/*  Making Movies from the Beginning — design system
    ------------------------------------------------
    The Curionode editorial look — warm paper, Fraunces for display, Source
    Serif for prose, JetBrains Mono for numbers — with the workshop set into it
    like a monitor on a desk: the camera's picture is always shown on black, as
    a viewfinder shows it, whatever the page's theme.

    Colours are tokens, and canvases read them through js/figure.js. The dark
    values are written twice, once for a system preference and once for an
    explicit choice; tools/build.py fails if the two copies differ.
*/
@import url('../vendor/fonts/fonts.css');

:root {
    --paper: #fbf8f3;  --paper-deep: #f4ede0;  --paper-vellum: #f0e9da;  --paper-rule: #e3dac6;
    --ink: #1c1c1f;  --ink-soft: #3a3a3f;  --ink-mute: #6e6e74;  --ink-faint: #9a958b;
    --red: #b8312f;  --red-tint: #f5e7e3;  --blue: #1d4ed8;  --blue-tint: #e6ecf6;  --teal: #0f6e6a;  --teal-tint: #e1eeec;
    --plum: #5a3a7a;  --plum-tint: #ece2f0;  --ochre: #b3791f;  --ochre-tint: #f4e6c8;  --green: #2d6a4f;  --green-tint: #e0ede4;
    --sienna: #a8530c;  --olive: #5a5a1c;  --input: #fffefb;
    --fig-paper: #fffdf7;  --fig-grid: #cfc6b0;  --fig-rule: #e3dac6;  --fig-ink: #1c1c1f;  --fig-muted: #6e6e74;  --fig-faint: #9a958b;
    --fig-blue: #1d4ed8;  --fig-red: #b8312f;  --fig-green: #2d6a4f;  --fig-teal: #0f6e6a;  --fig-plum: #5a3a7a;  --fig-ochre: #b3791f;  --fig-sienna: #a8530c;  --fig-olive: #5a5a1c;
    --shadow: 0 2px 6px rgba(28, 28, 31, 0.06);  --shadow-lg: 0 10px 30px rgba(28, 28, 31, 0.14);
    --font-display: 'Fraunces', 'Iowan Old Style', Georgia, serif;
    --font-body: 'Source Serif 4', 'Iowan Old Style', Georgia, serif;
    --font-mono: 'JetBrains Mono', ui-monospace, Menlo, Consolas, monospace;
    --font-zh: 'PingFang SC', 'Hiragino Sans GB', 'Noto Serif CJK SC', 'Source Han Serif SC', 'Microsoft YaHei', serif;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
    --paper: #15140f;  --paper-deep: #1d1b14;  --paper-vellum: #211f17;  --paper-rule: #39342a;
    --ink: #ece5d6;  --ink-soft: #c8c0ae;  --ink-mute: #9b9384;  --ink-faint: #756e60;
    --red: #e2706a;  --red-tint: #3b211f;  --blue: #82a8f4;  --blue-tint: #1d2740;  --teal: #4fb5ae;  --teal-tint: #16302e;
    --plum: #b492d8;  --plum-tint: #2c2339;  --ochre: #e2b257;  --ochre-tint: #3b3017;  --green: #6cba8e;  --green-tint: #1a3026;
    --sienna: #e28c48;  --olive: #b8b86a;  --input: #1c1a13;
    --fig-paper: #18160f;  --fig-grid: #3a3427;  --fig-rule: #3a3427;  --fig-ink: #ece5d6;  --fig-muted: #9b9384;  --fig-faint: #756e60;
    --fig-blue: #82a8f4;  --fig-red: #e2706a;  --fig-green: #6cba8e;  --fig-teal: #4fb5ae;  --fig-plum: #b492d8;  --fig-ochre: #e2b257;  --fig-sienna: #e28c48;  --fig-olive: #b8b86a;
    --shadow: 0 2px 6px rgba(0, 0, 0, 0.38);  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
    }
}
:root[data-theme="dark"] {
    --paper: #15140f;  --paper-deep: #1d1b14;  --paper-vellum: #211f17;  --paper-rule: #39342a;
    --ink: #ece5d6;  --ink-soft: #c8c0ae;  --ink-mute: #9b9384;  --ink-faint: #756e60;
    --red: #e2706a;  --red-tint: #3b211f;  --blue: #82a8f4;  --blue-tint: #1d2740;  --teal: #4fb5ae;  --teal-tint: #16302e;
    --plum: #b492d8;  --plum-tint: #2c2339;  --ochre: #e2b257;  --ochre-tint: #3b3017;  --green: #6cba8e;  --green-tint: #1a3026;
    --sienna: #e28c48;  --olive: #b8b86a;  --input: #1c1a13;
    --fig-paper: #18160f;  --fig-grid: #3a3427;  --fig-rule: #3a3427;  --fig-ink: #ece5d6;  --fig-muted: #9b9384;  --fig-faint: #756e60;
    --fig-blue: #82a8f4;  --fig-red: #e2706a;  --fig-green: #6cba8e;  --fig-teal: #4fb5ae;  --fig-plum: #b492d8;  --fig-ochre: #e2b257;  --fig-sienna: #e28c48;  --fig-olive: #b8b86a;
    --shadow: 0 2px 6px rgba(0, 0, 0, 0.38);  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.5);
}

/* ─── Base ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 17px/1.62 var(--font-body); font-optical-sizing: auto; }
::selection { background: var(--ochre-tint); }
a { color: var(--blue); text-underline-offset: 2px; }
code, kbd, .mono { font-family: var(--font-mono); font-size: 0.86em; }
p code, li code, dd code, .prose code, .info-box code, .marginalia code, .key-concept code, .quiz-container code { background: var(--paper-deep); border: 1px solid var(--paper-rule); border-radius: 3px; padding: 0 0.28em; }
button { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--blue); outline-offset: 2px; }
sub, sup { line-height: 0; }

/* ─── Topbar ───────────────────────────────────────────────── */
.topbar { position: sticky; top: 0; z-index: 20; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 12px 32px;
    background: color-mix(in srgb, var(--paper) 92%, transparent); backdrop-filter: blur(6px); border-bottom: 1px solid var(--paper-rule); }
.topbar-left { display: flex; align-items: baseline; gap: 20px; min-width: 0; }
.topbar-right { display: flex; align-items: center; gap: 8px; }
.topbar-back { font: 500 11px/1 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-mute); text-decoration: none; white-space: nowrap; }
.topbar-back:hover { color: var(--red); }
.topbar-title { font: 400 19px/1.2 var(--font-display); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topbar-title .icon { font: 600 12px/1 var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--red); margin-right: 10px; }
.lang-btn { border: 1px solid var(--paper-rule); background: var(--paper); font: 500 12px/1 var(--font-mono); padding: 6px 12px; border-radius: 3px; cursor: pointer; }
.lang-btn:hover { border-color: var(--ink-mute); }

/* ─── The plate ────────────────────────────────────────────── */
.main-content { max-width: 1080px; margin: 0 auto; padding: 34px 32px 80px; }
.plate-meta { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding-bottom: 10px; border-bottom: 1px solid var(--paper-rule);
    font: 500 11px/1.6 var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-mute); }
.plate-meta b { color: var(--red); font-weight: 600; margin-right: 8px; }
.thread { display: inline-block; margin-left: 6px; padding: 0 5px; border: 1px solid var(--teal); color: var(--teal); border-radius: 2px; font-size: 10px; }
h1.plate-title { font: 400 clamp(36px, 6vw, 56px)/1.05 var(--font-display); font-variation-settings: 'opsz' 144, 'SOFT' 30; letter-spacing: -0.02em; margin: 32px 0 14px; }
h1.plate-title em { color: var(--red); }
.plate-deck { font: italic 20px/1.45 var(--font-body); color: var(--ink-soft); margin: 0 0 32px; max-width: 720px; }
.info-box.lede { border-left: 3px solid var(--ink); padding: 2px 0 2px 18px; margin: 0 0 30px; max-width: 720px; }
.info-box.lede p { margin: 0 0 12px; }
.info-box.lede > p:first-child::first-letter { float: left; font: 400 66px/0.84 var(--font-display); color: var(--red); margin: 6px 10px 0 0; }
.info-box.lede > p.preview { font-style: italic; padding-top: 12px; border-top: 1px solid var(--paper-rule); font-size: 15px; color: var(--ink-soft); }
.formula-group { display: flex; flex-wrap: wrap; gap: 18px 40px; align-items: center; background: var(--paper-deep); border-top: 1px solid var(--paper-rule); border-bottom: 1px solid var(--paper-rule); padding: 20px 26px; margin: 0 0 30px; max-width: 760px; }
.formula { font-size: 17px; overflow-x: auto; max-width: 100%; }
.formula[data-eq]::after { content: '(' attr(data-eq) ')'; margin-left: 16px; font: italic 13px var(--font-body); color: var(--ink-faint); }
.learning-objectives { border-top: 1px solid var(--ink); padding-top: 14px; margin: 0 0 34px; max-width: 720px; }
.learning-objectives-title, .section-title { font: 600 11px/1.4 var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-mute); }
.learning-objectives-title::before { content: '§ '; color: var(--red); }
.learning-objectives ul { list-style: none; padding: 0; margin: 12px 0 0; counter-reset: obj; }
.learning-objectives li { counter-increment: obj; position: relative; padding: 6px 0 6px 36px; border-bottom: 1px solid var(--paper-rule); }
.learning-objectives li::before { content: counter(obj, decimal-leading-zero); position: absolute; left: 0; top: 7px; font: italic 14px var(--font-display); color: var(--red); }
.section-title { margin: 20px 0 16px; display: flex; align-items: center; gap: 12px; }
.section-title::before { content: ''; width: 26px; border-top: 1px solid var(--ink-mute); }
h2 { font: 400 30px/1.2 var(--font-display); letter-spacing: -0.01em; margin: 44px 0 14px; }
.prose { max-width: 720px; }
.prose p { margin: 0; }
.prose p + p { text-indent: 1.4em; margin-top: 12px; }
.marginalia { margin: 28px 0; padding: 12px 16px; max-width: 760px; border-left: 2px solid var(--red); background: var(--red-tint); font: italic 15px/1.55 var(--font-body); color: var(--ink-soft); }
/* The two optional boxes: the arithmetic behind a plate, and something to try with a phone. */
.aside-box { margin: 24px 0; padding: 12px 16px 14px; max-width: 760px; border: 1px solid var(--paper-rule); background: var(--paper-deep); font-size: 15.5px; color: var(--ink-soft); }
.aside-box > b { display: block; margin-bottom: 4px; font: 600 11px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--teal); }
.aside-box.shoot > b { color: var(--sienna); }
.aside-box p { margin: 6px 0 0; }
dl.terms { max-width: 720px; margin: 0; }
dl.terms dt { font: italic 18px var(--font-display); margin-top: 14px; }
dl.terms dd { margin: 4px 0 0; padding-bottom: 12px; border-bottom: 1px solid var(--paper-rule); color: var(--ink-soft); }
.key-concept { margin: 40px 0; padding: 4px 0 4px 22px; max-width: 720px; border-left: 3px solid var(--red); font: italic 21px/1.45 var(--font-body); }
.key-concept::before { content: 'In short'; display: block; margin-bottom: 6px; font: 600 11px/1 var(--font-mono); font-style: normal; letter-spacing: 0.14em; text-transform: uppercase; color: var(--red); }
html[lang="zh"] .key-concept::before { content: '要点'; }
.key-concept strong { font-weight: 600; }
.threads { max-width: 720px; margin: 0 0 20px; font-size: 15px; color: var(--ink-soft); }
.threads-title { font: 600 11px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-mute); }
.threads ul { margin: 6px 0 0; padding-left: 1.2em; }
.section-break { text-align: center; margin: 46px 0 20px; color: var(--ink-faint); }
.section-break::before { content: '⁂'; font-size: 22px; }
.nav-footer { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; border-top: 1px solid var(--paper-rule); padding-top: 16px;
    font: 500 12px var(--font-mono); letter-spacing: 0.08em; text-transform: uppercase; }
.nav-footer a { color: var(--ink-soft); text-decoration: none; }
.nav-footer a:hover { color: var(--red); }
.nav-footer a.nav-report { color: var(--ink-faint); }

/* ─── Figures and controls ─────────────────────────────────── */
main { counter-reset: fig; }
.figure { margin: 0 0 26px; counter-increment: fig; }
.figure-caption { margin-top: 10px; font: italic 14px/1.5 var(--font-body); color: var(--ink-soft); max-width: 780px; }
.figure-caption::before { content: 'Fig. ' counter(fig) '.'; margin-right: 8px; font: 600 11px var(--font-mono); font-style: normal; letter-spacing: 0.1em; text-transform: uppercase; color: var(--red); }
html[lang="zh"] .figure-caption::before { content: '图 ' counter(fig); }
.btn, .seg button, .chip { border: 1px solid var(--paper-rule); background: var(--paper); color: var(--ink-soft); font: 500 12px/1 var(--font-mono); padding: 7px 10px; border-radius: 3px; cursor: pointer; white-space: nowrap; }
.btn:hover, .seg button:hover, .chip:hover { border-color: var(--ink-mute); color: var(--ink); }
.btn.primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.btn[disabled] { opacity: 0.45; cursor: default; }
.seg { display: inline-flex; flex-wrap: wrap; }
.seg button { border-radius: 0; margin-left: -1px; }
.seg button:first-child { border-radius: 3px 0 0 3px; margin-left: 0; }
.seg button:last-child { border-radius: 0 3px 3px 0; }
.seg button[aria-pressed="true"], .chip[aria-pressed="true"] { background: var(--ink); color: var(--paper); border-color: var(--ink); position: relative; }
input[type="range"] { accent-color: var(--red); }
input[type="checkbox"] { accent-color: var(--red); }

/* ─── The workshop ─────────────────────────────────────────── */
.ws { border: 1px solid var(--paper-rule); background: var(--fig-paper); box-shadow: var(--shadow); }
.ws-bar { display: flex; flex-wrap: wrap; gap: 8px 12px; align-items: center; padding: 8px 12px; border-bottom: 1px solid var(--paper-rule); background: var(--paper); font: 12px var(--font-mono); color: var(--ink-mute); }
.ws-bar .sp { flex: 1; }
.ws-title { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-soft); }
.chips { display: inline-flex; flex-wrap: wrap; gap: 5px; }
.ws-note { padding: 9px 14px; border-top: 1px solid var(--paper-rule); background: var(--paper); font: 14px/1.5 var(--font-body); color: var(--ink-soft); }
.ws-body { padding: 12px; }
canvas { display: block; width: 100%; }
/* dials and the numbers they give */
.ctl-grid { display: grid; gap: 7px; margin-bottom: 12px; }
.ctl { display: grid; grid-template-columns: minmax(7em, 0.9fr) minmax(0, 1.4fr) 4.6em; gap: 8px; align-items: center; font: 13px var(--font-body); color: var(--ink-soft); }
.ctl label { line-height: 1.25; }
.ctl input[type=range] { width: 100%; min-width: 0; }
.ctl .seg { grid-column: 2 / 4; }
.ctl .seg button { padding: 5px 8px; font-size: 11.5px; }
.ctl input[type=checkbox] { justify-self: start; }
.ctl:has(input[type=checkbox]) { grid-template-columns: auto 1fr; }
.ctl-v { font: 12px var(--font-mono); color: var(--ink); text-align: right; white-space: nowrap; }
dl.readouts { margin: 0; display: grid; grid-template-columns: 1fr; border-top: 1px solid var(--paper-rule); }
dl.readouts > div { display: flex; justify-content: space-between; gap: 10px; padding: 4px 0; border-bottom: 1px solid var(--paper-rule); font-size: 13.5px; }
dl.readouts dt { color: var(--ink-mute); }
dl.readouts dd { margin: 0; font: 600 12.5px var(--font-mono); color: var(--ink); text-align: right; }
/* the stage: frame on black, plan on paper */
.st-body { display: grid; grid-template-columns: minmax(0, 1.65fr) minmax(250px, 1fr); gap: 12px; }
.st-left, .st-right { min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.st-frames { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 8px; }
.st-frame { min-width: 0; }
.st-canvas { background: #000; }
.st-plan .st-canvas { background: var(--fig-paper); border: 1px solid var(--paper-rule); }
.st-cap { font: 600 10.5px var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-mute); margin: 0 0 4px; }
.st-ovbar { display: flex; flex-wrap: wrap; gap: 6px 10px; align-items: center; font: 12px var(--font-mono); color: var(--ink-mute); }
.st-ovbar .seg button { font-size: 11px; padding: 5px 7px; }
.st-time { display: flex; gap: 8px; align-items: center; }
.st-time:empty { display: none; }
.st-time input { flex: 1; min-width: 0; }
.st-tl { font: 12px var(--font-mono); color: var(--ink-soft); white-space: nowrap; }
.st-side { min-width: 0; }
/* the cutting room */
.cr-body { display: flex; flex-direction: column; gap: 8px; }
.cr-top { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(220px, 1fr); gap: 12px; }
.cr-viewer { background: #000; min-width: 0; }
.cr-transport, .cr-tools, .cr-bin { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; }
.cr-transport input { flex: 1; min-width: 80px; }
.cr-tc { font: 12px var(--font-mono); color: var(--ink-soft); }
.cr-trim, .cr-jl { display: inline-flex; gap: 4px; flex-wrap: wrap; }
.cr-trim[hidden], .cr-jl[hidden], .cr-trans[hidden], .cr-tools button[hidden] { display: none; }
.cr-binh { font: 12px var(--font-body); color: var(--ink-mute); margin-right: 4px; }
.cr-edl { margin: 8px 0 0; padding: 8px 10px; font: 11px/1.5 var(--font-mono); color: var(--ink); background: var(--paper-deep); border: 1px solid var(--paper-rule); border-radius: 3px; overflow-x: auto; white-space: pre; }
.cr-tl { border: 1px solid var(--paper-rule); cursor: pointer; }
/* the board: cards, bins, orders, maps */
.bd-body { display: flex; flex-direction: column; gap: 10px; }
.bd-h { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-mute); margin-bottom: 6px; width: 100%; }
.bd-pool { display: flex; flex-wrap: wrap; gap: 6px; padding: 10px; border: 1px dashed var(--paper-rule); background: var(--paper); min-height: 54px; }
.bd-bins { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 8px; }
.bin { border: 1px solid var(--paper-rule); background: var(--paper); padding: 8px; min-height: 90px; display: flex; flex-direction: column; gap: 5px; cursor: pointer; }
.bin.ready { border-color: var(--blue); box-shadow: inset 0 0 0 1px var(--blue); }
.bin-h { font: 600 12px var(--font-mono); color: var(--ink); border-bottom: 1px solid var(--paper-rule); padding-bottom: 4px; margin-bottom: 2px; }
.card { text-align: left; border: 1px solid var(--paper-rule); background: var(--fig-paper); padding: 6px 9px; border-radius: 3px; cursor: pointer; font: 14px/1.35 var(--font-body); color: var(--ink); }
.card.sel { border-color: var(--blue); background: var(--blue-tint); }
.card.ok { border-color: var(--green); background: var(--green-tint); }
.card.no { border-color: var(--red); background: var(--red-tint); }
.bd-empty { margin: 0; font-style: italic; color: var(--ink-mute); }
.bd-foot { font: 600 12px var(--font-mono); color: var(--ink-soft); }
.bd-order { margin: 0; padding: 0 0 0 1.6em; }
.bd-order li { display: flex; justify-content: space-between; gap: 10px; align-items: center; padding: 6px 8px; margin: 4px 0; border: 1px solid var(--paper-rule); background: var(--paper); }
.bd-order li.ok { border-color: var(--green); }
.bd-order small { display: block; color: var(--ink-mute); font-size: 13px; }
.ord-b { display: inline-flex; gap: 4px; }
.bd-mapbody { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(200px, 1fr); }
.bd-map { min-width: 0; grid-row: span 2; }
.bd-info { padding: 10px 12px; border: 1px solid var(--paper-rule); background: var(--paper); font-size: 15px; color: var(--ink-soft); min-height: 80px; }
.bd-info p { margin: 6px 0 0; }
.bd-keys { display: flex; flex-wrap: wrap; gap: 4px; align-content: flex-start; }
.bd-year { font: 600 22px var(--font-mono); color: var(--red); margin-right: 12px; }
.bd-y { font: 12px var(--font-mono); color: var(--ink-mute); }
.bd-range { width: 100%; }
.calc-body { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(240px, 1fr); }
.bd-strip { border: 1px solid var(--paper-rule); }
.bd-strip canvas { display: block; width: 100%; cursor: pointer; }
.op-body { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(220px, 1fr); gap: 14px; }
.op-fig { min-width: 0; border: 1px solid var(--paper-rule); }
.gd-body { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(240px, 1fr); gap: 14px; }
.gd-left { min-width: 0; border: 1px solid var(--paper-rule); align-self: start; }
.gd-left canvas, .gd-scope canvas { display: block; width: 100%; }
.gd-right { min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.gd-scope { border: 1px solid var(--paper-rule); }
.gd-vec { max-width: 220px; }
.gd-time { display: flex; gap: 8px; align-items: center; padding: 6px 8px; border-top: 1px solid var(--paper-rule); }
.gd-time .bd-range { flex: 1; }
.op-fig canvas { display: block; width: 100%; cursor: crosshair; }
.calc-fig { min-width: 0; border: 1px solid var(--paper-rule); }

/* tasks: graded by measuring what the reader made */
.tasks { margin: 18px 0 8px; }
.task { border: 1px solid var(--paper-rule); background: var(--paper); margin: 10px 0; padding: 12px 16px; }
.task-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; }
.task-head p { margin: 0; }
.task-state { font: 600 11px var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-faint); white-space: nowrap; }
.task.solved { border-color: var(--green); background: var(--green-tint); }
.task.solved .task-state { color: var(--green); }
.task .row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 8px; }
.task .msg { font: 14px/1.5 var(--font-body); margin-top: 8px; color: var(--ink-soft); }
.task .msg:empty { display: none; }
.task .opts { display: grid; gap: 5px; margin-top: 8px; }
.task .opts button { text-align: left; border: 1px solid var(--paper-rule); background: var(--paper); padding: 6px 10px; border-radius: 3px; cursor: pointer; font: 14px/1.4 var(--font-body); }
.task .opts button.right { border-color: var(--green); background: var(--green-tint); }
.task .opts button.wrong { border-color: var(--red); background: var(--red-tint); }
.drill-score { font: 600 13px var(--font-mono); color: var(--ink-soft); margin: 8px 0; }

/* ─── The knowledge check ─────────────────────────────────── */
.quiz-container { margin: 46px 0 0; max-width: 780px; }
.quiz-title { font: 400 28px var(--font-display); margin: 0 0 4px; }
.quiz-sub { font: italic 15px var(--font-body); color: var(--ink-mute); margin: 0 0 16px; }
.quiz-q { border-top: 1px solid var(--paper-rule); padding: 16px 0; }
.quiz-q-text { margin: 0 0 10px; }
.quiz-q-text b { font: 600 12px var(--font-mono); color: var(--red); margin-right: 8px; }
.quiz-opts { display: grid; gap: 6px; }
.quiz-opt { text-align: left; border: 1px solid var(--paper-rule); background: var(--paper); cursor: pointer; padding: 8px 12px; border-radius: 3px; font: 15px/1.45 var(--font-body); }
.quiz-opt:hover:not([disabled]) { border-color: var(--ink-mute); }
.quiz-opt.right { border-color: var(--green); background: var(--green-tint); }
.quiz-opt.wrong { border-color: var(--red); background: var(--red-tint); }
.quiz-opt[disabled] { cursor: default; }
.quiz-expl { margin: 10px 0 0; font-size: 15px; color: var(--ink-soft); padding-left: 12px; border-left: 2px solid var(--paper-rule); }
.quiz-score { font: 600 13px var(--font-mono); margin-top: 14px; color: var(--ink-soft); }

/* ─── Projects and the journey map (Vol. XXXI) ─────────────── */
.brief-h { font: 600 11px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--red); margin-top: 16px; }
.brief { list-style: none; margin: 10px 0; padding: 0; counter-reset: brief; }
.brief li { counter-increment: brief; display: grid; grid-template-columns: 2.2em 1fr 6.5em; gap: 10px; align-items: baseline; padding: 9px 12px; border: 1px solid var(--paper-rule); border-left: 4px solid var(--ink-faint); background: var(--paper); margin: 6px 0; font: 15px/1.45 var(--font-body); }
.brief li::before { content: counter(brief, decimal-leading-zero); font: 600 12px var(--font-mono); color: var(--red); }
.brief li em { font: 600 11px var(--font-mono); font-style: normal; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-faint); text-align: right; }
.brief li.met { border-left-color: var(--green); background: var(--green-tint); }
.brief li.met em { color: var(--green); }
.brief-bar { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-top: 10px; }
.brief-score { font: 600 13px var(--font-mono); color: var(--ink-soft); margin-right: auto; }
.journey { padding: 14px 16px; background: var(--paper); border: 1px solid var(--paper-rule); }
.jsum { display: flex; flex-wrap: wrap; gap: 6px 22px; font: 14px var(--font-body); color: var(--ink-soft); margin-bottom: 10px; }
.jsum b { font: 600 18px var(--font-mono); color: var(--ink); }
.jkey { display: flex; flex-wrap: wrap; gap: 4px 18px; font: 12px var(--font-mono); color: var(--ink-mute); margin-bottom: 12px; }
.jkey span { display: inline-flex; align-items: center; gap: 6px; }
.jrow { display: grid; grid-template-columns: 3.4em 15em 1fr; gap: 8px; align-items: center; padding: 3px 0; border-top: 1px solid var(--paper-rule); }
.jvol { font: 600 12px var(--font-mono); color: var(--red); }
.jname { font: 13px var(--font-body); color: var(--ink-soft); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.jcells { display: flex; flex-wrap: wrap; gap: 3px; }
.jc { display: inline-block; width: 13px; height: 13px; border: 1px solid var(--paper-rule); background: var(--paper-deep); }
.jc.opened { background: var(--ochre-tint); border-color: var(--ochre); }
.jc.read { background: var(--blue-tint); border-color: var(--blue); }
.jc.mastered { background: var(--green); border-color: var(--green); }
.jc.project { outline: 2px solid var(--red); outline-offset: 1px; }

/* ─── Chinese ──────────────────────────────────────────────── */
html[lang="zh"] body { font-family: var(--font-body), var(--font-zh); }
html[lang="zh"] h1.plate-title, html[lang="zh"] h2 { font-family: var(--font-display), var(--font-zh); letter-spacing: 0; }
html[lang="zh"] .info-box.lede > p:first-child::first-letter { float: none; font: inherit; color: inherit; margin: 0; }
html[lang="zh"] .prose p + p { text-indent: 2em; }

/* ─── Narrow viewports ─────────────────────────────────────── */
@media (max-width: 900px) {
    .st-body, .cr-top, .calc-body, .bd-mapbody, .op-body, .gd-body { grid-template-columns: minmax(0, 1fr); }
    .bd-map { grid-row: auto; }
}
@media (max-width: 760px) {
    body { font-size: 16px; }
    .topbar { padding: 10px 16px; }
    .topbar-title { display: none; }
    .main-content { padding: 22px 16px 60px; }
    .ws-body { padding: 8px; }
    .ctl { grid-template-columns: minmax(6em, 1fr) minmax(0, 1.3fr) 4.2em; }
}
@media (max-width: 620px) {
    .brief li { grid-template-columns: 2em 1fr; } .brief li em { grid-column: 2; text-align: left; }
    .jrow { grid-template-columns: 3em 1fr; } .jcells { grid-column: 1 / -1; }
}

/* the sound desk */
.sd-body { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(240px, 1fr); gap: 12px; }
.sd-left, .sd-right { min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.sd-pic { background: #000; }
.sd-sub { min-height: 1.6em; text-align: center; font: italic 15px var(--font-body); color: var(--ink); background: var(--paper-deep); padding: 3px 8px; }
.sd-lanes, .sd-spec { border: 1px solid var(--paper-rule); cursor: pointer; }
.sd-trans { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.sd-tl { font: 12px var(--font-mono); color: var(--ink-soft); }
.sd-h { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-mute); margin: 2px 0 6px; }
.sd-strip { display: grid; grid-template-columns: 10px minmax(5em, 1fr) auto auto minmax(60px, 1.2fr) 4.4em; gap: 6px; align-items: center; padding: 3px 0; border-bottom: 1px solid var(--paper-rule); font-size: 13.5px; }
.sd-dot { width: 10px; height: 10px; border-radius: 50%; }
.sd-strip .btn { padding: 4px 7px; }
.sd-strip .btn[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.sd-g { font: 11.5px var(--font-mono); text-align: right; color: var(--ink); }
.sd-strip input { width: 100%; min-width: 0; }
.sd-vk { display: block; font-size: 14px; color: var(--ink-soft); }
@media (max-width: 900px) { .sd-body { grid-template-columns: minmax(0, 1fr); } }

/* the writers' room: an editor and the formatted page */
.wr-body { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr); gap: 12px; }
.wr-left, .wr-right { min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.wr-bar { font: 12px var(--font-mono); color: var(--ink-mute); }
.wr-edit { width: 100%; min-height: 360px; flex: 1; resize: vertical; border: 1px solid var(--paper-rule); background: var(--input); color: var(--ink); font: 13px/1.55 var(--font-mono); padding: 10px 12px; tab-size: 4; }
.wr-page { background: #fffefa; color: #1c1c1f; border: 1px solid var(--paper-rule); box-shadow: var(--shadow); padding: 18px 22px; min-height: 260px; max-height: 460px; overflow: auto; font: 13px/1.5 'Courier New', Courier, var(--font-mono), var(--font-zh); }
.wr-page .wr-h { font-weight: 700; text-transform: none; margin-top: 4px; }
.wr-page .wr-a { margin: 0; }
.wr-page .wr-c { margin: 0 0 0 38%; }
.wr-page .wr-p { margin: 0 0 0 31%; font-style: italic; }
.wr-page .wr-d { margin: 0 18% 0 22%; }
.wr-page .wr-t { text-align: right; }
.wr-page .wr-gap { height: 1.5em; }
.wr-page .wr-empty { color: #888; font-style: italic; }
.wr-page mark { padding: 0 1px; }
.wr-page mark.wr-cam { background: #cfe0ff; }
.wr-page mark.wr-think { background: #ffd9d3; }
.wr-page mark.wr-cost { background: #ffe9a8; }
@media (max-width: 900px) { .wr-body { grid-template-columns: minmax(0, 1fr); } }
.ll-slots { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 10px; }
.ll-slot { display: flex; flex-direction: column; gap: 5px; }
.ll-out { border: 1px solid var(--paper-rule); background: var(--paper); padding: 10px 14px; font: italic 17px/1.5 var(--font-body); }
.ll-out p { margin: 4px 0 0; }
.ll-gap { display: inline-block; min-width: 6em; border-bottom: 1px dashed var(--ink-faint); color: var(--ink-faint); font-style: normal; font-size: 13px; }