:root {
  --bg: #f6f4ef;
  --surface: #ffffff;
  --surface-2: #efece5;
  --text: #1d1e21;
  --muted: #6a6b70;
  --line: #e2ded5;
  --accent: #2f5bd3;
  --brand: #2f5bd3;
  --ok: #1f8a4c;
  --ok-bg: #e6f4ec;
  --bad: #c0392b;
  --bad-bg: #fbeae7;
  --warn: #b7791f;
  --warn-bg: #fdf3e1;
  --reading: #2f6fd6;
  --reading-bg: #e7eefb;
  --extra-bg: #eaf5ec;
  --extra-line: #2e7d32;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 20, 30, .05), 0 4px 16px rgba(20, 20, 30, .04);
  --serif: "Iowan Old Style", "Charter", "Georgia", "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16171a; --surface: #1f2024; --surface-2: #26272c; --text: #ececee; --muted: #9a9ba3; --line: #33343a;
    --ok: #4cc27f; --ok-bg: #19302a; --bad: #ff7b6b; --bad-bg: #3a2220; --warn: #e3a948; --warn-bg: #362b17;
    --reading: #7aa7ff; --reading-bg: #1f2a40; --extra-bg: #1b2b1f; --extra-line: #5fb867; --brand: #7aa0ff;
    --shadow: none; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #16171a; --surface: #1f2024; --surface-2: #26272c; --text: #ececee; --muted: #9a9ba3; --line: #33343a;
  --ok: #4cc27f; --ok-bg: #19302a; --bad: #ff7b6b; --bad-bg: #3a2220; --warn: #e3a948; --warn-bg: #362b17;
  --reading: #7aa7ff; --reading-bg: #1f2a40; --extra-bg: #1b2b1f; --extra-line: #5fb867; --brand: #7aa0ff;
  --shadow: none; color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.5 var(--sans); }
a { color: inherit; }
h1, h2, h3 { line-height: 1.25; margin: 0; }
main { max-width: 860px; margin: 0 auto; padding: 8px 16px 80px; outline: none; }
.muted { color: var(--muted); }
.loading, .empty { color: var(--muted); text-align: center; padding: 60px 0; }
.empty.small { padding: 24px 0; }

/* верхняя панель */
.topbar { position: sticky; top: 0; z-index: 5; display: flex; justify-content: space-between; align-items: center; gap: 12px;
  max-width: 860px; margin: 0 auto; padding: 12px 16px; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); }
.brand { font-weight: 700; text-decoration: none; letter-spacing: -.01em; }
.sync-btn { display: inline-flex; align-items: center; gap: 8px; font: inherit; font-size: 14px; color: var(--muted); background: var(--surface);
  border: 1px solid var(--line); border-radius: 999px; padding: 6px 12px; cursor: pointer; }
.sync-btn:hover { color: var(--text); }
.sync-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
.sync-dot[data-state="ok"] { background: var(--ok); }
.sync-dot[data-state="syncing"] { background: var(--reading); }
.sync-dot[data-state="offline"] { background: var(--warn); }

/* кнопки */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; min-height: 44px; padding: 10px 18px; border-radius: 10px;
  border: 1px solid transparent; background: var(--brand); color: #fff; font: inherit; font-weight: 600; text-decoration: none; cursor: pointer; }
.btn:hover { filter: brightness(1.08); }
.btn-ghost { background: transparent; color: var(--text); border-color: var(--line); }
.btn-ghost:hover { background: var(--surface-2); filter: none; }
.btn[disabled] { opacity: .6; cursor: default; }
.btn-row { display: flex; flex-wrap: wrap; gap: 10px; }
.btn-row.end { justify-content: flex-end; }
.btn-row.center { justify-content: center; }
.link-btn { color: var(--brand); text-decoration: none; font-size: 14px; font-weight: 600; margin-left: auto; }

/* крошки */
.crumbs { display: flex; flex-wrap: wrap; gap: 6px; font-size: 14px; color: var(--muted); margin: 8px 0 16px; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--text); }

/* главная */
.hero { padding: 24px 0 20px; }
.hero h1 { font-size: clamp(28px, 5vw, 40px); letter-spacing: -.02em; }
.hero p { color: var(--muted); max-width: 600px; margin: 10px 0 0; font-size: 17px; }
.subjects { display: grid; gap: 14px; }
.subject-card { display: block; text-decoration: none; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 20px; box-shadow: var(--shadow); border-top: 4px solid var(--accent); }
.subject-card:hover { border-color: color-mix(in srgb, var(--accent) 50%, var(--line)); border-top-color: var(--accent); }
.subject-card-head { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; margin-bottom: 14px; }
.subject-card h2 { font-size: 20px; }
.subject-card p { margin: 10px 0 0; font-size: 14px; }
.big-num { font-size: 28px; font-weight: 700; font-variant-numeric: tabular-nums; }
.big-num small { font-size: 16px; color: var(--muted); font-weight: 500; }

/* полоса прогресса */
.bar { display: flex; height: 8px; border-radius: 99px; overflow: hidden; background: var(--surface-2); gap: 2px; }
.seg { display: block; height: 100%; }
.seg.st-learned { background: var(--ok); }
.seg.st-review { background: var(--warn); }
.seg.st-reading { background: var(--reading); }
.seg.st-new { background: var(--surface-2); }

/* предмет */
.subject-head { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow);
  display: grid; gap: 16px; border-top: 4px solid var(--accent); }
.subject-head h1 { font-size: clamp(22px, 4vw, 30px); letter-spacing: -.015em; }
.subject-head .btn { justify-self: start; }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.stats div { display: grid; }
.stats b { font-size: 24px; font-variant-numeric: tabular-nums; }
.stats span { font-size: 13px; color: var(--muted); }
.tip { font-size: 14px; color: var(--muted); margin: 14px 4px 0; }

.cards { display: grid; gap: 12px; margin-top: 14px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.card h3 { font-size: 17px; }
.card p { margin: 4px 0 0; font-size: 14px; }
.muted-card { background: transparent; box-shadow: none; border-style: dashed; }
.check-card, .test-card { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 14px; }
.check-card > div:first-child, .test-card > div:first-child { flex: 1 1 280px; }
.review-card { background: var(--warn-bg); border-color: color-mix(in srgb, var(--warn) 35%, transparent); }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.chip { min-width: 40px; height: 40px; padding: 0 10px; display: inline-flex; align-items: center; justify-content: center; border-radius: 10px;
  background: var(--surface); border: 1px solid color-mix(in srgb, var(--warn) 40%, transparent); text-decoration: none; font-weight: 600; font-variant-numeric: tabular-nums; }

.filters { display: flex; flex-wrap: wrap; gap: 6px; margin: 22px 0 6px; }
.filters button { font: inherit; font-size: 14px; border: 1px solid var(--line); background: var(--surface); color: var(--text); border-radius: 999px;
  padding: 7px 14px; cursor: pointer; white-space: nowrap; }
.filters button span { color: var(--muted); margin-left: 2px; font-variant-numeric: tabular-nums; }
.filters button[aria-selected="true"] { background: var(--text); color: var(--bg); border-color: var(--text); }
.filters button[aria-selected="true"] span { color: inherit; opacity: .7; }

.sec { margin-top: 20px; }
.sec-title { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin: 0 4px 8px; }
.q-row { display: flex; align-items: center; gap: 12px; padding: 12px 14px; text-decoration: none; background: var(--surface);
  border: 1px solid var(--line); border-bottom-width: 0; }
.sec .q-row:first-of-type, .forgotten .q-row:first-of-type { border-top-left-radius: 12px; border-top-right-radius: 12px; }
.sec .q-row:last-child, .forgotten .q-row:last-child { border-bottom-width: 1px; border-bottom-left-radius: 12px; border-bottom-right-radius: 12px; }
.q-row:hover { background: var(--surface-2); }
.q-num { flex: none; width: 30px; height: 30px; border-radius: 8px; background: var(--surface-2); display: inline-flex; align-items: center;
  justify-content: center; font-size: 14px; font-weight: 600; font-variant-numeric: tabular-nums; }
.q-num.st-reading { background: var(--reading-bg); color: var(--reading); }
.q-num.st-learned { background: var(--ok-bg); color: var(--ok); }
.q-num.st-review { background: var(--warn-bg); color: var(--warn); }
.q-title { flex: 1; min-width: 0; font-size: 15px; }
.q-title small { display: block; color: var(--muted); font-size: 13px; margin-top: 2px; }

.pill { flex: none; font-size: 12px; font-weight: 600; padding: 3px 9px; border-radius: 999px; white-space: nowrap; }
.pill.st-new { background: var(--surface-2); color: var(--muted); }
.pill.st-reading { background: var(--reading-bg); color: var(--reading); }
.pill.st-learned { background: var(--ok-bg); color: var(--ok); }
.pill.st-review { background: var(--warn-bg); color: var(--warn); }

/* материал */
.material { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 28px clamp(18px, 5vw, 48px) 36px; }
.q-head { border-bottom: 1px solid var(--line); padding-bottom: 18px; margin-bottom: 8px; }
.eyebrow { font-size: 13px; color: var(--muted); margin: 0 0 8px; }
.q-head h1 { font-size: clamp(21px, 3.6vw, 28px); letter-spacing: -.015em; }
.q-badge { display: inline-flex; align-items: center; justify-content: center; min-width: 1.5em; height: 1.5em; border-radius: 8px;
  background: var(--brand); color: #fff; font-size: .8em; margin-right: 10px; vertical-align: .08em; padding: 0 6px; }
.q-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 14px; font-size: 14px; }
.prose { font-family: var(--serif); font-size: 18px; line-height: 1.65; }
.prose p { margin: 14px 0; }
.prose h3 { font-family: var(--sans); font-size: 19px; margin: 30px 0 6px; }
.prose h4 { font-family: var(--sans); font-size: 16px; margin: 22px 0 4px; }
.prose ul, .prose ol { padding-left: 1.3em; margin: 10px 0; }
.prose li { margin: 6px 0; }
.prose li > ul, .prose li > ol { margin: 4px 0; }
.prose strong { font-weight: 700; }
.prose a { color: var(--brand); }
.prose .summary { background: var(--surface-2); border-radius: 10px; padding: 12px 16px; }
.prose aside { border-left: 4px solid var(--extra-line); background: var(--extra-bg); border-radius: 0 10px 10px 0; padding: 4px 16px; margin: 18px 0; font-size: 16.5px; }
.prose aside.note-warn { border-left-color: var(--warn); background: var(--warn-bg); }
.prose aside p { margin: 10px 0; }
.table-wrap { position: relative; overflow-x: auto; margin: 16px 0; }
.prose table { border-collapse: collapse; width: 100%; font-family: var(--sans); font-size: 15px; line-height: 1.45; }
.prose th, .prose td { border: 1px solid var(--line); padding: 8px 10px; vertical-align: top; text-align: left; }
.prose th { background: var(--surface-2); }
.material + .card { margin-top: 16px; }

.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.pager a { display: block; padding: 14px 16px; border: 1px solid var(--line); border-radius: 12px; text-decoration: none; font-size: 15px;
  font-weight: 600; background: var(--surface); white-space: nowrap; }
.pager .next { text-align: right; }
.pager a:hover { background: var(--surface-2); }

/* тест */
.quiz { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); padding: 22px clamp(16px, 4vw, 32px) 26px; }
.quiz-top { display: flex; justify-content: space-between; font-size: 14px; font-weight: 600; }
.quiz-progress { height: 4px; background: var(--surface-2); border-radius: 9px; overflow: hidden; margin: 10px 0 20px; }
.quiz-progress span { display: block; height: 100%; background: var(--brand); transition: width .25s; }
.quiz-q { font-size: clamp(19px, 3vw, 22px); margin-bottom: 18px; letter-spacing: -.01em; }
.options { display: grid; gap: 10px; }
.option { display: flex; gap: 12px; align-items: flex-start; text-align: left; font: inherit; font-size: 16px; color: var(--text); background: var(--surface);
  border: 1.5px solid var(--line); border-radius: 12px; padding: 13px 14px; cursor: pointer; min-height: 52px; }
.option:hover:not([disabled]) { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 6%, var(--surface)); }
.option .key { flex: none; width: 26px; height: 26px; border-radius: 7px; background: var(--surface-2); display: inline-flex; align-items: center;
  justify-content: center; font-size: 13px; font-weight: 700; color: var(--muted); }
.option[disabled] { cursor: default; }
.option.correct { border-color: var(--ok); background: var(--ok-bg); }
.option.correct .key { background: var(--ok); color: #fff; }
.option.wrong { border-color: var(--bad); background: var(--bad-bg); }
.option.wrong .key { background: var(--bad); color: #fff; }
.option.dim { opacity: .55; }
.feedback { margin: 18px 0 16px; padding: 12px 16px; border-radius: 12px; font-size: 15px; }
.feedback.ok { background: var(--ok-bg); }
.feedback.ok b { color: var(--ok); }
.feedback.bad { background: var(--bad-bg); }
.feedback.bad b { color: var(--bad); }

.result { text-align: center; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 34px 20px; box-shadow: var(--shadow); }
.result .score { font-size: 56px; font-weight: 800; letter-spacing: -.03em; font-variant-numeric: tabular-nums; }
.result .score small { font-size: 26px; color: var(--muted); font-weight: 600; }
.result.passed .score { color: var(--ok); }
.result.failed .score { color: var(--warn); }
.result h2 { font-size: 22px; margin: 6px 0; }
.result p { max-width: 520px; margin: 0 auto 20px; }
.forgotten { margin-top: 16px; }
.forgotten h3 { margin-bottom: 12px; }
.mistakes { margin-top: 24px; }
.mistakes h3 { font-size: 17px; margin: 0 4px 10px; }
.mistake { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; margin-bottom: 10px; }
.mistake p { margin: 4px 0; font-size: 15px; }
.m-q { font-weight: 600; }
.m-a.bad { color: var(--bad); }
.m-a.ok { color: var(--ok); }

/* синхронизация */
dialog { border: 1px solid var(--line); border-radius: 16px; padding: 0; background: var(--surface); color: var(--text); width: min(460px, calc(100% - 32px)); }
dialog::backdrop { background: rgba(0, 0, 0, .35); }
.sync { padding: 22px; }
.sync h2 { font-size: 20px; }
.sync h3 { font-size: 15px; margin-top: 20px; }
.sync p { margin: 6px 0; font-size: 14px; }
.code-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.code-row .btn { flex: 1 0 auto; }
.code-row code { flex: 1 1 190px; white-space: nowrap; font-size: 18px; letter-spacing: .04em; background: var(--surface-2); border-radius: 10px; padding: 10px 12px; text-align: center; user-select: all; }
.code-row input { flex: 1 1 190px; min-width: 0; font: inherit; font-size: 17px; padding: 10px 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); color: var(--text); }
.err { color: var(--bad); min-height: 1.2em; }

@media (max-width: 560px) {
  .prose { font-size: 17px; }
  .stats b { font-size: 20px; }
  .q-row .pill { display: none; }
}

/* форматы заданий */
.type-tag { display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: .03em; text-transform: uppercase; color: var(--brand);
  background: color-mix(in srgb, var(--brand) 10%, transparent); border-radius: 6px; padding: 3px 8px; margin: 0 0 10px; }
.options.multi .key { border-radius: 6px; }
.option.picked { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 8%, var(--surface)); }
.option.picked .key { background: var(--brand); color: #fff; }
.option.missed { border-color: var(--ok); border-style: dashed; }
.option.missed .key { background: var(--ok-bg); color: var(--ok); }
.option .tag { margin-left: auto; font-style: normal; font-size: 12px; font-weight: 600; color: var(--ok); white-space: nowrap; padding-left: 8px; }

.answer-input, .gap-input, .match select { font: inherit; color: var(--text); background: var(--bg); border: 1.5px solid var(--line); border-radius: 10px; }
.answer-input { width: 100%; font-size: 18px; padding: 12px 14px; }
.answer-input:focus, .gap-input:focus, .match select:focus { outline: none; border-color: var(--brand); box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 18%, transparent); }
.answer-input.ok, .gap-input.ok { border-color: var(--ok); background: var(--ok-bg); }
.answer-input.bad, .gap-input.bad { border-color: var(--bad); background: var(--bad-bg); }
.right-answer { margin: 10px 2px 0; font-size: 15px; }

.gaps-text { font-family: var(--serif); font-size: 19px; line-height: 2.2; margin: 0; }
.gap { display: inline-flex; flex-direction: column; vertical-align: middle; line-height: 1.2; }
.gap-input { font-family: var(--sans); font-size: 16px; padding: 5px 8px; max-width: 100%; text-align: center; }
.gap-fix { font-family: var(--sans); font-size: 13px; font-weight: 600; color: var(--ok); text-align: center; padding-top: 2px; }

.match { display: grid; gap: 10px; }
.match-row { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.2fr); gap: 10px; align-items: center; padding: 10px 12px;
  border: 1.5px solid var(--line); border-radius: 12px; }
.match-left { font-weight: 600; }
.match select { width: 100%; padding: 9px 10px; font-size: 15px; }
.match-row.ok { border-color: var(--ok); background: var(--ok-bg); }
.match-row.bad { border-color: var(--bad); background: var(--bad-bg); }
.match-fix { grid-column: 2; font-size: 14px; font-weight: 600; color: var(--ok); }

.order { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.order li { display: flex; align-items: center; gap: 10px; padding: 8px 8px 8px 12px; border: 1.5px solid var(--line); border-radius: 12px; background: var(--surface); }
.order-n { flex: none; width: 26px; height: 26px; border-radius: 7px; background: var(--surface-2); display: inline-flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700; color: var(--muted); }
.order-text { flex: 1; min-width: 0; }
.order-btns { display: flex; gap: 4px; flex: none; }
.mini { width: 40px; height: 40px; border-radius: 9px; border: 1px solid var(--line); background: var(--surface-2); color: var(--text); font: inherit; font-size: 18px; cursor: pointer; }
.mini:hover:not([disabled]) { border-color: var(--brand); }
.mini[disabled] { opacity: .3; cursor: default; }
.order li.ok { border-color: var(--ok); background: var(--ok-bg); }
.order li.bad { border-color: var(--bad); background: var(--bad-bg); }
.order-fix { flex: none; font-size: 13px; font-weight: 600; color: var(--bad); padding-right: 6px; }

.tf { display: grid; gap: 10px; }
.tf-row { display: flex; align-items: center; gap: 12px; padding: 10px 12px; border: 1.5px solid var(--line); border-radius: 12px; }
.tf-text { flex: 1; min-width: 0; }
.tf-text small { display: block; color: var(--bad); font-weight: 600; margin-top: 3px; }
.tf-btns { display: inline-flex; flex: none; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.seg-btn { font: inherit; font-size: 14px; font-weight: 600; padding: 9px 12px; border: 0; background: var(--surface); color: var(--muted); cursor: pointer; min-height: 40px; }
.seg-btn + .seg-btn { border-left: 1px solid var(--line); }
.seg-btn.on { background: var(--text); color: var(--bg); }
.seg-btn[disabled] { cursor: default; }
.tf-row.ok { border-color: var(--ok); background: var(--ok-bg); }
.tf-row.bad { border-color: var(--bad); background: var(--bad-bg); }

.quiz .btn-row.end { margin-top: 18px; }
@media (max-width: 560px) {
  .match-row { grid-template-columns: 1fr; }
  .match-fix { grid-column: 1; }
  .tf-row { flex-direction: column; align-items: stretch; }
  .tf-btns .seg-btn { flex: 1; }
}
.quiz-top { align-items: center; gap: 12px; }
.link-btn.quit { margin-left: 0; background: none; border: 0; font: inherit; font-size: 14px; color: var(--muted); cursor: pointer; padding: 6px 0; }
.link-btn.quit:hover { color: var(--bad); }

/* перетаскивание в задании «по порядку» */
.order-hint { font-size: 13px; color: var(--muted); margin: -8px 0 10px; }
.order { position: relative; }
.order.draggable li { cursor: grab; touch-action: none; user-select: none; -webkit-user-select: none; }
.order.draggable li .mini { touch-action: manipulation; }
.grip { flex: none; width: 10px; height: 18px; margin-left: -2px; opacity: .45;
  background-image: radial-gradient(circle, var(--muted) 1.4px, transparent 1.6px); background-size: 5px 6px; }
.order li.dragging { cursor: grabbing; position: relative; z-index: 2; border-color: var(--brand);
  box-shadow: 0 10px 24px rgba(20, 20, 40, .18); background: var(--surface); }
.order.is-dragging li:not(.dragging) { transition: none; }

/* соответствие перетаскиванием */
.match.dnd .match-row { grid-template-columns: minmax(0, 1fr) minmax(0, 1.3fr); }
.slot { min-height: 46px; border: 1.5px dashed var(--line); border-radius: 10px; padding: 4px; display: flex; align-items: center;
  background: var(--bg); transition: border-color .12s, background .12s; cursor: pointer; }
.slot.filled { border-style: solid; border-color: transparent; background: transparent; padding: 0; }
.slot.over, .pool.over { border-color: var(--brand); border-style: solid; background: color-mix(in srgb, var(--brand) 8%, var(--bg)); }
.slot-ph { font-size: 13px; color: var(--muted); padding: 0 8px; }
.pool { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 14px; padding: 12px; border: 1.5px dashed var(--line); border-radius: 12px;
  min-height: 60px; align-items: center; }
.pool.empty { justify-content: center; }
.chip-card { display: inline-flex; align-items: center; padding: 10px 12px; border-radius: 10px; background: var(--surface);
  border: 1.5px solid var(--line); box-shadow: 0 1px 2px rgba(20, 20, 40, .06); font-size: 15px; line-height: 1.3;
  cursor: grab; touch-action: none; user-select: none; -webkit-user-select: none; }
.slot .chip-card { width: 100%; }
.chip-card:hover:not(.static) { border-color: var(--brand); }
.chip-card.sel { border-color: var(--brand); background: color-mix(in srgb, var(--brand) 10%, var(--surface)); box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 18%, transparent); }
.chip-card.lifted { opacity: .35; }
.chip-card.static { cursor: default; box-shadow: none; }
.chip-card.ghost { position: fixed; left: 0; top: 0; z-index: 50; pointer-events: none; cursor: grabbing; border-color: var(--brand);
  box-shadow: 0 12px 28px rgba(20, 20, 40, .22); }
.match-row.ok .chip-card, .match-row.bad .chip-card { background: transparent; border-color: transparent; padding: 4px 0; }
@media (max-width: 560px) {
  .match.dnd .match-row { grid-template-columns: 1fr; gap: 6px; }
}

/* строка «Источники: …» под ответом */
.prose .sources { font-family: var(--sans); font-size: 13px; color: var(--muted); margin-top: 18px; padding-top: 10px; border-top: 1px solid var(--line); }
.prose .sources strong, .prose .sources em { font-weight: 400; font-style: normal; }

/* студенческая радость */
.quiz-q.joy { font-size: clamp(20px, 3.4vw, 24px); background: linear-gradient(135deg, color-mix(in srgb, var(--warn) 14%, var(--surface)), color-mix(in srgb, var(--ok) 12%, var(--surface)));
  border-radius: 14px; padding: 22px 20px; line-height: 1.4; }
.quiz-q.joy::before { content: "☺"; display: block; font-size: 30px; margin-bottom: 6px; }
.option.joy-next { justify-content: center; font-weight: 700; }

/* формулы и рисунки */
.math-display { position: relative; display: block; overflow-x: auto; overflow-y: hidden; padding: 4px 0; text-align: center; }
.prose .katex { font-size: 1.05em; }
.prose figure { margin: 18px 0 6px; text-align: center; }
.prose img.fig { max-width: 100%; height: auto; border-radius: 8px; background: #fff; }
.prose .caption { font-family: var(--sans); font-size: 14px; color: var(--muted); text-align: center; margin-top: 0; }
.prose aside.note-key { border-left-color: var(--brand); background: color-mix(in srgb, var(--brand) 7%, var(--surface)); }
.prose td .math-display, .prose th .math-display { text-align: left; }
.quiz .katex { font-size: 1.05em; }

/* задачи */
.part-tag { display: inline-block; margin: 0 8px 10px 0; font-size: 12px; font-weight: 700; letter-spacing: .03em; text-transform: uppercase;
  color: var(--muted); background: var(--surface-2); border-radius: 6px; padding: 3px 8px; }
.problem { display: grid; gap: 10px; }
.pf { display: grid; grid-template-columns: minmax(0, auto) minmax(0, 1fr); gap: 6px 12px; align-items: center; padding: 10px 12px;
  border: 1.5px solid var(--line); border-radius: 12px; }
.pf-label { font-weight: 600; white-space: nowrap; }
.pf .answer-input, .pf select { width: 100%; font: inherit; font-size: 17px; padding: 10px 12px; border-radius: 10px; border: 1.5px solid var(--line); background: var(--bg); color: var(--text); }
.pf.ok { border-color: var(--ok); background: var(--ok-bg); }
.pf.bad { border-color: var(--bad); background: var(--bad-bg); }
.pf-fix { grid-column: 1 / -1; font-size: 14px; font-weight: 600; color: var(--ok); }
.pf-hint { font-size: 13px; color: var(--muted); margin: 10px 2px 0; }
.solution { margin-top: 16px; border: 1px solid var(--line); border-radius: 12px; padding: 4px 16px 6px; background: var(--surface); }
.solution summary { cursor: pointer; font-weight: 700; padding: 8px 0; }
.solution p { margin: 8px 0; line-height: 1.55; }
.mistake .solution { margin-top: 8px; }
.result .parts { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px 16px; margin: 4px auto 10px; font-weight: 600; font-size: 15px; }
.result .parts .ok { color: var(--ok); }
.result .parts .bad { color: var(--bad); }
@media (max-width: 560px) { .pf { grid-template-columns: 1fr; } .pf-label { white-space: normal; } }