/* Бусина — дизайн-токены.
   Layout: тетрадь в клетку. Узкая колонка текста справа от красной «полевой» линии;
   на полях живут оглавление и пометки учителя. Тренажёры — в тёмной «раме соробана». */
:root {
  --paper: #f5f7fb;
  --paper-2: #ffffff;
  --grid: rgba(64, 104, 178, .10);
  --ink: #1b2747;
  --ink-soft: #4a5679;
  --ink-faint: #7d87a3;
  --rule: #d9deea;
  --margin: #c93a52;          /* красная линия полей */
  --bead: #e2a136;            /* самшитовая косточка */
  --bead-deep: #b9771a;
  --frame: #262b3a;           /* рама соробана */
  --frame-2: #343a4d;
  --frame-ink: #eef1f8;
  --ok: #23845f;
  --ok-bg: #e3f3ec;
  --bad: #c0392b;
  --bad-bg: #fbe9e7;
  --focus: #3a6fd8;
  --shadow: 0 1px 0 rgba(27, 39, 71, .06), 0 8px 24px -12px rgba(27, 39, 71, .25);

  --f-display: "Unbounded", "Arial Black", system-ui, sans-serif;
  --f-body: "Golos Text", "Segoe UI", system-ui, -apple-system, sans-serif;
  --f-hand: "Caveat", "Segoe Print", "Comic Sans MS", cursive;

  --s-1: .25rem; --s-2: .5rem; --s-3: .75rem; --s-4: 1rem; --s-5: 1.5rem; --s-6: 2rem; --s-7: 3rem; --s-8: 4.5rem;
  --r-sm: 6px; --r-md: 12px; --r-lg: 20px;
  --measure: 68ch;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #121729; --paper-2: #1a2036; --grid: rgba(140, 170, 235, .07);
    --ink: #e7ebf6; --ink-soft: #b3bbd3; --ink-faint: #8a93ae; --rule: #2c3450;
    --margin: #ff6f86; --bead: #f0b752; --bead-deep: #d29133;
    --frame: #0b0f1d; --frame-2: #222a42; --frame-ink: #eef1f8;
    --ok: #4cc795; --ok-bg: #163a2e; --bad: #ff7a6b; --bad-bg: #3d1f1f; --focus: #7aa4ff;
    --shadow: 0 1px 0 rgba(0,0,0,.3), 0 10px 28px -14px rgba(0,0,0,.7);
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #121729; --paper-2: #1a2036; --grid: rgba(140, 170, 235, .07);
  --ink: #e7ebf6; --ink-soft: #b3bbd3; --ink-faint: #8a93ae; --rule: #2c3450;
  --margin: #ff6f86; --bead: #f0b752; --bead-deep: #d29133;
  --frame: #0b0f1d; --frame-2: #222a42; --frame-ink: #eef1f8;
  --ok: #4cc795; --ok-bg: #163a2e; --bad: #ff7a6b; --bad-bg: #3d1f1f; --focus: #7aa4ff;
  --shadow: 0 1px 0 rgba(0,0,0,.3), 0 10px 28px -14px rgba(0,0,0,.7);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: 5rem; }
body {
  margin: 0; background-color: var(--paper); color: var(--ink);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 22px 22px;
  font: 400 1.0625rem/1.65 var(--f-body);
}
img, svg { max-width: 100%; }
a { color: inherit; text-decoration-color: var(--margin); text-decoration-thickness: 1.5px; text-underline-offset: 3px; }
a:hover { color: var(--margin); }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; border-radius: 4px; }
h1, h2, h3 { font-family: var(--f-display); font-weight: 600; line-height: 1.2; text-wrap: balance; letter-spacing: -.01em; }
.wrap { width: 100%; max-width: 1180px; margin-inline: auto; padding-inline: max(16px, 4vw); }
.skip { position: absolute; left: -999px; top: 0; background: var(--ink); color: var(--paper); padding: var(--s-2) var(--s-4); z-index: 99; }
.skip:focus { left: 16px; }

/* ── Шапка ───────────────────────────────────────── */
.top {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 30;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--rule);
}
.top .wrap { display: flex; align-items: center; gap: var(--s-4); min-height: 64px; }
.logo { display: flex; align-items: center; gap: .55rem; text-decoration: none; font: 700 1.15rem var(--f-display); letter-spacing: -.02em; }
.logo svg { width: 30px; height: 30px; flex: none; }
.nav { display: flex; gap: .2rem; margin-left: auto; flex-wrap: wrap; }
.nav a { text-decoration: none; padding: .45rem .7rem; border-radius: 999px; font-size: .95rem; color: var(--ink-soft); }
.nav a:hover { color: var(--ink); background: var(--paper-2); }
.nav a[aria-current="page"] { color: var(--ink); background: var(--paper-2); box-shadow: inset 0 0 0 1px var(--rule); }
.icon-btn { flex: none; width: 40px; height: 40px; display: grid; place-items: center; border: 1px solid var(--rule); background: var(--paper-2); color: var(--ink); border-radius: 50%; cursor: pointer; }
.icon-btn svg { width: 18px; height: 18px; }
.menu-btn { display: none; }
@media (max-width: 900px) {
  .menu-btn { display: grid; margin-left: auto; }
  .nav { display: none; position: absolute; left: 0; right: 0; top: 100%; flex-direction: column; background: var(--paper-2); border-bottom: 1px solid var(--rule); padding: var(--s-3) max(16px, 4vw); box-shadow: var(--shadow); }
  .nav.open { display: flex; }
  .nav a { padding: .75rem .5rem; border-radius: var(--r-sm); }
}

/* ── Шапка статьи ────────────────────────────────── */
.crumbs { font-size: .875rem; color: var(--ink-faint); padding-top: var(--s-5); display: flex; flex-wrap: wrap; gap: .4rem; }
.crumbs a { color: var(--ink-soft); }
.page-head { padding-block: var(--s-4) var(--s-5); max-width: 860px; }
.page-head h1 { font-size: clamp(1.75rem, 1.1rem + 2.6vw, 2.9rem); margin: 0 0 var(--s-4); }
.meta-line { display: flex; flex-wrap: wrap; gap: var(--s-2) var(--s-5); color: var(--ink-faint); font-size: .9rem; margin-bottom: var(--s-4); }
.meta-line b { color: var(--ink-soft); font-weight: 500; }
.lead p { font-size: 1.2rem; line-height: 1.55; max-width: var(--measure); margin: 0; }

/* ── Раскладка «тетрадь»: поля + колонка ─────────── */
.sheet { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 0 var(--s-6); padding-block: var(--s-6) var(--s-8); align-items: start; }
.sheet > .field { position: sticky; top: 88px; padding-right: var(--s-4); }
.sheet > .body { border-left: 2px solid var(--margin); padding-left: var(--s-6); min-width: 0; }
@media (max-width: 960px) {
  .sheet { grid-template-columns: minmax(0, 1fr); }
  .sheet > .field { position: static; padding: 0 0 var(--s-5); }
  .sheet > .body { padding-left: var(--s-4); }
}
.toc { font-size: .92rem; }
.toc-title { font: 600 .95rem var(--f-display); margin: 0 0 var(--s-3); }
.toc ol { list-style: none; margin: 0; padding: 0; display: grid; gap: .1rem; counter-reset: t; }
.toc li { counter-increment: t; }
.toc a { display: grid; grid-template-columns: 1.8rem 1fr; text-decoration: none; color: var(--ink-soft); padding: .3rem .4rem; border-radius: var(--r-sm); line-height: 1.35; }
.toc a::before { content: counter(t); font-variant-numeric: tabular-nums; color: var(--ink-faint); }
.toc a:hover, .toc a.on { color: var(--ink); background: var(--paper-2); }
.toc a.on::before { color: var(--margin); }
@media (max-width: 960px) {
  .toc { background: var(--paper-2); border: 1px solid var(--rule); border-radius: var(--r-md); }
  .toc details > summary { cursor: pointer; padding: var(--s-3) var(--s-4); list-style: none; }
  .toc details > summary::-webkit-details-marker { display: none; }
  .toc details[open] > summary { border-bottom: 1px solid var(--rule); }
  .toc details ol { padding: var(--s-3); }
}
.margin-note { font: 500 1.35rem/1.15 var(--f-hand); color: var(--margin); margin-top: var(--s-5); transform: rotate(-1.5deg); }

/* ── Текст статьи (разметка ТЗ og1) ─────────────── */
.body > * { max-width: var(--measure); }
.body > table, .body > .tbl, .body > .tool { max-width: none; }
.body h2 { margin: var(--s-7) 0 var(--s-4); font-size: clamp(1.35rem, 1.1rem + 1vw, 1.65rem) !important; position: relative; }
.body h2:first-child { margin-top: 0; }
.body h2::before { content: ""; position: absolute; left: calc(-1 * var(--s-6) - 8px); top: .35em; width: 14px; height: 14px; border-radius: 50%; background: var(--bead); box-shadow: inset -3px -3px 0 var(--bead-deep); }
@media (max-width: 960px) { .body h2::before { left: calc(-1 * var(--s-4) - 8px); } }
.body h3 { margin: var(--s-5) 0 var(--s-2); font-size: 1.12rem !important; }
.body p { margin: 0 0 var(--s-4); }
.body p[style*="justify"] { text-align: left !important; hyphens: auto; }
@media (min-width: 700px) { .body p[style*="justify"] { text-align: justify !important; } }
.body sup { font-size: .7em; line-height: 0; }
.body sup a { text-decoration: none; color: var(--margin); font-weight: 600; }
.text-blue { color: var(--focus); }
.b-500 { font-weight: 500; }
.mb-3 { margin-bottom: var(--s-4); }
.big-dash-list { list-style: none; padding: 0; margin: 0 0 var(--s-4); display: grid; gap: var(--s-2); }
.big-dash-list li { position: relative; padding-left: 1.6rem; }
.big-dash-list li::before { content: ""; position: absolute; left: 0; top: .78em; width: 1rem; height: 2px; background: var(--margin); }
.custom-num-list { list-style: none; padding: 0; margin: 0 0 var(--s-4); counter-reset: n; display: grid; gap: var(--s-3); }
.custom-num-list li { counter-increment: n; position: relative; padding-left: 2.6rem; }
.custom-num-list li::before { content: counter(n); position: absolute; left: 0; top: .05em; width: 1.85rem; height: 1.85rem; border-radius: 50%; display: grid; place-items: center; font: 600 .85rem var(--f-display); background: var(--bead); color: #2a1a02; }
.tbl { overflow-x: auto; margin: 0 0 var(--s-5); border-radius: var(--r-md); border: 1px solid var(--rule); background: var(--paper-2); }
.body table { border-collapse: collapse; width: 100%; font-size: .95rem; min-width: 520px; border: 0 !important; }
.body th, .body td { padding: .65rem .8rem !important; border: 0; border-bottom: 1px solid var(--rule); text-align: left; vertical-align: top; }
.body tr[style*="background"] { background: color-mix(in srgb, var(--bead) 18%, var(--paper-2)) !important; }
.body tr[style*="background"] td, .body th { font-weight: 600; }
.body tbody tr:last-child td { border-bottom: 0; }
.body blockquote { margin: 0 0 var(--s-5); padding: var(--s-4) var(--s-5); background: var(--paper-2); border-radius: var(--r-md); border: 1px solid var(--rule); position: relative; }
.body blockquote p:last-child { margin-bottom: 0; }
.body blockquote.myth { border-color: color-mix(in srgb, var(--margin) 45%, var(--rule)); }
.body blockquote.myth::before { content: "Миф"; position: absolute; top: -.75rem; left: var(--s-4); background: var(--paper); padding: 0 .4rem; font: 600 1.25rem var(--f-hand); color: var(--margin); }
.body blockquote.note::before { content: "Не путать"; position: absolute; top: -.75rem; left: var(--s-4); background: var(--paper); padding: 0 .4rem; font: 600 1.25rem var(--f-hand); color: var(--focus); }
.body h2 + h3 { margin-top: var(--s-3); }
.sources p { font-size: .92rem; color: var(--ink-soft); }

/* ── Кнопки и поля ───────────────────────────────── */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: .5rem; min-height: 44px; padding: .55rem 1.15rem; border-radius: 999px; border: 1.5px solid var(--ink); background: var(--ink); color: var(--paper); font: 600 .95rem var(--f-body); cursor: pointer; text-decoration: none; }
.btn:hover { background: var(--margin); border-color: var(--margin); color: #fff; }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { color: #fff; }
.btn.bead { background: var(--bead); border-color: var(--bead); color: #2a1a02; }
.btn.bead:hover { background: var(--bead-deep); border-color: var(--bead-deep); color: #fff; }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.field-row { display: flex; flex-wrap: wrap; gap: var(--s-4); }
.ctl { display: grid; gap: .3rem; min-width: 0; }
.ctl label, .ctl .lbl { font-size: .85rem; color: inherit; opacity: .8; }
.ctl select, .ctl input[type="number"], .ctl input[type="text"] { min-height: 42px; padding: .4rem .7rem; border-radius: var(--r-sm); border: 1px solid var(--frame-2); background: var(--frame-2); color: var(--frame-ink); font: 500 1rem var(--f-body); min-width: 0; }
.seg { display: inline-flex; flex-wrap: wrap; border-radius: 999px; padding: 3px; gap: 2px; background: var(--frame-2); }
.seg button { border: 0; background: transparent; color: var(--frame-ink); opacity: .75; padding: .45rem .85rem; border-radius: 999px; font: 500 .9rem var(--f-body); cursor: pointer; min-height: 36px; }
.seg button[aria-pressed="true"] { background: var(--bead); color: #2a1a02; opacity: 1; }
input[type="range"] { accent-color: var(--bead); width: 100%; }

/* ── Рама тренажёра ──────────────────────────────── */
.tool { background: var(--frame); color: var(--frame-ink); border-radius: var(--r-lg); padding: clamp(1rem, 2.5vw, 2rem); margin-block: var(--s-4) var(--s-2); box-shadow: var(--shadow); position: relative; }
.tool::before, .tool::after { content: ""; position: absolute; left: 22px; right: 22px; height: 6px; border-radius: 3px; background: repeating-linear-gradient(90deg, var(--frame-2) 0 14px, transparent 14px 22px); }
.tool::before { top: 8px; } .tool::after { bottom: 8px; }
.tool h2 { font-size: 1.15rem; margin: 0; color: var(--frame-ink); }
.tool-grid { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(260px, 1fr); gap: var(--s-5); align-items: start; }
@media (max-width: 860px) { .tool-grid { grid-template-columns: minmax(0, 1fr); } }
.panel { background: var(--frame-2); border-radius: var(--r-md); padding: var(--s-4); display: grid; gap: var(--s-4); min-width: 0; }
.stage { min-height: 260px; border-radius: var(--r-md); background: radial-gradient(120% 90% at 50% 40%, var(--frame-2), var(--frame)); display: grid; place-items: center; text-align: center; padding: var(--s-5); position: relative; overflow: hidden; }
.flash-num { font: 700 clamp(4rem, 3rem + 7vw, 8.5rem)/1 var(--f-display); font-variant-numeric: tabular-nums; letter-spacing: -.03em; color: var(--frame-ink); }
.flash-num.neg { color: #ff9aa9; }
.stage-hint { font-size: .95rem; opacity: .75; max-width: 34ch; }
.stage-hand { font: 600 1.6rem var(--f-hand); color: var(--bead); }
.answer-row { display: flex; gap: var(--s-2); flex-wrap: wrap; justify-content: center; }
.answer-row input { width: 9ch; min-height: 52px; text-align: center; font: 700 1.6rem var(--f-display); border-radius: var(--r-md); border: 2px solid var(--bead); background: var(--frame); color: var(--frame-ink); }
.verdict { padding: var(--s-3) var(--s-4); border-radius: var(--r-md); font-weight: 600; }
.verdict.ok { background: var(--ok-bg); color: var(--ok); }
.verdict.bad { background: var(--bad-bg); color: var(--bad); }
.stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--s-2); }
.stat { background: var(--frame); border-radius: var(--r-sm); padding: .55rem .6rem; }
.stat b { display: block; font: 600 1.25rem var(--f-display); font-variant-numeric: tabular-nums; }
.stat span { font-size: .75rem; opacity: .7; }
.seq { display: flex; flex-wrap: wrap; gap: .35rem; justify-content: center; font-variant-numeric: tabular-nums; }
.seq span { background: var(--frame); padding: .15rem .55rem; border-radius: 999px; font-weight: 600; }
.timerbar { position: absolute; left: 0; bottom: 0; height: 4px; background: var(--bead); width: 100%; transform-origin: left; }
.tool small, .tool .muted { opacity: .72; }
.tool a { color: var(--bead); }
.hist { list-style: none; padding: 0; margin: 0; display: grid; gap: .3rem; font-size: .88rem; max-height: 180px; overflow: auto; }
.hist li { display: flex; justify-content: space-between; gap: var(--s-2); background: var(--frame); padding: .35rem .6rem; border-radius: var(--r-sm); }
.ok-t { color: var(--ok); } .bad-t { color: var(--bad); }

/* ── Соробан ─────────────────────────────────────── */
.soroban { width: 100%; display: block; touch-action: manipulation; user-select: none; -webkit-user-select: none; }
.soroban .frame { fill: #3b2a1a; }
.soroban .rod { stroke: #c9b79a; stroke-width: 3; }
.soroban .beam { fill: #2a1d12; }
.soroban .dot { fill: #f3e6cf; }
.soroban .bead path { fill: var(--bead); stroke: var(--bead-deep); stroke-width: 1.5; }
.soroban .bead.on path { fill: #f6c86a; }
.soroban .bead { transition: transform .22s cubic-bezier(.3,1.4,.5,1); cursor: pointer; }
.soroban.static .bead { cursor: default; }
.soroban .lbl { fill: var(--frame-ink); font: 600 15px var(--f-display); opacity: .85; }
.soroban .bead:focus-visible path { stroke: var(--focus); stroke-width: 3; }
.readout { display: flex; align-items: baseline; justify-content: center; gap: var(--s-3); font-family: var(--f-display); }
.readout b { font-size: clamp(2rem, 1.6rem + 2vw, 3rem); font-variant-numeric: tabular-nums; }
.formula-tags { display: flex; flex-wrap: wrap; gap: .35rem; }
.formula-tags span { font-size: .82rem; padding: .2rem .6rem; border-radius: 999px; background: var(--frame); }
.formula-tags span.brat { box-shadow: inset 0 0 0 1.5px var(--bead); }
.formula-tags span.drug { box-shadow: inset 0 0 0 1.5px #7fb8ff; }

/* ── Главная ─────────────────────────────────────── */
.hero { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: var(--s-6); align-items: center; padding-block: var(--s-7) var(--s-6); }
@media (max-width: 900px) { .hero { grid-template-columns: minmax(0, 1fr); padding-block: var(--s-5); } }
.hero h1 { font-size: clamp(2rem, 1.2rem + 3.4vw, 3.6rem); margin: 0 0 var(--s-4); letter-spacing: -.03em; }
.hero p { font-size: 1.15rem; color: var(--ink-soft); max-width: 46ch; margin: 0 0 var(--s-5); }
.hero .actions { display: flex; gap: var(--s-3); flex-wrap: wrap; }
.demo { background: var(--frame); border-radius: var(--r-lg); padding: var(--s-5); color: var(--frame-ink); box-shadow: var(--shadow); display: grid; gap: var(--s-4); }
.demo-top { display: flex; justify-content: space-between; align-items: center; gap: var(--s-3); }
.demo-flash { font: 700 3.4rem/1 var(--f-display); font-variant-numeric: tabular-nums; min-width: 3ch; text-align: right; }
.demo-cap { font: 600 1.45rem/1.1 var(--f-hand); color: var(--bead); }
.section { padding-block: var(--s-7); }
.section > h2 { font-size: clamp(1.5rem, 1.1rem + 1.4vw, 2.1rem); margin: 0 0 var(--s-2); }
.section > .sub { color: var(--ink-soft); margin: 0 0 var(--s-5); max-width: 60ch; }
.tray { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--s-4); }
@media (max-width: 1000px) { .tray { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) { .tray { grid-template-columns: minmax(0, 1fr); } }
.tile { display: grid; grid-template-rows: auto auto 1fr auto; gap: var(--s-2); padding: var(--s-5); background: var(--paper-2); border: 1px solid var(--rule); border-radius: var(--r-md); text-decoration: none; transition: border-color .15s, transform .15s; }
.tile:hover { border-color: var(--bead); transform: translateY(-2px); color: inherit; }
.tile svg { width: 44px; height: 44px; }
.tile h3 { margin: 0; font-size: 1.1rem; }
.tile p { margin: 0; color: var(--ink-soft); font-size: .95rem; }
.tile .go { font-weight: 600; color: var(--margin); font-size: .92rem; }
.path { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: var(--s-4); counter-reset: p; }
@media (max-width: 1000px) { .path { grid-template-columns: minmax(0, 1fr); } }
.path li { counter-increment: p; border-top: 2px solid var(--ink); padding-top: var(--s-3); }
.path li::before { content: counter(p); font: 700 2rem var(--f-display); color: var(--bead-deep); display: block; }
.path b { display: block; font-family: var(--f-display); font-weight: 600; margin-block: .2rem; }
.path span { color: var(--ink-soft); font-size: .95rem; }
.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: var(--s-6); align-items: start; }
@media (max-width: 860px) { .split { grid-template-columns: minmax(0, 1fr); } }
.prose p { max-width: 62ch; color: var(--ink-soft); }
.reads { list-style: none; padding: 0; margin: 0; display: grid; gap: 0; border-top: 1px solid var(--rule); }
.reads a { display: grid; gap: .15rem; padding: var(--s-4) 0; border-bottom: 1px solid var(--rule); text-decoration: none; }
.reads a b { font-family: var(--f-display); font-weight: 600; }
.reads a span { color: var(--ink-soft); font-size: .95rem; }

/* ── Виджеты родителей и прогресс ────────────────── */
.check-list { list-style: none; padding: 0; margin: 0; display: grid; gap: .4rem; }
.check-list label { display: grid; grid-template-columns: 22px 1fr; gap: .6rem; align-items: start; padding: .5rem .6rem; border-radius: var(--r-sm); background: var(--frame); cursor: pointer; }
.check-list input { width: 18px; height: 18px; margin-top: .2rem; accent-color: var(--bead); }
.meter { height: 10px; border-radius: 99px; background: var(--frame); overflow: hidden; }
.meter i { display: block; height: 100%; background: var(--bead); width: 0; transition: width .3s; }
.calc-out { display: grid; gap: .4rem; }
.calc-out div { display: flex; justify-content: space-between; gap: var(--s-3); padding: .45rem .6rem; background: var(--frame); border-radius: var(--r-sm); font-variant-numeric: tabular-nums; }
.calc-out b { font-family: var(--f-display); font-weight: 600; }
.chart { width: 100%; height: auto; display: block; }
.chart .grid line { stroke: var(--frame-2); }
.chart text { fill: var(--frame-ink); font: 12px var(--f-body); opacity: .75; }
.trick-card { background: var(--frame-2); border-radius: var(--r-md); padding: var(--s-4); display: grid; gap: var(--s-3); min-width: 0; }
.trick-card h3 { margin: 0; font-size: 1.05rem; color: var(--frame-ink); }
.trick-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); gap: var(--s-4); }
.trick-q { font: 700 1.8rem var(--f-display); font-variant-numeric: tabular-nums; }
.steps { margin: 0; padding-left: 1.2rem; font-size: .92rem; opacity: .9; }
.confirm { display: flex; gap: var(--s-2); align-items: center; flex-wrap: wrap; }

/* ── Подвал ──────────────────────────────────────── */
.foot { border-top: 1px solid var(--rule); background: var(--paper-2); padding-block: var(--s-6); margin-top: var(--s-6); font-size: .92rem; color: var(--ink-soft); }
.foot .cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: var(--s-5); }
@media (max-width: 760px) { .foot .cols { grid-template-columns: minmax(0, 1fr); } }
.foot h3 { font-size: .95rem; margin: 0 0 var(--s-2); color: var(--ink); }
.foot ul { list-style: none; margin: 0; padding: 0; display: grid; gap: .3rem; }
.foot a { color: var(--ink-soft); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}
.ph { font: 600 1.05rem var(--f-display); margin: 0; color: var(--frame-ink); }
.stats.four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
@media (max-width: 600px) { .stats.four { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.demo-flash { white-space: nowrap; transition: opacity .2s; }
.hero .demo p { color: var(--frame-ink); opacity: .78; font-size: .92rem; max-width: none; }

/* ── Таблица умножения ── */
.mt-wrap { overflow-x: auto; background: var(--frame-2); border-radius: var(--r-md); padding: .5rem; }
.mt { border-collapse: separate; border-spacing: 3px; width: 100%; min-width: 420px; font-variant-numeric: tabular-nums; }
.mt th, .mt td { text-align: center; padding: 0; height: 2.3rem; border-radius: 6px; }
.mt th { font: 600 .9rem var(--f-display); color: var(--bead); }
.mt td button, .mt td input { width: 100%; height: 100%; min-height: 2.3rem; border: 0; border-radius: 6px; background: var(--frame); color: var(--frame-ink); font: 500 .95rem var(--f-body); cursor: pointer; text-align: center; }
.mt td input { background: transparent; box-shadow: inset 0 0 0 1.5px var(--bead); cursor: text; }
.mt .on button, .mt th.on { background: color-mix(in srgb, var(--bead) 28%, var(--frame)); }
.mt td.hit button { background: var(--bead); color: #2a1a02; font-weight: 700; }
.mt td.good input { box-shadow: inset 0 0 0 2px var(--ok); }
.mt td.bad input { box-shadow: inset 0 0 0 2px var(--bad); }

/* ── Лист с примерами ── */
.ws-sheet { background: #fff; color: #1b2747; border-radius: var(--r-md); padding: 1.2rem 1.4rem; min-width: 0; }
.ws-head { display: flex; justify-content: space-between; flex-wrap: wrap; gap: .5rem; border-bottom: 1.5px solid #1b2747; padding-bottom: .5rem; margin-bottom: .8rem; font-size: .95rem; }
.ws-list { columns: 2; column-gap: 2rem; margin: 0; padding-left: 1.6rem; font: 500 1.05rem/2.1 var(--f-body); font-variant-numeric: tabular-nums; }
.ws-list b { color: #c93a52; }
@media (max-width: 520px) { .ws-list { columns: 1; } }
@media print {
  body.print-ws * { visibility: hidden !important; }
  body.print-ws .ws-sheet, body.print-ws .ws-sheet * { visibility: visible !important; }
  body.print-ws .ws-sheet { position: absolute; left: 0; top: 0; width: 100%; padding: 0; }
  body.print-ws { background: #fff !important; }
}

/* ── Связанные материалы и хабы ── */
.related { padding-block: var(--s-6); border-top: 1px solid var(--rule); }
.related h2 { font-size: clamp(1.25rem, 1.05rem + .8vw, 1.6rem); margin: 0 0 var(--s-4); }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 280px), 1fr)); gap: var(--s-4); }
.card { display: grid; gap: .35rem; align-content: start; padding: var(--s-4) var(--s-5); background: var(--paper-2); border: 1px solid var(--rule); border-radius: var(--r-md); text-decoration: none; }
.card:hover { border-color: var(--bead); color: inherit; }
.card b { font-family: var(--f-display); font-weight: 600; line-height: 1.3; }
.card span { color: var(--ink-soft); font-size: .93rem; }
.card i { font-style: normal; font-size: .8rem; color: var(--margin); font-weight: 600; }
.hub-intro { max-width: var(--measure); }
.hub-intro p { color: var(--ink-soft); }
.search-box { display: flex; gap: var(--s-2); flex-wrap: wrap; margin-bottom: var(--s-5); }
.search-box input { flex: 1 1 260px; min-height: 48px; border-radius: 999px; border: 1.5px solid var(--rule); background: var(--paper-2); color: var(--ink); padding: 0 1.2rem; font: 500 1.05rem var(--f-body); }
.search-box input:focus { border-color: var(--bead); outline: none; }
mark { background: color-mix(in srgb, var(--bead) 40%, transparent); color: inherit; border-radius: 3px; padding: 0 2px; }
.sitemap-group { margin-bottom: var(--s-6); }
.sitemap-group h2 { font-size: 1.3rem; margin: 0 0 var(--s-3); }
.sitemap-group ul { margin: 0; padding-left: 1.2rem; display: grid; gap: .3rem; columns: 2; }
@media (max-width: 700px) { .sitemap-group ul { columns: 1; } }
.err-404 { padding-block: var(--s-8); max-width: 640px; }
.err-404 .num { font: 700 clamp(5rem, 3rem + 10vw, 9rem)/1 var(--f-display); color: var(--bead); }
h1, h2, h3 { overflow-wrap: break-word; hyphens: auto; }
@media (max-width: 699px) { .lead p { text-align: left !important; } }