/* Дизайн-система «Тёмная бумага + медь».
   Неоскевоморфизм: поверхности выглядят как слои плотного картона —
   приподнятые (raised) с бликом сверху-слева и тенью снизу-справа,
   вдавленные (inset) для полей ввода и дорожек, медь — единственный акцент.
   Описание системы: Obsidian → «Проект ЕГЭ Школа/Дизайн-система.md». */
:root {
  color-scheme: dark;

  /* бумага */
  --bg: #151311;
  --paper: #201d19;
  --paper-hi: #29251f;
  --paper-lo: #1a1714;
  --edge-hi: rgba(255, 236, 214, .075);
  --edge-lo: rgba(0, 0, 0, .5);

  /* текст */
  --text: #ece2d3;
  --muted: #a09280;
  --faint: #6f6558;

  /* медь */
  --cu: #c47a48;
  --cu-hi: #e6a676;
  --cu-lo: #87471f;
  --cu-text: #e9a273;
  --cu-glow: rgba(214, 130, 74, .32);

  /* состояния */
  --ok: #a3c785;
  --ok-bg: rgba(163, 199, 133, .09);
  --bad: #e27f62;
  --bad-bg: rgba(226, 127, 98, .09);

  /* тени-объёмы */
  --raised: inset 1px 1px 0 var(--edge-hi), inset -1px -1px 0 rgba(0, 0, 0, .35), 3px 5px 12px rgba(0, 0, 0, .45), 1px 1px 2px rgba(0, 0, 0, .5);
  --raised-lg: inset 1px 1px 0 var(--edge-hi), inset -1px -1px 0 rgba(0, 0, 0, .35), 6px 10px 26px rgba(0, 0, 0, .5), 1px 2px 3px rgba(0, 0, 0, .5);
  --inset: inset 2px 2px 6px rgba(0, 0, 0, .6), inset -1px -1px 0 var(--edge-hi);
  --fold: linear-gradient(135deg, rgba(255, 240, 220, .035) 0 50%, rgba(0, 0, 0, .07) 50% 100%);
  --copper: linear-gradient(180deg, var(--cu-hi) 0%, var(--cu) 45%, var(--cu-lo) 100%);

  --font-d: "Roboto Condensed", "Arial Narrow", system-ui, sans-serif;
  --font-b: "Roboto", system-ui, -apple-system, "Segoe UI", sans-serif;
  --r: 5px;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  background-color: var(--bg);
  /* лёгкая фактура картона */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 1 0 0 0 0 .93 0 0 0 0 .85 0 0 0 .035 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  color: var(--text);
  font: 400 16px/1.6 var(--font-b);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--cu-text); text-decoration: none; }
h1, h2, h3, h4 { font-family: var(--font-d); line-height: 1.2; margin: 0 0 .5em; text-wrap: balance; letter-spacing: .01em; }
h1 { font-size: 30px; font-weight: 700; }
h2 { font-size: 22px; font-weight: 700; }
::selection { background: var(--cu); color: #fff; }
:focus-visible { outline: 2px solid var(--cu-hi); outline-offset: 2px; }

.container {
  max-width: 1000px; margin: 0 auto;
  padding-block: 28px 72px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}

.ico { width: 18px; height: 18px; flex: none; stroke: currentColor; fill: none; stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; vertical-align: -3px; }
.ico.lg { width: 28px; height: 28px; stroke-width: 1.4; }
.ico.xl { width: 64px; height: 64px; stroke-width: 1.1; }

/* ---------- шапка ---------- */
body::before {
  content: ""; position: fixed; inset: 0 0 auto; height: env(safe-area-inset-top, 0px); z-index: 11; background: var(--paper);
}
.topbar {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 10;
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  padding-block: 10px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  background: var(--paper);
  box-shadow: inset 0 -1px 0 rgba(0, 0, 0, .6), 0 1px 0 var(--edge-hi), 0 6px 18px rgba(0, 0, 0, .35);
}
.logo { display: flex; align-items: center; gap: 10px; font: 700 19px/1 var(--font-d); color: var(--text); text-transform: uppercase; letter-spacing: .06em; }
.logo-mark {
  display: grid; place-items: center; width: 32px; height: 32px; border-radius: 4px;
  background: var(--copper); color: #fff4ea; font-size: 18px;
  box-shadow: inset 1px 1px 0 rgba(255, 230, 205, .45), inset -1px -1px 0 rgba(0, 0, 0, .3), 2px 3px 8px rgba(0, 0, 0, .5);
  text-shadow: 0 1px 1px rgba(0, 0, 0, .35);
}
.nav { display: flex; gap: 6px; margin-left: auto; flex-wrap: wrap; padding: 4px; border-radius: 6px; background: var(--paper-lo); box-shadow: var(--inset); }
.nav a { display: flex; align-items: center; gap: 7px; padding: 7px 14px; border-radius: 4px; color: var(--muted); font: 500 15px/1.2 var(--font-d); letter-spacing: .02em; }
.nav a:hover { color: var(--text); }
.nav a.active { background: var(--paper-hi); color: var(--cu-text); box-shadow: var(--raised); }
.badge {
  display: inline-block; min-width: 20px; padding: 1px 6px; border-radius: 3px;
  background: var(--copper); color: #fff; font: 700 12px/1.4 var(--font-d); text-align: center;
  box-shadow: inset 1px 1px 0 rgba(255, 230, 205, .4);
}

/* ---------- поверхности ---------- */
.card {
  position: relative;
  background: var(--fold), var(--paper);
  border-radius: var(--r);
  box-shadow: var(--raised);
  padding: 20px;
}
.grid { display: grid; gap: 16px; }
.grid-3 { grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); }
.grid-2 { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }

/* работа над ошибками */
.ok-text { color: var(--ok); }
.mist-subj { display: flex; flex-direction: column; gap: 12px; }
.mist-subj b { font: 700 18px/1.25 var(--font-d); }
.mist-nums { display: flex; gap: 18px; flex-wrap: wrap; font: 500 13px/1.3 var(--font-d); color: var(--muted); text-transform: uppercase; letter-spacing: .05em; }
.mist-nums b { font: 700 22px/1 var(--font-d); color: var(--text); margin-right: 4px; text-transform: none; }
.mist-topics { display: flex; flex-direction: column; gap: 12px; }
.mist-topic { padding: 14px 18px; }
.mist-subj-h { display: flex; align-items: center; gap: 8px; margin: 10px 0 0; font: 600 15px/1.3 var(--font-d); color: var(--muted); }
.mist-head { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.mist-head .info { flex: 1; min-width: 200px; }
.mist-head b { font: 600 17px/1.3 var(--font-d); }
.mist-list { margin-top: 10px; }
.mist-list summary { cursor: pointer; font: 500 13px/1.4 var(--font-d); color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.mist-list ol { margin: 10px 0 0; padding-left: 22px; display: flex; flex-direction: column; gap: 8px; }
.mist-list li { display: flex; flex-direction: column; gap: 2px; }
.mist-q { font-size: 15px; line-height: 1.45; }
.grid-4 { grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); }
.muted { color: var(--muted); }
.small { font-size: 14px; }
.spacer { flex: 1; }
.row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.row > * { min-width: 0; }

/* Заголовок раздела: картонная плашка + полоса до края, как в референсе */
.section-title {
  display: flex; align-items: center; gap: 0;
  margin: 40px 0 16px;
  font: 700 15px/1 var(--font-d); text-transform: uppercase; letter-spacing: .1em; color: var(--text);
}
.section-title > span {
  padding: 9px 14px; background: var(--paper-hi); border-radius: 3px 0 0 3px; box-shadow: var(--raised); white-space: nowrap;
}
.section-title::after {
  content: ""; flex: 1; height: 22px; background: var(--fold), var(--paper); border-radius: 0 3px 3px 0;
  box-shadow: inset 1px 1px 0 var(--edge-hi), 3px 5px 10px rgba(0, 0, 0, .35);
}

/* ---------- главная ---------- */
.hero {
  padding: 34px 32px;
  background:
    linear-gradient(115deg, transparent 0 62%, rgba(196, 122, 72, .09) 62% 63%, transparent 63%),
    linear-gradient(115deg, transparent 0 70%, rgba(0, 0, 0, .14) 70%),
    var(--fold), var(--paper);
  box-shadow: var(--raised-lg);
  overflow: hidden;
}
.hero h1 { font-size: clamp(28px, 5vw, 42px); text-transform: uppercase; letter-spacing: .03em; margin-bottom: 10px; }
.hero h1 em { font-style: normal; color: var(--cu-text); }
.hero p { margin: 0; color: var(--muted); max-width: 58ch; }
.hero-tag {
  display: inline-block; margin-bottom: 14px; padding: 4px 12px 4px 10px;
  background: var(--copper); color: #fff3e8; font: 600 12px/1.4 var(--font-d); text-transform: uppercase; letter-spacing: .1em;
  clip-path: polygon(0 0, 100% 0, calc(100% - 8px) 50%, 100% 100%, 0 100%);
  box-shadow: inset 1px 1px 0 rgba(255, 230, 205, .4);
}

.stat { display: flex; align-items: center; gap: 14px; padding: 16px 18px; }
.stat .ico { color: var(--cu-text); }
.stat b { display: block; font: 700 28px/1.1 var(--font-d); font-variant-numeric: tabular-nums; }
.stat span { font: 500 13px/1.3 var(--font-d); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }

.subject-card { display: flex; flex-direction: column; gap: 14px; color: var(--text); transition: transform .15s, box-shadow .15s; }
.subject-card:hover { transform: translate(-1px, -2px); box-shadow: var(--raised-lg); }
.subject-card:active { transform: none; box-shadow: var(--inset); }
.subject-card b { font: 700 18px/1.25 var(--font-d); }
.subject-icon {
  display: grid; place-items: center; flex: none; width: 52px; height: 52px; border-radius: 4px;
  background: var(--copper); color: #fff3e8; font: 700 21px/1 var(--font-d);
  filter: hue-rotate(var(--hue, 0deg));
  box-shadow: inset 1px 1px 0 rgba(255, 230, 205, .45), inset -2px -2px 0 rgba(0, 0, 0, .25), 3px 5px 12px rgba(0, 0, 0, .5);
  text-shadow: 0 1px 2px rgba(0, 0, 0, .35);
}

/* Линейный прогресс: вдавленная дорожка + медная лента со стрелкой */
.progress { height: 12px; border-radius: 3px; background: var(--paper-lo); box-shadow: var(--inset); padding: 2px; }
.progress > i {
  display: block; height: 100%; min-width: 0; border-radius: 2px;
  background: var(--copper);
  clip-path: polygon(0 0, calc(100% - 5px) 0, 100% 50%, calc(100% - 5px) 100%, 0 100%);
  box-shadow: inset 0 1px 0 rgba(255, 230, 205, .45);
}

/* ---------- кнопки ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  padding: 10px 20px; border: 0; border-radius: 4px;
  background: var(--fold), var(--paper-hi); color: var(--text);
  font: 600 15px/1.2 var(--font-d); letter-spacing: .04em; text-transform: uppercase;
  box-shadow: var(--raised); cursor: pointer; transition: transform .08s, box-shadow .08s, filter .15s;
}
.btn:hover { filter: brightness(1.12); }
.btn:active { transform: translateY(1px); box-shadow: var(--inset); }
.btn:disabled { opacity: .45; cursor: default; filter: none; transform: none; box-shadow: var(--inset); }
.btn.primary { background: var(--copper); color: #fff6ee; text-shadow: 0 1px 1px rgba(0, 0, 0, .35); box-shadow: inset 1px 1px 0 rgba(255, 230, 205, .45), inset -1px -1px 0 rgba(0, 0, 0, .3), 3px 5px 12px rgba(0, 0, 0, .45); }
.btn.primary:active { box-shadow: inset 2px 3px 6px rgba(0, 0, 0, .45); }
.btn.ok { color: var(--ok); box-shadow: var(--raised), inset 0 0 0 1px rgba(163, 199, 133, .4); }
.btn.bad { color: var(--bad); box-shadow: var(--raised), inset 0 0 0 1px rgba(226, 127, 98, .45); }
.btn.ghost { background: transparent; box-shadow: none; color: var(--muted); }
.btn.ghost:hover { color: var(--text); filter: none; }
.btn.small { padding: 7px 14px; font-size: 13px; }

/* ---------- навигация ---------- */
.crumbs { display: inline-flex; flex-wrap: wrap; gap: 4px 6px; align-items: center; margin-bottom: 18px; padding: 6px 14px; border-radius: 4px; background: var(--paper); box-shadow: var(--raised); font: 500 14px/1.3 var(--font-d); color: var(--muted); }
.crumbs a { color: var(--muted); }
.crumbs a:hover { color: var(--cu-text); }
.crumbs .sep { color: var(--faint); }
.crumbs .here { color: var(--cu-text); }

.tabs { display: flex; gap: 6px; padding: 5px; background: var(--paper-lo); box-shadow: var(--inset); border-radius: 6px; width: max-content; max-width: 100%; margin-bottom: 18px; }
.tabs a { display: flex; align-items: center; gap: 8px; padding: 9px 20px; border-radius: 4px; color: var(--muted); font: 600 15px/1.2 var(--font-d); letter-spacing: .03em; }
.tabs a:hover { color: var(--text); }
.tabs a.active { background: var(--fold), var(--paper-hi); color: var(--cu-text); box-shadow: var(--raised), inset 0 0 0 1px rgba(214, 130, 74, .55); }

.topic-list { display: flex; flex-direction: column; gap: 10px; }
.topic-row { display: flex; align-items: center; gap: 16px; padding: 14px 18px; color: var(--text); transition: transform .12s, box-shadow .12s; }
.topic-row:hover { transform: translateX(2px); box-shadow: var(--raised), inset 3px 0 0 var(--cu); }
.topic-row:active { box-shadow: var(--inset); transform: none; }
.topic-row b { font: 600 17px/1.3 var(--font-d); }
.num {
  display: grid; place-items: center; flex: none; width: 44px; height: 44px; border-radius: 4px;
  background: var(--fold), var(--paper-hi); box-shadow: var(--raised);
  font: 700 18px/1 var(--font-d); color: var(--cu-text); font-variant-numeric: tabular-nums;
}
.topic-row .info { flex: 1; min-width: 0; }
.topic-row .progress { margin-top: 8px; max-width: 300px; height: 10px; }
.topic-row .meta { font: 500 13px/1.5 var(--font-d); color: var(--muted); text-align: right; white-space: nowrap; }

/* ---------- теория ---------- */
.theory { font-size: 17px; padding: 28px 32px; }
.theory > * { max-width: 72ch; }
.theory h3 { margin-top: 1.6em; font-size: 20px; text-transform: uppercase; letter-spacing: .05em; color: var(--cu-text); }
.theory h3:first-child { margin-top: 0; }
.theory ul, .theory ol { padding-left: 1.3em; }
.theory li { margin: .35em 0; }
.theory li::marker { color: var(--cu); }
.theory b { color: #fff4e6; }
.theory .tbl, .theory table { max-width: 100%; }
.theory table { display: block; overflow-x: auto; border-collapse: collapse; margin: 1.2em 0; font-size: 15px; border-radius: 4px; box-shadow: var(--raised); background: var(--paper-hi); }
.theory td, .theory th { padding: 8px 12px; text-align: left; vertical-align: top; border-bottom: 1px solid rgba(0, 0, 0, .35); box-shadow: 0 1px 0 var(--edge-hi); }
.theory th { font: 600 13px/1.3 var(--font-d); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); background: var(--paper); }
.tip, .warn, .example { position: relative; border-radius: 4px; padding: 14px 18px; margin: 1.2em 0; background: var(--paper-lo); box-shadow: var(--inset); }
.tip { border-left: 4px solid var(--cu); }
.warn { border-left: 4px solid var(--bad); }
.example { background: var(--fold), var(--paper-hi); box-shadow: var(--raised); }
.theory details.q { margin: 1.2em 0; padding: 12px 18px; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); border-left: 4px solid var(--cu-lo); }
.theory details.q > summary { cursor: pointer; list-style: none; font-weight: 500; }
.theory details.q > summary::-webkit-details-marker { display: none; }
.theory details.q > summary::before { content: "Проверь себя"; display: inline-block; margin-right: 10px; padding: 2px 10px 2px 8px; background: var(--paper-hi); box-shadow: var(--raised); color: var(--cu-text); font: 600 11px/1.5 var(--font-d); text-transform: uppercase; letter-spacing: .1em; border-radius: 3px; }
.theory details.q > summary::after { content: "показать ответ"; margin-left: 8px; color: var(--faint); font: 500 12px/1 var(--font-d); text-transform: uppercase; letter-spacing: .06em; }
.theory details.q[open] > summary::after { content: "скрыть"; }
.theory details.q > div { margin-top: 10px; padding-top: 10px; box-shadow: inset 0 1px 0 rgba(0, 0, 0, .4), inset 0 2px 0 var(--edge-hi); }
.theory ol.steps { counter-reset: st; list-style: none; padding-left: 0; }
.theory ol.steps > li { counter-increment: st; position: relative; padding-left: 40px; margin: .7em 0; }
.theory ol.steps > li::before { content: counter(st); position: absolute; left: 0; top: 0; width: 26px; height: 26px; border-radius: 50%; display: grid; place-items: center; background: var(--copper); color: #fff3e8; font: 600 13px/1 var(--font-d); }
.example::before { content: "Пример"; display: inline-block; margin-bottom: 6px; padding: 2px 10px 2px 8px; background: var(--copper); color: #fff3e8; font: 600 11px/1.5 var(--font-d); text-transform: uppercase; letter-spacing: .1em; clip-path: polygon(0 0, 100% 0, calc(100% - 6px) 50%, 100% 100%, 0 100%); }
.katex { color: #f5ebde; text-transform: none; letter-spacing: normal; }
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 6px 0; }

/* ---------- задания ---------- */
.task-card { display: flex; flex-direction: column; gap: 18px; padding: 22px 24px; }
.task-head { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; font-size: 14px; }
.chip {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 14px 3px 10px; background: var(--paper-hi);
  font: 600 13px/1.4 var(--font-d); letter-spacing: .04em; color: var(--text);
  clip-path: polygon(0 0, 100% 0, calc(100% - 7px) 50%, 100% 100%, 0 100%);
  box-shadow: inset 1px 1px 0 var(--edge-hi);
}
.chip-gen { background: var(--copper); color: #fff3e8; }
.chip-ok { background: #2a3324; color: var(--ok); }
.chip-hard { background: #3a2622; color: #e8a58c; }
.chip-bad { background: #3a231d; color: var(--bad); }
.task-q { font-size: 17px; line-height: 1.65; }
.task-q p { margin: 0 0 .6em; }
.task-q .opt { margin: 6px 0; padding: 6px 12px; border-radius: 3px; background: var(--paper-lo); box-shadow: var(--inset); }
.answer-row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.input {
  flex: 1; min-width: 170px; padding: 12px 16px; border: 1px solid transparent; border-radius: 4px;
  background: var(--paper-lo); color: var(--text); font: 500 17px/1.3 var(--font-b);
  box-shadow: var(--inset); transition: box-shadow .15s, border-color .15s;
}
.input::placeholder { color: var(--faint); }
.input:focus { outline: none; border-color: var(--cu); box-shadow: var(--inset), 0 0 0 3px var(--cu-glow), 0 0 18px var(--cu-glow); }
.input.ok { border-color: rgba(163, 199, 133, .6); background: var(--ok-bg); }
.input.bad { border-color: rgba(226, 127, 98, .7); background: var(--bad-bg); }

/* Баннер результата — как Alert Banner из референса */
.feedback {
  display: flex; align-items: center; gap: 10px;
  padding: 13px 18px; border-radius: 4px; font: 600 16px/1.3 var(--font-d); letter-spacing: .02em;
  background: var(--fold), var(--paper-hi); box-shadow: var(--raised);
}
.feedback.ok { color: var(--ok); box-shadow: var(--raised), inset 4px 0 0 var(--ok); }
.feedback.bad { color: var(--bad); box-shadow: var(--raised), inset 4px 0 0 var(--bad); }
.solution { padding: 16px 20px; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); }
.solution h4 { font-size: 13px; text-transform: uppercase; letter-spacing: .1em; color: var(--cu-text); }
.task-foot { display: flex; gap: 10px; justify-content: flex-end; flex-wrap: wrap; padding-top: 14px; box-shadow: inset 0 1px 0 rgba(0, 0, 0, .4), inset 0 2px 0 var(--edge-hi); }

/* ---------- пробный вариант ---------- */
.variant-bar { position: sticky; top: calc(env(safe-area-inset-top, 0px) + 58px); z-index: 5; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; padding: 12px 18px; margin-bottom: 18px; box-shadow: var(--raised-lg); }
.timer { font: 700 24px/1 var(--font-d); font-variant-numeric: tabular-nums; color: var(--cu-text); padding: 6px 12px; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); }
.v-task { margin-bottom: 12px; }
.v-task .task-q { margin: 10px 0 14px; }
.v-task summary { font: 500 14px/1.4 var(--font-d); text-transform: uppercase; letter-spacing: .06em; }
.result-big { font: 800 48px/1 var(--font-d); color: var(--cu-text); font-variant-numeric: tabular-nums; }
.score-table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.score-table td { padding: 8px 4px; box-shadow: inset 0 -1px 0 rgba(0, 0, 0, .35); }

/* ---------- пустые состояния ---------- */
.empty { display: flex; flex-direction: column; align-items: center; gap: 10px; text-align: center; padding: 48px 20px; }
.empty .ico { color: var(--cu); margin-bottom: 6px; }
.empty p { max-width: 46ch; margin: 0 0 8px; }

/* ---------- чипы в списке тем ---------- */
.chips { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 8px; }
.chips .ico { width: 14px; height: 14px; }

/* Урок: оглавление + глава */
.lesson-grid { display: grid; grid-template-columns: 270px minmax(0, 1fr); gap: 18px; align-items: start; }
.chapters { position: sticky; top: 76px; padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.ch-head { display: flex; justify-content: space-between; align-items: baseline; font-family: var(--font-d); }
.chapters ol { list-style: none; margin: 4px 0 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.chapters a { display: flex; align-items: center; gap: 10px; padding: 8px 10px; border-radius: 4px; color: var(--muted); font: 500 15px/1.3 var(--font-d); }
.chapters a:hover { color: var(--text); background: var(--paper-lo); }
.chapters a.active { color: var(--cu-text); background: var(--paper-hi); box-shadow: var(--raised), inset 0 0 0 1px rgba(214, 130, 74, .45); }
.ch-n { display: grid; place-items: center; flex: none; width: 24px; height: 24px; border-radius: 3px; background: var(--paper-lo); box-shadow: var(--inset); font-size: 13px; }
.chapters a.done .ch-n { color: var(--ok); }
.chapters a.done .ch-n .ico { width: 15px; height: 15px; }
.ch-label { display: inline-block; margin-bottom: 8px; padding: 2px 12px 2px 8px; background: var(--copper); color: #fff3e8; font: 600 12px/1.6 var(--font-d); text-transform: uppercase; letter-spacing: .1em; clip-path: polygon(0 0, 100% 0, calc(100% - 7px) 50%, 100% 100%, 0 100%); }
.lesson h2 { font-size: 28px; margin-bottom: .7em; }
.lesson-nav { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 28px; padding-top: 18px; box-shadow: inset 0 1px 0 rgba(0, 0, 0, .4), inset 0 2px 0 var(--edge-hi); max-width: none !important; }
.lesson ~ p, .lesson > p.small { max-width: none; }

/* ---------- заголовок карточки с пояснением (админка) ---------- */
.ext-h { display: flex; flex-direction: column; gap: 4px; }
.ext-h b { font: 700 17px/1.3 var(--font-d); }

/* ---------- графики в заданиях (EGE.plot) ---------- */
.plot { margin: 12px 0 4px; padding: 12px; width: fit-content; max-width: 100%; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); }
.plot svg { display: block; width: 440px; max-width: 100%; height: auto; }
.plot .pg { stroke: rgba(236, 226, 211, .09); stroke-width: 1; }
.plot .pa { stroke: var(--muted); stroke-width: 1.4; fill: none; }
.plot .ph { fill: var(--muted); }
.plot .pl { stroke: var(--cu-hi); stroke-width: 2.6; fill: none; stroke-linejoin: round; stroke-linecap: round; }
.plot .pl.b { stroke: #8fb3d9; stroke-dasharray: 6 4; }
.plot .pl.c { stroke: #8fb3d9; }
.plot .pl.t { stroke: var(--muted); stroke-width: 1.5; }
.plot .pd { fill: var(--cu-hi); }
.plot .pt { fill: var(--muted); font: 500 11px var(--font-b); font-variant-numeric: tabular-nums; }
.plot .pn { fill: var(--text); font: 600 12px var(--font-b); }
.plot .pgd { stroke: var(--muted); stroke-width: 1.1; stroke-dasharray: 4 4; fill: none; }

/* ---------- рисунки (EGE.fig) ---------- */
.fig .f { stroke: #d6c8b6; stroke-width: 1.8; fill: none; stroke-linecap: round; stroke-linejoin: round; }
.fig .f.thin { stroke-width: 1.1; stroke: #a99987; }
.fig .f.bold { stroke-width: 2.6; }
.fig .f.heavy { stroke-width: 5; }
.fig .f.grid { stroke: rgba(236, 226, 211, .1); stroke-width: 1; }
.fig .f.wire { stroke: #d6c8b6; stroke-width: 2; }
.fig .f.el, .fig .f.body { fill: #3a322a; }
.fig .f.solid { fill: #d6c8b6; }
.fig .f.slope { fill: rgba(214, 200, 182, .07); }
.fig .f.zone { fill: rgba(143, 179, 217, .06); stroke: rgba(143, 179, 217, .35); stroke-dasharray: 5 4; }
.fig .f.fld { stroke: #8fb3d9; stroke-width: 1.5; }
.fig .f.fldd { fill: #8fb3d9; stroke: #8fb3d9; }
.fig .f.mN { fill: #6b3a2c; } .fig .f.mS { fill: #2f4256; }
.fig .f.rope { stroke: #bfae98; stroke-width: 1.4; }
.fig .f.axis { stroke: #a99987; stroke-width: 1.3; stroke-dasharray: 9 3 2 3; }
.fig .f.lens { stroke: #8fb3d9; stroke-width: 2.6; }
.fig .f.ray { stroke: var(--cu-hi); stroke-width: 1.5; }
.fig .f.ray.d, .fig .f.dash, .fig .f.a.dash { stroke-dasharray: 5 4; }
.fig .f.water { fill: rgba(143, 179, 217, .28); stroke: none; }
.fig .f.glass { stroke-width: 2.4; }
.fig .f.needle { stroke: var(--cu-hi); stroke-width: 2.4; }
.fig .f.obj { fill: rgba(214, 130, 74, .35); stroke: var(--cu-hi); }
.fig .f.a { stroke-width: 2.4; }
.fig .f.a.v { stroke: var(--cu-hi); } .fig .fh.v { fill: var(--cu-hi); }
.fig .f.a.b { stroke: #8fb3d9; } .fig .fh.b { fill: #8fb3d9; }
.fig .f.a.m { stroke: #a99987; stroke-width: 1.4; } .fig .fh.m { fill: #a99987; }
.fig .fdot { fill: #d6c8b6; }
.fig .fdot.v { fill: var(--cu-hi); } .fig .fdot.b { fill: #8fb3d9; }
.fig .f.open { fill: #1d1915; stroke-width: 2; }
.fig .f.v { stroke: var(--cu-hi); }
.fig .ft { fill: var(--text); font: 600 13px var(--font-b); }
.fig .ft .sub { font-size: 9.5px; }
.fig .ft.lbl.v { fill: var(--cu-text); } .fig .ft.lbl.b { fill: #a9c6e6; }
.fig .ft.meter { font: 700 13px var(--font-d); }
.fig .ft.mag { fill: #f3e6d6; font: 700 15px var(--font-d); }
.fig .ft.big { font: 700 22px var(--font-d); fill: var(--cu-text); }

/* ---------- аккаунты: вход, пользователь в шапке, админка ---------- */
body.locked .nav { display: none; }
.user-box { display: flex; align-items: center; gap: 8px; }
.user-box:empty { display: none; }
.user-name { display: flex; align-items: center; gap: 6px; font: 600 14px/1 var(--font-d); color: var(--muted); }
.user-name .ico { width: 16px; height: 16px; color: var(--cu-text); }
.user-box .btn.small { padding: 6px 10px; }
.sync { width: 8px; height: 8px; border-radius: 50%; background: var(--ok); box-shadow: 0 0 0 3px rgba(163, 199, 133, .15); }
.sync[data-state="pending"] { background: var(--cu-hi); box-shadow: 0 0 0 3px var(--cu-glow); }
.sync[data-state="error"] { background: var(--bad); box-shadow: 0 0 0 3px var(--bad-bg); }

.login-wrap { display: grid; place-items: center; min-height: 60vh; }
.login { display: flex; flex-direction: column; gap: 14px; width: min(420px, 100%); padding: 28px; }
.login h1 { margin: 0; }
.login .hero-tag { align-self: flex-start; margin: 0; }
.field { display: flex; flex-direction: column; gap: 6px; }
.field > span { font: 600 13px/1 var(--font-d); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.field .input { min-width: 0; width: 100%; }

.admin-new { display: flex; flex-direction: column; gap: 14px; margin-top: 8px; }
.admin-fields { display: grid; grid-template-columns: 1fr 1fr auto auto; gap: 10px; align-items: end; }
.feedback.creds { display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; font-family: var(--font-b); font-weight: 500; }
.feedback.creds b { color: var(--text); font-family: ui-monospace, Consolas, monospace; }
.user-list { display: flex; flex-direction: column; gap: 10px; }
.user-row { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1.6fr) auto; gap: 10px 18px; align-items: center; padding: 14px 18px; }
.user-main b { display: inline-flex; align-items: center; gap: 6px; font: 600 17px/1.3 var(--font-d); margin-right: 6px; }
.user-main b .ico { width: 16px; height: 16px; color: var(--cu-text); }
.user-main .chip { margin-right: 4px; }
.user-stats { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: 13px; color: var(--muted); }
.user-stats b { color: var(--text); font: 700 15px/1 var(--font-d); font-variant-numeric: tabular-nums; }
.user-actions { display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end; }
.user-msg { grid-column: 1 / -1; }

/* ---------- бренд ---------- */
.logo em { font-style: normal; color: var(--cu-text); }
.hero .countdown { position: absolute; right: 28px; top: 50%; transform: translateY(-50%); display: flex; align-items: center; gap: 10px; padding: 14px 18px; border-radius: 6px; background: var(--paper-lo); box-shadow: var(--inset); }
.hero .countdown b { font: 800 46px/1 var(--font-d); color: var(--cu-text); font-variant-numeric: tabular-nums; }
.hero .countdown span { font: 600 12px/1.3 var(--font-d); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.hero:has(.countdown) p { max-width: 50ch; }
.stat b small { font-size: 16px; color: var(--muted); font-weight: 600; }

/* ---------- номера ЕГЭ ---------- */
.num.sm { width: 30px; height: 30px; font-size: 15px; }
.vscore { font: 700 22px/1.1 var(--font-d); font-variant-numeric: tabular-nums; }
.grid.forecast { grid-template-columns: 1.3fr 1fr 1fr; }
.stat.big b { font-size: 44px; color: var(--cu-text); }
.kim-wrap { padding: 6px 4px; overflow-x: auto; }
.kim-table { width: 100%; min-width: 640px; border-collapse: collapse; font-variant-numeric: tabular-nums; }
.kim-table th { padding: 8px 10px; text-align: left; font: 600 12px/1.3 var(--font-d); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.kim-table td { padding: 10px; vertical-align: middle; box-shadow: inset 0 -1px 0 rgba(0, 0, 0, .35); }
.kim-table .c { text-align: center; }
.kim-table td b { font: 600 15px/1.3 var(--font-d); }
.kim-table .bar { width: 140px; }
.kim-table tr.good .num { color: var(--ok); }
.kim-table tr.low .num { color: var(--bad); }
.meter { height: 10px; border-radius: 3px; background: var(--paper-lo); box-shadow: var(--inset); padding: 2px; }
.meter > i { display: block; height: 100%; border-radius: 2px; background: var(--copper); }
tr.good .meter > i, .kim-tile.good .kn { background: linear-gradient(180deg, #c3dfa9, var(--ok) 50%, #6f9452); }
tr.low .meter > i, .kim-tile.low .kn { background: linear-gradient(180deg, #f1a58e, var(--bad) 50%, #a9523a); }
.kim-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 10px; }
.kim-tile { display: flex; flex-direction: column; gap: 4px; padding: 12px 14px; color: var(--text); transition: transform .12s, box-shadow .12s; }
.kim-tile:hover { transform: translate(-1px, -2px); box-shadow: var(--raised-lg); }
.kim-tile:active { transform: none; box-shadow: var(--inset); }
.kim-tile b { font: 600 15px/1.25 var(--font-d); }
.kim-tile .kn { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 4px; background: var(--paper-hi); box-shadow: var(--raised); font: 700 15px/1 var(--font-d); color: var(--cu-text); }
.kim-tile.good .kn, .kim-tile.low .kn { color: #1b1712; }
.kim-tile.mid .kn { background: var(--copper); color: #fff3e8; }

.forecast-card { display: flex; align-items: center; gap: 22px; color: var(--text); }
.forecast-card:hover { box-shadow: var(--raised-lg); }
.fc-score { display: flex; align-items: center; gap: 10px; padding: 12px 18px; border-radius: 6px; background: var(--paper-lo); box-shadow: var(--inset); }
.fc-score b { font: 800 44px/1 var(--font-d); color: var(--cu-text); font-variant-numeric: tabular-nums; }
.fc-score span { font: 600 12px/1.3 var(--font-d); text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.fc-body { flex: 1; display: flex; flex-direction: column; gap: 10px; min-width: 0; }
.kim-strip { display: grid; grid-template-columns: repeat(13, 1fr); gap: 4px; }
.kim-strip i { display: grid; place-items: center; height: 24px; border-radius: 3px; font: 600 11px/1 var(--font-d); font-style: normal; color: var(--faint); background: var(--paper-lo); box-shadow: var(--inset); }
.kim-strip i.good { background: #3b4a30; color: var(--ok); box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .06); }
.kim-strip i.mid { background: #4a3324; color: var(--cu-hi); box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .06); }
.kim-strip i.low { background: #4a2a22; color: var(--bad); box-shadow: inset 1px 1px 0 rgba(255, 255, 255, .06); }

/* ---------- план и календарь ---------- */
.session-card { display: block; color: var(--text); transition: box-shadow .12s, transform .12s; }
.session-card:hover { box-shadow: var(--raised-lg); transform: translateY(-1px); }
.session-card b { font: 700 19px/1.25 var(--font-d); }
.session-card .meta { font: 700 18px/1 var(--font-d); color: var(--cu-text); }
.session-card.done .num { color: var(--ok); }
.mini-steps { list-style: none; margin: 14px 0 0; padding: 12px 0 0; display: flex; flex-direction: column; gap: 6px; box-shadow: inset 0 1px 0 rgba(0, 0, 0, .4), inset 0 2px 0 var(--edge-hi); }
.mini-steps li { display: flex; align-items: center; gap: 10px; font-size: 15px; color: var(--muted); }
.mini-steps li .ico { color: var(--cu-text); }
.mini-steps li.done { color: var(--faint); text-decoration: line-through; }
.mini-steps li.done .ico { color: var(--ok); }
.step-list { display: flex; flex-direction: column; gap: 10px; margin-top: 18px; }
.step { display: flex; align-items: center; gap: 16px; padding: 14px 18px; }
.step .info { flex: 1; min-width: 0; }
.step b { font: 600 17px/1.3 var(--font-d); }
.step.done b { color: var(--muted); }
.check-btn { display: grid; place-items: center; flex: none; width: 34px; height: 34px; padding: 0; border: 0; border-radius: 5px; background: var(--paper-lo); box-shadow: var(--inset); color: var(--ok); cursor: pointer; }
.check-btn:hover:not(:disabled) { box-shadow: var(--inset), 0 0 0 2px var(--cu-glow); }
.check-btn:disabled { cursor: default; }
.step.done .check-btn { background: var(--ok-bg); }
.legend { display: flex; flex-wrap: wrap; gap: 6px 18px; margin: -4px 0 12px; align-items: center; }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.legend i { font-style: normal; }
.sw { display: inline-block; width: 14px; height: 14px; border-radius: 3px; }
.sw.ok { background: var(--ok-bg); box-shadow: inset 0 0 0 1px rgba(163, 199, 133, .6); }
.sw.miss { background: var(--bad-bg); box-shadow: inset 0 0 0 1px rgba(226, 127, 98, .6); }
.month { margin-bottom: 14px; padding: 16px; }
.month h3 { margin: 0 0 10px; font-size: 17px; text-transform: uppercase; letter-spacing: .08em; color: var(--cu-text); }
.cal { display: grid; grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 5px; }
.cal .wd { font: 600 11px/1 var(--font-d); text-transform: uppercase; letter-spacing: .08em; color: var(--faint); text-align: center; padding-bottom: 4px; }
.day { min-height: 74px; padding: 6px; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); display: flex; flex-direction: column; gap: 4px; color: var(--muted); overflow: hidden; }
.day.blank { background: none; box-shadow: none; }
.day.past { opacity: .62; }
.day .dn { font: 600 13px/1 var(--font-d); font-variant-numeric: tabular-nums; }
.day.has { background: var(--fold), var(--paper-hi); box-shadow: var(--raised); color: var(--text); opacity: 1; }
.day.has:hover { box-shadow: var(--raised-lg), inset 0 0 0 1px rgba(214, 130, 74, .5); }
.day.has.ok { box-shadow: var(--raised), inset 0 0 0 1px rgba(163, 199, 133, .55); }
.day.has.ok .dn::after { content: " ✓"; color: var(--ok); }
.day.has.miss { box-shadow: var(--raised), inset 0 0 0 1px rgba(226, 127, 98, .55); }
.day.today { box-shadow: var(--inset), 0 0 0 2px var(--cu); opacity: 1; }
.day.has.today { box-shadow: var(--raised), 0 0 0 2px var(--cu); }
.day.exam { background: var(--copper); color: #fff3e8; box-shadow: var(--raised); opacity: 1; }
.day .tt { font: 500 11px/1.25 var(--font-d); color: var(--muted); display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.tag { display: inline-block; align-self: flex-start; padding: 1px 6px; border-radius: 3px; font: 700 10px/1.5 var(--font-d); text-transform: uppercase; letter-spacing: .06em; }
.tag.ph { background: var(--copper); color: #fff3e8; }
.tag.soon { color: var(--faint); box-shadow: inset 0 0 0 1px rgba(160, 146, 128, .25); }
.tag.exam { background: #fff3e8; color: var(--cu-lo); }

@media (max-width: 860px) {
  .grid.forecast { grid-template-columns: 1fr 1fr; }
  .grid.forecast .big { grid-column: 1 / -1; }
  .hero .countdown { position: static; transform: none; margin-top: 18px; width: max-content; }
}
@media (max-width: 640px) {
  .grid-4 { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .stat { flex-direction: column; align-items: flex-start; gap: 8px; padding: 14px; }
  .stat b { font-size: 24px; }
  .day { min-height: 48px; padding: 4px; }
  .day .tt { display: none; }
  .day .tag { font-size: 9px; padding: 0 3px; }
  .forecast-card { flex-direction: column; align-items: stretch; }
  .kim-strip { grid-template-columns: repeat(9, 1fr); }
  .step { flex-wrap: wrap; }
  .step .btn { margin-left: 50px; }
  .logo { font-size: 16px; }
}

@media (max-width: 860px) {
  .lesson-grid { grid-template-columns: minmax(0, 1fr); }
  .chapters { position: static; }
  .user-row { grid-template-columns: 1fr; }
  .user-actions { justify-content: flex-start; }
  .admin-fields { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 520px) {
  .admin-fields { grid-template-columns: 1fr; }
  .user-name { display: none; }
}

@media (max-width: 640px) {
  h1 { font-size: 24px; }
  .container { padding-block: 18px 56px; }
  .topic-row .meta { display: none; }
  .hero { padding: 24px 20px; }
  .theory { padding: 20px 18px; }
  .task-card { padding: 18px; }
  .nav { margin-left: 0; width: 100%; }
  .nav a { flex: 1; justify-content: center; padding: 7px 8px; }
  .variant-bar { top: calc(env(safe-area-inset-top, 0px) + 104px); }
  .section-title > span { white-space: normal; }
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}

/* ---------- вкладки предметов и фильтр глав ---------- */
.subj-tabs { overflow-x: auto; }
.subj-dot { display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 4px; background: var(--copper); color: #fff3e8; font: 700 12px/1 var(--font-d); filter: hue-rotate(var(--hue, 0deg)); }
.ch-filter { margin: -6px 0 14px; flex-wrap: nowrap; }
.ch-filter select { flex: 1; min-width: 0; max-width: 520px; padding-block: 8px; }
.day.has > a { display: block; }

/* ---------- мини-тест в конце главы ---------- */
.mini-test { margin-top: 22px; padding: 18px 20px; box-shadow: var(--raised), inset 4px 0 0 var(--cu); }
.mini-test h3 { margin: 0 0 6px; }
.mini-test.pass { box-shadow: var(--raised), inset 4px 0 0 var(--ok); }
.mini-test.fail { box-shadow: var(--raised), inset 4px 0 0 var(--bad); }
.mini-test .task-q { margin: 12px 0; }

/* ---------- формулы и поиск ---------- */
.f-tools { margin: 4px 0 18px; flex-wrap: nowrap; }
.f-tools .input { flex: 1; min-width: 0; }
.f-topic { margin-bottom: 12px; }
.f-topic h3 { margin: 0 0 8px; font-size: 18px; }
.f-topic h3 a { color: var(--cu-text); }
.f-topic h4 { display: none; }
.f-topic table { margin: 6px 0; }
.s-hit { display: block; padding: 12px 16px; margin-bottom: 8px; color: var(--text); }
.s-hit:hover { box-shadow: var(--raised-lg), inset 0 0 0 1px rgba(214, 130, 74, .5); }
.s-hit .small { margin-top: 4px; }
mark { background: rgba(214, 130, 74, .35); color: var(--text); border-radius: 2px; padding: 0 1px; }

/* ---------- статистика и рейтинг ---------- */
.bars { display: block; width: 100%; height: auto; }
.bars .bar { fill: var(--cu); }
.bars .bar.sun { fill: rgba(160, 146, 128, .45); }
.bars .pg { stroke: rgba(236, 226, 211, .09); }
.bars .pt { fill: var(--muted); font: 500 10px var(--font-b); }
.kim-table td.up { color: var(--ok); font-weight: 600; }
.kim-table td.down { color: var(--bad); font-weight: 600; }
.lb-table tr.me td { background: rgba(214, 130, 74, .12); }
.lb-table .num.top { background: var(--copper); color: #fff3e8; }

/* ---------- список вариантов ---------- */
.var-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(130px, 1fr)); gap: 10px; }
.var-tile { display: flex; flex-direction: column; gap: 6px; padding: 12px 14px; color: var(--text); }
.var-tile .vn { font: 800 24px/1 var(--font-d); color: var(--cu-text); }
.var-tile.good { box-shadow: var(--raised), inset 0 -3px 0 var(--ok); }
.var-tile.mid { box-shadow: var(--raised), inset 0 -3px 0 var(--cu); }
.var-tile.low { box-shadow: var(--raised), inset 0 -3px 0 var(--bad); }
.var-tile:hover { box-shadow: var(--raised-lg), inset 0 0 0 1px rgba(214, 130, 74, .5); }

@media (max-width: 640px) {
  .nav { flex-wrap: nowrap; overflow-x: auto; scrollbar-width: none; }
  .nav::-webkit-scrollbar { display: none; }
  .nav a { flex: none; padding: 7px 10px; font-size: 13px; white-space: nowrap; }
}

/* ---------- печать (шпаргалка формул, уроки) ---------- */
@media print {
  :root { color-scheme: light; }
  body, .container, .card, .theory, .f-topic { background: #fff !important; color: #000 !important; box-shadow: none !important; }
  .topbar, .crumbs, .no-print, .lesson-nav, .chapters, #mini-test, .tabs { display: none !important; }
  .katex, .theory td, .theory th, h1, h2, h3, h4, a { color: #000 !important; }
  .theory table { box-shadow: none !important; background: #fff !important; }
  .theory td, .theory th { border-bottom: 1px solid #bbb !important; box-shadow: none !important; }
  .section-title span { background: none !important; color: #000 !important; box-shadow: none !important; }
  .f-topic { break-inside: avoid; border: 1px solid #ccc; }
  body::before { display: none !important; }
}

/* ---------- урок: широкое окно, режим чтения, блоки, проверки (2026-11-01) ---------- */
body.lesson-mode .container { max-width: 1480px; }
body.lesson-mode .lesson-grid { grid-template-columns: 300px minmax(0, 1fr); gap: 20px; }
.lesson.theory { font-size: 17.5px; padding: 30px 40px; }
.lesson.theory > * { max-width: 980px; }
.lesson.theory > figure, .lesson.theory > .plot, .lesson.theory > table, .lesson.theory > .lesson-nav { max-width: none; }
.lesson-bar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; max-width: none !important; }
.lesson-bar .ch-label { margin-bottom: 0; }
.chapters { max-height: calc(100vh - 96px); overflow-y: auto; }
.chapters .ch-head { width: 100%; background: none; border: 0; padding: 0; color: inherit; cursor: pointer; text-align: left; gap: 8px; align-items: center; }
.ch-caret { display: none; }
.ch-caret .ico { transform: rotate(90deg); transition: transform .2s; }
.chapters.collapsed .ch-caret .ico { transform: none; }
.ch-block { margin: 10px 0 2px; padding: 0 10px; font: 600 11px/1.4 var(--font-d); text-transform: uppercase; letter-spacing: .1em; color: var(--faint); }
.ch-block:first-child { margin-top: 0; }
.chapters a.ch-test { color: var(--cu-text); box-shadow: inset 3px 0 0 var(--cu); }
.chapters a.ch-test .ch-n { color: var(--cu-text); }
.chapters a.ch-test.done { box-shadow: inset 3px 0 0 var(--ok); }
.ch-tag { display: block; font-style: normal; font: 600 10px/1.4 var(--font-d); text-transform: uppercase; letter-spacing: .12em; color: var(--cu); }
.chapters a.done .ch-tag { color: var(--ok); }
.focus-exit { display: none; position: fixed; right: 16px; top: 12px; z-index: 30; }
body.lesson-mode.focus .topbar, body.lesson-mode.focus .crumbs, body.lesson-mode.focus #app > h1, body.lesson-mode.focus #app > .tabs, body.lesson-mode.focus .chapters { display: none; }
body.lesson-mode.focus .lesson-grid { grid-template-columns: minmax(0, 1fr); }
body.lesson-mode.focus .container { max-width: 1180px; padding-top: 14px; }
body.lesson-mode.focus .focus-exit { display: inline-flex; }
body.lesson-mode.focus .lesson-bar { padding-right: 150px; }

/* Счётчик прочтения главы */
.read-meter { display: flex; align-items: center; gap: 10px; margin-top: 28px; padding: 12px 16px; border-radius: 4px; background: var(--paper-lo); box-shadow: var(--inset); color: var(--muted); font-size: 15px; max-width: none !important; }
.read-meter b { color: var(--text); }
.read-meter.ok { color: var(--ok); }

/* Блоки текста урока */
.simple, .def, .rule { position: relative; border-radius: 4px; padding: 14px 18px; margin: 1.2em 0; }
.simple { background: rgba(120, 170, 220, .06); box-shadow: var(--inset); border-left: 4px solid #7fa7cf; }
.simple::before, .def::before, .rule::before { display: block; margin-bottom: 6px; font: 600 11px/1.5 var(--font-d); text-transform: uppercase; letter-spacing: .1em; }
.simple::before { content: "Простыми словами"; color: #9cc0e2; }
.def { background: var(--paper-hi); box-shadow: var(--raised); border-left: 4px solid var(--cu-hi); }
.def::before { content: "Строго"; color: var(--cu-text); }
.rule { background: var(--fold), var(--paper-hi); box-shadow: var(--raised), inset 0 0 0 1px rgba(214, 130, 74, .55); text-align: left; }
.rule::before { content: "Запомни"; color: var(--cu-text); }
.hl { background: linear-gradient(transparent 55%, rgba(214, 130, 74, .35) 55%); color: #fff4e6; padding: 0 2px; }
.theory figure { margin: 1.2em 0; }

/* Глава-проверка */
.test-intro p { margin: .4em 0; }
.test-intro .ok { color: var(--ok); }
.test-intro .warn-line { color: var(--muted); font-size: 15px; }
.test-list { list-style: none; counter-reset: tq; padding: 0 !important; margin: 18px 0 0; display: flex; flex-direction: column; gap: 14px; max-width: none !important; }
.test-q { counter-increment: tq; position: relative; padding: 16px 18px 16px 58px; border-radius: 4px; background: var(--paper-hi); box-shadow: var(--raised); margin: 0 !important; }
.test-q::before { content: counter(tq); position: absolute; left: 16px; top: 16px; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; background: var(--copper); color: #fff3e8; font: 600 14px/1 var(--font-d); }
.test-q .answer-row { margin-top: 10px; }
.test-q .input { max-width: 260px; }
.test-q .feedback { margin-top: 10px; }
.test-q .solution { margin-top: 10px; }
.test-submit { margin-top: 18px; max-width: none !important; }

/* Шаги занятия */
.step .check-btn { display: grid; place-items: center; cursor: default; font: 600 14px/1 var(--font-d); color: var(--muted); }
.step.step-test { box-shadow: var(--raised), inset 4px 0 0 var(--cu); }
.step-prog { display: flex; align-items: center; gap: 10px; margin-top: 8px; max-width: 360px; }
.step-prog .progress { flex: 1; }

/* Справочник */
.ref-cats { display: flex; flex-direction: column; gap: 14px; margin-top: 14px; }
.ref-cat { padding: 0; }
.ref-cat > summary { display: flex; align-items: center; gap: 12px; padding: 16px 20px; cursor: pointer; list-style: none; font: 600 18px/1.3 var(--font-d); }
.ref-cat > summary::-webkit-details-marker { display: none; }
.ref-cat > summary .muted { margin-left: auto; font-family: var(--font-b); }
.ref-cat > summary .ch-caret { display: inline-flex; }
.ref-cat[open] > summary .ch-caret .ico { transform: rotate(90deg); }
.ref-cat > summary .ch-caret .ico { transform: none; }
.ref-cat ul { list-style: none; margin: 0; padding: 4px 20px 16px; columns: 2 380px; column-gap: 28px; }
.ref-cat li { break-inside: avoid; padding: 6px 0; border-bottom: 1px solid rgba(0, 0, 0, .3); box-shadow: 0 1px 0 var(--edge-hi); }
.ref-cat li a { color: var(--text); }
.ref-cat li a:hover { color: var(--cu-text); }

@media (max-width: 860px) {
  body.lesson-mode .lesson-grid { grid-template-columns: minmax(0, 1fr); gap: 12px; }
  .chapters { max-height: none; }
  .ch-caret { display: inline-flex; margin-left: auto; }
  .chapters.collapsed ol, .chapters.collapsed .progress { display: none; }
  .lesson.theory { padding: 20px 18px; font-size: 17px; }
  body.lesson-mode.focus .lesson-bar { padding-right: 0; }
  .focus-exit { top: auto; bottom: 14px; right: 14px; }
}
@media (max-width: 640px) {
  body.lesson-mode .container { padding-left: 8px; padding-right: 8px; }
  .lesson.theory { padding: 16px 14px; }
  .test-q { padding: 14px 14px 14px 50px; }
  .test-q::before { left: 12px; top: 14px; }
  .lesson.theory table { font-size: 14px; }
}
@media print {
  .read-meter, .lesson-bar, .focus-exit { display: none !important; }
}

/* ---------- телефон: шапка не липнет, урок мельче, шаги занятия в полную ширину (2026-11-02) ---------- */
@media (max-width: 640px) {
  .topbar { position: relative; top: 0; gap: 10px; padding-block: 8px; }
  .variant-bar { top: env(safe-area-inset-top, 0px); }
  .step { gap: 10px 12px; padding: 12px 14px; }
  .step .info { flex: 1 1 calc(100% - 50px); }
  .step .info .muted { display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
  .step .btn { margin-left: 46px; }
  .step b { font-size: 16px; }
  .lesson.theory { font-size: 15px; line-height: 1.55; padding: 14px 12px; }
  .lesson h2 { font-size: 21px; }
  .lesson.theory h3 { font-size: 16px; }
  .lesson.theory table { font-size: 12.5px; }
  .lesson.theory td, .lesson.theory th { padding: 6px 8px; }
  .lesson.theory th { font-size: 11px; }
  .lesson.theory .katex-display { overflow-x: auto; overflow-y: hidden; padding: 2px 0; }
  .simple, .def, .rule, .tip, .warn, .example { padding: 10px 12px; }
  .theory ol.steps > li { padding-left: 34px; }
  #app > h1 { font-size: 21px; }
}
@media (max-width: 640px) { .theory td .katex, .theory th .katex { white-space: nowrap; } }
/* Телефон: ничего в уроке не расширяет страницу (широкие таблицы и формулы прокручиваются внутри себя) */
@media (max-width: 860px) { .lesson.theory, .lesson-grid { overflow-x: hidden; overflow-x: clip; } .lesson.theory table, .lesson.theory .katex-display { max-width: 100%; } }