/* ВП02 — светлая и тёмная темы на общих токенах ../shared/theme.css (подключается раньше этого файла).
   Внешних шрифтов и фреймворков нет. Собственные переменные страницы ссылаются на токены --t-*. */
:root {
  --bg: var(--t-bg); --surface: var(--t-surface); --surface-2: var(--t-surface-2); --ink: var(--t-ink); --ink-2: var(--t-ink-2); --muted: var(--t-muted);
  --line: var(--t-line); --line-2: var(--t-line-2); --code: var(--t-code);
  --accent: var(--t-accent); --accent-ink: var(--t-accent-ink); --accent-soft: var(--t-accent-soft);
  --ok: var(--t-ok); --ok-soft: var(--t-ok-soft); --bad: var(--t-bad); --bad-soft: var(--t-bad-soft);
  --ok-ink: #14532d; --bad-ink: #7f1d1d;
  /* нейтральные подложки: дорожки, чипы, наведение — полупрозрачный цвет текста, поэтому работают в обеих темах */
  --soft: color-mix(in srgb, var(--t-ink) 5%, transparent); --track: color-mix(in srgb, var(--t-ink) 9%, transparent);
  --warm: #fff4ea; --note: #fff8eb;
  --ink-inv: #fff;           /* текст на плашках цвета --ink */
  --stage: #fbfcfd;          /* фон сцен и графиков */
  /* цвета графиков (семантика неизменна, в тёмной теме — светлее) */
  --truth: #16a34a; --est: #ea7a1c; --plan: #9aa4b5; --noise: #7c3aed; --slip: #0891b2; --err: #dc2626;
  --path-l: #2563eb; --path-r: #9333ea;
  --grid: #e7eaf0; --axis: #c5ccd8; --tick: #8a93a5;
  --bot-body: #dbe4ff; --bot-edge: #5b7bd8; --wheel: #1d2433; --wheel-ink: #fff; --route-fill: #f0fdf4; --robot-fill: #eef2ff; --robot-edge: #94a3b8;
  --editor: #0f172a; --editor-bar: #1e293b;
  --r: 14px; --r-sm: 9px; --shadow: var(--t-shadow);
  --font: var(--t-font);
  --mono: var(--t-mono);
  --top: 60px;
}
/* тёмная тема: по выбору (data-theme) или по системе без выбора — так же, как в theme.css */
:root[data-theme="dark"] {
  --ok-ink: var(--t-ok); --bad-ink: var(--t-bad); --warm: rgba(255, 154, 69, .12); --note: rgba(255, 179, 71, .10); --ink-inv: #0b111b; --stage: var(--t-bg-2);
  --truth: #3ddc84; --est: #ff9a45; --plan: #7d8aa0; --noise: #b197fc; --slip: #3cc8e8; --err: #ff6b78; --path-l: #6ea8ff; --path-r: #c792ff;
  --grid: rgba(140, 180, 240, .12); --axis: rgba(140, 180, 240, .34); --tick: #8d9bb0;
  --bot-body: rgba(110, 168, 255, .22); --bot-edge: #6ea8ff; --wheel: #c8d3e2; --wheel-ink: #0b111b; --route-fill: rgba(61, 220, 132, .10); --robot-fill: rgba(110, 168, 255, .12); --robot-edge: #6c7b90;
  --editor: #0a1019; --editor-bar: #121b29;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ok-ink: var(--t-ok); --bad-ink: var(--t-bad); --warm: rgba(255, 154, 69, .12); --note: rgba(255, 179, 71, .10); --ink-inv: #0b111b; --stage: var(--t-bg-2);
    --truth: #3ddc84; --est: #ff9a45; --plan: #7d8aa0; --noise: #b197fc; --slip: #3cc8e8; --err: #ff6b78; --path-l: #6ea8ff; --path-r: #c792ff;
    --grid: rgba(140, 180, 240, .12); --axis: rgba(140, 180, 240, .34); --tick: #8d9bb0;
    --bot-body: rgba(110, 168, 255, .22); --bot-edge: #6ea8ff; --wheel: #c8d3e2; --wheel-ink: #0b111b; --route-fill: rgba(61, 220, 132, .10); --robot-fill: rgba(110, 168, 255, .12); --robot-edge: #6c7b90;
    --editor: #0a1019; --editor-bar: #121b29;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--top) + 16px); -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } *, *::before, *::after { transition: none !important; animation: none !important; } }
body { overflow-x: clip; margin: 0; color: var(--ink); font: 17px/1.6 var(--font); } /* фон с текстурой — body.t-page из theme.css */
h1, h2, h3, h4 { line-height: 1.22; margin: 0 0 .5em; letter-spacing: -.01em; }
h2 { font-size: clamp(24px, 3vw, 32px); }
h3 { font-size: 19px; }
h4 { font-size: 16px; }
p { margin: 0 0 .8em; }
a { color: var(--accent); text-underline-offset: 3px; }
code, .mono { font-family: var(--mono); font-size: .88em; }
code { background: var(--code); padding: .08em .35em; border-radius: 5px; }
small, .small { font-size: 14px; }
.muted { color: var(--muted); }
math { font-size: 1.06em; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--ink-inv); padding: 8px 14px; border-radius: 8px; z-index: 100; }
.skip:focus { left: 8px; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 45%, transparent); outline-offset: 2px; }

/* ── top bar ── */
.topbar { position: sticky; top: 0; z-index: 30; height: var(--top); background: var(--t-raised); backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.topbar-inner { height: 100%; max-width: 1400px; margin: 0 auto; padding: 0 20px; display: flex; align-items: center; gap: 24px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand-mark { background: var(--ink); color: var(--ink-inv); font: 700 12px/1 var(--font); padding: 8px 7px; border-radius: 8px; letter-spacing: .04em; }
.brand-text { font-weight: 700; font-size: 16px; line-height: 1.1; }
.brand-text small { display: block; font-weight: 500; font-size: 12px; color: var(--muted); }
.topbar-status { display: flex; align-items: center; gap: 12px; }
.progress-mini { display: flex; align-items: center; gap: 8px; font-size: 14px; color: var(--muted); font-variant-numeric: tabular-nums; white-space: nowrap; }
progress { appearance: none; width: 90px; height: 8px; border: 0; border-radius: 99px; background: var(--track); overflow: hidden; }
progress::-webkit-progress-bar { background: var(--track); border-radius: 99px; }
progress::-webkit-progress-value { background: var(--ok); border-radius: 99px; transition: width .3s; }
progress::-moz-progress-bar { background: var(--ok); }
.chip { display: inline-flex; align-items: center; gap: 6px; background: var(--accent-soft); color: var(--accent); font-weight: 600; font-size: 13px; padding: 4px 10px; border-radius: 99px; white-space: nowrap; }
.chip.soft { background: var(--soft); color: var(--ink-2); font-weight: 500; }
.chip.ok { background: var(--ok-soft); color: var(--ok); }

/* ── learn / do modes ── */
body[data-view="learn"] [data-part="do"], body[data-view="do"] [data-part="learn"] { display: none !important; }
.mode-switch { display: inline-flex; background: var(--track); border-radius: 11px; padding: 3px; margin-left: auto; }
.mode-switch button { border: 0; background: none; font: 600 14.5px var(--font); color: var(--ink-2); padding: 7px 14px; border-radius: 8px; cursor: pointer; display: inline-flex; gap: 7px; align-items: center; white-space: nowrap; }
.mode-switch button b { width: 20px; height: 20px; display: grid; place-items: center; border-radius: 50%; background: var(--track); font-size: 12px; }
.mode-switch button[aria-selected="true"] { background: var(--surface); color: var(--ink); box-shadow: 0 1px 3px rgba(16,24,40,.12); }
.mode-switch button[aria-selected="true"] b { background: var(--accent); color: var(--accent-ink); }
.btn.small { padding: 8px 12px; font-size: 14px; }
.rail-title { margin: 0 0 6px 10px; font-size: 12px; text-transform: uppercase; letter-spacing: .08em; font-weight: 700; color: var(--muted); }
.rail-cta { margin-top: 16px; font-size: 14px; }
.go-card { display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap; background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 25%, transparent); }
.go-card h3 { margin-bottom: 4px; }
.go-card p { margin: 0; }
.do-strip { margin-top: 28px; display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; padding: 14px 20px; font-size: 15.5px; }
.do-strip-actions { display: flex; gap: 8px; }
.ref { width: min(760px, calc(100vw - 24px)); max-height: calc(100vh - 40px); padding: 0; border: 0; border-radius: 16px; box-shadow: 0 20px 60px rgba(0,0,0,.25); color: var(--ink); background: var(--surface); }
.ref::backdrop { background: rgba(15,23,42,.45); }
.ref > header { position: sticky; top: 0; background: var(--surface); display: flex; justify-content: space-between; align-items: center; padding: 14px 20px; border-bottom: 1px solid var(--line); z-index: 1; }
.ref > header h2 { margin: 0; font-size: 22px; }
.ref-body { padding: 8px 22px 22px; }
.ref-body h3 { margin-top: 18px; font-size: 16px; }
.ref-formulas { display: grid; grid-template-columns: 1fr 1fr; gap: 6px; }
.ref-formulas .formula { margin: 0; }
.ref-formulas .wide { grid-column: 1 / -1; }
.ref .glossary { grid-template-columns: 1fr 1fr; gap: 8px; }
.ref .glossary > div { padding: 10px 12px; }

/* ── layout ── */
.layout { max-width: 1400px; margin: 0 auto; display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 32px; padding: 0 20px; }
.rail { position: sticky; top: calc(var(--top) + 24px); align-self: start; padding-top: 28px; }
.steps-nav { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; }
.steps-nav a { display: flex; align-items: center; gap: 10px; padding: 7px 10px; border-radius: 9px; color: var(--ink-2); text-decoration: none; font-size: 15px; }
.steps-nav a:hover { background: var(--soft); }
.steps-nav i { flex: none; width: 24px; height: 24px; display: grid; place-items: center; font-style: normal; font-size: 12px; font-weight: 700; border-radius: 50%; background: var(--track); color: var(--ink-2); }
.steps-nav i.ok { background: var(--ok); color: var(--ink-inv); font-size: 0; }
.steps-nav i.ok::before { content: "✓"; font-size: 13px; }
.steps-nav small { margin-left: auto; color: var(--muted); font-variant-numeric: tabular-nums; }
.rail-note { margin-top: 18px; font-size: 13px; color: var(--muted); line-height: 1.45; }
main { min-width: 0; padding-bottom: 60px; overflow-x: clip; }

/* ── generic blocks ── */
.section { padding: 56px 0 8px; }
.section-head { max-width: 860px; margin-bottom: 24px; }
.section-lead { color: var(--ink-2); font-size: 18px; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: 12.5px; font-weight: 700; color: var(--accent); margin-bottom: 8px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 22px 24px; box-shadow: var(--shadow); }
.card.accent { border-left: 4px solid var(--accent); }
.two-col { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; align-items: start; }
.three-col { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 20px; }
.note { font-size: 14.5px; color: var(--ink-2); background: var(--note); border-radius: 8px; padding: 8px 12px; margin: 12px 0 0; }
.callout { margin-top: 20px; background: var(--accent-soft); border-radius: var(--r); padding: 18px 22px; display: grid; grid-template-columns: auto 1fr; gap: 6px 16px; }
.callout strong { font-size: 17px; }
.callout p { margin: 0; grid-column: 1 / -1; color: var(--ink-2); }

/* buttons & forms */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font: 600 15.5px/1 var(--font); padding: 12px 18px; border-radius: 10px; border: 1px solid var(--line-2); background: var(--surface); color: var(--ink); cursor: pointer; text-decoration: none; transition: background .15s, border-color .15s, transform .05s; }
.btn:hover { background: var(--surface-2); }
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { background: color-mix(in srgb, var(--accent) 86%, var(--ink)); }
.btn.ghost { background: transparent; }
.btn.wide { width: 100%; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.link-btn { background: none; border: 0; color: var(--accent); font: 500 14.5px var(--font); cursor: pointer; padding: 4px 0; }
.link-btn:disabled { color: var(--muted); opacity: .6; cursor: not-allowed; }
.icon-btn { width: 40px; height: 40px; flex: none; border-radius: 50%; border: 1px solid var(--line-2); background: var(--surface); font-size: 15px; cursor: pointer; display: grid; place-items: center; color: var(--ink); }
.icon-btn:hover:not(:disabled) { background: var(--surface-2); }
.icon-btn:disabled { opacity: .4; }
label { display: grid; gap: 6px; font-size: 15px; font-weight: 600; color: var(--ink-2); }
label small { font-weight: 400; color: var(--muted); }
input, select, textarea { font: 400 16px/1.4 var(--font); color: var(--ink); background: var(--surface); border: 1px solid var(--line-2); border-radius: var(--r-sm); padding: 10px 12px; width: 100%; transition: border-color .15s, box-shadow .15s; }
textarea { resize: vertical; min-height: 76px; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
input.correct { border-color: var(--ok); background: var(--ok-soft); }
input.incorrect { border-color: var(--bad); background: var(--bad-soft); }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 14px; }
.feedback:empty { display: none; }
.feedback { margin-top: 14px; padding: 11px 14px; border-radius: 10px; font-size: 15.5px; background: var(--soft); }
.feedback.success { background: var(--ok-soft); color: var(--ok-ink); }
.feedback.error { background: var(--bad-soft); color: var(--bad-ink); }
.form { margin-top: 18px; display: grid; gap: 14px; }
.form .actions { margin-top: 0; }
.answer-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; }
.answer-grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); margin: 14px 0 0; }
.answer-grid input { font-family: var(--mono); font-size: 17px; }

/* glossary term */
.term { border-bottom: 1.5px dotted var(--accent); cursor: help; position: relative; }
.term::after { content: attr(data-tip); position: absolute; left: 50%; bottom: calc(100% + 8px); transform: translateX(-50%) translateY(4px); width: max-content; max-width: 280px; background: var(--ink); color: var(--ink-inv); font: 400 14px/1.45 var(--font); padding: 9px 12px; border-radius: 9px; opacity: 0; pointer-events: none; transition: opacity .15s, transform .15s; z-index: 20; text-transform: none; letter-spacing: 0; white-space: normal; }
.term:hover::after, .term:focus::after { opacity: 1; transform: translateX(-50%) translateY(0); }

/* swatches & legend */
.sw { display: inline-block; width: 18px; height: 4px; border-radius: 2px; vertical-align: middle; background: var(--plan); }
.sw.truth { background: var(--truth); } .sw.est { background: var(--est); } .sw.noise { background: var(--noise); } .sw.slip { background: var(--slip); }
.sw.cmp { background: repeating-linear-gradient(90deg, var(--noise) 0 3px, transparent 3px 6px); }
.sw.plan { background: repeating-linear-gradient(90deg, var(--plan) 0 5px, transparent 5px 9px); }
.legend { display: flex; flex-wrap: wrap; gap: 6px 18px; font-size: 14px; color: var(--ink-2); margin: 10px 0 0; }
.legend span { display: inline-flex; align-items: center; gap: 7px; }

/* details */
.more { margin-top: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); }
.more > summary { cursor: pointer; list-style: none; padding: 14px 20px; font-weight: 600; display: flex; align-items: center; gap: 10px; }
.more > summary::-webkit-details-marker { display: none; }
.more > summary::before { content: "›"; font-size: 22px; line-height: 1; color: var(--accent); transition: transform .15s; }
.more[open] > summary::before { transform: rotate(90deg); }
.more-body { padding: 4px 22px 18px; margin: 0; }
.more.slim > summary { padding: 10px 16px; font-size: 15px; }
.more.slim { box-shadow: none; }
.more > .muted.small { padding: 0 22px 16px; }

/* ── hero & demo ── */
.hero { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: 40px; align-items: center; padding: 44px 0 16px; }
.hero h1 { font-size: clamp(32px, 4.2vw, 50px); letter-spacing: -.025em; margin-bottom: 20px; }
.hero h1 em { font-style: normal; color: var(--est); }
.lead { font-size: 18.5px; color: var(--ink-2); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }
.demo { margin: 0; background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); padding: 16px 18px 18px; }
.demo-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.demo-tag { font-size: 13px; color: var(--muted); }
.demo-stage { position: relative; border-radius: 12px; background: var(--stage); border: 1px solid var(--line); overflow: hidden; aspect-ratio: 640 / 420; }
.demo-stage::after { content: attr(data-result); position: absolute; left: 12px; right: 12px; bottom: 12px; background: rgba(29,36,51,.9); color: #fff; font-size: 14.5px; padding: 9px 13px; border-radius: 10px; opacity: 0; transform: translateY(6px); transition: opacity .35s, transform .35s; }
.demo-stage.hold::after { opacity: 1; transform: none; }
.demo-caption { display: grid; grid-template-columns: auto 1fr; gap: 14px; margin-top: 14px; min-height: 104px; }
.demo-step { font: 700 13px var(--font); background: var(--ink); color: var(--ink-inv); border-radius: 8px; padding: 6px 8px; height: fit-content; font-variant-numeric: tabular-nums; }
.demo-caption strong { font-size: 17px; }
.demo-caption p { margin: 4px 0 0; color: var(--ink-2); font-size: 15.5px; }
.demo-controls { display: flex; gap: 12px; align-items: center; margin-top: 8px; }
.demo-scenes { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px; flex: 1; align-items: start; }
.demo-scenes button { text-align: left; background: none; border: 0; padding: 0; font: 500 12.5px/1.3 var(--font); color: var(--muted); cursor: pointer; }
.demo-scenes button.active { color: var(--ink); font-weight: 600; }
.demo-scenes .bar { display: block; height: 4px; border-radius: 2px; background: var(--track); overflow: hidden; margin-bottom: 6px; }
.demo-scenes .bar > span { display: block; height: 100%; width: 0; background: var(--accent); }
.demo-scenes button.done .bar > span { width: 100% !important; background: color-mix(in srgb, var(--accent) 35%, var(--track)); }
.demo .legend { font-size: 13.5px; }

/* SVG scenes */
.mi { font-family: "Cambria Math", "STIX Two Math", "Times New Roman", serif; font-style: italic; }
.scene { display: block; width: 100%; height: auto; font-family: var(--font); }
.scene-tick { font-size: 11px; fill: var(--tick); }
.scene-label { font-size: 13px; font-weight: 600; fill: var(--ink-2); }
.scene-gap { font-size: 13px; font-weight: 700; paint-order: stroke; stroke: var(--stage); stroke-width: 4px; }

/* ── brief ── */
.brief-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.brief-grid .card { padding: 20px; }
.brief-grid h3 { font-size: 17px; }
.brief-grid p, .brief-grid li { font-size: 15.5px; }
.mini-steps { margin: 0; padding-left: 20px; display: grid; gap: 4px; }
.mini-steps a { color: var(--ink); text-decoration: none; }
.checks, .score, .qs { margin: 0; padding: 0; list-style: none; display: grid; gap: 6px; }
.checks li { padding-left: 24px; position: relative; }
.checks li::before { content: "✓"; position: absolute; left: 0; color: var(--ok); font-weight: 700; }
.score li { display: flex; gap: 10px; align-items: baseline; }
.score b { flex: none; width: 24px; height: 24px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent); border-radius: 6px; font-size: 13px; }
.qs li { padding-left: 20px; position: relative; font-size: 15.5px; }
.qs li::before { content: "?"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }

/* ── ideas ── */
.ideas { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.idea { position: relative; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 22px 22px 12px; box-shadow: var(--shadow); }
.idea-num { position: absolute; top: 18px; right: 18px; width: 30px; height: 30px; display: grid; place-items: center; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 800; }
.idea h3 { padding-right: 36px; font-size: 18px; }
.idea p { font-size: 15.5px; color: var(--ink-2); }
.formula { margin: 10px 0; padding: 10px 6px; background: var(--surface-2); color: var(--ink); border-radius: 10px; overflow-x: auto; }
.formula math { font-size: 1.18em; }
.formula-stack { display: grid; gap: 4px; }
.sandbox { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); gap: 24px; margin-top: 20px; align-items: center; }
.sandbox-stage { background: var(--stage); border: 1px solid var(--line); border-radius: 12px; }
.slider { margin: 12px 0; grid-template-columns: 1fr auto; align-items: center; }
.slider > span { display: inline-flex; align-items: baseline; gap: 6px; }
.slider output { font: 600 15px var(--mono); color: var(--accent); }
.slider input { grid-column: 1 / -1; padding: 0; border: 0; accent-color: var(--accent); }
.slider input:focus { box-shadow: none; }
.sandbox-values { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin: 14px 0 0; }
.sandbox-values > div { background: var(--surface-2); border-radius: 9px; padding: 8px 12px; }
.sandbox-values dt { font-size: 14px; color: var(--muted); }
.sandbox-values dd { margin: 0; font: 600 15px var(--mono); }
.sandbox-values > div:nth-child(3) { grid-column: 1 / -1; }
.sb-legend { grid-column: 1 / -1; background: none !important; display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 13.5px; color: var(--ink-2); padding: 0 !important; }
.sb-legend span { display: inline-flex; align-items: center; gap: 6px; }
.sb-bot rect { fill: var(--bot-body); stroke: var(--bot-edge); stroke-width: 1.5; }
.sb-bot .wheel { fill: var(--wheel); stroke: none; }
.sb-bot .nose { fill: var(--bot-edge); }
.sb-bot { opacity: .7; }
.sb-bot.ghost { opacity: .28; }
.more h4 { display: flex; align-items: center; gap: 8px; }
.more .three-col p { font-size: 15.5px; color: var(--ink-2); }

/* ── playground ── */
.playground { display: grid; grid-template-columns: 320px minmax(0, 1fr); gap: 24px; align-items: start; }
.pg-controls { display: grid; gap: 4px; }
.pg-controls .slider { margin: 8px 0; }
.pg-seed { display: grid; grid-template-columns: 1fr auto; gap: 10px; align-items: end; margin-top: 6px; }
.pg-metrics { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin: 12px 0 6px; }
.pg-metrics > div { background: var(--surface-2); border-radius: 9px; padding: 8px 11px; }
.pg-metrics > div.key { background: var(--warm); }
.pg-metrics dt { font-size: 12.5px; color: var(--muted); }
.pg-metrics dd { margin: 0; font: 700 16px var(--mono); }
#pg-hint { min-height: 3em; }
@media (max-width: 960px) { .playground { grid-template-columns: minmax(0, 1fr); } .playground > div:last-child { order: -1; } }

/* ── variant / passport ── */
.who { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 16px; }
.passport { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 16px; }
.pass-card h3 { font-size: 17px; }
.mini { display: block; width: 100%; max-width: 230px; margin: 0 auto 8px; }
.mini-t { font-size: 12px; fill: var(--muted); font-family: var(--font); }
.mini-w { font-size: 14px; font-weight: 700; fill: var(--wheel-ink); font-family: var(--font); }
.kv { margin: 0; display: grid; gap: 0; }
.kv > div { display: flex; justify-content: space-between; gap: 12px; padding: 8px 0; border-top: 1px solid var(--line); font-size: 15px; }
.kv dt { color: var(--ink-2); }
.kv dd { margin: 0; font-weight: 600; text-align: right; font-variant-numeric: tabular-nums; }
.err-list { list-style: none; margin: 0 0 12px; padding: 0; display: grid; gap: 12px; }
.err-list li { display: grid; grid-template-columns: 18px 1fr; gap: 10px; align-items: baseline; font-size: 15px; }
.err-list .sw { width: 14px; height: 14px; border-radius: 4px; }
.err-list small { color: var(--muted); }
.q-box { background: var(--note); border-radius: 10px; padding: 12px 14px; font-size: 15px; }
.q-box p { margin: 4px 0 0; }

/* ── steps ── */
.step { border-top: 1px solid var(--line); margin-top: 40px; }
.step-head { display: flex; align-items: center; gap: 18px; margin-bottom: 12px; }
.step-head h2 { margin: 0; }
.step-head .eyebrow { margin-bottom: 4px; }
.step-num { flex: none; width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center; background: var(--ink); color: var(--ink-inv); font-size: 24px; font-weight: 800; }
.step-badge { margin-left: auto; flex: none; font-size: 13.5px; font-weight: 600; padding: 6px 12px; border-radius: 99px; background: var(--track); color: var(--muted); }
.step-badge.ok { background: var(--ok-soft); color: var(--ok); }
.step-badge.ok::before { content: "✓ "; }
.step-goal { max-width: 900px; color: var(--ink-2); font-size: 17px; margin-bottom: 18px; }
.task h3 { font-size: 18px; }
.givens { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0 14px; }
.givens span { background: var(--accent-soft); padding: 6px 12px; border-radius: 9px; font-size: 15.5px; }
.hint-list, .worked { display: grid; gap: 8px; padding-left: 40px; }
.worked { padding-left: 22px; }
.block { font-weight: 600; }

/* code */
.map { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 14.5px; }
.map caption { text-align: left; font-weight: 600; font-size: 14px; color: var(--muted); padding-bottom: 6px; }
.map td { border-top: 1px solid var(--line); padding: 7px 4px; }
.editor-wrap { background: var(--editor); border: 1px solid var(--line); border-radius: var(--r); padding: 0 0 14px; overflow: hidden; box-shadow: var(--shadow); }
.editor-bar { display: flex; justify-content: space-between; align-items: center; padding: 8px 14px; background: var(--editor-bar); color: #94a3b8; font: 13px var(--mono); }
.editor-bar .link-btn { color: #93b4ff; font-size: 13px; }
.code { background: transparent; color: #e2e8f0; border: 0; border-radius: 0; font: 14.5px/1.6 var(--mono); padding: 14px 16px; min-height: 340px; tab-size: 2; white-space: pre; }
.code:focus { box-shadow: none; }
.editor-wrap .actions { padding: 0 14px; margin-top: 4px; }
.tests { list-style: none; padding: 0; margin: 14px 0 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 8px; }
.tests li { display: flex; gap: 10px; padding: 10px 12px; border-radius: 10px; background: var(--surface); border: 1px solid var(--line); font-size: 15px; }
.tests li.pass > span { color: var(--ok); font-weight: 700; }
.tests li.fail { border-color: color-mix(in srgb, var(--bad) 35%, transparent); background: var(--bad-soft); }
.tests li.fail > span { color: var(--bad); font-weight: 700; }
.tests small { display: block; color: var(--bad-ink); font-family: var(--mono); font-size: 12.5px; margin-top: 2px; word-break: break-word; }

/* research */
.research { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; margin-bottom: 20px; }
.rq { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 14px; display: flex; flex-direction: column; gap: 8px; }
.rq.done { border-color: color-mix(in srgb, var(--ok) 35%, transparent); background: color-mix(in srgb, var(--ok) 4%, var(--surface)); }
.rq header { display: flex; align-items: center; gap: 8px; }
.rq-key { font: 800 13px var(--font); background: var(--ink); color: var(--ink-inv); padding: 3px 7px; border-radius: 6px; }
.rq.done .rq-key { background: var(--ok); }
.rq h4 { margin: 0; font-size: 15px; }
.rq-count { margin-left: auto; font-size: 13px; color: var(--muted); font-variant-numeric: tabular-nums; }
.rq p { font-size: 14px; color: var(--ink-2); margin: 0; flex: 1; }
.rq-runs { display: flex; flex-wrap: wrap; gap: 6px; }
.rq-runs button { font: 500 13px var(--font); padding: 6px 9px; border-radius: 8px; border: 1px solid var(--line-2); background: var(--surface); cursor: pointer; color: var(--ink); }
.rq-runs button:hover { border-color: var(--accent); }
.rq-runs button.ok { background: var(--ok-soft); border-color: color-mix(in srgb, var(--ok) 35%, transparent); color: var(--ok); }
.rq-runs button.active { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

/* lab workspace */
.lab { display: grid; grid-template-columns: minmax(0, 1fr) 340px; gap: 20px; align-items: start; }
.lab-view { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 16px; box-shadow: var(--shadow); }
.lab-view-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 10px; }
.lab-view-head strong { font-size: 17px; }
.compare { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 500; margin: -2px 0 10px; }
.compare select { width: auto; max-width: 100%; padding: 6px 8px; font-size: 14px; }
.world { position: relative; border-radius: 12px; background: var(--stage); border: 1px solid var(--line); aspect-ratio: 640 / 420; overflow: hidden; }
.world.empty svg { opacity: 0; }
.world.empty::after { content: attr(data-empty); position: absolute; inset: 0; display: grid; place-items: center; color: var(--muted); font-size: 16px; text-align: center; padding: 20px; background: repeating-linear-gradient(0deg, transparent 0 39px, var(--grid) 39px 40px), repeating-linear-gradient(90deg, transparent 0 39px, var(--grid) 39px 40px); }
.playback { display: flex; align-items: center; gap: 10px; margin-top: 12px; }
.playback input[type=range] { flex: 1; padding: 0; border: 0; accent-color: var(--accent); }
.playback input[type=range]:focus { box-shadow: none; }
.playback select { width: auto; padding: 7px 8px; font-size: 14px; }
#lab-time-label { min-width: 92px; text-align: right; color: var(--muted); }
.metrics { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 8px; margin-top: 14px; }
.metrics:empty { display: none; }
.metric { background: var(--surface-2); border-radius: 10px; padding: 9px 11px; cursor: help; }
.metric span { display: block; font-size: 12.5px; color: var(--muted); line-height: 1.3; }
.metric strong { font: 700 17px var(--mono); }
.metric small { font: 500 12px var(--font); color: var(--muted); }
.metric.key { background: var(--warm); }
.chart { margin-top: 10px; }
.readout { padding: 0 16px 14px; line-height: 1.8; }
.lab-panel { background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); padding: 18px; box-shadow: var(--shadow); display: grid; gap: 12px; position: sticky; top: calc(var(--top) + 16px); }
.panel-steps { list-style: none; counter-reset: ps; margin: 0; padding: 0; display: grid; gap: 16px; }
.panel-steps > li { counter-increment: ps; display: grid; gap: 8px; padding-left: 34px; position: relative; }
.panel-steps > li::before { content: counter(ps); position: absolute; left: 0; top: 0; width: 24px; height: 24px; display: grid; place-items: center; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font: 700 13px var(--font); }
.panel-steps h4 { margin: 0; font-size: 16px; }
.panel-steps h4 small { color: var(--muted); font-weight: 500; }
.panel-steps p { margin: 0; }
.conditions ul { margin: 0; padding-left: 18px; font-size: 14.5px; color: var(--ink-2); display: grid; gap: 2px; }
.engine { font-size: 14px; }
.engine select { font-size: 15px; }
.free { display: grid; gap: 10px; padding: 4px 16px 16px; }
.free label { font-size: 14px; }
.free input, .free select { padding: 8px 10px; font-size: 15px; }
.table-head { display: flex; justify-content: space-between; align-items: baseline; margin: 28px 0 10px; }
.table-head h3 { margin: 0; }
.table-scroll { overflow-x: auto; background: var(--surface); border: 1px solid var(--line); border-radius: var(--r); }
.runs { width: 100%; border-collapse: collapse; font-size: 15px; }
.runs th { text-align: left; font-size: 13px; color: var(--muted); font-weight: 600; padding: 10px 12px; border-bottom: 1px solid var(--line); white-space: nowrap; }
.runs td { padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.runs tr:last-child td { border-bottom: 0; }
.runs td small { display: block; color: var(--muted); font-size: 13px; }
.runs .num { font-family: var(--mono); font-size: 14px; white-space: nowrap; }
.row-actions { white-space: nowrap; text-align: right; }
.row-actions button { font: 500 13.5px var(--font); padding: 5px 10px; border-radius: 7px; border: 1px solid var(--line-2); background: var(--surface); color: var(--ink); cursor: pointer; }
.row-actions .danger { color: var(--bad); margin-left: 4px; }

/* analysis & report */
.noise-values { margin: 12px 0 0; font-size: 15px; }
.mini-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.mini-table th { font-weight: 600; color: var(--muted); text-align: left; padding: 4px 6px; }
.mini-table td { font-family: var(--mono); padding: 4px 6px; background: var(--surface-2); }
.conclusions { display: grid; gap: 14px; }
.conclusions label { font-size: 15px; }
.checklist { list-style: none; padding: 0; margin: 0 0 4px; display: grid; gap: 8px; }
.checklist li { padding-left: 30px; position: relative; font-size: 15.5px; color: var(--ink-2); }
.checklist li::before { content: ""; position: absolute; left: 0; top: 2px; width: 20px; height: 20px; border-radius: 6px; border: 2px solid var(--line-2); }
.checklist li.ok { color: var(--ink); }
.checklist li.ok::before { content: "✓"; background: var(--ok); border-color: var(--ok); color: var(--ink-inv); font-size: 13px; font-weight: 700; display: grid; place-items: center; }
.actions.wrap .btn { flex: 1 1 auto; }

/* glossary & footer */
.glossary { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; margin: 0; }
.glossary > div { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; }
.glossary dt { font-weight: 700; margin-bottom: 4px; }
.glossary dd { margin: 0; font-size: 15px; color: var(--ink-2); }
.footer { margin-top: 56px; padding-top: 20px; border-top: 1px solid var(--line); font-size: 15px; }
.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%); background: var(--ink); color: var(--ink-inv); padding: 12px 18px; border-radius: 12px; font-size: 15px; box-shadow: 0 10px 30px rgba(0,0,0,.2); z-index: 50; max-width: calc(100vw - 32px); }

/* ── responsive ── */
@media (max-width: 1280px) {
  .brief-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 1100px) {
  .layout { grid-template-columns: minmax(0, 1fr); }
  .rail { display: none; }
  .hero { grid-template-columns: minmax(0, 1fr); }
  .lab { grid-template-columns: minmax(0, 1fr); }
  .lab-panel { position: static; }
  .passport { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .passport .pass-card:last-child { grid-column: 1 / -1; }
}
@media (max-width: 820px) {
  body { font-size: 16px; }
  .ref-btn { display: none; }
  .ref-formulas, .ref .glossary { grid-template-columns: minmax(0, 1fr); }
  .topbar-status { margin-left: auto; }
  .two-col, .three-col, .ideas, .sandbox, .passport, .who, .glossary { grid-template-columns: minmax(0, 1fr); }
  .research { grid-template-columns: minmax(0, 1fr); }
  .answer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .card { padding: 18px; }
  .section { padding-top: 40px; }
  .step-head { flex-wrap: wrap; }
  .step-num { width: 44px; height: 44px; font-size: 20px; }
  .step-badge { margin-left: 62px; }
}
@media (max-width: 560px) {
  .layout { padding: 0 14px; }
  .brand-text { display: none; }
  progress { display: none; }
  .topbar-inner { gap: 10px; padding: 0 12px; }
  .mode-switch button { padding: 7px 9px; font-size: 13.5px; }
  .mode-switch button b { display: none; }
  #variant-chip { display: none; }
  .brief-grid { grid-template-columns: minmax(0, 1fr); }
  .metrics { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .demo { padding: 12px; }
  .demo-scenes { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .demo-caption { min-height: 132px; }
  .hero h1 { font-size: 30px; }
  .sandbox-values { grid-template-columns: minmax(0, 1fr); }
  .playback select { display: none; }
  .term::after { left: 0; transform: translateY(4px); max-width: min(280px, 80vw); }
  .term:hover::after, .term:focus::after { transform: none; }
}
@media print {
  .topbar, .rail, .demo, .hero-actions, .lab-panel, .playback { display: none !important; }
  .layout { display: block; }
}
/* переключатель темы в шапке: на узком экране — только значок */
@media (max-width: 560px) { .topbar .t-toggle .t-tx { display: none; } }