/*  Psychology from the Beginning — design system
    ----------------------------------------------------
    The Curionode editorial look in this course's own colours: a cool paper,
    Fraunces for display, Source Serif for prose, JetBrains Mono for numbers,
    and indigo where other courses use red.

    Figure colours are tokens with one meaning each: blue is the reader's own
    data, ochre published data and norms, teal a model's prediction, plum the
    brain and the body, red errors, thresholds and limits, green what is right
    or met, sienna a stimulus, olive a second group, ink outlines and text.
    Canvases read them through js/figure.js as FIG. The dark values are written
    twice — for the system preference and for an explicit choice — and must
    stay identical.
*/
@import url('../vendor/fonts/fonts.css');

:root {
    --paper: #f9f8f4;  --paper-deep: #efede6;  --paper-vellum: #eceae2;  --paper-rule: #d9d5c8;
    --ink: #1a1b22;  --ink-soft: #383a46;  --ink-mute: #696b78;  --ink-faint: #9896a0;
    --accent: #3b3f9c;  --accent-tint: #e7e8f6;
    --red: #b0322f;  --red-tint: #f6e5e2;  --blue: #2257c4;  --blue-tint: #e5ecf7;  --teal: #0f6e69;  --teal-tint: #def0ec;
    --plum: #6a3c87;  --plum-tint: #efe3f3;  --ochre: #b0761a;  --ochre-tint: #f5e8cb;  --green: #2b6b4d;  --green-tint: #dfede4;
    --sienna: #a3550f;  --olive: #5d5d20;  --input: #fffffb;
    --fig-paper: #fdfcf8;  --fig-grid: #d0ccbf;  --fig-rule: #ddd8cb;  --fig-ink: #1a1b22;  --fig-muted: #696b78;  --fig-faint: #a19fa8;
    --fig-blue: #2257c4;  --fig-red: #b0322f;  --fig-green: #2b6b4d;  --fig-teal: #0f6e69;  --fig-plum: #7a45a0;  --fig-ochre: #c07d12;  --fig-sienna: #a3550f;  --fig-olive: #6b6b28;
    --shadow: 0 2px 6px rgba(26, 27, 34, 0.06);  --shadow-lg: 0 10px 30px rgba(26, 27, 34, 0.15);
    --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;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
    --paper: #121318;  --paper-deep: #1a1b22;  --paper-vellum: #1e1f27;  --paper-rule: #34364a;
    --ink: #e7e6ee;  --ink-soft: #c4c3d0;  --ink-mute: #9795a6;  --ink-faint: #706e80;
    --accent: #a9adf5;  --accent-tint: #24264a;
    --red: #e7746c;  --red-tint: #3a2020;  --blue: #8aaaf3;  --blue-tint: #1c2540;  --teal: #57b8af;  --teal-tint: #15302d;
    --plum: #c39be0;  --plum-tint: #2d2238;  --ochre: #e8b75d;  --ochre-tint: #3a3017;  --green: #70bd92;  --green-tint: #1a3025;
    --sienna: #e3904e;  --olive: #b7b76c;  --input: #191a21;
    --fig-paper: #15161c;  --fig-grid: #353749;  --fig-rule: #34364a;  --fig-ink: #e7e6ee;  --fig-muted: #9795a6;  --fig-faint: #727085;
    --fig-blue: #8aaaf3;  --fig-red: #e7746c;  --fig-green: #70bd92;  --fig-teal: #57b8af;  --fig-plum: #c39be0;  --fig-ochre: #e8b75d;  --fig-sienna: #e3904e;  --fig-olive: #b7b76c;
    --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: #121318;  --paper-deep: #1a1b22;  --paper-vellum: #1e1f27;  --paper-rule: #34364a;
    --ink: #e7e6ee;  --ink-soft: #c4c3d0;  --ink-mute: #9795a6;  --ink-faint: #706e80;
    --accent: #a9adf5;  --accent-tint: #24264a;
    --red: #e7746c;  --red-tint: #3a2020;  --blue: #8aaaf3;  --blue-tint: #1c2540;  --teal: #57b8af;  --teal-tint: #15302d;
    --plum: #c39be0;  --plum-tint: #2d2238;  --ochre: #e8b75d;  --ochre-tint: #3a3017;  --green: #70bd92;  --green-tint: #1a3025;
    --sienna: #e3904e;  --olive: #b7b76c;  --input: #191a21;
    --fig-paper: #15161c;  --fig-grid: #353749;  --fig-rule: #34364a;  --fig-ink: #e7e6ee;  --fig-muted: #9795a6;  --fig-faint: #727085;
    --fig-blue: #8aaaf3;  --fig-red: #e7746c;  --fig-green: #70bd92;  --fig-teal: #57b8af;  --fig-plum: #c39be0;  --fig-ochre: #e8b75d;  --fig-sienna: #e3904e;  --fig-olive: #b7b76c;
    --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(--accent-tint); }
a { color: var(--accent); text-underline-offset: 2px; }
code, kbd, .mono { font-family: var(--font-mono); font-size: 0.86em; }
kbd { border: 1px solid var(--paper-rule); border-bottom-width: 2px; border-radius: 3px; padding: 0 0.35em; background: var(--paper-deep); }
p code, li code, dd 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(--accent); outline-offset: 2px; }
sub, sup { line-height: 0; }
h1, h2, h3 { font-family: var(--font-display); font-weight: 400; letter-spacing: -0.01em; }
html[lang^="zh"] body { font-family: var(--font-body), 'Songti SC', 'Noto Serif CJK SC', 'Source Han Serif SC', serif; }
.btn { border: 1px solid var(--paper-rule); background: var(--paper); color: var(--ink); cursor: pointer; font: 13px var(--font-mono); padding: 6px 12px; border-radius: 3px; }
.btn:hover { background: var(--paper-deep); }
.btn.primary { background: var(--accent); color: var(--paper); border-color: var(--accent); }
.btn:disabled { opacity: 0.5; cursor: default; }
.seg { display: inline-flex; flex-wrap: wrap; border: 1px solid var(--paper-rule); border-radius: 3px; overflow: hidden; }
.seg button { border: 0; border-right: 1px solid var(--paper-rule); background: var(--paper); padding: 5px 10px; cursor: pointer; font: 12.5px var(--font-mono); }
.seg button:last-child { border-right: 0; }
.seg button[aria-pressed="true"] { background: var(--accent); color: var(--paper); }

/* ─── Plate frame ──────────────────────────────────────────── */
.topbar { position: sticky; top: 0; z-index: 10; display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 9px 22px; background: var(--paper); border-bottom: 1px solid var(--paper-rule); }
.topbar-left { display: flex; align-items: center; gap: 16px; min-width: 0; }
.topbar-back { font: 13px var(--font-mono); color: var(--ink-mute); text-decoration: none; white-space: nowrap; }
.topbar-title { font: 15px var(--font-display); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topbar-title .icon { font: 600 11px var(--font-mono); letter-spacing: 0.1em; color: var(--accent); margin-right: 6px; text-transform: uppercase; }
.lang-btn { border: 1px solid var(--paper-rule); background: var(--paper); border-radius: 3px; padding: 4px 12px; cursor: pointer; font-size: 14px; }
.main-content { max-width: 940px; margin: 0 auto; padding: 26px 28px 60px; }
.plate-meta { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px 18px; font: 12px/1.5 var(--font-mono); color: var(--ink-mute); border-bottom: 1px solid var(--paper-rule); padding-bottom: 8px; }
.plate-meta b { color: var(--accent); font-weight: 600; }
.thread { display: inline-block; margin-left: 6px; padding: 0 6px; border: 1px solid var(--teal); color: var(--teal); border-radius: 2px; font: 600 11px var(--font-mono); }
.plate-title { font-size: 46px; line-height: 1.05; margin: 22px 0 10px; }
.plate-title em { color: var(--accent); }
.plate-deck { font: italic 20px/1.45 var(--font-body); color: var(--ink-soft); margin: 0 0 22px; }
.info-box.lede { border-left: 3px solid var(--accent); padding: 2px 0 2px 18px; margin: 0 0 22px; }
.info-box.lede p { margin: 0 0 12px; }
.preview { color: var(--ink-soft); font-size: 15.5px; }
.formula-group { display: flex; flex-wrap: wrap; gap: 6px 26px; justify-content: center; margin: 4px 0 18px; padding: 8px 0; border-top: 1px solid var(--paper-rule); border-bottom: 1px solid var(--paper-rule); }
.formula { font-size: 17px; overflow-x: auto; max-width: 100%; }
.learning-objectives { background: var(--paper-deep); border: 1px solid var(--paper-rule); padding: 12px 18px; margin: 0 0 26px; }
.learning-objectives-title, .threads-title, .example-label { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-mute); }
.learning-objectives ul { margin: 6px 0 0; padding-left: 20px; }
.section-title { font: 600 12px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); margin: 26px 0 8px; display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.model-chip, .grade-chip { font: 11px var(--font-mono); letter-spacing: 0.02em; text-transform: none; padding: 1px 8px; border-radius: 2px; }
.model-chip { color: var(--teal); border: 1px dashed var(--teal); }
.grade-chip { border: 1px solid currentColor; }
.grade-chip.settled { color: var(--green); }
.grade-chip.supported { color: var(--teal); }
.grade-chip.disputed { color: var(--ochre); }
.grade-chip.failed { color: var(--red); }
.figure { margin: 0 0 18px; }
.figure-caption { font: italic 14px/1.5 var(--font-body); color: var(--ink-mute); margin-top: 8px; }
h2 { font-size: 28px; margin: 34px 0 10px; }
.prose p { margin: 0 0 14px; }
.marginalia { border-left: 2px solid var(--plum); padding: 4px 0 4px 14px; font-size: 15px; color: var(--ink-soft); margin: 20px 0; }
dl.terms { display: grid; grid-template-columns: minmax(120px, 210px) 1fr; gap: 6px 18px; margin: 0; }
dl.terms dt { font: 600 14.5px var(--font-body); }
dl.terms dd { margin: 0; font-size: 15.5px; color: var(--ink-soft); }
.key-concept { margin: 26px 0; padding: 14px 18px; background: var(--accent-tint); border-left: 3px solid var(--accent); font-size: 17.5px; }
.threads, .sources { margin: 22px 0; font-size: 14.5px; color: var(--ink-soft); }
.threads ul, .sources ul { margin: 6px 0 0; padding-left: 20px; }
.sources .src { font: 12.5px var(--font-mono); color: var(--ink-mute); }
.example { border: 1px solid var(--paper-rule); background: var(--paper-vellum); padding: 12px 18px; margin: 22px 0; }
.example-title { font: 17px var(--font-display); margin: 4px 0 6px; }
.example ol { margin: 0; padding-left: 22px; font-size: 15.5px; }
.example li { margin: 3px 0; }
.section-break { height: 1px; background: var(--paper-rule); margin: 30px 0 14px; }
.nav-footer { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font: 13.5px var(--font-mono); }
.nav-footer a { text-decoration: none; }
.nav-report { color: var(--ink-mute) !important; }
.disclaimer { font: 12px/1.5 var(--font-body); color: var(--ink-faint); margin-top: 28px; }
.notice { border-left: 3px solid var(--accent); background: var(--accent-tint); padding: 9px 14px; margin: 12px 0 4px; font-size: 14.5px; line-height: 1.5; color: var(--ink-soft); }
.notice b { color: var(--accent); font-weight: 600; }
.care { border-left: 3px solid var(--plum); background: var(--plum-tint); padding: 9px 14px; margin: 12px 0 14px; font-size: 14.5px; line-height: 1.5; color: var(--ink-soft); }
.care b { color: var(--plum); font-weight: 600; }

/* ─── Workshop ─────────────────────────────────────────────── */
.ws { border: 1px solid var(--paper-rule); background: var(--paper-vellum); padding: 10px; }
.ws-fig { display: flex; flex-wrap: wrap; gap: 6px; }
.ws-panel { background: var(--fig-paper); border: 1px solid var(--fig-rule); overflow: hidden; }
.ws-panel canvas { display: block; touch-action: manipulation; }
.ws-anim { display: flex; align-items: center; gap: 10px; margin: 8px 0 0; }
.ws-anim:empty { display: none; }
.ws-anim input { flex: 1; }
.ws-anim .t { font: 12px var(--font-mono); color: var(--ink-mute); min-width: 90px; }
.ws-body { display: grid; grid-template-columns: 1fr 300px; gap: 12px; margin-top: 10px; }
.ws-controls { display: flex; flex-direction: column; gap: 6px; }
.ctl { display: grid; grid-template-columns: minmax(130px, 210px) 1fr auto; align-items: center; gap: 10px; font-size: 14px; }
.ctl label { color: var(--ink-soft); }
.ctl input[type=range] { width: 100%; accent-color: var(--accent); }
.ctl output { font: 12.5px var(--font-mono); white-space: nowrap; min-width: 84px; text-align: right; }
.ctl .seg { grid-column: 2 / 4; }
.rail-stats { display: flex; flex-direction: column; gap: 3px; border-left: 1px solid var(--paper-rule); padding-left: 12px; }
.stat { display: flex; justify-content: space-between; gap: 10px; font-size: 13.5px; border-bottom: 1px dotted var(--paper-rule); padding: 2px 0; }
.stat .k { color: var(--ink-mute); flex: 0 1 auto; min-width: 40%; }
.stat .v { font: 13px var(--font-mono); text-align: right; overflow-wrap: anywhere; }
.stat .v small { color: var(--ink-mute); font-size: 11px; }
.rail-stats .stat.mine { color: var(--blue); font: 12px var(--font-mono); }
.ws-note { margin-top: 10px; font-size: 15px; color: var(--ink-soft); }
.ws-note:empty, .ws-ch:empty { display: none; }
.ws-ch { margin-top: 10px; }
.ch-title { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--green); }
.ws-ch ol { list-style: none; padding: 0; margin: 4px 0 0; }
.ws-ch li { display: flex; gap: 8px; align-items: baseline; font-size: 14.5px; padding: 2px 0; }
.ws-ch .box { display: inline-flex; width: 16px; height: 16px; border: 1px solid var(--ink-faint); border-radius: 2px; align-items: center; justify-content: center; font-size: 12px; flex: none; transform: translateY(2px); }
.ws-ch li.ok .box { background: var(--green); border-color: var(--green); color: var(--paper); }
.ws-ch li.was .box { border-color: var(--green); color: var(--green); }
table.ws-table { border-collapse: collapse; width: 100%; font: 12.5px var(--font-mono); background: var(--fig-paper); }
table.ws-table th, table.ws-table td { border-bottom: 1px solid var(--fig-rule); padding: 4px 8px; text-align: left; vertical-align: top; }
table.ws-table th { color: var(--ink-mute); font-weight: 600; }
table.ws-table tr.hl td { background: var(--accent-tint); }
.ws-table-title { font: 600 11px var(--font-mono); padding: 6px 8px 0; }

/* ─── The experiment bench ─────────────────────────────────── */
.xp { border: 1px solid var(--paper-rule); background: var(--paper-deep); padding: 10px 12px; width: 100%; }
.xp-bar { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.xp-bar .st { font: 12.5px var(--font-mono); color: var(--ink-mute); }
.xp-intro { font-size: 15px; line-height: 1.5; color: var(--ink-soft); margin: 6px 0; }
.xp-stage { position: relative; margin: 8px 0; background: var(--fig-paper); border: 1px solid var(--fig-rule); display: none; outline: none; }
.xp-stage.on { display: block; }
.xp-stage canvas { display: block; margin: 0 auto; }
.xp-keys { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; padding: 8px; border-top: 1px solid var(--fig-rule); }
.xp-keys button { min-width: 72px; padding: 10px 14px; border: 1px solid var(--paper-rule); background: var(--paper); border-radius: 4px; cursor: pointer; font: 14px var(--font-mono); touch-action: manipulation; }
.xp-keys button:active { background: var(--accent-tint); }
.xp-entry { display: flex; gap: 8px; justify-content: center; padding: 8px; border-top: 1px solid var(--fig-rule); flex-wrap: wrap; }
.xp-entry input { width: min(420px, 90%); border: 1px solid var(--paper-rule); background: var(--input); color: var(--ink); padding: 7px 10px; font: 15px var(--font-mono); }
.xp-note { font: italic 12.5px/1.45 var(--font-body); color: var(--ink-faint); margin: 6px 0 0; }

/* ─── The scale bench ──────────────────────────────────────── */
.sc { width: 100%; }
.sc-item { display: grid; grid-template-columns: 26px 1fr; gap: 6px 10px; padding: 8px 0; border-bottom: 1px solid var(--paper-rule); }
.sc-item .n { font: italic 14px var(--font-display); color: var(--accent); }
.sc-item .opts { grid-column: 2; display: flex; flex-wrap: wrap; gap: 4px; }
.sc-item .opts button { border: 1px solid var(--paper-rule); background: var(--paper); padding: 4px 9px; font: 12px var(--font-mono); border-radius: 3px; cursor: pointer; }
.sc-item .opts button[aria-pressed="true"] { background: var(--accent); color: var(--paper); border-color: var(--accent); }

/* ─── Practice, drills, projects ───────────────────────────── */
.try-block, .project-block, .mis-block, .journey { border: 1px solid var(--paper-rule); padding: 12px 16px; margin: 14px 0; background: var(--paper); }
.try-block:empty, .project-block:empty { display: none; }
.try-title, .pj-title { font: 600 11px var(--font-mono); letter-spacing: 0.12em; text-transform: uppercase; color: var(--blue); }
.try-q { margin: 6px 0; }
.try-row { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.try-row input { width: 150px; border: 1px solid var(--paper-rule); background: var(--input); color: var(--ink); padding: 5px 8px; font: 14px var(--font-mono); }
.try-row .u { font: 13px var(--font-mono); color: var(--ink-mute); }
.try-msg { font-size: 14.5px; color: var(--ink-soft); margin-top: 6px; min-height: 1.2em; }
.drill-head { font: 12px var(--font-mono); color: var(--ink-mute); }
.drill-done { font: 22px var(--font-display); margin: 6px 0 10px; }
.pj-checks { list-style: none; padding: 0; }
.pj-checks li { display: flex; gap: 8px; padding: 2px 0; }
.pj-checks .box { width: 16px; flex: none; text-align: center; }
.pj-checks li.ok .box { color: var(--green); }
.pj-checks li.no .box { color: var(--red); }
.pj-foot { display: flex; align-items: center; gap: 12px; font: 13px var(--font-mono); flex-wrap: wrap; }
.from { font: 11px var(--font-mono); color: var(--ink-faint); }
.jm-sum { font: 14px var(--font-mono); margin-bottom: 8px; }
.jm-key { font-size: 13px; color: var(--ink-mute); display: flex; align-items: center; gap: 6px; flex-wrap: wrap; margin-bottom: 10px; }
.jm-vol { margin: 6px 0; }
.jm-name { font: 13px var(--font-display); }
.jm-cells { display: flex; flex-wrap: wrap; gap: 3px; }
.jm-cell { display: inline-flex; width: 24px; height: 22px; border: 1px solid var(--paper-rule); align-items: center; justify-content: center; font: 10px var(--font-mono); color: var(--ink-mute); text-decoration: none; }
.jm-cell.open { background: var(--blue-tint); }
.jm-cell.read { background: var(--green); color: var(--paper); border-color: var(--green); }
.jm-cell.cap { background: var(--ochre); color: var(--paper); border-color: var(--ochre); }

/* ─── Knowledge check ──────────────────────────────────────── */
.quiz-container { margin-top: 30px; }
.quiz-head { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 1px solid var(--ink); }
.quiz-head h3 { font-size: 24px; margin: 0 0 6px; }
.quiz-score { font: 13px var(--font-mono); color: var(--ink-mute); }
.quiz-q { padding: 10px 0; border-bottom: 1px solid var(--paper-rule); }
.quiz-q p { margin: 0 0 8px; }
.quiz-q .n { font: italic 15px var(--font-display); color: var(--accent); margin-right: 8px; }
.quiz-opts { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.quiz-opts button { text-align: left; border: 1px solid var(--paper-rule); background: var(--paper); padding: 7px 10px; cursor: pointer; font-size: 15px; border-radius: 3px; }
.quiz-opts button:hover:not(:disabled) { background: var(--paper-deep); }
.quiz-opts button.right { background: var(--green-tint); border-color: var(--green); }
.quiz-opts button.wrong { background: var(--red-tint); border-color: var(--red); }
.quiz-opts button:disabled { cursor: default; color: var(--ink); }
.quiz-why { font-size: 14.5px; color: var(--ink-soft); margin-top: 6px; }
.quiz-foot { padding: 12px 0; }

@media (max-width: 760px) {
    .main-content { padding: 18px 16px 50px; }
    .plate-title { font-size: 34px; }
    .ws-body { grid-template-columns: 1fr; }
    .rail-stats { border-left: 0; padding-left: 0; }
    .ctl { grid-template-columns: 1fr auto; }
    .ctl label, .ctl .seg { grid-column: 1 / 3; }
    .quiz-opts { grid-template-columns: 1fr; }
    dl.terms { grid-template-columns: 1fr; }
    .topbar { padding: 8px 12px; }
}