode-range: U+0030-0039,U+0041-005A; font-display: block; }
:root { --class-font: 'Maoken Assorted Sans','LXGW ZhenKai GB','Noto Sans SC',sans-serif; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--space-0); }
.reveal { font: 32px/1.42 var(--class-font); color: var(--ink); font-synthesis: none; }
.reveal .slides { text-align: left; }
.reveal .slides section { padding: 0; }
.reveal .slides section.slide { height: 720px; --text: var(--ink); --subtext: var(--muted); color: var(--text); }
.reveal .slides section.day { --text: var(--day-ink); --subtext: var(--day-ink); }
.slide-content { position: relative; height: 100%; padding: 66px 72px 76px; isolation: isolate; }
.slide-header { display: flex; justify-content: space-between; align-items: center; font-size: 22px; color: var(--subtext); margin-bottom: 26px; }
.reveal h1, .reveal h2, .reveal h3, .reveal p { margin: 0; font-weight: 400; }
.reveal h1 { font: 80px/1.22 var(--class-font); letter-spacing: .01em; }
.reveal h2 { font: 54px/1.22 var(--class-font); margin-bottom: 28px; }
.reveal h3 { font: 34px/1.35 var(--class-font); margin-bottom: 14px; }
.reveal p + p { margin-top: 18px; }
.reveal strong { font-weight: 400; }
.reveal em { font-style: normal; }
.reveal a { color: inherit; text-decoration-thickness: 2px; text-underline-offset: 6px; }
.reveal a:focus-visible, button:focus-visible { outline: 3px solid var(--gold); outline-offset: 5px; }
.ty-en { font-family: 'Paper Cuts 2',var(--class-font); letter-spacing: .14em; }
.ty-ui, .katex .text { font-family: 'Noto Sans SC',sans-serif; }
.reveal .katex { font-size: 1.05em; }
.reveal .katex-display { margin: 0; text-align: left; }
.reveal .katex-display > .katex { text-align: left; }
.muted, .caption { color: var(--subtext); }
.caption { font-size: 24px; line-height: 1.5; }
.slide-footer { position: absolute; bottom: 35px; left: 72px; font-size: 20px; color: var(--subtext); }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 44px; align-items: center; }
.two-col.wide-left { grid-template-columns: 1.18fr 1fr; }
.paper { position: relative; color: var(--day-ink); --subtext: var(--day-muted); width: 100%; aspect-ratio: 1431 / 906; padding: 13% 8%; display: flex; flex-direction: column; justify-content: center; isolation: isolate; }
.paper::before, .paper::after { content: ''; position: absolute; inset: 0; z-index: -1; background: url('../assets/cards/card-ivory-14x10-a-v2.png') center / 100% 100% no-repeat; }
.paper::before { transform: translate(4px,6px); filter: brightness(0); opacity: .55; }
.day .paper::before { opacity: .32; }
.paper.b { aspect-ratio: 1438 / 898; }
.paper.b::before, .paper.b::after { background-image: url('../assets/cards/card-ivory-14x10-b-v2.png'); }
.paper.cream { aspect-ratio: 1719 / 786; padding: 10% 8%; }
.paper.cream::before, .paper.cream::after { background-image: url('../assets/cards/card-cream-24x10-a-v2.png'); }
.paper .caption { margin-top: 16px; }
.reveal .slide .fragment { transition: opacity var(--motion-duration, .5s) var(--motion-easing, ease-out), transform var(--motion-duration, .5s) var(--motion-easing, ease-out), box-shadow var(--motion-duration, .5s) var(--motion-easing, ease-out); transform: translateY(12px); }
.reveal .slide .fragment.visible { transform: none; }
.reduced-motion .reveal .slide .fragment { transition: none; transform: none; }
.reveal aside.notes { display: none !important; }
.reveal .slide-number { right: 72px; bottom: 30px; background: none; color: var(--text,var(--ink)); font: 22px var(--class-font); padding: 0; }
body[data-board='day'] .reveal .slide-number { color: var(--day-ink); }
.reveal .progress { height: 4px; color: var(--gold); }
.reveal .controls { bottom: 58px; right: 16px; color: var(--ice-0); font-size: 6px; }
body[data-board='day'] .reveal .controls { color: var(--day-ink); }
/* Reveal marks the current overview page with its theme's link colour, which this deck has no theme for. */
.reveal.overview .slides section.present { outline: 12px solid var(--gold); }
.deck-tools { flex-wrap: wrap; justify-content: flex-end; max-width: calc(100vw - 32px); position: fixed; top: 10px; right: 16px; z-index: 40; display: flex; gap: 12px; opacity: 0; transition: opacity .15s; }
.deck-tools:hover, .deck-tools:focus-within { opacity: 1; }
.deck-tools button, .deck-tools a, .deck-tools select { font: 15px var(--class-font); color: var(--ink); background: var(--space-0); border: 0; padding: 7px 10px; cursor: pointer; text-decoration: none; }
body:fullscreen .deck-tools { display: none; }
.slide-background-content { background-color: var(--space-0); }
.title-layout { display: grid; grid-template-columns: 1.05fr 1fr; align-items: center; gap: 16px; margin-top: 38px; }
.title-layout .subtitle { margin-top: 28px; font-size: 30px; }
.title-layout .ty-en { color: var(--subtext); font-size: 23px; margin-top: 30px; }
.diagram { width: 100%; height: auto; display: block; }
.question-lead { max-width: 1020px; font-size: 68px; line-height: 1.3; margin: 48px 0 36px; }
.question-mark { display: inline-block; color: var(--gold); text-shadow: 4px 5px var(--space-1); }
.prompt-line { margin-top: 28px !important; font-size: 32px; }
.discussion .paper { min-height: 0; }
.discussion .paper h3 { font-size: 34px; }
.discussion .paper p { font-size: 29px; }
.discussion h2 { margin-bottom: 16px; }
.derivation h2 { margin-bottom: 20px; }
.derivation .given { font-size: 28px; color: var(--subtext); margin-bottom: 24px; }
.derivation .formula-step { display: grid; grid-template-columns: 132px 1fr; align-items: center; gap: 16px; margin-top: 20px; }
.formula-step .step-label { font-size: 25px; color: var(--subtext); }
.formula-step .math-block { font-size: 32px; }
.formula-step.long .math-block { font-size: 28px; }
.derivation .takeaway { margin-top: 26px; font-size: 30px; }
.evidence .two-col { grid-template-columns: 1fr 1.08fr; gap: 52px; }
.evidence .math-block { margin-top: 30px; }
.task .two-col { grid-template-columns: 1.1fr 1fr; align-items: start; gap: 54px; }
.task .steps { list-style: none; padding: 0; margin: 8px 0 0; counter-reset: task; }
.task .steps li { position: relative; padding-left: 58px; margin-bottom: 26px; font-size: 30px; }
.task .steps li::before { counter-increment: task; content: counter(task); position: absolute; left: 0; font: 40px 'Paper Cuts 2'; color: var(--text); }
.task .paper { padding: 13% 8%; }
.task .command { margin-top: 20px; font-size: 22px; line-height: 1.6; }
.reveal pre, .reveal code { font-family: 'Noto Sans SC',monospace; font-size: .85em; }
.reveal pre { white-space: pre-wrap; overflow-wrap: anywhere; }
.comparison table { width: 100%; border-collapse: collapse; font-size: 30px; margin-top: 26px; }
.comparison th { font-size: 25px; font-weight: 400; color: var(--text); border-bottom: 3px solid var(--text); padding: 0 10px 16px; }
.comparison td { border-bottom: 1px solid var(--subtext); padding: 19px 10px; }
.comparison th:first-child, .comparison td:first-child { text-align: left; }
.comparison th:not(:first-child), .comparison td:not(:first-child) { text-align: right; }
.comparison .prompt-line { margin-top: 32px !important; }
.closing .question-lead { font-size: 62px; margin-top: 30px; }
.closing .two-col { margin-top: 34px; }
.closing .paper { font-size: 30px; }
.backup .two-col { align-items: start; margin-top: 40px; }
.backup .math-block { font-size: 35px; margin: 24px 0; }
.backup .caption { margin-top: 22px; }
@media print {
  body { print-color-adjust: exact; -webkit-print-color-adjust: exact; }
  .deck-tools, .reveal .controls, .reveal .progress { display: none !important; }
  .reveal .slide .fragment { transform: none; transition: none; }
  .reveal .slide-number { color: inherit; }
  .reveal .pdf-page .slide-number { right: 72px; bottom: 30px; }
}

/* Projection refinements: keep controls and data clear of the footer. */
.task .paper { font-size: 28px; padding: 10% 8%; }
.task .paper .caption { font-size: 23px; }
.task .command { margin-top: 14px; font-size: 24px; line-height: 1.5; }
.task .command code { font-size: 22px; }
.comparison td { padding: 13px 10px; }
.comparison .prompt-line { margin-top: 22px !important; font-size: 29px; }
.slide.day .slide-header { color: var(--day-ink); }

/* All layout types consume the same semantic colors, in either mode. */
.deck-tools select { max-width: 130px; }
.deck-tools [hidden], .deck-tools[hidden] { display: none; }
select:focus-visible { outline: 3px solid var(--gold); outline-offset: 3px; }
body[data-preview] .deck-tools { display: none; }
.reveal .slide-number { color: var(--current-text, var(--day-ink)); }
.reveal .slide-number-pdf { color: var(--text); font: 22px var(--class-font); }

/* Classroom motion: explicit start/end states, reversible with fragments. */
.reveal .slides section.slide, .reveal > .backgrounds .slide-background,
.reveal .progress span { transition-duration: var(--motion-duration, .5s); transition-timing-function: var(--motion-easing, ease-out); }
.reveal .slide .fragment.motion-fade { transform: none; }
.reveal .slide .fragment.motion-rise { transform: translateY(18px); }
.reveal .slide .fragment.motion-paper { transform: translateY(-38px) rotate(-3deg); transform-origin: 50% 30%; }
.reveal .slide .fragment.motion-focus { opacity: 1; visibility: inherit; transform: none; box-shadow: inset 0 0 transparent; }
.reveal .slide .fragment.motion-focus.visible { box-shadow: inset 0 -5px var(--gold); }
.reveal .slide .fragment.visible { transform: none; }
.reveal .slide .focus-claim { display: inline-block; padding: 10px 0; font-size: 40px; }
.motion-study .two-col { margin-top: 32px; }
.motion-study .paper p { font-size: 30px; }
.motion-study .lead { font-size: 40px; margin: 48px 0 26px; }
.motion-study .formula-step { margin-top: 36px; }
.motion-study .focus-claim + .caption { margin-top: 38px; }
.morph-diagram { position: absolute; width: 470px; top: 166px; left: 390px; }
.morph-to .morph-diagram { width: 410px; top: 202px; left: 72px; }
.morph-copy { position: absolute; left: 585px; top: 258px; width: 590px; }
.morph-copy .math-block { margin: 32px 0; }
.motion-study .transition-question { font-size: 66px; margin: 64px 0 32px; }
.reduced-motion .reveal .slide .fragment { transition: none; transform: none; }
@media print {
  .reveal .slides section.slide, .reveal > .backgrounds .slide-background,
  .reveal .slide .fragment { transition: none !important; transform: none; }
}
.motion-reset .reveal .slides section, .motion-reset .reveal .slide-background,
.motion-reset .reveal .fragment { transition: none !important; }
.reduced-motion .reveal [data-auto-animate-target] { transition-duration: 0s !important; transition-delay: 0s !important; }

/* Compact classroom heading: main question left, unchanged context label right. */
.slide.compact-heading .slide-header {
  position:absolute;top:38px;right:64px;height:55px;margin:0;
  display:flex;align-items:center;justify-content:flex-end;
  font-size:20px;color:var(--subtext);white-space:nowrap;
}
.slide.compact-heading .lesson-heading h1,
.slide.compact-heading .lesson-heading h2 {
  font:46px/1.2 var(--class-font);letter-spacing:.01em;
  margin:0 300px 12px 0;white-space:nowrap;
}