/*  Piano from the Beginning — design system
    ----------------------------------------
    Score paper: ivory ground, charcoal ink, Fraunces for display, Source Serif
    for prose, JetBrains Mono for numbers and note names. The accent is the red
    of hammer felt; the right hand is drawn in it and the left hand in blue,
    on every keyboard, score and graph in the course.

    A plate is a title, a lede, a workshop (the bench, with its controls and
    readings beside it), the prose, an "At the piano" box, terms, try-its and
    the ten-question check. Colours are tokens; canvases read the --fig-* ones
    through js/figure.js. The dark values are written twice, once for a system
    preference and once for an explicit choice, and tools/build.py fails if the
    two copies differ.
*/
@import url('../vendor/fonts/fonts.css');

:root {
    --paper: #f8f6f1;  --paper-deep: #efebe2;  --paper-rule: #ddd6c8;
    --ink: #1d1c22;  --ink-soft: #393841;  --ink-mute: #66646e;  --ink-faint: #98948c;
    --accent: #9c3d2e;  --accent-tint: #f3e1dc;  --blue: #2c5a8c;  --blue-tint: #dfe8f2;  --red: #a8322b;  --green: #2f6b46;  --green-tint: #dcefe3;  --ochre: #a8781e;  --ochre-tint: #f4e7c9;
    --input: #fffefa;
    --fig-paper: #fffdf9;  --fig-grid: #d6cfc0;  --fig-rule: #e9e3d7;  --fig-ink: #1d1c22;  --fig-muted: #66646e;  --fig-faint: #a39e94;
    --fig-blue: #2c5a8c;  --fig-red: #9c3d2e;  --fig-green: #2f6b46;  --fig-teal: #17706c;  --fig-plum: #6a3d7a;  --fig-ochre: #a8781e;  --fig-sienna: #94501c;  --fig-olive: #62621f;
    --fig-rh: #9c3d2e;  --fig-lh: #2c5a8c;  --fig-ivory: #fffdf6;  --fig-ebony: #22212a;  --fig-wood: #8a5a33;  --fig-felt: #c9b48e;  --fig-steel: #8e959c;  --fig-brass: #b59339;  --fig-skin: #e8c4a6;
    --shadow: 0 2px 6px rgba(29, 28, 34, 0.07);
    --font-display: 'Fraunces', 'Iowan Old Style', Georgia, serif;
    --font-body: 'Source Serif 4', 'Iowan Old Style', Georgia, 'Songti SC', 'Noto Serif CJK SC', serif;
    --font-mono: 'JetBrains Mono', ui-monospace, Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
    --paper: #141418;  --paper-deep: #1c1c21;  --paper-rule: #33333b;
    --ink: #ebe8e1;  --ink-soft: #c9c5bc;  --ink-mute: #9d9a93;  --ink-faint: #706d68;
    --accent: #e3846f;  --accent-tint: #3a211c;  --blue: #84a9da;  --blue-tint: #1c2735;  --red: #e7746a;  --green: #74bf90;  --green-tint: #183022;  --ochre: #e2b25a;  --ochre-tint: #382d16;
    --input: #1a1a1f;
    --fig-paper: #18181d;  --fig-grid: #3a3a42;  --fig-rule: #29292f;  --fig-ink: #ebe8e1;  --fig-muted: #9d9a93;  --fig-faint: #6c6964;
    --fig-blue: #84a9da;  --fig-red: #e3846f;  --fig-green: #74bf90;  --fig-teal: #58b8b1;  --fig-plum: #bf98d0;  --fig-ochre: #e2b25a;  --fig-sienna: #d98b52;  --fig-olive: #bdbd6c;
    --fig-rh: #e3846f;  --fig-lh: #84a9da;  --fig-ivory: #e6e1d4;  --fig-ebony: #0c0c10;  --fig-wood: #a47a50;  --fig-felt: #b9a580;  --fig-steel: #8c939a;  --fig-brass: #c8a650;  --fig-skin: #c9a68a;
    --shadow: 0 2px 6px rgba(0, 0, 0, 0.45);
    }
}
:root[data-theme="dark"] {
    --paper: #141418;  --paper-deep: #1c1c21;  --paper-rule: #33333b;
    --ink: #ebe8e1;  --ink-soft: #c9c5bc;  --ink-mute: #9d9a93;  --ink-faint: #706d68;
    --accent: #e3846f;  --accent-tint: #3a211c;  --blue: #84a9da;  --blue-tint: #1c2735;  --red: #e7746a;  --green: #74bf90;  --green-tint: #183022;  --ochre: #e2b25a;  --ochre-tint: #382d16;
    --input: #1a1a1f;
    --fig-paper: #18181d;  --fig-grid: #3a3a42;  --fig-rule: #29292f;  --fig-ink: #ebe8e1;  --fig-muted: #9d9a93;  --fig-faint: #6c6964;
    --fig-blue: #84a9da;  --fig-red: #e3846f;  --fig-green: #74bf90;  --fig-teal: #58b8b1;  --fig-plum: #bf98d0;  --fig-ochre: #e2b25a;  --fig-sienna: #d98b52;  --fig-olive: #bdbd6c;
    --fig-rh: #e3846f;  --fig-lh: #84a9da;  --fig-ivory: #e6e1d4;  --fig-ebony: #0c0c10;  --fig-wood: #a47a50;  --fig-felt: #b9a580;  --fig-steel: #8c939a;  --fig-brass: #c8a650;  --fig-skin: #c9a68a;
    --shadow: 0 2px 6px rgba(0, 0, 0, 0.45);
}

/* ─── Base ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 17px/1.66 var(--font-body); font-optical-sizing: auto; }
::selection { background: var(--ochre-tint); }
a { color: var(--accent); text-underline-offset: 2px; }
code { font: 0.86em var(--font-mono); background: var(--paper-deep); padding: 0 4px; border-radius: 3px; }
h2 { font: 400 27px/1.25 var(--font-display); margin: 38px 0 12px; letter-spacing: -0.01em; }
.btn { border: 1px solid var(--ink-soft); background: var(--ink); color: var(--paper); padding: 5px 14px; border-radius: 3px; cursor: pointer; font: 13px var(--font-mono); }
.btn:hover { background: var(--ink-soft); }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn-quiet { background: transparent; color: var(--ink-soft); border-color: var(--paper-rule); }
.btn-quiet:hover { background: var(--paper-deep); }
.btn.on { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ─── Top bar ──────────────────────────────────────────────── */
.topbar { position: sticky; top: 0; z-index: 20; display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 8px 20px; background: color-mix(in srgb, var(--paper) 92%, transparent); backdrop-filter: blur(6px); border-bottom: 1px solid var(--paper-rule); font: 13px var(--font-mono); }
.topbar a { color: var(--ink-soft); text-decoration: none; }
.topbar a:hover { color: var(--accent); }
.topbar-left { display: flex; gap: 14px; align-items: center; min-width: 0; }
.topbar-title { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--ink-mute); }
.topbar-right { display: flex; gap: 8px; align-items: center; }
.lang-btn { border: 1px solid var(--paper-rule); background: var(--paper); border-radius: 3px; padding: 2px 10px; cursor: pointer; font: 13px var(--font-mono); color: var(--ink-soft); }

/* ─── Plate ────────────────────────────────────────────────── */
.main-content { max-width: 1080px; margin: 0 auto; padding: 26px 28px 70px; }
.plate-meta { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font: 12px var(--font-mono); color: var(--ink-mute); border-bottom: 2px solid var(--ink); padding-bottom: 6px; }
.plate-meta b { color: var(--ink-soft); font-weight: 600; }
.thread { display: inline-block; border: 1px solid var(--ink-faint); border-radius: 2px; padding: 0 4px; margin-left: 5px; font-size: 11px; color: var(--ink-soft); }
.plate-title { font: 400 50px/1.08 var(--font-display); letter-spacing: -0.02em; margin: 24px 0 8px; }
.plate-title em { color: var(--accent); }
.plate-deck { font: italic 21px/1.45 var(--font-body); color: var(--ink-soft); max-width: 46em; margin: 0 0 18px; }
.lede { border-left: 3px solid var(--accent); padding: 2px 0 2px 20px; margin: 18px 0; max-width: 50em; }
.lede p { margin: 0 0 10px; }
.learning-objectives { background: var(--paper-deep); border: 1px solid var(--paper-rule); padding: 12px 18px; margin: 20px 0; max-width: 50em; }
.learning-objectives-title, .section-title { font: 600 11.5px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--accent); margin: 0 0 4px; }
.section-title { margin: 30px 0 8px; }
.learning-objectives ul { margin: 4px 0 0; padding-left: 20px; }
.figure { border: 1px solid var(--paper-rule); background: var(--fig-paper); box-shadow: var(--shadow); }
.figure-caption { font: 14.5px/1.5 var(--font-body); color: var(--ink-mute); padding: 10px 16px; border-top: 1px solid var(--paper-rule); }
.prose { max-width: 46em; }
.prose p { margin: 0 0 14px; }
.piano-box { border: 1px solid var(--paper-rule); border-left: 4px solid var(--blue); background: var(--blue-tint); padding: 12px 18px; margin: 22px 0; max-width: 46em; }
.piano-box-title { font: 600 11.5px var(--font-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--blue); margin-bottom: 4px; }
.piano-box p { margin: 0 0 8px; }
.terms { display: grid; grid-template-columns: max-content 1fr; gap: 6px 18px; max-width: 50em; }
.terms dt { font-weight: 600; }
.terms dd { margin: 0; color: var(--ink-soft); }
.key-idea { border: 1px solid var(--ink); padding: 12px 18px; margin: 26px 0; max-width: 46em; font-style: italic; }
.sources { font-size: 14.5px; color: var(--ink-mute); max-width: 50em; }
.plate-nav { display: flex; justify-content: space-between; gap: 16px; margin: 40px 0 10px; border-top: 1px solid var(--paper-rule); padding-top: 14px; font-size: 15px; }
.plate-nav a { text-decoration: none; }
.plate-footer { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; font: 12px var(--font-mono); color: var(--ink-faint); margin-top: 20px; }

/* ─── Workshop ─────────────────────────────────────────────── */
.ws { display: grid; grid-template-columns: minmax(0, 1fr) 260px; }
.ws-stage { padding: 12px; border-right: 1px solid var(--paper-rule); min-width: 0; }
.ws-rail { padding: 12px 14px; display: flex; flex-direction: column; gap: 12px; font-size: 14px; }
.ws canvas { display: block; width: 100%; touch-action: none; }
.ws-panel + .ws-panel { margin-top: 10px; }
.ws-ptitle { font: 600 11px var(--font-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-mute); margin: 2px 0 4px; }
.ctl label { display: flex; justify-content: space-between; font: 12.5px var(--font-mono); color: var(--ink-soft); }
.ctl input[type=range] { width: 100%; accent-color: var(--accent); }
.ctl select { width: 100%; font: 13px var(--font-mono); background: var(--input); color: var(--ink); border: 1px solid var(--paper-rule); padding: 3px; }
.ctl .val { color: var(--accent); }
.stats { display: grid; gap: 4px; }
.stat { display: flex; justify-content: space-between; gap: 8px; border-bottom: 1px dotted var(--paper-rule); font: 12.5px var(--font-mono); padding: 2px 0; }
.stat span:first-child { color: var(--ink-mute); }
.stat b { color: var(--ink); font-weight: 600; text-align: right; }
.stat.good b { color: var(--green); }
.stat.bad b { color: var(--red); }
.ws-buttons { display: flex; flex-wrap: wrap; gap: 6px; }
.ws-note { font: 13px/1.45 var(--font-body); color: var(--ink-mute); }
.ws-msg { font: 13px var(--font-mono); color: var(--ink-soft); min-height: 1.4em; }
.ws-answers { display: flex; flex-wrap: wrap; gap: 6px; }
.ws-answers button { border: 1px solid var(--paper-rule); background: var(--paper); color: var(--ink); padding: 4px 10px; border-radius: 3px; cursor: pointer; font: 13px var(--font-mono); }
.ws-answers button.right { background: var(--green-tint); border-color: var(--green); }
.ws-answers button.wrong { background: var(--accent-tint); border-color: var(--accent); }
.input-bar { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; font: 12px var(--font-mono); color: var(--ink-mute); padding: 6px 12px; border-bottom: 1px solid var(--paper-rule); background: var(--paper-deep); }
.input-bar .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--ink-faint); display: inline-block; }
.input-bar .dot.live { background: var(--green); }

/* ─── Try-its, drills, projects, journey ───────────────────── */
.try { border: 1px solid var(--paper-rule); padding: 12px 16px; margin: 10px 0; max-width: 46em; }
.try-q { margin-bottom: 8px; }
.try-opts { display: flex; flex-wrap: wrap; gap: 6px; }
.try-opt { border: 1px solid var(--paper-rule); background: var(--paper); color: var(--ink); padding: 5px 11px; border-radius: 3px; cursor: pointer; font: 14.5px var(--font-body); text-align: left; }
.try-opt.right { background: var(--green-tint); border-color: var(--green); }
.try-opt.wrong { background: var(--accent-tint); border-color: var(--accent); }
.try-why { margin-top: 8px; color: var(--ink-soft); font-size: 15px; }
.drill { padding: 16px 18px; }
.drill-head { display: flex; justify-content: space-between; font: 12.5px var(--font-mono); color: var(--ink-mute); margin-bottom: 10px; }
.drill-src { font: 12px var(--font-mono); color: var(--ink-faint); margin-top: 10px; }
.project { border: 2px solid var(--ink); padding: 14px 18px; margin: 18px 0; }
.project h3 { font: 400 22px var(--font-display); margin: 0 0 6px; }
.brief { list-style: none; padding: 0; margin: 8px 0; }
.brief li { padding: 3px 0 3px 26px; position: relative; font-size: 15px; }
.brief li::before { content: '○'; position: absolute; left: 4px; color: var(--ink-faint); }
.brief li.ok::before { content: '✓'; color: var(--green); }
.brief li.no::before { content: '✗'; color: var(--red); }
.verdict { font: 600 13px var(--font-mono); padding: 6px 10px; display: inline-block; }
.verdict.pass { background: var(--green-tint); color: var(--green); }
.verdict.fail { background: var(--accent-tint); color: var(--accent); }
.journey { padding: 16px; }
.journey-sum { font: 13px var(--font-mono); color: var(--ink-mute); margin-bottom: 10px; }
.journey-vol { display: grid; grid-template-columns: 220px 1fr; gap: 10px; align-items: center; padding: 3px 0; border-bottom: 1px solid var(--paper-rule); }
.journey-vol .jn { font: 13.5px var(--font-body); }
.jcells { display: flex; flex-wrap: wrap; gap: 3px; }
.jcell { width: 16px; height: 16px; border: 1px solid var(--paper-rule); background: var(--paper); display: inline-block; }
.jcell.seen { background: var(--blue-tint); border-color: var(--blue); }
.jcell.passed { background: var(--green); border-color: var(--green); }

/* ─── Knowledge check ──────────────────────────────────────── */
.quiz { border-top: 2px solid var(--ink); margin-top: 40px; padding-top: 10px; max-width: 50em; }
.quiz-head { display: flex; justify-content: space-between; align-items: baseline; }
.quiz-head h3 { font: 400 25px var(--font-display); margin: 0 0 8px; }
.quiz-score { font: 13px var(--font-mono); color: var(--ink-mute); }
.quiz-q { border-bottom: 1px solid var(--paper-rule); padding: 10px 0; }
.quiz-q p { margin: 0 0 8px; }
.quiz-q .n { font: 13px var(--font-mono); color: var(--accent); }
.quiz-opts { display: grid; gap: 5px; }
.quiz-opts button { text-align: left; border: 1px solid var(--paper-rule); background: var(--paper); color: var(--ink); padding: 6px 12px; border-radius: 3px; cursor: pointer; font: 15.5px/1.45 var(--font-body); }
.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(--accent-tint); border-color: var(--accent); }
.quiz-why { margin-top: 8px; font-size: 15px; color: var(--ink-soft); }
.quiz-foot { margin-top: 12px; }

/* ─── Report dialog ────────────────────────────────────────── */
.report-link { color: var(--ink-faint); }
.report-bg { position: fixed; inset: 0; background: rgba(20, 18, 24, 0.35); z-index: 90; }
.report-dialog { position: fixed; z-index: 91; left: 50%; top: 12vh; transform: translateX(-50%); width: min(520px, 94vw); background: var(--paper); border: 1px solid var(--paper-rule); box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2); padding: 18px 20px; }
.report-dialog h3 { font: 400 23px var(--font-display); margin: 0 0 8px; }
.report-note { font-size: 14px; color: var(--ink-mute); margin: 0 0 8px; }
.report-sel { font-size: 14px; border-left: 3px solid var(--paper-rule); margin: 6px 0; padding-left: 10px; color: var(--ink-soft); }
.report-dialog textarea, .report-dialog input { width: 100%; border: 1px solid var(--paper-rule); background: var(--input); color: var(--ink); border-radius: 3px; padding: 6px 8px; margin-top: 6px; font: 14px var(--font-body); }
.report-hp { position: absolute; left: -9999px; width: 1px; height: 1px; }
.report-actions { display: flex; gap: 8px; justify-content: flex-end; align-items: center; margin-top: 10px; }
.report-status { flex: 1; font: 12.5px var(--font-mono); color: var(--ink-mute); }

@media (max-width: 820px) {
    .ws { grid-template-columns: minmax(0, 1fr); }
    .ws-stage { border-right: none; border-bottom: 1px solid var(--paper-rule); }
    .plate-title { font-size: 34px; }
    .main-content { padding: 18px 16px 50px; }
    .terms { grid-template-columns: 1fr; }
    .journey-vol { grid-template-columns: 1fr; }
    .topbar { padding: 8px 16px; }
}
@media print { .topbar, .ws-rail, .quiz, .try-block, .plate-footer { display: none; } }