:root {
  color-scheme: light;
  --bg: #f7f8f4;
  --surface: #ffffff;
  --surface-2: #f1f3ee;
  --surface-3: #e9ece6;
  --text: #17201b;
  --muted: #626b65;
  --faint: #636c66;
  --border: #dde2dc;
  --border-strong: #cbd2cc;
  --accent: #2f65d5;
  --accent-hover: #2857bc;
  --accent-solid: #2f65d5;
  --accent-solid-hover: #2857bc;
  --accent-soft: #edf3ff;
  --green: #267954;
  --green-soft: #e8f6ef;
  --violet: #6b50ca;
  --violet-soft: #f0edfb;
  --amber: #8f5d0f;
  --amber-soft: #faf1df;
  --danger: #b5433e;
  --focus-ring: #000000;
  --shadow: 0 12px 36px rgba(29, 42, 34, 0.07);
  --sidebar: 252px;
  --topbar: 72px;
  --radius-sm: 9px;
  --radius: 14px;
  --radius-lg: 20px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #10130f;
  --surface: #171b17;
  --surface-2: #1d221d;
  --surface-3: #252b25;
  --text: #edf1eb;
  --muted: #a1aaa2;
  --faint: #8c968d;
  --border: #2d342e;
  --border-strong: #3b443c;
  --accent: #75a0fa;
  --accent-hover: #8bb0ff;
  --accent-solid: #2f65d5;
  --accent-solid-hover: #2857bc;
  --accent-soft: #1b2943;
  --green: #75c9a4;
  --green-soft: #183126;
  --violet: #a691ee;
  --violet-soft: #29233d;
  --amber: #dfb264;
  --amber-soft: #382c17;
  --danger: #ee8e88;
  --focus-ring: #ffffff;
  --shadow: 0 14px 40px rgba(0, 0, 0, 0.22);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: "Segoe UI Variable", "Segoe UI", system-ui, sans-serif; font-size: 15px; line-height: 1.6; -webkit-font-smoothing: antialiased; }
button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; text-decoration: none; }
button { color: inherit; }
:focus-visible { outline: 3px solid var(--focus-ring); outline-offset: 2px; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3, strong { text-wrap: balance; }
h1, h2, h3 { font-family: "Segoe UI Variable Display", "Segoe UI", system-ui, sans-serif; letter-spacing: -0.035em; line-height: 1.18; }
.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; }
.skip-link { position: fixed; z-index: 200; left: 16px; top: -60px; background: var(--text); color: var(--bg); padding: 10px 15px; border-radius: 8px; transition: top .2s; }
.skip-link:focus { top: 12px; }
.boot-screen, .fatal-error { min-height: 100vh; display: grid; place-content: center; justify-items: center; gap: 12px; padding: 24px; color: var(--muted); text-align: center; }
.boot-screen h1 { margin: 8px 0 0; color: var(--text); font-size: clamp(30px, 5vw, 48px); }
.boot-screen p { max-width: 650px; margin: 0; }
.boot-screen .boot-status { margin-top: 8px; color: var(--faint); font-size: 12px; }
.fatal-error { text-align: center; padding: 24px; }
.fatal-error strong { color: var(--text); font-size: 24px; }

.app-shell { min-height: 100vh; }
.sidebar { position: fixed; inset: 0 auto 0 0; z-index: 40; width: var(--sidebar); padding: 24px 18px; background: var(--surface); border-right: 1px solid var(--border); display: flex; flex-direction: column; }
.brand { display: flex; align-items: center; gap: 12px; padding: 0 8px 25px; border-bottom: 1px solid var(--border); }
.brand-mark { width: 38px; height: 38px; flex: 0 0 auto; display: block; border-radius: 11px; box-shadow: inset 0 0 0 1px rgba(255,255,255,.18); }
.brand > span:last-child { display: grid; line-height: 1.2; }
.brand strong { font: 700 15px "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.brand small { margin-top: 4px; color: var(--muted); font-size: 10px; letter-spacing: .02em; }
.sidebar nav { display: grid; gap: 4px; padding: 22px 0; }
.nav-link { position: relative; display: flex; align-items: center; gap: 12px; min-height: 44px; padding: 0 12px; border-radius: 9px; color: var(--muted); font-weight: 600; transition: .18s ease; }
.nav-link:hover { color: var(--text); background: var(--surface-2); }
.nav-link.is-active { color: var(--accent); background: var(--accent-soft); }
.nav-link.is-active::before { content: ""; position: absolute; left: -18px; height: 22px; width: 3px; border-radius: 0 3px 3px 0; background: var(--accent); }
.nav-link b { margin-left: auto; min-width: 22px; height: 22px; padding: 0 6px; border-radius: 11px; display: grid; place-items: center; background: var(--surface-3); color: var(--text); font-size: 11px; }
.sidebar-foot { margin-top: auto; border-top: 1px solid var(--border); padding: 20px 7px 0; }
.data-note { display: flex; gap: 10px; align-items: flex-start; }
.status-dot { flex: 0 0 auto; margin-top: 6px; width: 7px; height: 7px; border-radius: 50%; background: #42a879; box-shadow: 0 0 0 4px var(--green-soft); }
.data-note > span:last-child { display: grid; }
.data-note strong { font-size: 12px; }
.data-note small { max-width: 155px; margin-top: 3px; color: var(--faint); font-size: 10px; line-height: 1.45; }
.page-column { padding-left: var(--sidebar); min-height: 100vh; }
.topbar { position: sticky; top: 0; z-index: 30; height: var(--topbar); padding: 0 clamp(22px, 4vw, 58px); background: color-mix(in srgb, var(--bg) 89%, transparent); backdrop-filter: blur(18px); border-bottom: 1px solid var(--border); display: flex; align-items: center; gap: 18px; }
.search-trigger { width: min(360px, 38vw); height: 40px; padding: 0 12px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); color: var(--muted); display: flex; align-items: center; gap: 10px; cursor: pointer; text-align: left; box-shadow: 0 1px 2px rgba(0,0,0,.02); }
.search-trigger:hover { border-color: var(--border-strong); }
.search-trigger kbd { margin-left: auto; }
kbd { border: 1px solid var(--border); border-bottom-color: var(--border-strong); background: var(--surface-2); border-radius: 5px; padding: 1px 6px; color: var(--faint); font: 500 11px "Segoe UI Variable", "Segoe UI", sans-serif; }
.topbar-actions { margin-left: auto; display: flex; align-items: center; gap: 18px; }
.text-link { color: var(--muted); font-size: 13px; font-weight: 600; }
.text-link:hover { color: var(--accent); }
.icon-button { width: 40px; height: 40px; padding: 0; border: 1px solid var(--border); border-radius: 9px; display: grid; place-items: center; background: var(--surface); cursor: pointer; transition: .18s ease; }
.icon-button:hover { background: var(--surface-2); border-color: var(--border-strong); }
.mobile-menu { display: none; }
.sidebar-scrim { display: none; }
.main-content { width: 100%; }
.page { width: min(1180px, calc(100% - clamp(38px, 8vw, 104px))); margin: 0 auto; padding: clamp(42px, 6vw, 78px) 0 90px; }
.page-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; margin-bottom: 42px; }
.page-head > div { max-width: 690px; }
.page-head h1 { margin-bottom: 13px; font-size: clamp(34px, 4.2vw, 54px); font-weight: 700; }
.page-head > div > p:last-child { max-width: 600px; margin-bottom: 0; color: var(--muted); font-size: 17px; }
.eyebrow, .overline { margin-bottom: 9px; color: var(--accent); font-size: 11px; font-weight: 700; letter-spacing: .13em; text-transform: uppercase; }
.button { min-height: 42px; padding: 0 17px; border: 1px solid transparent; border-radius: 9px; display: inline-flex; align-items: center; justify-content: center; gap: 9px; font-weight: 700; font-size: 13px; cursor: pointer; transition: .18s ease; }
.button--primary { background: var(--accent-solid); color: white; box-shadow: 0 6px 15px color-mix(in srgb, var(--accent-solid) 20%, transparent); }
.button--primary:hover { background: var(--accent-solid-hover); transform: translateY(-1px); }
.button--secondary { border-color: var(--border); background: var(--surface); }
.button--secondary:hover { border-color: var(--border-strong); background: var(--surface-2); }
.button--full { width: 100%; }
.button--icon-text { background: var(--surface); border-color: var(--border); }
.button--icon-text.is-active { color: var(--accent); background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 30%, var(--border)); }
.badge { display: inline-flex; align-items: center; min-height: 24px; padding: 2px 8px; border: 1px solid var(--border); border-radius: 6px; color: var(--muted); background: var(--surface-2); font-size: 10px; font-weight: 700; letter-spacing: .035em; }
.badge--core, .badge--accent { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 22%, transparent); background: var(--accent-soft); }
.badge--recognize { color: var(--violet); border-color: color-mix(in srgb, var(--violet) 22%, transparent); background: var(--violet-soft); }
.badge--success { color: var(--green); border-color: color-mix(in srgb, var(--green) 22%, transparent); background: var(--green-soft); }
.eyebrow-row { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; min-height: 24px; }
.meta-row { display: flex; flex-wrap: wrap; gap: 18px; color: var(--faint); font-size: 12px; }
.meta-row span { display: inline-flex; align-items: center; gap: 6px; }
.progress-track { width: 100%; height: 6px; overflow: hidden; border-radius: 20px; background: var(--surface-3); }
.progress-track span { display: block; height: 100%; border-radius: inherit; background: var(--accent); transition: width .35s ease; }
.stretched-link { position: absolute; inset: 0; border-radius: inherit; }

/* Dashboard */
.dashboard-grid { display: grid; grid-template-columns: 1.6fr repeat(3, 1fr); gap: 14px; }
.hero-progress, .progress-card, .panel { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.hero-progress { position: relative; grid-column: 1 / -1; min-height: 230px; padding: clamp(28px, 5vw, 48px); display: flex; justify-content: space-between; align-items: center; overflow: hidden; }
.hero-progress::after { content: ""; position: absolute; width: 310px; height: 310px; right: -65px; border: 1px solid color-mix(in srgb, var(--accent) 18%, transparent); border-radius: 50%; }
.hero-progress__copy { position: relative; z-index: 1; max-width: 680px; }
.hero-progress h2 { max-width: 650px; margin: 9px 0 12px; font-size: clamp(25px, 3.2vw, 38px); }
.hero-progress p { max-width: 600px; color: var(--muted); }
.lesson-orbit { position: relative; z-index: 1; flex: 0 0 auto; width: 112px; height: 112px; margin-right: 55px; border: 6px solid var(--accent-soft); border-top-color: var(--accent); border-right-color: var(--accent); border-radius: 50%; display: grid; place-content: center; text-align: center; transform: rotate(12deg); }
.lesson-orbit span, .lesson-orbit small { transform: rotate(-12deg); }
.lesson-orbit span { font: 800 32px/1 "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.lesson-orbit small { margin-top: 7px; color: var(--faint); }
.progress-card { padding: 21px; }
.progress-card__head { display: flex; align-items: center; justify-content: space-between; color: var(--muted); font-size: 13px; font-weight: 700; }
.metric-icon { width: 36px; height: 36px; border-radius: 10px; display: grid; place-items: center; background: var(--green-soft); color: var(--green); font-weight: 800; }
.metric-icon--violet { color: var(--violet); background: var(--violet-soft); }
.metric-icon--amber { color: var(--amber); background: var(--amber-soft); }
.progress-card h3 { margin: 20px 0 5px; font-size: 16px; }
.progress-card p { margin-bottom: 18px; color: var(--muted); font-size: 12px; }
.dashboard-lower { margin-top: 14px; display: grid; grid-template-columns: 1.7fr 1fr; gap: 14px; }
.panel { padding: 25px; }
.panel-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 18px; margin-bottom: 18px; }
.panel-heading .eyebrow { margin-bottom: 6px; }
.panel-heading h2 { margin: 0; font-size: 19px; }
.panel-heading > a { color: var(--accent); display: flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 700; }
.mini-lessons { display: grid; }
.mini-lessons a { padding: 12px 2px; border-top: 1px solid var(--border); display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 13px; }
.mini-lessons a:hover strong { color: var(--accent); }
.lesson-state { width: 34px; height: 34px; border: 1px solid var(--border); border-radius: 9px; display: grid; place-items: center; color: var(--muted); font-size: 11px; font-weight: 700; }
.lesson-state.is-done { color: var(--green); background: var(--green-soft); border-color: transparent; }
.mini-lessons a > span:nth-child(2) { display: grid; }
.mini-lessons strong { font-size: 13px; }
.mini-lessons small { margin-top: 2px; color: var(--faint); font-size: 10px; }
.review-count { min-height: 130px; display: grid; place-content: center; justify-items: center; }
.review-count strong { font: 800 48px/1 "Segoe UI Variable Display", "Segoe UI", sans-serif; color: var(--accent); }
.review-count span { margin-top: 7px; color: var(--muted); font-size: 12px; }
.quiet-success { min-height: 180px; display: grid; place-content: center; justify-items: center; text-align: center; color: var(--green); }
.quiet-success strong { margin-top: 10px; }
.quiet-success p { max-width: 240px; margin: 5px 0 0; color: var(--muted); font-size: 12px; }

/* Learn */
.course-summary { min-height: 82px; margin-bottom: 22px; padding: 18px 22px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 26px; }
.course-summary > div { display: grid; }
.course-summary strong { font: 700 17px "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.course-summary span, .course-summary p { margin: 0; color: var(--muted); font-size: 11px; }
.course-outline { display: grid; gap: 34px; }
.course-section { display: grid; gap: 12px; }
.course-section__heading { display: flex; align-items: baseline; gap: 10px; padding: 0 4px; }
.course-section__heading span { color: var(--faint); font-size: 10px; font-weight: 800; letter-spacing: .08em; }
.course-section__heading h2 { margin: 0; font-size: 15px; letter-spacing: .04em; text-transform: uppercase; }
.lesson-list { display: grid; gap: 7px; }
.lesson-card { position: relative; min-height: 102px; padding: 17px 20px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 18px; transition: .2s ease; }
.lesson-card:hover { border-color: var(--border-strong); box-shadow: var(--shadow); transform: translateY(-1px); }
.lesson-card.is-complete { background: color-mix(in srgb, var(--green-soft) 25%, var(--surface)); }
.lesson-number { width: 46px; height: 46px; border: 1px solid var(--border); border-radius: 12px; display: grid; place-items: center; color: var(--faint); font: 700 13px "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.is-complete .lesson-number { color: var(--green); background: var(--green-soft); border-color: transparent; }
.lesson-card__body h3 { margin: 4px 0; font-size: 17px; }
.lesson-card__body > p { max-width: 760px; margin: 0 0 5px; color: var(--muted); font-size: 12px; }
.technical-topics { display: block; color: var(--faint); font-size: 10px; font-weight: 650; letter-spacing: .025em; }
.lesson-card__progress { max-width: 340px; margin-top: 9px; display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 10px; }
.lesson-card__progress > span { color: var(--muted); font-size: 9px; white-space: nowrap; }
.lesson-card__progress .progress-track { height: 4px; }
.inline-code { padding: .08em .36em; border: 1px solid var(--border); border-radius: 5px; background: var(--surface-2); color: var(--text); font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: .9em; white-space: nowrap; }
.dashboard-complete-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.lesson-open { display: inline-flex; align-items: center; gap: 8px; color: var(--accent); font-size: 12px; font-weight: 700; }
.breadcrumbs { display: flex; align-items: center; gap: 6px; margin-bottom: 30px; color: var(--faint); font-size: 12px; }
.breadcrumbs a:hover { color: var(--accent); }
.lesson-hero { padding-bottom: 42px; display: grid; grid-template-columns: 1.3fr .8fr; align-items: end; gap: 70px; border-bottom: 1px solid var(--border); }
.lesson-hero h1 { margin-bottom: 15px; font-size: clamp(34px, 4.5vw, 56px); }
.lesson-hero > div:first-child > p:last-child { max-width: 680px; margin-bottom: 0; color: var(--muted); font-size: 17px; }
.lesson-goal { padding: 20px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: flex; gap: 13px; }
.lesson-goal > span { color: var(--accent); }
.lesson-goal strong { font-size: 12px; }
.lesson-goal p { margin: 6px 0 0; color: var(--muted); font-size: 12px; line-height: 1.55; }
.lesson-progress { margin: 26px 0 65px; display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 28px; }
.lesson-progress > div { display: grid; min-width: 135px; }
.lesson-progress strong { font: 700 16px "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.lesson-progress span { color: var(--faint); font-size: 10px; }
.lesson-section, .review-section { margin-top: 64px; }
.section-heading { margin-bottom: 24px; }
.section-heading h2 { margin-bottom: 8px; font-size: 25px; }
.section-heading > p:last-child { max-width: 600px; margin-bottom: 0; color: var(--muted); }
.term-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 13px; }
.term-card { position: relative; min-width: 0; padding: 23px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); transition: .18s ease; }
.term-card:hover { border-color: var(--border-strong); box-shadow: 0 10px 26px rgba(30,45,36,.06); transform: translateY(-1px); }
.term-card__link { position: absolute; inset: 0; border-radius: inherit; }
.term-card__head { position: relative; pointer-events: none; display: flex; justify-content: space-between; gap: 12px; }
.term-card h3 { margin: 10px 0 0; font-size: 19px; }
.term-card > p { margin: 17px 0 21px; color: var(--muted); font-size: 13px; line-height: 1.65; }
.card-action { position: relative; z-index: 2; pointer-events: auto; flex: 0 0 auto; width: 34px; height: 34px; }
.card-action.is-active { color: var(--amber); background: var(--amber-soft); border-color: transparent; }
.learned-mark { display: inline-flex; align-items: center; gap: 3px; color: var(--green); font-size: 10px; font-weight: 700; }
.term-card__footer { padding-top: 15px; border-top: 1px solid var(--border); display: flex; justify-content: space-between; gap: 12px; color: var(--faint); font-size: 10px; }
.detail-link { display: inline-flex; align-items: center; gap: 5px; color: var(--accent); font-weight: 700; }
.recognize-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--surface); }
.recognize-list a { min-width: 0; padding: 17px 19px; display: grid; grid-template-columns: minmax(100px, .5fr) 1fr auto; align-items: center; gap: 16px; border-bottom: 1px solid var(--border); }
.recognize-list a:nth-child(odd) { border-right: 1px solid var(--border); }
.recognize-list a:hover { background: var(--surface-2); }
.recognize-list strong { font-size: 13px; }
.recognize-list span { overflow: hidden; color: var(--muted); font-size: 11px; text-overflow: ellipsis; white-space: nowrap; }
.lesson-finish { margin-top: 64px; padding: 25px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: flex; align-items: center; justify-content: space-between; gap: 25px; }
.lesson-finish > div { display: flex; align-items: center; gap: 16px; }
.finish-icon { width: 46px; height: 46px; border-radius: 12px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); }
.lesson-finish h2 { margin-bottom: 4px; font-size: 17px; }
.lesson-finish p { margin: 0; color: var(--muted); font-size: 12px; }
.lesson-pagination, .term-pagination { margin-top: 55px; padding-top: 25px; border-top: 1px solid var(--border); display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.lesson-pagination a, .term-pagination a { display: grid; }
.lesson-pagination a.next, .term-pagination a.next { text-align: right; }
.lesson-pagination small, .term-pagination small { margin-bottom: 4px; color: var(--faint); font-size: 10px; text-transform: uppercase; letter-spacing: .06em; }
.lesson-pagination strong, .term-pagination strong { font-size: 12px; }
.lesson-pagination a:hover strong, .term-pagination a:hover strong { color: var(--accent); }

/* Glossary */
.filter-panel { padding: 14px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: grid; grid-template-columns: 1fr 190px 240px; gap: 10px; }
.inline-search { height: 42px; padding: 0 12px; border: 1px solid var(--border); border-radius: 8px; display: flex; align-items: center; gap: 9px; color: var(--faint); background: var(--bg); }
.inline-search input { width: 100%; border: 0; background: transparent; color: var(--text); }
select { height: 42px; padding: 0 34px 0 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); color: var(--text); }
.alphabet-filter { margin: 19px 0; display: flex; flex-wrap: wrap; gap: 3px; }
.alphabet-filter button { min-width: 31px; height: 31px; padding: 0 8px; border: 0; border-radius: 6px; background: transparent; color: var(--muted); cursor: pointer; font-size: 11px; font-weight: 700; }
.alphabet-filter button:hover, .alphabet-filter button.is-active { color: var(--accent); background: var(--accent-soft); }
.results-bar { padding: 17px 2px; border-top: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; }
.results-bar strong { font-size: 13px; }
.results-bar span { color: var(--faint); font-size: 11px; }
.glossary-list { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.term-card--compact { padding: 19px; }
.term-card--compact h3 { font-size: 16px; }
.term-card--compact > p { min-height: 62px; margin: 13px 0 16px; display: -webkit-box; overflow: hidden; -webkit-box-orient: vertical; -webkit-line-clamp: 3; font-size: 12px; }

/* Term detail */
.term-hero { padding-bottom: 34px; border-bottom: 1px solid var(--border); }
.term-title-row { margin-top: 20px; display: flex; justify-content: space-between; align-items: end; gap: 25px; }
.term-title-row h1 { margin: 0; font-size: clamp(40px, 6vw, 70px); }
.aliases { margin: 8px 0 0; color: var(--faint); font-size: 12px; }
.term-actions { display: flex; gap: 8px; }
.definition-box { margin: 32px 0 60px; padding: clamp(26px, 4vw, 40px); border-left: 3px solid var(--accent); border-radius: 0 var(--radius) var(--radius) 0; background: var(--accent-soft); }
.definition-box > p:last-child { max-width: 900px; margin: 0; font-size: clamp(20px, 2.5vw, 28px); line-height: 1.5; letter-spacing: -.015em; }
.term-content-grid { display: grid; grid-template-columns: minmax(0, 1fr) 260px; gap: clamp(35px, 6vw, 76px); }
.detail-section { margin-bottom: 52px; }
.context-block blockquote { margin: 0; padding: 21px 24px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); font-size: 16px; font-style: italic; }
.memory-hook { padding: 23px; border: 1px solid color-mix(in srgb, var(--amber) 30%, var(--border)); border-radius: var(--radius); display: flex; gap: 16px; background: var(--amber-soft); }
.memory-hook__icon { width: 34px; height: 34px; flex: 0 0 auto; border-radius: 9px; display: grid; place-items: center; background: var(--surface); color: var(--amber); }
.memory-hook .eyebrow { color: var(--amber); }
.memory-hook p:last-child { margin: 0; font-size: 15px; }
.code-block { overflow: hidden; border: 1px solid #313936; border-radius: var(--radius); background: #141916; color: #e8eee9; box-shadow: var(--shadow); }
.code-block__bar { height: 42px; padding: 0 15px; border-bottom: 1px solid #2a312d; display: flex; align-items: center; justify-content: space-between; color: #8f9b93; font-size: 10px; text-transform: uppercase; letter-spacing: .07em; }
.code-block__bar span { display: inline-flex; align-items: center; gap: 7px; }
.copy-code { border: 0; background: transparent; color: #aeb8b1; cursor: pointer; font-size: 10px; text-transform: none; }
.code-block pre { margin: 0; padding: 22px; overflow: auto; }
.code-block code { font: 13px/1.8 "Cascadia Code", Consolas, monospace; }
.tok-keyword { color: #c792ea; }.tok-string { color: #c3e88d; }.tok-number { color: #f78c6c; }.tok-type { color: #82aaff; }
.related-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 8px; }
.related-grid a { min-height: 48px; padding: 0 14px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); display: flex; align-items: center; justify-content: space-between; gap: 10px; font-size: 12px; font-weight: 700; }
.related-grid a:hover { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 35%, var(--border)); }
.term-side { display: grid; align-content: start; gap: 12px; }
.side-card { padding: 18px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.learn-toggle { width: 100%; padding: 12px; border: 1px solid var(--border); border-radius: 9px; background: var(--bg); display: flex; align-items: center; gap: 10px; text-align: left; cursor: pointer; }
.learn-toggle > span:first-child { width: 32px; height: 32px; border-radius: 8px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); }
.learn-toggle > span:last-child { display: grid; }
.learn-toggle strong { font-size: 11px; }
.learn-toggle small { color: var(--faint); font-size: 9px; }
.learn-toggle.is-learned { border-color: color-mix(in srgb, var(--green) 30%, var(--border)); }
.learn-toggle.is-learned > span:first-child { color: var(--green); background: var(--green-soft); }
.side-card dl { margin: 0; }
.side-card dl > div { padding: 9px 0; border-top: 1px solid var(--border); display: flex; justify-content: space-between; gap: 12px; font-size: 11px; }
.side-card dt { color: var(--faint); }.side-card dd { margin: 0; font-weight: 700; }.side-card dd a { color: var(--accent); }

/* Quiz, review, empty */
.quiz-toolbar { margin-bottom: 35px; padding: 16px 20px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: grid; grid-template-columns: auto 1fr 260px; align-items: center; gap: 25px; }
.quiz-toolbar > div { display: grid; min-width: 110px; }.quiz-toolbar strong { font-size: 14px; }.quiz-toolbar span { color: var(--faint); font-size: 10px; }
.quiz-group { margin-top: 50px; }.quiz-group__head { margin-bottom: 15px; }.quiz-group__head span { color: var(--accent); font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: .1em; }.quiz-group__head h2 { margin: 4px 0 0; font-size: 20px; }
.quiz-card { padding: 25px; border: 1px solid var(--border); border-bottom-width: 0; background: var(--surface); display: grid; grid-template-columns: auto 1fr; gap: 20px; }
.quiz-card:first-of-type { border-radius: var(--radius) var(--radius) 0 0; }.quiz-card:last-child { border-bottom-width: 1px; border-radius: 0 0 var(--radius) var(--radius); }.quiz-card:only-of-type { border-radius: var(--radius); }
.quiz-card__count { width: 35px; height: 35px; border: 1px solid var(--border); border-radius: 9px; display: grid; place-items: center; color: var(--faint); font: 700 10px "Segoe UI Variable Display", "Segoe UI", sans-serif; }
.quiz-card h3 { margin: 0 0 18px; font-size: 17px; }.quiz-card .eyebrow { margin-bottom: 7px; }.quiz-card .button { min-height: 36px; }
.quiz-answer { margin-top: 20px; padding: 20px; border-radius: 10px; background: var(--surface-2); }.quiz-answer > p:nth-child(2) { font-size: 14px; }
.self-rating { padding-top: 16px; border-top: 1px solid var(--border); display: flex; align-items: center; gap: 8px; }.self-rating > span { margin-right: auto; color: var(--muted); font-size: 11px; }.self-rating button { min-height: 32px; padding: 0 10px; border: 1px solid var(--border); border-radius: 7px; background: var(--surface); display: inline-flex; align-items: center; gap: 5px; cursor: pointer; font-size: 10px; font-weight: 700; }.self-rating button.is-selected { color: var(--accent); background: var(--accent-soft); border-color: transparent; }
.empty-state { min-height: 360px; padding: 50px 20px; border: 1px dashed var(--border-strong); border-radius: var(--radius-lg); display: grid; place-content: center; justify-items: center; text-align: center; }.empty-icon { width: 52px; height: 52px; margin-bottom: 17px; border-radius: 14px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); }.empty-state h2 { margin-bottom: 7px; font-size: 20px; }.empty-state p { max-width: 420px; margin-bottom: 20px; color: var(--muted); }

/* Search dialog and toast */
.search-dialog { width: min(680px, calc(100vw - 30px)); max-height: min(650px, calc(100vh - 60px)); margin: 8vh auto 0; padding: 0; border: 1px solid var(--border-strong); border-radius: 15px; background: var(--surface); color: var(--text); box-shadow: 0 30px 100px rgba(0,0,0,.25); overflow: hidden; }
.search-dialog::backdrop { background: rgba(12,16,13,.48); backdrop-filter: blur(4px); }
.search-dialog__head { padding: 13px; border-bottom: 1px solid var(--border); }.search-field { height: 46px; padding: 0 12px; border: 1px solid var(--border); border-radius: 9px; display: flex; align-items: center; gap: 10px; color: var(--faint); background: var(--bg); }.search-field input { width: 100%; border: 0; background: transparent; color: var(--text); font-size: 15px; }
.search-results { min-height: 260px; max-height: 450px; padding: 8px; overflow: auto; }.search-intro { min-height: 240px; display: grid; place-content: center; justify-items: center; color: var(--faint); text-align: center; }.search-intro p { max-width: 300px; margin: 10px 0 0; }.search-result-meta { padding: 8px 10px; color: var(--faint); font-size: 10px; text-transform: uppercase; letter-spacing: .08em; }
.search-result { padding: 10px; border-radius: 9px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 12px; }.search-result:hover, .search-result.is-selected { background: var(--accent-soft); }.search-result__icon { width: 34px; height: 34px; border-radius: 8px; display: grid; place-items: center; color: var(--accent); background: var(--surface); font-weight: 700; }.search-result > span:nth-child(2) { min-width: 0; display: grid; }.search-result strong { font-size: 12px; }.search-result small { overflow: hidden; color: var(--muted); font-size: 10px; text-overflow: ellipsis; white-space: nowrap; }.search-result em { color: var(--faint); font-size: 9px; font-style: normal; text-transform: uppercase; }
.search-dialog__foot { height: 40px; padding: 0 14px; border-top: 1px solid var(--border); display: flex; align-items: center; gap: 18px; color: var(--faint); font-size: 10px; }.search-dialog__foot span { display: flex; align-items: center; gap: 4px; }
.toast-region { position: fixed; z-index: 100; right: 22px; bottom: 22px; display: grid; gap: 8px; }.toast { min-width: 220px; padding: 12px 15px; border: 1px solid var(--border-strong); border-radius: 9px; background: var(--text); color: var(--bg); box-shadow: var(--shadow); font-size: 12px; animation: toast-in .2s ease; } @keyframes toast-in { from { opacity: 0; transform: translateY(8px); } }

/* Lesson 01 guided learning */
.guided-landing__hero { padding-bottom: 54px; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(280px, .65fr); align-items: end; gap: clamp(38px, 7vw, 90px); }
.guided-landing__hero h1 { max-width: 760px; margin-bottom: 18px; font-size: clamp(36px, 5vw, 62px); }
.guided-landing__hero > div > p:last-of-type { max-width: 680px; color: var(--muted); font-size: 17px; }
.guided-start-actions { margin-top: 27px; display: flex; align-items: center; gap: 16px; }
.guided-start-actions > span { color: var(--faint); font-size: 11px; }
.button--large { min-height: 48px; padding-inline: 21px; }
.guided-promise { padding: 23px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.guided-promise > p:nth-child(2) { margin-bottom: 18px; color: var(--muted); font-size: 13px; }
.guided-promise ul { margin: 0; padding: 16px 0 0; border-top: 1px solid var(--border); display: grid; gap: 10px; list-style: none; }
.guided-promise li { display: flex; align-items: flex-start; gap: 8px; color: var(--muted); font-size: 11px; }
.guided-promise li svg { flex: 0 0 auto; margin-top: 2px; color: var(--green); }
.guided-outline { margin-top: 62px; }
.guided-outline > ol { margin: 0; padding: 0; border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; background: var(--surface); list-style: none; }
.guided-outline li { min-height: 75px; padding: 13px 18px; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 15px; }
.guided-outline li:last-child { border-bottom: 0; }
.guided-outline li.is-next { background: var(--accent-soft); }
.guided-outline li.is-done { background: color-mix(in srgb, var(--green-soft) 32%, var(--surface)); }
.outline-index { width: 38px; height: 38px; border: 1px solid var(--border); border-radius: 10px; display: grid; place-items: center; color: var(--faint); font-size: 11px; font-weight: 700; }
.is-done .outline-index { border-color: transparent; color: var(--green); background: var(--green-soft); }
.guided-outline li > div { display: grid; }
.guided-outline small { color: var(--faint); font-size: 9px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; }
.guided-outline strong { margin-top: 2px; font-size: 14px; }
.guided-outline li > a { display: inline-flex; align-items: center; gap: 6px; color: var(--accent); font-size: 11px; font-weight: 700; }
.recognize-preview { margin-top: 18px; padding: 27px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); display: grid; grid-template-columns: .8fr 1.2fr; align-items: center; gap: 35px; }
.recognize-preview h2 { margin-bottom: 7px; font-size: 20px; }
.recognize-preview p:last-child { margin: 0; color: var(--muted); font-size: 12px; }
.recognize-chips { display: flex; flex-wrap: wrap; gap: 7px; }
.recognize-chips span { padding: 6px 9px; border: 1px solid var(--border); border-radius: 7px; color: var(--muted); background: var(--bg); font-size: 10px; font-weight: 600; }

.guided-topic-page { width: min(1040px, calc(100% - clamp(38px, 8vw, 104px))); }
.guided-topnav { margin-bottom: 38px; padding-bottom: 16px; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: 1fr minmax(220px, 320px) 1fr; align-items: center; gap: 20px; color: var(--faint); font-size: 10px; font-weight: 600; }
.guided-topnav > a:hover { color: var(--accent); }
.guided-topnav > div { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 11px; }
.guided-topnav > span:last-child { text-align: right; }
.guided-topic-hero { min-height: 190px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 25px; }
.topic-number { width: 64px; height: 64px; border-radius: 17px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); font-size: 17px; font-weight: 800; }
.guided-topic-hero h1 { margin-bottom: 10px; font-size: clamp(36px, 5vw, 60px); }
.guided-topic-hero > div:nth-child(2) > p:last-child { max-width: 690px; margin: 0; color: var(--muted); font-size: 15px; }
.topic-complete-mark { align-self: start; margin-top: 45px; padding: 6px 9px; border-radius: 7px; display: inline-flex; align-items: center; gap: 5px; color: var(--green); background: var(--green-soft); font-size: 10px; font-weight: 700; }
.prerequisite-box { margin: 0 0 30px 89px; padding: 16px 18px; border: 1px solid color-mix(in srgb, var(--accent) 24%, var(--border)); border-radius: 11px; display: flex; align-items: flex-start; gap: 12px; background: var(--accent-soft); }
.prerequisite-box > span { color: var(--accent); }
.prerequisite-box > div { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; }
.prerequisite-box strong { width: 100%; margin-bottom: 3px; font-size: 11px; }
.prerequisite-box a { padding: 4px 7px; border: 1px solid color-mix(in srgb, var(--accent) 22%, transparent); border-radius: 6px; display: inline-flex; align-items: center; gap: 4px; color: var(--accent); background: var(--surface); font-size: 10px; font-weight: 700; }
.guided-content { border-top: 1px solid var(--border); }
.guided-section { padding: clamp(38px, 6vw, 68px) 0; border-bottom: 1px solid var(--border); display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: clamp(25px, 5vw, 65px); }
.guided-section__label { display: flex; align-items: flex-start; gap: 10px; color: var(--faint); }
.guided-section__label > span { width: 30px; height: 30px; flex: 0 0 auto; border: 1px solid var(--border); border-radius: 8px; display: grid; place-items: center; font-size: 9px; font-weight: 700; }
.guided-section__label > p { margin: 6px 0 0; font-size: 10px; font-weight: 700; letter-spacing: .065em; text-transform: uppercase; }
.guided-section__body { min-width: 0; max-width: 710px; }
.guided-section__body > p { font-size: 16px; line-height: 1.75; }
.guided-fast p { margin-bottom: 16px; font-size: clamp(18px, 2vw, 22px); line-height: 1.65; letter-spacing: -.012em; }
.inline-term { margin: 0 1px; padding: 0; border: 0; border-bottom: 1px dashed var(--accent); background: transparent; color: var(--accent); cursor: help; font: inherit; }
.inline-term > span { width: 14px; height: 14px; margin-left: 3px; border-radius: 50%; display: inline-grid; place-items: center; color: var(--accent); background: var(--accent-soft); font-size: 8px; font-weight: 800; vertical-align: 2px; }
.quick-reference-box { padding: 20px; border: 1px dashed var(--border-strong); border-radius: 11px; background: var(--surface); }
.quick-reference-box > p { margin-bottom: 14px; color: var(--muted); font-size: 12px; }
.quick-reference-box > div { display: flex; flex-wrap: wrap; gap: 7px; }
.inline-term--chip { padding: 6px 9px; border: 1px solid color-mix(in srgb, var(--accent) 24%, var(--border)); border-radius: 7px; background: var(--accent-soft); font-size: 11px; font-weight: 700; }
.mental-model { padding: 25px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.mental-model > p:first-child { color: var(--muted); }
.model-flow { margin: 20px 0; display: grid; justify-items: start; gap: 8px; }
.model-flow > div { width: min(100%, 500px); min-height: 48px; padding: 8px 13px; border: 1px solid var(--border); border-radius: 9px; display: flex; align-items: center; gap: 12px; background: var(--bg); }
.model-flow > div > span { width: 25px; height: 25px; flex: 0 0 auto; border-radius: 7px; display: grid; place-items: center; color: var(--accent); background: var(--accent-soft); font-size: 9px; font-weight: 700; }
.model-flow strong { font-size: 12px; }
.flow-arrow { margin-left: 18px; color: var(--accent); }
.model-conclusion { margin: 0; padding-top: 17px; border-top: 1px solid var(--border); font-weight: 600; }
.godot-context-list { margin: 0; padding: 0; display: grid; gap: 8px; list-style: none; }
.godot-context-list li { padding: 13px 15px; border: 1px solid var(--border); border-radius: 9px; display: flex; align-items: flex-start; gap: 9px; background: var(--surface); font-size: 13px; }
.godot-context-list svg { flex: 0 0 auto; margin-top: 3px; color: var(--accent); }
.guided-example > p { color: var(--muted); }
.example-flow { padding: 22px; border: 1px solid var(--border); border-radius: var(--radius); display: flex; align-items: center; flex-wrap: wrap; gap: 10px; background: var(--surface); }
.example-flow span { padding: 9px 11px; border-radius: 8px; background: var(--surface-2); font-size: 11px; font-weight: 700; }
.example-flow b { color: var(--accent); }
.code-lines { margin: 15px 0 0; padding: 18px 18px 18px 40px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); }
.code-lines li { padding: 4px 0 4px 7px; color: var(--muted); font-size: 12px; }
.recognize-callouts { display: grid; grid-template-columns: 1fr; gap: 12px; }
.recognize-callouts article { padding: 20px; border: 1px solid color-mix(in srgb, var(--violet) 22%, var(--border)); border-radius: 11px; background: var(--violet-soft); }
.recognize-callouts article > span { color: var(--violet); font-size: 9px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.recognize-callouts h3 { margin: 6px 0; font-size: 14px; }
.recognize-callouts p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.55; }
.recognize-callouts dl { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; margin: 16px 0 0; }
.recognize-callouts dl > div { padding: 12px; border: 1px solid color-mix(in srgb, var(--violet) 15%, var(--border)); border-radius: 8px; background: color-mix(in srgb, var(--surface) 72%, transparent); }
.recognize-callouts dt { margin-bottom: 5px; color: var(--violet); font-size: 9px; font-weight: 800; letter-spacing: .06em; text-transform: uppercase; }
.recognize-callouts dd { margin: 0; color: var(--text); font-size: 12px; line-height: 1.55; }
.recognize-model { display: flex; align-items: center; gap: 7px; margin-top: 12px; padding: 12px; border-radius: 8px; background: color-mix(in srgb, var(--surface) 80%, transparent); }
.recognize-model span { flex: 1; font-size: 11px; line-height: 1.45; text-align: center; }
.recognize-model b { color: var(--violet); }
.recognize-callouts .recognize-example, .recognize-callouts .recognize-distinction { margin-top: 10px; padding-top: 10px; border-top: 1px solid color-mix(in srgb, var(--violet) 16%, var(--border)); }
.recognize-callouts .recognize-distinction strong { color: var(--text); }
.guided-bridge { margin: 8px 0 18px; padding: 22px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.guided-bridge h2 { margin: 5px 0 13px; font-size: 19px; }
.guided-bridge p:last-child { margin: 13px 0 0; color: var(--muted); font-size: 13px; line-height: 1.65; }
.bridge-flow { display: flex; align-items: center; gap: 8px; }
.bridge-flow span { flex: 1; padding: 9px 11px; border-radius: 8px; background: var(--surface-2); font-size: 11px; font-weight: 700; text-align: center; }
.bridge-flow b { color: var(--accent); }
.lesson-relation-summary { margin: 50px 0 24px; padding: 30px; border: 1px solid var(--border-strong); border-radius: var(--radius); background: var(--surface); }
.summary-groups { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.summary-groups article { padding: 18px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface-2); }
.summary-groups h3 { margin: 0 0 13px; font-size: 14px; }
.summary-groups article > div { display: flex; flex-direction: column; align-items: stretch; gap: 5px; }
.summary-groups article > div span { padding: 7px 9px; border-radius: 7px; background: var(--surface); font-size: 11px; font-weight: 700; text-align: center; }
.summary-groups article > div b { color: var(--accent); text-align: center; }
.summary-groups article p, .summary-closing { color: var(--muted); font-size: 12px; line-height: 1.6; }
.summary-closing { margin: 18px 0 0; padding-top: 18px; border-top: 1px solid var(--border); }
.common-mistake { padding: 20px; border: 1px solid color-mix(in srgb, var(--amber) 30%, var(--border)); border-radius: 11px; display: flex; align-items: flex-start; gap: 13px; background: var(--amber-soft); }
.common-mistake > span { width: 30px; height: 30px; flex: 0 0 auto; border-radius: 8px; display: grid; place-items: center; color: var(--amber); background: var(--surface); font-weight: 800; }
.common-mistake p { margin: 2px 0 0; font-size: 14px; }
.mini-check { padding: clamp(24px, 4vw, 38px); border: 1px solid var(--border-strong); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow); }
.mini-check h2 { max-width: 610px; margin-bottom: 23px; font-size: clamp(20px, 3vw, 28px); }
.mini-check__answer { margin-top: 22px; padding: 19px; border-radius: 10px; background: var(--green-soft); }
.mini-check__answer p:last-child { margin: 0; color: var(--text); }
.guided-navigation { position: sticky; z-index: 10; bottom: 15px; margin-top: 28px; padding: 13px; border: 1px solid var(--border-strong); border-radius: 13px; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; background: color-mix(in srgb, var(--surface) 92%, transparent); backdrop-filter: blur(16px); box-shadow: 0 16px 45px rgba(20,30,23,.14); }
.guided-navigation .button { min-height: 54px; padding-inline: 16px; display: flex; flex-direction: column; align-items: flex-start; gap: 1px; }
.guided-navigation .button:last-child { align-items: flex-end; text-align: right; }
.guided-navigation .button > span { font-size: 9px; font-weight: 500; opacity: .92; }
.guided-finish-button { grid-column: 2; flex-direction: row !important; align-items: center !important; justify-content: center; }
.quick-term-dialog { width: min(440px, calc(100vw - 30px)); padding: 29px; border: 1px solid var(--border-strong); border-radius: 15px; background: var(--surface); color: var(--text); box-shadow: 0 25px 80px rgba(0,0,0,.24); }
.quick-term-dialog::backdrop { background: rgba(12,16,13,.42); backdrop-filter: blur(3px); }
.quick-term-dialog > .icon-button { position: absolute; top: 13px; right: 13px; width: 34px; height: 34px; }
.quick-term-dialog h2 { margin: 9px 38px 12px 0; font-size: 25px; }
.quick-term-dialog > p:last-child { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.quick-term-example { margin-top: 16px; padding: 13px 15px; border: 1px solid var(--border); border-radius: 9px; background: var(--surface-2); }
.quick-term-example strong { display: block; margin-bottom: 5px; color: var(--faint); font-size: 9px; letter-spacing: .07em; text-transform: uppercase; }
.quick-term-example p { margin: 0; font-family: ui-monospace, "Cascadia Code", Consolas, monospace; font-size: 12px; line-height: 1.6; }
.quick-term-dialog .quick-term-context { margin-top: 14px; padding: 12px 14px; border-left: 3px solid var(--accent); border-radius: 0 8px 8px 0; background: var(--surface-2); color: var(--text); font-size: 12px; }

@media (max-width: 1100px) {
  .dashboard-grid { grid-template-columns: repeat(3, 1fr); }.hero-progress { grid-column: 1 / -1; }.glossary-list { grid-template-columns: repeat(2, 1fr); }.lesson-hero { gap: 35px; }.recognize-list { grid-template-columns: 1fr; }.recognize-list a:nth-child(odd) { border-right: 0; }
}

@media (max-width: 820px) {
  :root { --topbar: 64px; }
  .sidebar { transform: translateX(-101%); transition: transform .24s ease; box-shadow: 20px 0 45px rgba(0,0,0,.12); }.menu-open .sidebar { transform: translateX(0); }.sidebar-scrim { position: fixed; z-index: 35; inset: 0; width: 100%; height: 100%; border: 0; background: rgba(10,14,11,.46); }.menu-open .sidebar-scrim { display: block; }
  .page-column { padding-left: 0; }.mobile-menu { display: grid; }.topbar { padding: 0 18px; }.search-trigger { flex: 1; width: auto; }.topbar-learn { display: none; }.page { width: min(100% - 36px, 720px); padding-top: 42px; }
  .page-head { align-items: flex-start; }.page-head h1 { font-size: 38px; }.dashboard-grid { grid-template-columns: 1fr; }.hero-progress { min-height: 260px; }.lesson-orbit { margin-right: 10px; }.progress-card { grid-column: auto; }.dashboard-lower { grid-template-columns: 1fr; }
  .lesson-hero { grid-template-columns: 1fr; }.term-content-grid { grid-template-columns: 1fr; }.term-side { grid-template-columns: repeat(2, 1fr); grid-row: 1; }.glossary-list { grid-template-columns: repeat(2, 1fr); }.filter-panel { grid-template-columns: 1fr 1fr; }.filter-panel .inline-search { grid-column: 1 / -1; }.quiz-toolbar { grid-template-columns: auto 1fr; }.quiz-toolbar select { grid-column: 1 / -1; }.term-grid { grid-template-columns: 1fr; }
  .guided-landing__hero { grid-template-columns: 1fr; align-items: start; }.recognize-preview { grid-template-columns: 1fr; }.guided-section { grid-template-columns: 145px minmax(0, 1fr); gap: 25px; }.prerequisite-box { margin-left: 0; }
}

@media (max-width: 560px) {
  .topbar { gap: 10px; }.search-trigger span { display: none; }.search-trigger { flex: 0 1 125px; }.search-trigger kbd { display: none; }.topbar-actions { margin-left: auto; }.page { width: min(100% - 28px, 520px); padding: 32px 0 65px; }.page-head { margin-bottom: 30px; flex-direction: column; }.page-head h1 { font-size: 32px; }.page-head > div > p:last-child { font-size: 15px; }
  .hero-progress { min-height: 350px; padding: 25px; align-items: flex-start; }.lesson-orbit { position: absolute; right: 22px; bottom: 22px; width: 82px; height: 82px; margin: 0; }.hero-progress::after { width: 210px; height: 210px; right: -70px; bottom: -65px; }.dashboard-grid { grid-template-columns: 1fr; }.dashboard-lower { grid-template-columns: 1fr; }
  .course-summary { grid-template-columns: 1fr auto; }.course-summary .progress-track { grid-column: 1 / -1; grid-row: 2; }.lesson-card { grid-template-columns: auto 1fr; padding: 20px 17px; gap: 13px; }.lesson-open { display: none; }.lesson-number { width: 39px; height: 39px; }.lesson-card__body h3 { font-size: 16px; }.lesson-card__body > p { font-size: 12px; }.lesson-card .meta-row { gap: 9px; }
  .lesson-hero h1 { font-size: 34px; }.lesson-progress { grid-template-columns: 1fr; gap: 12px; margin-bottom: 50px; }.recognize-list a { grid-template-columns: 1fr auto; gap: 4px 10px; }.recognize-list a span { grid-column: 1; white-space: normal; }.recognize-list a svg { grid-column: 2; grid-row: 1 / 3; }.lesson-finish { align-items: stretch; flex-direction: column; }.lesson-pagination, .term-pagination { gap: 10px; }.lesson-pagination strong, .term-pagination strong { display: none; }
  .filter-panel { grid-template-columns: 1fr; }.filter-panel .inline-search { grid-column: auto; }.glossary-list { grid-template-columns: 1fr; }.alphabet-filter { max-height: 105px; overflow: auto; }.term-title-row { align-items: flex-start; flex-direction: column; }.term-title-row h1 { font-size: 42px; }.term-actions { width: 100%; }.term-actions .button { flex: 1; }.definition-box { margin-bottom: 42px; }.definition-box > p:last-child { font-size: 19px; }.term-side { grid-template-columns: 1fr; }.related-grid { grid-template-columns: 1fr; }
  .quiz-toolbar { grid-template-columns: 1fr; gap: 13px; }.quiz-toolbar select { grid-column: auto; }.quiz-card { padding: 19px 15px; gap: 12px; }.quiz-card__count { width: 30px; height: 30px; }.self-rating { align-items: stretch; flex-direction: column; }.self-rating > span { margin: 0 0 4px; }.self-rating button { justify-content: center; }.search-dialog { margin-top: 10px; max-height: calc(100vh - 20px); }.search-dialog__foot { display: none; }
  .guided-landing__hero { padding-bottom: 38px; }.guided-landing__hero h1 { font-size: 35px; }.guided-start-actions { align-items: stretch; flex-direction: column; }.guided-start-actions > span { text-align: center; }.guided-promise { padding: 19px; }.guided-outline { margin-top: 45px; }.guided-outline li { padding: 12px; }.guided-outline li > a { font-size: 0; }.guided-outline li > a svg { width: 19px; height: 19px; }.recognize-preview { padding: 20px; }
  .guided-topic-page { width: min(100% - 28px, 520px); }.guided-topnav { grid-template-columns: auto 1fr; }.guided-topnav > span:last-child { display: none; }.guided-topnav > div { grid-template-columns: 1fr; gap: 5px; text-align: right; }.guided-topic-hero { min-height: auto; padding-bottom: 32px; grid-template-columns: auto 1fr; align-items: start; gap: 14px; }.topic-number { width: 44px; height: 44px; border-radius: 12px; font-size: 12px; }.guided-topic-hero h1 { font-size: 33px; }.topic-complete-mark { grid-column: 2; margin: -18px 0 0; justify-self: start; }.guided-section { padding: 42px 0; grid-template-columns: 1fr; gap: 18px; }.guided-section__label { align-items: center; }.guided-section__label > p { margin-top: 0; }.guided-fast p { font-size: 18px; }.mental-model { padding: 19px; }.recognize-callouts dl, .summary-groups { grid-template-columns: 1fr; }.recognize-model, .bridge-flow { align-items: stretch; flex-direction: column; }.recognize-model b, .bridge-flow b { transform: rotate(90deg); align-self: center; }.guided-bridge, .lesson-relation-summary { padding: 20px; }.example-flow { align-items: flex-start; flex-direction: column; }.example-flow b { transform: rotate(90deg); align-self: center; }.guided-navigation { bottom: 8px; padding: 8px; }.guided-navigation .button { min-height: 50px; padding: 8px 10px; font-size: 10px; }.guided-navigation .button > span { display: none; }.quick-term-dialog { padding: 24px; }
}

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; } }