:root {
  --bg: #F7FBFB;
  --bg-alt: #D6F0EE;
  --card: #ffffff;
  --fg: #264653;
  --muted: #4a6b6c;
  --faint: #81a49f;
  --border: #c8e3e1;
  --border-strong: #96cbc7;
  --grid: rgba(42, 157, 143, 0.08);
  --link: #2A9D8F;
  --brand: #2A9D8F;
  --brand-hover: #21867a;
  --brand-fg: #ffffff;
  --brand-soft: #D6F0EE;
  --header: rgba(247, 251, 251, 0.94);
  --ink: #264653;
  --ink-fg: #F7FBFB;
  --ink-muted: #4a6b6c;
  --ink-border: #c8e3e1;
  --ok: #2A9D8F;
  --ok-bg: #D6F0EE;
  --err: #E76F51;
  --err-bg: rgba(231, 111, 81, 0.10);
  --warn: #E76F51;
  --warn-bg: rgba(231, 111, 81, 0.08);
  --shadow-sm: 0 1px 3px rgba(38, 70, 83, 0.05);
  --shadow: 0 1px 3px rgba(38, 70, 83, 0.05), 0 8px 24px rgba(38, 70, 83, 0.06);
  --shadow-lg: 0 2px 4px rgba(38, 70, 83, 0.05), 0 24px 56px rgba(38, 70, 83, 0.12);
  --radius: 14px;
  --radius-sm: 10px;
  --wrap: 1200px;
  --h1: clamp(28px, 3.6vw, 36px);
  --h2: 20px;
  --h3: 16px;
  --sans: "Segoe UI Variable Text", "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Arial, sans-serif;
  --display: var(--sans);
  --mono: ui-monospace, "Cascadia Code", Consolas, Menlo, monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #1c323c;
    --bg-alt: #264653;
    --card: #203a45;
    --fg: #F7FBFB;
    --muted: #D6F0EE;
    --faint: #8bb5b3;
    --border: #2d505c;
    --border-strong: #2A9D8F;
    --grid: rgba(42, 157, 143, 0.12);
    --link: #5ec7bb;
    --brand: #2A9D8F;
    --brand-hover: #36b5a5;
    --brand-soft: rgba(42, 157, 143, 0.22);
    --header: rgba(28, 50, 60, 0.94);
    --ink: #203a45;
    --ink-border: #2d505c;
    --ok: #2A9D8F;
    --ok-bg: rgba(42, 157, 143, 0.2);
    --err: #E76F51;
    --err-bg: rgba(231, 111, 81, 0.2);
    --warn: #E76F51;
    --warn-bg: rgba(231, 111, 81, 0.15);
    --shadow-sm: none;
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
    --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.45);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #1c323c;
  --bg-alt: #264653;
  --card: #203a45;
  --fg: #F7FBFB;
  --muted: #D6F0EE;
  --faint: #8bb5b3;
  --border: #2d505c;
  --border-strong: #2A9D8F;
  --grid: rgba(42, 157, 143, 0.12);
  --link: #5ec7bb;
  --brand: #2A9D8F;
  --brand-hover: #36b5a5;
  --brand-soft: rgba(42, 157, 143, 0.22);
  --header: rgba(28, 50, 60, 0.94);
  --ink: #203a45;
  --ink-border: #2d505c;
  --ok: #2A9D8F;
  --ok-bg: rgba(42, 157, 143, 0.2);
  --err: #E76F51;
  --err-bg: rgba(231, 111, 81, 0.2);
  --warn: #E76F51;
  --warn-bg: rgba(231, 111, 81, 0.15);
  --shadow-sm: none;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
  --shadow-lg: 0 24px 56px rgba(0, 0, 0, 0.45);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scrollbar-gutter: stable; scroll-behavior: smooth; scroll-padding-top: 84px; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  margin: 0;
  overflow-x: clip;
  font: 16px/1.6 var(--sans);
  background: var(--bg);
  color: var(--fg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--link); text-underline-offset: 2px; }
[hidden] { display: none !important; }
h1, h2, h3, h4 { font-family: var(--display); letter-spacing: -0.02em; line-height: 1.15; }
h1 { font-size: var(--h1); font-weight: 750; margin: 0 0 10px; }
h2 { font-size: var(--h2); font-weight: 700; margin: 0 0 10px; }
h3 { font-size: var(--h3); font-weight: 650; margin: 0 0 8px; }
.katex { font-size: 1.1em; }
sup, sub { font-size: 0.72em; line-height: 0; }

.muted { color: var(--muted); }
.small { font-size: 14px; }
.icon { flex: none; width: 1.15em; height: 1.15em; }

:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 4px; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px 24px;
  min-height: 64px;
  padding: 10px max(16px, calc((100% - var(--wrap)) / 2));
  background: var(--header);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font: 750 19px var(--display);
  letter-spacing: -0.025em;
  color: var(--fg);
  text-decoration: none;
  white-space: nowrap;
}
.brand-mark { width: 30px; height: 30px; flex: none; }
.brand small { font: 500 13px var(--sans); letter-spacing: 0; color: var(--muted); margin-left: 2px; }
.site-nav { display: flex; align-items: center; gap: 2px; }
.site-nav > a:not(.button) {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 11px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  border-radius: 8px;
  transition: color 0.15s, background 0.15s;
}
.site-nav > a:not(.button):hover { color: var(--fg); background: var(--bg-alt); }
.site-nav > a.is-current { color: var(--brand); background: var(--brand-soft); }
.site-nav .button { min-height: 38px; padding: 6px 14px; margin-left: 6px; font-size: 14px; }
.nav-cart { position: relative; }
.cart-count {
  display: inline-grid;
  place-items: center;
  min-width: 19px;
  height: 19px;
  padding: 0 5px;
  font: 700 11px var(--sans);
  color: var(--brand-fg);
  background: var(--brand);
  border-radius: 999px;
}
.cart-count.is-empty { display: none; }
.nav-toggle { display: none; min-height: 44px; min-width: 44px; width: 44px; height: 44px; padding: 0; background: transparent; color: var(--fg); border-color: var(--border); }
.nav-toggle:hover { background: var(--bg-alt); }

/* Buttons */
button, .button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 9px 18px;
  font: 600 15px var(--sans);
  color: var(--brand-fg);
  background: var(--brand);
  border: 1px solid var(--brand);
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, color 0.15s, box-shadow 0.15s;
}
button:hover, .button:hover { background: var(--brand-hover); border-color: var(--brand-hover); }
button:disabled { opacity: 0.45; cursor: default; }
button.secondary, .button.secondary { background: var(--card); color: var(--fg); border-color: var(--border-strong); }
button.secondary:hover:not(:disabled), .button.secondary:hover { background: var(--bg-alt); border-color: var(--faint); }
.button-lg { min-height: 52px; padding: 12px 24px; font-size: 16px; }
.button-block { width: 100%; }
button.link, .link {
  min-height: 0;
  padding: 0;
  background: none;
  border: 0;
  color: var(--link);
  font-weight: 500;
  text-decoration: underline;
}
button.link:hover { background: none; }

/* Hero */
.hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--border); }
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 32px 32px;
  mask-image: radial-gradient(ellipse 85% 90% at 70% 40%, #000 25%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 85% 90% at 70% 40%, #000 25%, transparent 78%);
}
.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 56px;
  align-items: center;
  max-width: calc(var(--wrap) + 32px);
  margin: 0 auto;
  padding: 80px 16px 88px;
}
.eyebrow {
  display: inline-block;
  margin: 0 0 18px;
  padding: 4px 12px;
  color: var(--brand);
  background: var(--brand-soft);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 650;
}
.hero h1 { font-size: clamp(40px, 5.8vw, 66px); line-height: 1.14; letter-spacing: -0.038em; font-weight: 800; margin: 0 0 20px; }
.hero h1 em {
  font-style: normal;
  color: var(--err);
  text-decoration: underline wavy 3px;
  text-underline-offset: 8px;
  text-decoration-skip-ink: none;
}
.lede { font-size: 19px; line-height: 1.55; color: var(--muted); max-width: 50ch; margin: 0 0 30px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-note { margin: 20px 0 0; color: var(--muted); font-size: 14px; }

.demo { position: relative; padding: 22px; background: var(--card); border: 1px solid var(--border); border-radius: 18px; box-shadow: var(--shadow-lg); }
.demo-text { margin: 0 0 14px; font-size: 14.5px; line-height: 1.55; }
.demo .q-options { margin: 0; gap: 6px; }
.demo .q-option { min-height: 40px; padding: 6px 12px; cursor: default; }
.demo .q-option:hover { border-color: var(--border); }
.demo .q-option.is-correct:hover { border-color: var(--ok); }
.demo .q-option.is-wrong:hover { border-color: var(--err); }
.demo-note {
  margin: 12px 0 0;
  padding: 11px 13px;
  font-size: 14px;
  line-height: 1.45;
  color: var(--err);
  background: var(--err-bg);
  border-radius: var(--radius-sm);
}
.demo-note b { display: block; font-weight: 700; }

/* Sections */
.section { max-width: calc(var(--wrap) + 32px); margin: 0 auto; padding: 88px 16px; }
.band { background: var(--bg-alt); border-block: 1px solid var(--border); }
.section-head { margin-bottom: 36px; max-width: 62ch; }
.section-head h2 { font-size: var(--h1); font-weight: 750; }
.section-head p { margin: 0; }
.note { margin: 26px 0 0; font-size: 14px; }

.values { display: grid; grid-template-columns: repeat(3, 1fr); max-width: var(--wrap); margin: 0 auto; }
.values > div { display: flex; gap: 14px; padding: 28px 16px; }
.values strong { display: block; font-size: var(--h3); line-height: 1.3; }
.values span { color: var(--muted); font-size: 14.5px; line-height: 1.45; }
.tile-icon {
  display: inline-grid;
  place-items: center;
  flex: none;
  width: 40px;
  height: 40px;
  color: var(--brand);
  background: var(--brand-soft);
  border-radius: 10px;
}
.tile-icon .icon { width: 20px; height: 20px; }

.tiles { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.tile { padding: 26px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow-sm); }
.tile h3 { margin: 16px 0 6px; }
.tile p { margin: 0; color: var(--muted); font-size: 15px; }

.steps { list-style: none; counter-reset: step; display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; margin: 0; padding: 0; }
.steps li {
  counter-increment: step;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 22px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.steps li::before {
  content: counter(step);
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  margin-bottom: 8px;
  font: 700 14px var(--display);
  color: var(--brand-fg);
  background: var(--brand);
  border-radius: 50%;
}
.steps strong { font-size: var(--h3); line-height: 1.25; }
.steps span { color: var(--muted); font-size: 14.5px; line-height: 1.5; }

.cols { display: grid; grid-template-columns: 3fr 2fr; gap: 18px; align-items: start; }
.cover { padding: 26px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); }
.cover h3 { display: flex; align-items: center; gap: 9px; margin-bottom: 14px; }
.ticks { list-style: none; margin: 0; padding: 0; }
.cover-yes .ticks { columns: 2; column-gap: 28px; }
.ticks li { position: relative; padding: 5px 0 5px 24px; font-size: 15px; line-height: 1.4; break-inside: avoid; }
.ticks li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 10px;
  width: 11px;
  height: 6px;
  border-left: 2px solid var(--ok);
  border-bottom: 2px solid var(--ok);
  transform: rotate(-45deg);
}
.cover-no .ticks li::before { top: 14px; width: 11px; height: 0; border-left: 0; border-bottom: 2px solid var(--faint); transform: none; }
.cover-no .ticks li { color: var(--muted); }
.cover .small { margin: 14px 0 0; }

/* Pricing */
.pricing { display: grid; grid-template-columns: minmax(0, 1fr); }
.price-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  padding: 40px;
  color: var(--ink-fg);
  background: var(--ink);
  border: 1px solid var(--ink-border);
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
}
.price-card h3 { font-size: var(--h2); }
.price-card p { margin: 0; }
.price-card .muted { color: var(--ink-muted); }
.price { margin: 16px 0 2px !important; font: 800 clamp(34px, 5vw, 44px)/1.1 var(--display); letter-spacing: -0.03em; }
.price small { font-size: 16px; font-weight: 600; letter-spacing: 0; color: var(--ink-muted); }
.price-card .button { margin-top: 22px; background: #fff; border-color: #fff; color: #264653; }
.price-card .button:hover { background: #d6f0ee; border-color: #d6f0ee; }
.price-card .ticks li { font-size: 15px; padding-block: 7px; }
.price-card .ticks li::before { border-color: #2a9d8f; top: 13px; }
.price-desc { font-size: 13px; color: var(--ink-muted); margin-top: 16px !important; }

/* FAQ */
.faq { max-width: none; }
.faq details { padding: 0; border-bottom: 1px solid var(--border); }
.faq details:first-child { border-top: 1px solid var(--border); }
.faq summary { padding: 18px 34px 18px 2px; font-weight: 600; }
.faq p { margin: 0 0 18px; padding-right: 34px; color: var(--muted); }

details > summary { position: relative; cursor: pointer; list-style: none; }
details > summary::-webkit-details-marker { display: none; }
.faq summary::after, .weak summary::after, .review summary::after {
  content: "";
  position: absolute;
  right: 8px;
  top: 50%;
  width: 8px;
  height: 8px;
  margin-top: -6px;
  border-right: 2px solid var(--faint);
  border-bottom: 2px solid var(--faint);
  transform: rotate(45deg);
  transition: transform 0.15s;
}
details[open] > summary::after { transform: rotate(-135deg); margin-top: -2px; }

/* Question card */
.quiz-tabs { display: flex; gap: 6px; margin-bottom: 14px; }
.quiz-stack { display: grid; gap: 18px; }
.q-card { padding: 28px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.q-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; margin: 0 0 14px; color: var(--muted); font-size: 13px; font-weight: 500; }
.q-text { line-height: 1.6; }
.q-text p { margin: 0 0 12px; }
.q-options { display: grid; gap: 8px; margin: 18px 0 20px; }
.q-option {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 50px;
  padding: 8px 14px;
  background: var(--card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color 0.12s, background 0.12s;
}
.q-option:hover { border-color: var(--brand); }
.q-option input { position: absolute; opacity: 0; width: 1px; height: 1px; margin: 0; min-height: 0; }
.q-option:has(input:focus-visible) { outline: 2px solid var(--brand); outline-offset: 2px; }
.q-option:has(input:checked) { border-color: var(--brand); background: var(--brand-soft); box-shadow: inset 0 0 0 1px var(--brand); }
.q-option:has(input:disabled) { cursor: default; }
.q-option:has(input:disabled):not(.is-correct):not(.is-wrong) { opacity: 0.62; border-color: var(--border); }
.q-letter {
  display: grid;
  place-items: center;
  flex: none;
  width: 28px;
  height: 28px;
  font: 700 13px var(--sans);
  color: var(--muted);
  background: var(--bg-alt);
  border-radius: 50%;
}
.q-option:has(input:checked) .q-letter { color: var(--brand-fg); background: var(--brand); }
.q-value { font-variant-numeric: tabular-nums; }
.q-option.is-correct, .q-option.is-correct:has(input:checked) { border-color: var(--ok); background: var(--ok-bg); box-shadow: inset 0 0 0 1px var(--ok); opacity: 1; }
.q-option.is-wrong, .q-option.is-wrong:has(input:checked) { border-color: var(--err); background: var(--err-bg); box-shadow: inset 0 0 0 1px var(--err); opacity: 1; }
.q-option.is-correct .q-letter, .q-option.is-correct:has(input:checked) .q-letter { color: #fff; background: var(--ok); }
.q-option.is-wrong .q-letter, .q-option.is-wrong:has(input:checked) .q-letter { color: #fff; background: var(--err); }
.q-option.is-correct::after, .q-option.is-wrong::after { display: none !important; content: none !important; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .q-option.is-correct .q-letter, :root:not([data-theme="light"]) .q-option.is-wrong .q-letter { color: #ffffff; }
}
:root[data-theme="dark"] .q-option.is-correct .q-letter, :root[data-theme="dark"] .q-option.is-wrong .q-letter { color: #ffffff; }

.feedback { margin-top: 16px; padding: 16px 18px; border-radius: var(--radius-sm); background: var(--bg-alt); }
.feedback.ok { background: var(--ok-bg); }
.feedback.ok > strong { color: var(--ok); }
.feedback.bad { background: var(--err-bg); }
.feedback.bad > strong { color: var(--err); }
.feedback > strong { font-size: 16px; }
.feedback p { margin: 8px 0 0; }
.solution {
  margin-top: 12px !important;
  padding: 14px 16px;
  white-space: pre-line;
  font-size: 15px;
  line-height: 1.65;
  font-variant-numeric: tabular-nums;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
}
.next { margin-top: 14px; }

table.joint { width: auto; margin: 0 0 14px; font-variant-numeric: tabular-nums; }
table.joint th, table.joint td { text-align: center; padding: 7px 16px; border: 1px solid var(--border); font-size: 15px; }
table.joint th { background: var(--bg-alt); }

/* App pages */
.view { flex: 1; width: 100%; max-width: calc(var(--wrap) + 32px); min-height: 60vh; margin: 0 auto; padding: 44px 16px 72px; }
.page-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-end; gap: 10px 20px; margin-bottom: 26px; }
.page-head h1 { margin: 0; }
.page-head p { margin: 6px 0 0; max-width: 62ch; }
.view h2 { margin: 30px 0 12px; }

.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 20px; }
.chip { min-height: 38px; padding: 5px 15px; font-size: 14px; font-weight: 550; background: var(--card); color: var(--muted); border: 1px solid var(--border-strong); border-radius: 999px; }
.chip:hover:not(:disabled) { background: var(--bg-alt); border-color: var(--faint); color: var(--fg); }
.chip.is-active, .chip.is-active:hover:not(:disabled) { background: var(--brand); color: var(--brand-fg); border-color: var(--brand); }

.with-side { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 24px; align-items: start; }
.side { position: sticky; top: 84px; display: grid; gap: 14px; }
.side-card { padding: 20px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); }
.side-card h3 { margin-bottom: 12px; }
.side-list { margin: 0; padding-left: 18px; font-size: 14px; }
.side-list li { margin: 5px 0; }
.side-links { display: grid; gap: 7px; justify-items: start; }
.side-links button.link { font-size: 14px; text-align: left; text-decoration: none; }
.side-links button.link:hover { text-decoration: underline; }
.page-card { padding: 28px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.side-num { font: 750 34px/1.1 var(--display); letter-spacing: -0.03em; }
.side-num small { font-size: 15px; font-weight: 500; color: var(--muted); letter-spacing: 0; }

.bars { display: grid; gap: 12px; }
.bar-row { font-size: 14px; }
.bar-label { display: flex; justify-content: space-between; gap: 10px; margin-bottom: 4px; line-height: 1.35; }
.bar-label span:last-child { flex: none; color: var(--muted); font-variant-numeric: tabular-nums; }
.bar { height: 7px; background: var(--bg-alt); border-radius: 4px; overflow: hidden; }
.bar > i { display: block; height: 100%; background: var(--brand); border-radius: 4px; }
.bar.is-low > i { background: var(--err); }
.bar.is-high > i { background: var(--ok); }

.state { max-width: 560px; margin: 40px auto; padding: 40px 28px; text-align: center; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.state p { color: var(--muted); margin: 0 0 22px; }
.state .tile-icon { width: 52px; height: 52px; margin-bottom: 16px; border-radius: 14px; }
.state .tile-icon .icon { width: 26px; height: 26px; }

.total { font-size: 18px; font-weight: 650; }
.code { font-family: var(--mono); font-weight: 700; }
.box, .card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; margin-block: 18px; }
.box h2 { margin-top: 0; }
.box dl { margin: 0 0 12px; }

/* Forms */
.auth-wrap { display: grid; place-items: center; padding-top: 16px; }
.narrow { width: 100%; max-width: 420px; padding: 32px; background: var(--card); border: 1px solid var(--border); border-radius: 18px; box-shadow: var(--shadow); }
.narrow h1 { margin-bottom: 20px; }
.narrow button[type="submit"] { width: 100%; margin-top: 4px; }
.auth-links { margin: 18px 0 0; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 6px 14px; font-size: 14px; }

form label { display: block; margin-bottom: 16px; }
form label > span { display: block; font-size: 14px; font-weight: 550; margin-bottom: 5px; }
input, select, textarea {
  width: 100%;
  min-height: 44px;
  padding: 9px 12px;
  font: inherit;
  color: var(--fg);
  background: var(--card);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  transition: border-color 0.12s, box-shadow 0.12s;
}
input:focus, select:focus, textarea:focus { outline: 0; border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft); }
input::placeholder, textarea::placeholder { color: var(--faint); }
input[type="radio"], input[type="checkbox"] { width: auto; min-height: 0; accent-color: var(--brand); box-shadow: none; }
input.qty { width: 76px; }
fieldset { border: 0; margin: 0 0 18px; padding: 0; }
legend { padding: 0; margin-bottom: 8px; font-size: 14px; font-weight: 550; }
form label.radio { display: flex; gap: 10px; align-items: flex-start; margin: 0 0 16px; }
form label.radio > input { margin-top: 5px; }
.pay-option { display: flex !important; align-items: center; gap: 10px; min-height: 50px; margin: 0 0 8px !important; padding: 8px 14px; border: 1px solid var(--border-strong); border-radius: var(--radius-sm); cursor: pointer; }
.pay-option:has(input:checked) { border-color: var(--brand); background: var(--brand-soft); box-shadow: inset 0 0 0 1px var(--brand); }

.with-side > form { padding: 28px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); }
.summary { position: sticky; top: 84px; padding: 24px; background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--radius); }
.summary h2 { margin: 0 0 14px; }
.summary-line { display: flex; justify-content: space-between; gap: 14px; padding: 7px 0; font-size: 15px; font-variant-numeric: tabular-nums; }
.summary-line.total-line { margin-top: 8px; padding-top: 14px; border-top: 1px solid var(--border-strong); font-size: 16px; font-weight: 700; }
.summary .button, .summary button { width: 100%; margin-top: 16px; }
.summary-note { margin: 8px 0 0; font-size: 13px; color: var(--muted); }

.msg { padding: 11px 14px; border-radius: var(--radius-sm); margin: 12px 0; font-size: 15px; }
.msg:empty { display: none; }
.msg.error { background: var(--err-bg); color: var(--err); }
.msg.ok { background: var(--ok-bg); color: var(--ok); }
.msg.warn { background: var(--warn-bg); color: var(--warn); }

/* Mock exam */
.exam-facts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 22px 0; }
.exam-facts > div { padding: 18px; background: var(--bg-alt); border-radius: var(--radius-sm); }
.exam-facts strong { display: block; font: 750 26px/1.15 var(--display); letter-spacing: -0.02em; }
.exam-facts span { color: var(--muted); font-size: 14px; }

.exam-bar {
  position: sticky;
  top: 64px;
  z-index: 10;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 18px;
  margin: -44px calc(50% - 50vw) 24px;
  padding: 12px max(16px, calc((100vw - var(--wrap)) / 2));
  background: var(--header);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.exam-bar h1 { margin: 0; font-size: 18px; }
.exam-progress { color: var(--muted); font-size: 14px; }
.exam-clock { font: 700 22px var(--mono); font-variant-numeric: tabular-nums; }
.exam-clock.is-low { color: var(--err); }
.palette { display: grid; grid-template-columns: repeat(6, 1fr); gap: 6px; }
.pal { min-width: 44px; min-height: 44px; padding: 0; display: inline-flex; align-items: center; justify-content: center; background: var(--card); color: var(--muted); border: 1px solid var(--border-strong); font-size: 13px; font-weight: 550; border-radius: 8px; }
.pal:hover { background: var(--bg-alt); color: var(--fg); border-color: var(--faint); }
.pal.is-done { background: var(--brand-soft); color: var(--brand); border-color: transparent; font-weight: 700; }
.pal.is-done:hover { background: var(--brand-soft); color: var(--brand); border-color: var(--brand); }
.pal.is-current, .pal.is-current:hover { background: var(--brand); color: var(--brand-fg); border-color: var(--brand); }
.exam-nav { display: flex; justify-content: space-between; gap: 8px; }

.score { display: flex; flex-direction: column; align-items: center; justify-content: center; text-align: center; }
.ring { position: relative; width: 150px; height: 150px; margin-bottom: 14px; }
.ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring circle { fill: none; stroke-width: 11; stroke: var(--bg-alt); }
.ring circle.ring-fill { stroke: var(--brand); stroke-linecap: round; }
.ring div { position: absolute; inset: 0; display: grid; place-content: center; font: 800 32px/1 var(--display); letter-spacing: -0.03em; }
.ring small { display: block; margin-top: 3px; font-size: 13px; font-weight: 500; color: var(--muted); letter-spacing: 0; }
.review-list { display: grid; gap: 10px; }
.review { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.review summary { display: flex; align-items: center; gap: 10px; padding: 13px 40px 13px 14px; font-size: 15px; font-weight: 550; }
.review-body { padding: 4px 18px 18px; }

/* Lessons */
.lesson-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 18px; }
.lesson-card { display: block; padding: 24px; color: var(--fg); text-decoration: none; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s; }
.lesson-card:hover { border-color: var(--brand); box-shadow: var(--shadow); transform: translateY(-1px); }
.lesson-card h3 { margin: 14px 0 0; line-height: 1.3; }
.prose h2:first-child { margin-top: 0; }
.prose h2 { scroll-margin-top: 84px; }
.prose li { margin: 4px 0; }
.prose .q-card { margin: 20px 0; box-shadow: none; background: var(--bg-alt); }
.prose .q-option, .prose .solution { background: var(--card); }
.formula { display: grid; gap: 14px; margin: 16px 0; padding: 18px 16px; overflow-x: auto; background: var(--bg-alt); border-radius: var(--radius-sm); }
.solution { line-height: 2.1; }
.lesson-options { list-style: none; display: grid; gap: 4px; margin: 12px 0 16px; padding: 0; }
.back-link { display: inline-block; margin-bottom: 14px; font-size: 14px; color: var(--muted); text-decoration: none; }
.back-link:hover { color: var(--fg); }

/* Weak skills panel on small screens */
.weak { margin-bottom: 16px; }

/* Tables */
.scroll { overflow-x: auto; }
.table-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--border); vertical-align: top; font-size: 14px; }
tbody tr:last-child > td { border-bottom: 0; }
th { color: var(--muted); font-size: 12.5px; font-weight: 600; white-space: nowrap; }
.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }

dl { display: grid; grid-template-columns: max-content 1fr; gap: 8px 18px; }
dt { color: var(--muted); }
dd { margin: 0; overflow-wrap: anywhere; }
.copy-row { display: inline-flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.copy-row button { min-height: 30px; padding: 2px 10px; font-size: 13px; }

.badge { display: inline-block; padding: 2px 9px; border-radius: 999px; font-size: 12px; font-weight: 650; white-space: nowrap; background: var(--bg-alt); color: var(--muted); }
.badge.good { background: var(--ok-bg); color: var(--ok); }
.badge.bad { background: var(--err-bg); color: var(--err); }
.badge.warn { background: var(--warn-bg); color: var(--warn); }
.badge.info { background: var(--brand-soft); color: var(--brand); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--bg-alt); }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 14px 40px; max-width: calc(var(--wrap) + 32px); margin: 0 auto; padding: 30px 16px; color: var(--muted); font-size: 13.5px; }
.footer-inner p { margin: 0; max-width: 68ch; }
.footer-links { display: flex; gap: 18px; }
.footer-links a { color: var(--muted); }

/* Admin */
.admin { flex: 1; width: 100%; max-width: calc(var(--wrap) + 32px); margin: 0 auto; padding: 44px 16px 72px; }
.admin-shell { display: grid; grid-template-columns: 216px minmax(0, 1fr); gap: 28px; align-items: start; }
.tabs { position: sticky; top: 84px; display: grid; gap: 2px; }
.tab {
  justify-content: flex-start;
  min-height: 42px;
  padding: 8px 12px;
  color: var(--muted);
  background: transparent;
  border: 0;
  border-radius: var(--radius-sm);
  font-size: 14.5px;
  font-weight: 550;
  white-space: nowrap;
}
.tab:hover { color: var(--fg); background: var(--bg-alt); }
.tab.is-active, .tab.is-active:hover { color: var(--brand); background: var(--brand-soft); }
.admin-title { margin: 0 0 26px; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(128px, 1fr)); gap: 10px; margin-bottom: 20px; }
.stat { display: flex; flex-direction: column; gap: 2px; padding: 14px 16px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.stat strong { font: 750 24px/1.2 var(--display); letter-spacing: -0.02em; font-variant-numeric: tabular-nums; }
.stat span { color: var(--muted); font-size: 13px; }
.panel { margin-bottom: 20px; padding: 22px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); }
.panel h2 { margin-bottom: 4px; }
.panel > p { margin: 0 0 14px; }
.toolbar { display: flex; flex-wrap: wrap; gap: 10px; align-items: end; margin-block: 12px; }
.toolbar label { margin: 0; }
.toolbar label > span { display: block; font-size: 13px; color: var(--muted); margin-bottom: 3px; }
.toolbar input, .toolbar select { width: auto; min-width: 130px; }
.toolbar input.grow { min-width: 220px; }
input.count { width: 80px; min-height: 36px; padding: 5px 9px; }
.progress { height: 8px; margin: 12px 0 8px; background: var(--bg-alt); border-radius: 4px; overflow: hidden; }
.progress > div { height: 100%; width: 0; background: var(--brand); transition: width 0.2s; }
.q-row { cursor: pointer; }
.q-row:hover { background: var(--bg-alt); }
.q-row td:nth-child(2) { max-width: 460px; }
.clip { display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.mono { font-family: var(--mono); font-size: 13px; }
.detail > td { background: var(--bg-alt); }
.detail-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 24px; padding: 8px 4px; }
.detail h4 { margin: 12px 0 6px; font-size: 14px; }
.detail ul { list-style: none; margin: 0; padding: 0; }
.detail li { padding: 6px 0; border-top: 1px solid var(--border); }
.detail li.right { color: var(--ok); font-weight: 600; }
.pager { display: flex; align-items: center; gap: 12px; margin-top: 14px; }
.actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.panel .actions button, .pager button, td form.inline button, td > button { min-height: 36px; padding: 5px 12px; font-size: 14px; }
form.inline { display: inline-flex; flex-wrap: wrap; gap: 6px; align-items: center; margin: 0 6px 6px 0; }
form.inline input { width: 150px; min-height: 36px; padding: 5px 9px; font-size: 14px; }
.edit-form label { margin-bottom: 10px; }
.edit-form input { margin-bottom: 4px; }
.edit-options { display: grid; grid-template-columns: 30px 1fr; gap: 8px; align-items: start; margin-bottom: 8px; }
.mail-body { white-space: pre-wrap; word-break: break-all; }
.loading { color: var(--muted); }

@media (max-width: 980px) {
  .site-header { flex-wrap: wrap; }
  .nav-toggle { display: inline-flex; }
  .site-nav { display: none; flex-basis: 100%; flex-direction: column; align-items: stretch; padding: 6px 0 4px; }
  .site-nav.is-open { display: flex; }
  .site-nav > a:not(.button) { min-height: 44px; }
  .site-nav .button { margin: 6px 0 0; min-height: 44px; }
  .hero-inner { grid-template-columns: minmax(0, 1fr); gap: 40px; padding: 52px 16px 60px; }
  .steps { grid-template-columns: 1fr 1fr; }
  .cols { grid-template-columns: minmax(0, 1fr); }
  .with-side { grid-template-columns: minmax(0, 1fr); }
  .side, .summary { position: static; }
  .palette { grid-template-columns: repeat(10, 1fr); }
  .detail-grid { grid-template-columns: minmax(0, 1fr); }
  .admin-shell { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .tabs { position: static; display: flex; overflow-x: auto; padding-bottom: 4px; }
}

@media (max-width: 640px) {
  .values, .tiles, .steps, .exam-facts { grid-template-columns: minmax(0, 1fr); }
  .values > div { padding-block: 16px; }
  .section { padding-top: 60px; padding-bottom: 60px; }
  .q-card { padding: 20px; }
  .cover-yes .ticks { columns: 1; }
  .price-card { grid-template-columns: minmax(0, 1fr); gap: 22px; padding: 28px 22px; }
  .hero-actions .button { flex: 1 1 100%; }
  .narrow { padding: 24px 20px; }
  .palette { grid-template-columns: repeat(6, 1fr); }
  .exam-bar h1 { display: none; }
  dl { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  dd { margin-bottom: 8px; }
  .site-header { backdrop-filter: none; background: var(--bg); }
}
.value-text { margin: 0; }
@media (max-width: 980px) { .admin-nav { display: flex; flex-basis: auto; flex-direction: row; padding: 0; } }

/* Lesson library */
.course { margin-bottom: 36px; }
.course-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: flex-end; gap: 6px 24px; margin-bottom: 12px; }
.course-head h2 { margin: 0 0 2px; }
.course-head p { margin: 0; }
.course-meta { color: var(--muted); font-size: 14px; white-space: nowrap; }
.syllabus { list-style: none; margin: 0; padding: 0; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow-sm); overflow: hidden; }
.syllabus li + li { border-top: 1px solid var(--border); }
.syllabus a { display: grid; grid-template-columns: 34px minmax(0, 1fr) auto; align-items: center; gap: 14px; padding: 14px 20px; color: var(--fg); text-decoration: none; transition: background 0.12s; }
.syllabus a:hover { background: var(--bg-alt); }
.syllabus-num { color: var(--faint); font-size: 14px; font-weight: 600; font-variant-numeric: tabular-nums; }
.syllabus-main { display: grid; gap: 1px; }
.syllabus-main strong { font-weight: 600; line-height: 1.35; }
.syllabus-meta { display: flex; align-items: center; gap: 12px; white-space: nowrap; }

/* Lesson page */
.crumbs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; color: var(--muted); font-size: 14px; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--fg); text-decoration: underline; }
.prose .objectives { margin-bottom: 8px; padding: 18px 22px; background: var(--brand-soft); border-radius: var(--radius-sm); }
.prose .objectives h2 { margin: 0 0 8px; font-size: var(--h3); }
.prose .objectives ul { margin: 0; padding-left: 20px; }
.lesson-section { margin-top: 30px; scroll-margin-top: 84px; }
.lesson-section > h2 { margin: 0 0 10px; }
.lesson-section > p { margin: 0 0 12px; }
.lesson-section > ul, .lesson-section > ol { margin: 0 0 12px; padding-left: 22px; }
.callout { padding: 18px 22px; border-radius: var(--radius-sm); }
.callout > :last-child { margin-bottom: 0; }
.callout-warn { background: var(--warn-bg); }
.callout-summary { background: var(--bg-alt); border-left: 3px solid var(--brand); border-radius: 0 var(--radius-sm) var(--radius-sm) 0; }
.example-card { padding: 20px 22px; border: 1px solid var(--border-strong); border-radius: var(--radius-sm); }
.example-options { display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); gap: 8px; margin: 14px 0 16px; }
.example-option { display: flex; align-items: center; gap: 10px; min-height: 44px; padding: 6px 12px; color: var(--fg); font: inherit; text-align: left; background: var(--card); border: 1px solid var(--border-strong); border-radius: var(--radius-sm); cursor: pointer; transition: border-color 0.12s, background 0.12s; }
.example-option:hover:not(:disabled) { border-color: var(--brand); background: var(--brand-soft); }
.example-option:disabled { cursor: default; opacity: 1; }
.example-option:disabled:not(.is-correct):not(.is-wrong) { opacity: 0.6; }
.example-option .q-letter { width: 24px; height: 24px; font-size: 12px; }
.example-option.is-correct { border-color: var(--ok); background: var(--ok-bg); box-shadow: inset 0 0 0 1px var(--ok); }
.example-option.is-wrong { border-color: var(--err); background: var(--err-bg); box-shadow: inset 0 0 0 1px var(--err); }
.example-option.is-correct .q-letter { color: #fff; background: var(--ok); }
.example-option.is-wrong .q-letter { color: #fff; background: var(--err); }
.example-eyebrow { margin: 0 0 10px; color: var(--muted); font-size: 13px; font-weight: 600; letter-spacing: 0.01em; }
.example-feedback { margin: 0 0 14px; padding: 12px 16px; border-radius: var(--radius-sm); }
.example-feedback.ok { background: var(--ok-bg); }
.example-feedback.ok > strong { color: var(--ok); }
.example-feedback.bad { background: var(--err-bg); }
.example-feedback.bad > strong { color: var(--err); }
.example-result { margin: 0 0 8px; }
.example-answer h4 { margin: 16px 0 6px; font-size: 14px; }
.example-notes { margin: 0; padding-left: 0; list-style: none; font-size: 14.5px; }
.example-notes li { padding: 5px 0; border-top: 1px solid var(--border); }
.lesson-pager { display: grid; grid-template-columns: 1fr 1fr; align-items: stretch; gap: 14px; margin-top: 18px; }
.lesson-pager-link { display: grid; align-content: center; gap: 2px; padding: 14px 18px; color: var(--fg); text-decoration: none; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm); transition: border-color 0.12s; }
.lesson-pager-link:hover { border-color: var(--brand); }
.lesson-pager-link strong { font-weight: 600; line-height: 1.35; }
.lesson-pager-link.next { grid-column: 2; text-align: right; }
.outline { list-style: none; counter-reset: outline; margin: 0; padding: 0; font-size: 14px; }
.outline li { counter-increment: outline; display: flex; gap: 8px; padding: 5px 0; line-height: 1.35; }
.outline li::before { content: counter(outline); flex: none; width: 16px; color: var(--faint); font-variant-numeric: tabular-nums; }
.outline a { color: var(--muted); text-decoration: none; }
.outline a:hover { color: var(--fg); text-decoration: underline; }
.outline .is-current a { color: var(--brand); font-weight: 600; }
.side-links button.link { color: var(--muted); padding-left: 10px; border-left: 2px solid var(--border); border-radius: 0; }
.side-links { gap: 0; }
.side-links button.link { padding-block: 4px; }
.side-links button.link.is-example { padding-left: 22px; font-size: 13px; color: var(--faint); }
.side-links button.link.is-active { color: var(--brand); font-weight: 600; border-left-color: var(--brand); }
.lesson-side { max-height: calc(100vh - 100px); overflow-y: auto; scrollbar-width: thin; }
.outline-card summary { display: flex; justify-content: space-between; align-items: center; font-weight: 650; cursor: pointer; }
.outline-card[open] summary { margin-bottom: 10px; }

/* Lesson page: course chips, a reading bar, and a text column short enough to read comfortably. */
.course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 14px; margin: 4px 0 40px; }
.course-card { display: grid; align-content: start; gap: 6px; padding: 18px 20px; color: var(--fg); font: inherit; text-align: left; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow-sm); cursor: pointer; transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s; }
.course-card:hover { border-color: var(--brand); box-shadow: var(--shadow); transform: translateY(-1px); }
.course-card strong { font-size: 16px; line-height: 1.3; }
.course-card-meta { margin-top: 6px; color: var(--muted); font-size: 13px; font-weight: 600; }
.course-code { justify-self: start; padding: 2px 8px; color: var(--brand); font-size: 12px; font-weight: 700; letter-spacing: 0.04em; background: var(--brand-soft); border-radius: 999px; }
.course { scroll-margin-top: 84px; }
.lesson-head h1 { max-width: 30ch; }
.lesson-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 16px; margin: 6px 0 0; color: var(--muted); font-size: 14px; }
.read-progress { position: fixed; top: 0; left: 0; right: 0; z-index: 60; height: 3px; pointer-events: none; }
.read-progress i { display: block; height: 100%; background: var(--brand); transform: scaleX(0); transform-origin: left; }
.toc-mobile { display: none; margin-bottom: 16px; padding: 10px 14px; background: var(--bg-alt); border-radius: var(--radius-sm); }
.toc-mobile summary { font-weight: 600; cursor: pointer; }
.toc-mobile .side-links { margin-top: 10px; padding-left: 12px; }
.prose { font-size: 16.5px; line-height: 1.7; }
.lesson-section { margin-top: 38px; }
.lesson-section > h2 { font-size: 22px; }
.lesson-section > p, .lesson-section > ul, .lesson-section > ol, .objectives ul { max-width:none;width:100%; }
.example-card { background: var(--bg-alt); }
.example-card .solution { padding: 14px 16px; background: var(--card); border-radius: var(--radius-sm); }
@media (max-width: 980px) {
  .lesson-side { max-height: none; overflow: visible; }
  .lesson-side .toc-card { display: none; }
  .toc-mobile { display: block; }
}
@media (max-width: 640px) {
  .prose { font-size: 16px; }
  .formula { padding: 14px 10px; }
  .formula .katex { font-size: 1.05em; }
  .example-card { padding: 16px; }
}
@media (max-width: 640px) {
  .syllabus a { grid-template-columns: 26px minmax(0, 1fr); padding: 12px 14px; }
  .syllabus-meta { grid-column: 2; }
  .lesson-pager { grid-template-columns: minmax(0, 1fr); }
  .lesson-pager-link.next { grid-column: 1; }
  .page-card { padding: 20px; }
}

.lesson-section > h3 { margin: 22px 0 6px; font-size: 17px; }
.lesson-table { margin: 12px 0 16px; border: 1px solid var(--border); border-radius: var(--radius-sm); }
.lesson-table th { background: var(--bg-alt); white-space: normal; }
.callout .lesson-table { background: var(--card); }
.lesson-table .katex-html { white-space: nowrap; }

.formula { justify-items: center; }
.formula .katex-display { margin: 0; }
.formula .katex { font-size: 1.25em; }

.practice-courses { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.practice-layout { display:grid;grid-template-columns:280px minmax(0,1fr);gap:28px;align-items:start; }
.practice-question { min-width:0; }
.lesson-lab { margin:28px 0;padding:22px;border:1px solid var(--border-strong);border-radius:16px;background:var(--bg-alt); }
.lab-heading h3 { margin:5px 0 10px;font-size:21px; }.lab-heading p { color:var(--muted);font-size:14px; }
.lab-controls { display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:18px;margin:22px 0 12px; }
.lab-control { display:grid;grid-template-columns:1fr auto;gap:8px;font-size:12px;align-items:center; }.lab-control input { grid-column:1/-1;width:100%;accent-color:var(--brand);min-height:28px; }.lab-control output { font-variant-numeric:tabular-nums;font-weight:650;color:var(--fg); }
.lab-actions { display:flex;gap:18px;align-items:center;margin-bottom:18px; }.lab-actions button { font-size:12px; }
.lab-figure { margin:16px 0 24px;padding:16px 8px;background:var(--card);border:1px solid var(--border);border-radius:12px; }.lab-figure figcaption { padding:0 12px 8px;font-size:13px;font-weight:600; }.lab-figure svg { display:block;width:100%;height:auto;overflow:visible; }
.lab-grid { stroke:var(--border);stroke-width:1; }.lab-axis { stroke:var(--muted);stroke-width:1; }.lab-tick { fill:var(--muted);font:11px system-ui; }.lab-axis-title { fill:var(--fg);font:11px system-ui; }
.lab-line { fill:none;stroke-width:2.7;stroke-linejoin:round; }.lab-line.lab-series-1 { stroke-dasharray:7 4; }.lab-line.lab-series-2 { stroke-dasharray:2 4; }
.lab-series-0 { --series:var(--brand); }.lab-series-1 { --series:#2a9d8f; }.lab-series-2 { --series:#e76f51; }.lab-series-3 { --series:#264653; }
.lab-line { stroke:var(--series); }.lab-bar,.lab-point { fill:var(--series); }.lab-point { stroke:var(--card);stroke-width:1.5; }
.lab-legend { display:flex;flex-wrap:wrap;gap:8px 16px;padding:4px 14px 0;font-size:11px;color:var(--muted); }.lab-key:before { content:'';display:inline-block;width:14px;height:3px;vertical-align:middle;margin-right:6px;background:var(--series); }
.lab-metrics { display:grid;grid-template-columns:repeat(auto-fit,minmax(145px,1fr));gap:10px;margin:16px 0; }.lab-metrics>div { background:var(--card);border:1px solid var(--border);padding:12px;border-radius:9px; }.lab-metrics dt { color:var(--muted);font-size:11px;line-height:1.5; }.lab-metrics dd { margin:5px 0 0;font-size:21px;font-weight:650;font-variant-numeric:tabular-nums; }
.prose .lab-interpretation { font-size:14px;line-height:1.7; }.prose .lab-assumptions { font-size:12px;color:var(--muted); }.lab-data summary { cursor:pointer;font-size:12px;font-weight:600; }.lab-data table { font-size:12px; }
.lesson-checkpoint { margin:24px 0;padding:20px;border-left:3px solid var(--brand);background:var(--brand-soft);border-radius:0 10px 10px 0; }.lesson-checkpoint details summary { cursor:pointer;font-size:13px;font-weight:600; }.lesson-checkpoint .eyebrow { font-size:11px; }
@media(max-width:600px) { .lesson-lab { padding:14px;margin-left:-6px;margin-right:-6px; }.lab-controls { grid-template-columns:1fr; }.lab-heading h3 { font-size:18px; }.lab-metrics { grid-template-columns:1fr 1fr; }.lab-metrics dd { font-size:18px; } }
@media(prefers-reduced-motion:reduce) { .lesson-lab * { animation:none!important;transition:none!important; } }
.assessment-note { padding:12px 16px;margin:12px 0 20px;border:1px solid var(--border);border-radius:10px;background:var(--bg-alt);font-size:13px;line-height:1.65; }
.assessment-note summary { cursor:pointer;font-weight:600; }
.chapter-nav { border:1px solid var(--border);border-radius:14px;padding:18px;background:var(--card); }
.chapter-nav h3 { margin:0 0 12px;font-size:14px; }
.chapter-option { display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%;text-align:left;background:transparent;color:var(--fg);border:0;border-radius:8px;padding:12px 10px;line-height:1.5;font:inherit;font-size:13px; }
.chapter-option:hover { background:var(--bg-alt); }
.chapter-option.is-active { background:var(--brand-soft);color:var(--brand);font-weight:600; }
.chapter-count { min-width:28px;padding:2px 7px;border-radius:6px;background:var(--bg-alt);font-variant-numeric:tabular-nums;text-align:center; }
.practice-toolbar { display:flex;align-items:center;justify-content:space-between;gap:20px;margin:24px 0; }
.practice-toolbar h2 { font-size:22px;margin:4px 0; }
.practice-controls { display:flex;flex-wrap:wrap;align-items:center;gap:10px; }
.practice-controls select { min-height:40px;border:1px solid var(--border);border-radius:8px;padding:8px 12px;background:var(--card);color:var(--fg);font:inherit;font-size:13px; }
.course-generator { margin-bottom:20px; }
.generator-controls { display:flex;flex-wrap:wrap;gap:16px;align-items:end;margin:16px 0; }
.generator-controls label { max-width:200px; }
@media(max-width:800px) { .practice-layout { grid-template-columns:1fr; }.practice-toolbar { align-items:flex-start;flex-direction:column; }.chapter-nav { max-height:240px;overflow:auto; }.practice-layout>.side { display:block; }.practice-layout .side-card { display:none; } }
.practice-course { display: flex; flex-direction: column; align-items: start; }
.practice-course h2 { font-size: var(--h2); }
.practice-course .button { margin-top: auto; }
@media (max-width: 680px) { .practice-courses { grid-template-columns: minmax(0, 1fr); } }

.sr-only { position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0; }
.lab-tick,.lab-axis-title { font-family:var(--sans); }
.lesson-reference { margin:1.5rem 0;padding:1rem 1.25rem;border-left:3px solid var(--brand);background:var(--bg-alt);border-radius:8px; }
.lesson-reference p { color:var(--muted);font-size:.9rem; }

/* Lesson prose is cleanly left-aligned with natural line spacing; labels, formulas, tables and controls retain their alignment. */
.prose > section > p,.prose .lesson-checkpoint > p:not(.eyebrow),.prose .example-card > p { text-align:left;line-height:1.75;hyphens:none; }
.lesson-figure { margin:26px 0;border:1px solid var(--border);border-radius:14px;background:var(--bg-alt);overflow:hidden; }
.figure-heading { padding:18px 20px 0; }.figure-heading h3 { margin:8px 0 14px!important;font-size:19px; }
.figure-canvas { overflow-x:auto;margin:0 12px;background:#fff;border-radius:10px; }
.figure-canvas img { display:block;width:100%;height:auto;min-width:540px; }
.lesson-figure figcaption { padding:16px 20px;font-size:14px;line-height:1.8;text-align:left;hyphens:none; }
.optional-lab { margin:16px 0 28px;border:1px solid var(--border);border-radius:10px;padding:15px 18px; }
.optional-lab > summary { font-size:14px;font-weight:600;padding-right:24px; }.optional-lab .lesson-lab { margin-bottom:0; }
.lab-selection { stroke:var(--fg);stroke-width:1.5;stroke-dasharray:4 4; }.lab-selected-point { fill:var(--card);stroke:var(--fg);stroke-width:2; }
.lab-baseline { --series:#9492a2;opacity:.65;stroke-dasharray:3 5; }
.landing-courses { display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px; }
.landing-course { display:flex;flex-direction:column;gap:12px;padding:24px;border:1px solid var(--border);border-radius:16px;color:var(--fg);text-decoration:none;background:var(--card); }
.landing-course h3 { font-size:19px;margin:0; }.landing-course p { font-size:14px;line-height:1.7;color:var(--muted);margin:0; }.landing-course .course-code { align-self:flex-start; }.landing-course > span:last-child { margin-top:auto; }
.landing-course:hover { border-color:var(--brand);box-shadow:var(--shadow-sm); }
#pricing-area { grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;align-items:stretch; }
#pricing-area .price-card { display:flex;flex-direction:column;gap:20px;padding:26px;box-shadow:none;border-radius:16px; }
#pricing-area .price-card > div:first-child { display:flex;flex-direction:column;flex:1; }
#pricing-area .price-card h3 { font-size:22px;margin:12px 0;min-height:2.4em; }
#pricing-area .price { font-size:32px;margin-top:auto!important;padding-top:24px; }
#pricing-area .price-card .ticks li { font-size:13px; }
.catalog-code { align-self:flex-start;border:1px solid var(--ink-border);padding:5px 10px;border-radius:6px;font-weight:700;font-size:13px; }
.catalog-scope { color:var(--ink-muted);font-size:12px;line-height:1.6; }
.catalog-preview { display:inline-block;color:var(--ink-fg);font-size:14px;margin-top:16px;text-underline-offset:4px; }
@media(max-width:1000px) { .landing-courses,#pricing-area { grid-template-columns:repeat(2,minmax(0,1fr)); } }
@media(max-width:600px) { .landing-courses,#pricing-area { grid-template-columns:minmax(0,1fr); }.figure-heading { padding:14px 14px 0; }.lesson-figure figcaption { padding:14px; }.figure-canvas { margin:0 8px; }.optional-lab { padding:14px 10px; } }
#pricing-area .price-card > div:first-child { flex:0; }
#pricing-area .price-card > div:first-child > .price-desc { min-height:5.5em; }
#pricing-area .price-card > div:last-child { display:flex;flex-direction:column;flex:1; }
#pricing-area .catalog-preview { margin-top:auto;padding-top:16px; }
.prose .lesson-section > ul > li,.prose .example-answer > p,.prose .example-notes > li { text-align:left;line-height:1.75;hyphens:none; }
@media(max-width:600px) { #pricing-area .price-card > div:first-child > .price-desc { min-height:0; } }

.exam-course-grid { display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin:24px 0; }
.exam-course-card { display:flex;flex-direction:column;align-items:flex-start;gap:12px; }
.exam-course-card h2 { font-size:20px;line-height:1.4;margin:0; }.exam-course-card p { margin:0; }.exam-course-card .button { margin-top:auto; }
.course-launch { display:flex;flex-wrap:wrap;gap:12px; }.purchased-courses { display:grid;gap:16px;margin:24px 0; }
@media(max-width:1000px) { .exam-course-grid { grid-template-columns:repeat(2,minmax(0,1fr)); } }
@media(max-width:600px) { .exam-course-grid { grid-template-columns:minmax(0,1fr); } }

/* Admin question review */
.rv-head { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-bottom: 12px; }
.rv-title { flex: 1 1 260px; }
.rv-detail .chips { margin-bottom: 14px; }
.rv-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(280px, 1fr); gap: 28px; align-items: start; }
.rv-main h3, .rv-side h3 { margin: 18px 0 8px; font-size: 15px; }
.rv-main > h3:first-child, .rv-side > h3:first-child { margin-top: 0; }
.rv-main p { margin: 0 0 8px; }
.rv-options { list-style: none; display: grid; gap: 6px; margin: 14px 0; padding: 0; }
.rv-options li { display: grid; grid-template-columns: 26px minmax(0, 1fr); gap: 10px; padding: 8px 12px; border: 1px solid var(--border); border-radius: var(--radius-sm); }
.rv-options li.is-key { border-color: var(--ok); background: var(--ok-bg); }
.rv-letter { display: grid; place-items: center; width: 24px; height: 24px; font: 700 12px var(--sans); color: var(--muted); background: var(--bg-alt); border-radius: 50%; }
.rv-options li.is-key .rv-letter { color: #fff; background: var(--ok); }
.rv-note { margin-top: 2px; color: var(--muted); font-size: 13px; }
.rv-note.good { color: var(--ok); font-weight: 600; }
.rv-side textarea { width: 100%; margin-bottom: 8px; }
.rv-side .actions { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 8px; }
.rv-bar { display: grid; grid-template-columns: 18px minmax(0, 1fr) 80px; align-items: center; gap: 8px; margin: 4px 0; font-size: 13px; }
.rv-bar > div { height: 8px; background: var(--bg-alt); border-radius: 4px; overflow: hidden; }
.rv-bar i { display: block; height: 100%; background: var(--faint); }
.rv-bar.is-key i { background: var(--ok); }
.rv-report { margin-bottom: 10px; padding: 10px 12px; background: var(--bg-alt); border-radius: var(--radius-sm); }
.rv-report p { margin: 0 0 6px; }
.rv-report textarea { width: 100%; margin: 4px 0 8px; }
.rv-version { margin: 8px 0; padding: 8px 12px; border: 1px solid var(--border); border-radius: var(--radius-sm); }
.rv-edit { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 28px; align-items: start; }
.rv-preview { position: sticky; top: 84px; padding: 16px 18px; background: var(--bg-alt); border-radius: var(--radius-sm); }
.rv-preview p { margin: 0 0 8px; }
@media (max-width: 980px) {
  .rv-grid, .rv-edit { grid-template-columns: minmax(0, 1fr); }
  .rv-preview { position: static; }
}

/* Learner report link */
.q-footer { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; margin-top: 14px; }
.q-footer .next { margin: 0; }
.report-box { display: grid; gap: 8px; margin-top: 12px; max-width: 460px; }
.q-footer .report-box { margin-top: 0; }
.report-box button.link { justify-self: start; color: var(--muted); }
.report-box textarea { width: 100%; }
.report-box p { margin: 0; }
.rv-id { white-space: nowrap; }

/* Practice sets */
.set-panel { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 12px 16px; margin: 0 0 18px; padding: 14px 18px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); }
.set-panel label { display: grid; gap: 4px; margin: 0; font-size: 13px; color: var(--muted); }
.set-panel select { min-width: 150px; }
.set-panel button { min-height: 40px; }
.set-progress { margin: 0 0 0 auto; align-self: center; font-size: 14px; color: var(--muted); }
.set-progress strong { color: var(--fg); }
.set-results { display: grid; gap: 6px; margin: 0 0 18px; padding-left: 22px; }
.set-results li { padding: 4px 0; }
@media (max-width: 640px) {
  .set-progress { margin-left: 0; flex-basis: 100%; }
}

/* One explanation system for Practice, lessons and submitted mocks. */
.solution-explainer { margin-top:16px;color:var(--fg);font-weight:400; }
.solution-key { display:flex;align-items:center;gap:14px;padding:16px 18px;background:var(--brand-soft);border-radius:12px;margin-bottom:20px; }
.solution-key-letter { display:grid;place-items:center;flex:0 0 42px;height:42px;background:var(--brand);color:white;border-radius:10px;font-size:20px;font-weight:700; }
.solution-key .eyebrow { display:block;margin:0 0 3px;font-size:10px; }.solution-key-value { font-size:19px;font-weight:650;line-height:1.5; }
.solution-section { margin:16px 0;padding:18px 20px;border:1px solid var(--border);background:var(--card);border-radius:12px; }
.solution-section h4 { font-size:14px;margin:0 0 14px;color:var(--fg); }.solution-steps { list-style:none;padding:0!important;margin:0!important;display:grid;gap:16px; }
.solution-steps > li { display:grid;grid-template-columns:25px minmax(0,1fr);gap:12px;margin:0!important;font-size:15px;line-height:1.85; }
.solution-step-number { display:grid;place-items:center;width:24px;height:24px;border-radius:50%;background:var(--bg-alt);color:var(--muted);font-size:11px;font-weight:700;margin-top:2px; }
.solution-steps > li > div { min-width:0;overflow-wrap:break-word; }.solution-steps .katex-display { overflow-x:auto;overflow-y:hidden;max-width:100%; }
.solution-check { border-left:3px solid var(--brand);background:var(--bg-alt); }.solution-diagnosis { padding:12px 16px;border-left:3px solid var(--bad);margin-bottom:16px;background:var(--card);border-radius:0 8px 8px 0; }
.solution-diagnosis p { margin:6px 0 0; }.solution-alternatives { border:1px solid var(--border);background:var(--card);border-radius:10px;padding:14px 16px;margin-top:18px; }
.solution-alternatives summary { font-weight:600;font-size:14px; }.solution-alternatives table { margin-top:12px; }.solution-alternatives td:first-child { min-width:130px;width:35%; }.solution-alternatives .is-picked { background:var(--brand-soft); }
@media(max-width:600px) { .solution-section { padding:14px 12px; }.solution-key { padding:14px 12px; }.solution-key-value { font-size:17px; }.solution-steps > li { font-size:14px;gap:8px; }.solution-alternatives { padding:12px; } }

.solution-section .solution-note { margin:0;font-size:15px;line-height:1.85; }


.answer-pair { display:grid;grid-template-columns:repeat(2,minmax(90px,1fr));gap:12px;min-width:230px;max-width:100%; }
.answer-pair-cell { display:flex;flex-direction:column;gap:3px; }.answer-pair-cell small { font-size:10px;font-weight:600;line-height:1.3;opacity:.7; }.answer-pair-cell > span { font-variant-numeric:tabular-nums; }
@media(max-width:600px) { .answer-pair { min-width:0;width:100%;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px; } }



/* Courses Directory & Master Curriculum Suite */
.courses-hub { display: flex; flex-direction: column; gap: 24px; }
.curriculum-hero-banner {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  color: #fff;
  border-radius: 16px;
  padding: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}
.curriculum-hero-banner .eyebrow { color: #60a5fa; font-weight: 700; text-transform: uppercase; font-size: 11px; letter-spacing: 0.08em; margin-bottom: 6px; }
.curriculum-hero-banner h3 { color: #fff; font-size: 22px; font-weight: 750; margin: 0 0 8px; }
.curriculum-hero-banner p { color: #cbd5e1; font-size: 14px; line-height: 1.6; margin: 0; max-width: 650px; }
.curriculum-hero-banner .button { background: #3b82f6; color: #fff; border: none; white-space: nowrap; font-weight: 600; padding: 12px 20px; border-radius: 10px; }
.curriculum-hero-banner .button:hover { background: #2563eb; }

.course-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 10px 0 8px;
}
.filter-pill {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s ease;
}
.filter-pill:hover {
  background: var(--card);
  color: var(--fg);
  border-color: var(--brand);
}
.filter-pill.is-active {
  background: var(--brand);
  color: #fff;
  border-color: var(--brand);
}

.course-hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 24px;
}
.course-hub-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-radius: 16px;
  padding: 24px;
  border: 1px solid var(--border);
  background: var(--card);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.course-hub-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 24px -10px rgba(0, 0, 0, 0.08);
}
.course-card-top { display: flex; flex-direction: column; gap: 12px; }
.course-badges { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.course-hub-card h2 { font-size: 20px; margin: 0; line-height: 1.35; color: var(--fg); }
.course-alignment { font-size: 13px; color: var(--brand); margin: 0; line-height: 1.5; font-weight: 500; }
.course-overview-text { font-size: 14px; color: var(--fg); line-height: 1.6; margin: 0; }
.course-sources { font-size: 12px; line-height: 1.5; border-top: 1px dashed var(--border); padding-top: 10px; margin-top: 4px; }
.course-metrics { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 6px; }
.metric-pill {
  font-size: 12px;
  font-weight: 550;
  background: var(--bg-alt);
  color: var(--muted);
  padding: 4px 10px;
  border-radius: 6px;
}
.metric-pill.manual-available {
  background: #ecfdf5;
  color: #059669;
  border: 1px solid #a7f3d0;
}
.course-card-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
}
.link-btn {
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  padding: 6px 12px;
  border-radius: 6px;
  text-decoration: none;
}
.link-btn:hover {
  color: var(--brand);
  background: var(--bg-alt);
}

/* Course Detail View */
.course-detail-view { display: flex; flex-direction: column; gap: 24px; }
.course-detail-card h2 { margin: 0 0 12px; font-size: 18px; }
.detail-overview { font-size: 15px; line-height: 1.7; margin: 0 0 16px; }
.detail-treatises {
  background: var(--bg-alt);
  border-radius: 10px;
  padding: 16px;
  border-left: 4px solid var(--brand);
}
.detail-treatises h3 { margin: 0 0 6px; font-size: 14px; color: var(--fg); }
.detail-treatises p { margin: 0; font-size: 13px; color: var(--muted); line-height: 1.6; }

.modules-list {
  padding-left: 20px;
  margin: 12px 0 0;
  display: grid;
  gap: 10px;
}
.modules-list li { font-size: 14px; line-height: 1.6; }

.launchpad-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px;
  margin-top: 8px;
}

/* Manuals Catalog */
.manuals-catalog { display: flex; flex-direction: column; gap: 36px; }
.manual-group { display: flex; flex-direction: column; gap: 16px; }
.group-head h2 { font-size: 20px; margin: 0 0 6px; }
.group-head p { margin: 0; font-size: 14px; }
.manual-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 16px;
}
.manual-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 12px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  text-decoration: none;
  color: inherit;
  transition: transform 0.15s ease, border-color 0.15s ease;
}
.manual-card:hover {
  transform: translateY(-2px);
  border-color: var(--brand);
}
.manual-card h3 { font-size: 16px; line-height: 1.45; margin: 0; color: var(--fg); }

/* Manual Reader View */
.manual-page-view { max-width: 1280px; margin: 0 auto; width: 100%; }
.manual-container { display: flex; flex-direction: column; gap: 16px; }
.manual-crumbs { margin-bottom: 8px; }
.manual-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 36px;
  align-items: start;
}
.manual-article {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 40px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--fg);
  overflow-x: hidden;
}
.manual-article h1 { font-size: 26px; line-height: 1.35; margin: 0 0 20px; font-weight: 750; border-bottom: 2px solid var(--border); padding-bottom: 12px; }
.manual-article h2 { font-size: 20px; line-height: 1.4; margin: 32px 0 16px; font-weight: 700; border-bottom: 1px solid var(--border); padding-bottom: 8px; }
.manual-article h3 { font-size: 16px; line-height: 1.45; margin: 24px 0 12px; font-weight: 650; }
.manual-article h4 { font-size: 14px; margin: 18px 0 8px; font-weight: 650; }
.manual-para { margin: 0 0 18px; }
.manual-alert {
  background: var(--brand-soft);
  border-left: 4px solid var(--brand);
  padding: 14px 18px;
  border-radius: 0 10px 10px 0;
  margin: 18px 0;
  font-size: 14px;
}
.manual-table-wrap { margin: 20px 0; }
.manual-table th { background: var(--bg-alt); font-size: 13px; font-weight: 650; }
.manual-table td { font-size: 13.5px; }
.heading-anchor {
  color: var(--muted);
  opacity: 0.3;
  text-decoration: none;
  font-size: 0.85em;
  margin-left: 6px;
  transition: opacity 0.15s ease;
}
.heading-anchor:hover { opacity: 1; color: var(--brand); }

.manual-sidebar {
  position: sticky;
  top: 80px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-height: calc(100vh - 100px);
}
.manual-toc-card {
  overflow-y: auto;
  max-height: calc(100vh - 240px);
}
.manual-toc-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-right: 6px;
}
.toc-item {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.45;
  padding: 4px 6px;
  border-radius: 6px;
  border-left: 2px solid transparent;
  transition: all 0.1s ease;
}
.toc-item:hover {
  color: var(--fg);
  background: var(--bg-alt);
  border-left-color: var(--brand);
}
.toc-level-3 { padding-left: 16px; font-size: 12px; }
.manual-mobile-toc {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  margin-bottom: 12px;
}
@media (min-width: 992px) {
  .manual-mobile-toc { display: none; }
}

.manual-footer-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  margin-top: 36px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.manual-nav-prev, .manual-nav-next {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  gap: 4px;
  padding: 12px 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  max-width: 45%;
  transition: border-color 0.15s ease;
}
.manual-nav-prev:hover, .manual-nav-next:hover {
  border-color: var(--brand);
}
.manual-nav-next { align-items: flex-end; text-align: right; }

@media (max-width: 991px) {
  .manual-layout { grid-template-columns: 1fr; }
  .manual-sidebar { display: none; }
  .manual-article { padding: 24px 18px; font-size: 14.5px; }
  .curriculum-hero-banner { flex-direction: column; align-items: flex-start; padding: 20px; }
}