:root {
  color-scheme: light;
  --paper: #f4efe4;
  --paper-2: #ebe3d3;
  --card: #fbf8f1;
  --ink: #17211f;
  --muted: #5f6863;
  --line: #c9c0ad;
  --accent: #b14a32;
  --focus: #126c8d;
  --shadow: 0 12px 32px rgba(40, 35, 25, .09);
  --serif: Georgia, 'Times New Roman', serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max: 1320px;
}

[data-theme="dark"] {
  color-scheme: dark;
  --paper: #15201e;
  --paper-2: #1d2926;
  --card: #202d29;
  --ink: #f3ecde;
  --muted: #bac2bc;
  --line: #46534e;
  --shadow: 0 14px 36px rgba(0,0,0,.24);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 16px; line-height: 1.65; }
body::before { content: ''; position: fixed; inset: 0; pointer-events: none; opacity: .26; background-image: linear-gradient(to right, transparent calc(100% - 1px), var(--line) 1px), linear-gradient(to bottom, transparent calc(100% - 1px), var(--line) 1px); background-size: 48px 48px; mask-image: linear-gradient(to bottom, #000, transparent 45rem); z-index: -1; }
a { color: inherit; text-underline-offset: .18em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button, .button { border: 1px solid var(--ink); background: var(--ink); color: var(--paper); border-radius: 999px; padding: .65rem 1rem; font-weight: 700; }
.button-secondary { background: transparent; color: var(--ink); }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.skip-link { position: fixed; left: 1rem; top: 1rem; transform: translateY(-180%); z-index: 99; background: var(--ink); color: var(--paper); padding: .65rem 1rem; }
.skip-link:focus { transform: none; }
.site-header { max-width: var(--max); margin: auto; min-height: 76px; padding: 0 1.4rem; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: .65rem; text-decoration: none; font-family: var(--serif); font-weight: 700; font-size: 1.05rem; }
.brand-mark { width: 34px; height: 34px; display: grid; place-items: center; background: var(--ink); color: var(--paper); border-radius: 50% 50% 50% 12%; font-style: italic; }
.site-header nav { display: flex; gap: 1.2rem; align-items: center; }
.site-header nav a { text-decoration: none; font-size: .9rem; font-weight: 650; }
.theme-toggle { width: 38px; height: 38px; padding: 0; background: transparent; color: var(--ink); }
.nav-toggle { display: none; }
main { max-width: var(--max); margin: auto; padding: 0 clamp(1rem, 2vw, 1.75rem); }
h1, h2, h3 { font-family: var(--serif); line-height: 1.08; margin: 0 0 .8rem; text-wrap: balance; }
h1 { font-size: clamp(2.65rem, 5.2vw, 5.25rem); letter-spacing: -.045em; }
h2 { font-size: clamp(1.8rem, 3vw, 2.8rem); letter-spacing: -.03em; }
h3 { font-size: clamp(1.2rem, 1.6vw, 1.5rem); }
h4 { margin: 0; font-size: 1rem; line-height: 1.35; }
p { margin: 0 0 1rem; }
.eyebrow, .section-kicker { margin: 0 0 1.1rem; font-size: .72rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; color: var(--muted); }
.dek, .lead { font-family: var(--serif); font-size: clamp(1.25rem, 2.4vw, 1.8rem); line-height: 1.42; }
.fine-print { color: var(--muted); font-size: .8rem; }
.site-footer { max-width: var(--max); margin: 6rem auto 0; padding: 2rem 1.4rem 3rem; border-top: 1px solid var(--line); display: grid; grid-template-columns: 1fr auto; gap: 1rem 2rem; }
.site-footer nav { display: flex; gap: 1.2rem; }

/* Home — a folding decision atlas, not a dashboard */
.atlas-hero { min-height: 600px; padding: 6rem 0 4rem; display: grid; grid-template-columns: 7fr 5fr; align-items: end; gap: 3rem; }
.atlas-hero h1 span { display: block; }
.atlas-hero h1 .script { margin-left: 1.2em; color: var(--accent); font-style: italic; }
.hero-copy { max-width: 52rem; }
.hero-copy .dek { max-width: 44rem; }
.atlas-compass { aspect-ratio: 1; position: relative; border: 1px solid var(--line); border-radius: 50%; display: grid; place-items: center; background: color-mix(in srgb, var(--card) 76%, transparent); }
.atlas-compass::before, .atlas-compass::after { content: ''; position: absolute; inset: 12%; border: 1px solid var(--line); border-radius: 50%; }
.atlas-compass::after { inset: 30%; }
.compass-axis { position: absolute; width: 100%; border-top: 1px solid var(--line); transform: rotate(var(--angle)); }
.compass-center { width: 30%; aspect-ratio: 1; border-radius: 50% 50% 50% 14%; background: var(--ink); color: var(--paper); display: grid; place-items: center; text-align: center; font-family: var(--serif); font-size: 1.2rem; z-index: 2; transform: rotate(-8deg); }
.compass-label { position: absolute; max-width: 8rem; padding: .35rem .55rem; background: var(--paper); border: 1px solid var(--line); font-size: .7rem; font-weight: 800; text-align: center; }
.compass-label.label-1 { top: 7%; left: 38%; }
.compass-label.label-2 { top: 31%; right: -6%; }
.compass-label.label-3 { bottom: 8%; right: 15%; }
.compass-label.label-4 { bottom: 10%; left: 10%; }
.compass-label.label-5 { top: 28%; left: -7%; }
.stats-strip { border-block: 1px solid var(--line); padding: 1.1rem 0; display: flex; gap: 2rem; flex-wrap: wrap; font-size: .8rem; color: var(--muted); }
.stats-strip strong { color: var(--ink); font-size: 1.2rem; margin-right: .35rem; }
.discovery { padding: 6rem 0; }
.discovery-head { display: grid; grid-template-columns: 7fr 5fr; gap: 3rem; align-items: end; margin-bottom: 2rem; }
.search-shell { position: relative; }
.search-shell input { width: 100%; min-height: 58px; padding: .9rem 3rem .9rem 1rem; border: 1px solid var(--ink); background: var(--card); color: var(--ink); border-radius: 0; }
.search-shell kbd { position: absolute; right: 1rem; top: 1rem; border: 1px solid var(--line); padding: .25rem .45rem; background: var(--paper-2); color: var(--muted); }
.filters { padding: 1rem 0 1.5rem; display: grid; grid-template-columns: repeat(4, 1fr); gap: .7rem; border-bottom: 1px solid var(--line); }
.filters label { font-size: .72rem; font-weight: 800; text-transform: uppercase; letter-spacing: .08em; }
.filters select { display: block; width: 100%; margin-top: .35rem; padding: .65rem; border: 1px solid var(--line); background: var(--card); color: var(--ink); }
.problem-routes { display: flex; gap: .55rem; overflow-x: auto; padding: 1rem 0; }
.problem-routes button { white-space: nowrap; background: transparent; color: var(--ink); border-color: var(--line); padding: .45rem .8rem; font-size: .8rem; }
.problem-routes button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.directory-meta { min-height: 2rem; display: flex; justify-content: space-between; gap: 1rem; color: var(--muted); font-size: .86rem; }
.framework-grid { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.framework-card { min-height: 320px; position: relative; display: flex; flex-direction: column; padding: 1.35rem; background: var(--card); border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.framework-card::before { content: ''; width: 3.4rem; border-top: 4px solid var(--category); margin-bottom: 2.4rem; }
.framework-card h3 { font-size: 1.8rem; }
.framework-card .purpose { color: var(--muted); }
.card-meta { display: flex; flex-wrap: wrap; gap: .4rem; margin-top: auto; }
.card-meta span { border: 1px solid var(--line); padding: .2rem .45rem; font-size: .68rem; }
.card-actions { display: flex; align-items: center; justify-content: space-between; margin-top: 1.1rem; }
.card-actions a { font-weight: 800; text-decoration-thickness: 2px; }
.card-actions button { border: 0; padding: .3rem; background: transparent; color: var(--ink); border-radius: 0; }
.empty-state { grid-column: 1/-1; padding: 5rem 2rem; text-align: center; background: var(--card); }
.saved-strip { margin: 0 0 3rem; padding: 1.3rem; border: 1px solid var(--line); background: var(--paper-2); }
.saved-strip[hidden] { display: none; }
.saved-list { display: flex; gap: .7rem; flex-wrap: wrap; }
.saved-list a { background: var(--card); border: 1px solid var(--line); padding: .45rem .7rem; }
.alpha-nav { display: flex; flex-wrap: wrap; gap: .35rem; margin: 2rem 0; }
.alpha-nav button { min-width: 2rem; border-radius: 0; padding: .3rem; background: transparent; color: var(--ink); border-color: var(--line); }
.alpha-nav button[aria-pressed="true"] { background: var(--ink); color: var(--paper); border-color: var(--ink); }

/* Framework lesson */
.breadcrumbs { padding: 1.2rem 0; display: flex; gap: .6rem; color: var(--muted); font-size: .82rem; }
.lesson-hero { min-height: 510px; display: grid; grid-template-columns: 7fr 5fr; align-items: center; gap: 3rem; padding: 3.5rem 0; border-bottom: 1px solid var(--line); }
.lesson-title h1 { font-size: clamp(2.8rem, 5.4vw, 5.4rem); }
.lesson-title .dek { max-width: 47rem; }
.meta-row { display: flex; flex-wrap: wrap; gap: .55rem; margin: 1.5rem 0; }
.meta-row span, .case-label { padding: .25rem .55rem; border: 1px solid var(--line); color: var(--muted); font-size: .72rem; font-weight: 750; }
.hero-actions { display: flex; gap: .6rem; flex-wrap: wrap; }
.hero-actions .bookmark-button { order: 3; background: transparent; color: var(--ink); }
.hero-actions [data-progress] { order: 4; }
.hero-actions a[href="#quick-start"] { order: 1; background: var(--category); border-color: var(--category); color: #fff; }
.hero-actions a[href="#practice"] { order: 2; }
.bookmark-button[aria-pressed="true"], [data-progress][aria-pressed="true"] { background: var(--category); border-color: var(--category); color: white; }
.lesson-visual { min-height: 400px; margin: 0; padding: 2rem; display: flex; flex-direction: column; justify-content: center; background: var(--card); border: 1px solid var(--line); box-shadow: var(--shadow); }
.lesson-visual figcaption { margin-top: 2rem; color: var(--muted); font-size: .78rem; }
.diamonds { display: flex; justify-content: center; }
.diamonds > div { width: 48%; aspect-ratio: 1; transform: rotate(45deg); border: 2px solid var(--category); display: flex; align-items: center; justify-content: space-around; }
.diamonds > div + div { margin-left: -9%; }
.diamonds span { transform: rotate(-45deg); font-weight: 800; font-size: .72rem; }
.tree-visual { gap: 1.3rem; align-items: center; }
.tree-node, .tree-row span { border: 1px solid var(--line); padding: .5rem; background: var(--paper); text-align: center; font-size: .75rem; }
.root-node { border-color: var(--category); font-weight: 800; }
.tree-row { width: 100%; display: flex; gap: .7rem; justify-content: center; }
.tree-row span { flex: 1; position: relative; }
.tree-row .active { background: color-mix(in srgb, var(--category) 18%, var(--paper)); border-color: var(--category); }
.solutions { width: 80%; }
.tests { width: 65%; }
.formula-visual { align-items: center; font-family: var(--serif); font-size: 1.5rem; text-align: center; }
.formula-visual hr { width: 80%; border: 0; border-top: 2px solid var(--category); }
.forces-visual { display: grid; grid-template-columns: 1fr auto 1fr; gap: .6rem; align-items: center; }
.force { border: 1px solid var(--line); padding: 1rem; display: flex; flex-direction: column; }
.force.forward { border-color: var(--category); }
.force.back { grid-row: 2; }
.force.back:last-of-type { grid-column: 3; }
.switch { grid-row: 1/3; grid-column: 2; writing-mode: vertical-rl; color: var(--category); font-weight: 800; }
.canvas-visual { display: grid; grid-template-columns: 1fr auto 1fr; gap: 1rem; align-items: center; }
.canvas-visual > div { display: grid; gap: .5rem; }
.canvas-visual span, .canvas-visual b { padding: .6rem; border: 1px solid var(--line); }
.canvas-visual b { border-color: var(--category); }
.canvas-visual i { color: var(--category); font-family: var(--serif); font-size: 1.4rem; }
.okr-visual { gap: 1rem; }
.okr-objective { padding: 1rem; border: 2px solid var(--category); background: var(--paper); }
.okr-objective span, .okr-objective strong { display: block; }
.okr-objective span { color: var(--category); font-size: .68rem; font-weight: 850; text-transform: uppercase; letter-spacing: .1em; }
.okr-objective strong { margin-top: .35rem; font-family: var(--serif); font-size: 1.35rem; }
.okr-arrow { align-self: center; color: var(--category); font-size: 1.5rem; }
.kr-list { display: grid; gap: .55rem; }
.kr-list > div { display: grid; grid-template-columns: 2.7rem 1fr 7rem; gap: .55rem; align-items: center; font-size: .68rem; }
.kr-list i { height: .55rem; background: var(--paper-2); position: relative; overflow: hidden; }
.kr-list i::after { content: ''; position: absolute; inset: 0 auto 0 0; width: var(--progress); background: var(--category); }
.kr-list b { font-weight: 750; }
.sprint-visual { position: relative; align-items: center; }
.sprint-center { width: 42%; aspect-ratio: 1; display: grid; place-content: center; text-align: center; border-radius: 50%; background: var(--category); color: #fff; z-index: 2; }
.sprint-center span, .sprint-center b { display: block; }
.sprint-center span { font-size: .66rem; text-transform: uppercase; letter-spacing: .08em; }
.sprint-center b { margin-top: .3rem; font-family: var(--serif); }
.sprint-visual ol { position: absolute; inset: 3rem 1rem 5rem; margin: 0; padding: 0; list-style: none; border: 1px dashed var(--line); border-radius: 50%; }
.sprint-visual li { position: absolute; left: 50%; top: 50%; width: 4.5rem; padding: .4rem; transform: rotate(var(--a)) translateX(8.3rem) rotate(calc(-1 * var(--a))); translate: -50% -50%; text-align: center; border: 1px solid var(--line); background: var(--paper); font-size: .7rem; font-weight: 800; }
.heuristic-visual { align-items: center; }
.mock-window { width: 90%; border: 1px solid var(--ink); background: var(--paper); box-shadow: 8px 8px 0 var(--paper-2); }
.mock-bar { padding: .45rem; display: flex; gap: .3rem; border-bottom: 1px solid var(--line); }
.mock-bar i { width: .5rem; height: .5rem; border-radius: 50%; background: var(--line); }
.mock-body { min-height: 220px; padding: 2rem 1rem 1rem; display: grid; gap: .8rem; position: relative; }
.mock-body > span { height: .65rem; background: var(--paper-2); }
.mock-body > span:nth-child(2) { width: 70%; }.mock-body > span:nth-child(3) { width: 45%; }
.mock-body > button { width: 7rem; border-radius: 0; padding: .4rem; justify-self: end; pointer-events: none; }
.scan-mark { position: absolute; width: 1.8rem; height: 1.8rem; display: grid; place-items: center; border-radius: 50%; background: var(--category); color: #fff; font-size: .7rem; }
.scan-mark span { position: absolute; left: 2.1rem; width: 5.5rem; padding: .2rem; background: var(--ink); color: var(--paper); font-size: .6rem; }
.mark-one { top: 1rem; left: 12%; }.mark-two { top: 48%; left: 42%; }.mark-three { bottom: .8rem; right: 8rem; }
.funnel-visual ol { list-style: none; padding: 0; margin: 0; display: grid; place-items: center; }
.funnel-visual li { width: var(--w); min-width: 46%; padding: .5rem 1rem; color: white; background: color-mix(in srgb, var(--category) var(--c), var(--ink)); display: flex; justify-content: space-between; }
.funnel-visual li:nth-child(1) { --w:100%; --c:85%; }.funnel-visual li:nth-child(2) { --w:88%; --c:72%; }.funnel-visual li:nth-child(3) { --w:75%; --c:59%; }.funnel-visual li:nth-child(4) { --w:62%; --c:46%; }.funnel-visual li:nth-child(5) { --w:50%; --c:33%; }
.lesson-primer { display: grid; grid-template-columns: minmax(0,1fr) minmax(580px,1fr); gap: 3rem; align-items: center; padding: 6rem 0; border-bottom: 1px solid var(--line); scroll-margin-top: 1rem; }
.primer-title { max-width: 1050px; margin: 0; }
.primer-title h2 { max-width: 20ch; font-size: clamp(1.9rem,2.6vw,2.8rem); line-height: 1.1; }
.primer-title > p:last-child { max-width: 65ch; margin-top: 1.4rem; font-family: var(--serif); font-size: 1.25rem; }
.framework-machine { display: grid; grid-template-columns: 1fr 1.45fr 1fr; align-items: stretch; margin: 0; border: 1px solid var(--line); background: var(--card); box-shadow: var(--shadow); }
.before-after, .story-lab, .primer-footer { grid-column: 1 / -1; }
.machine-end, .machine-core { min-height: 260px; padding: 1.5rem; display: flex; flex-direction: column; justify-content: center; position: relative; }
.machine-end > span, .machine-core > span { margin-bottom: .75rem; font-size: .68rem; font-weight: 850; letter-spacing: .11em; text-transform: uppercase; }
.machine-end > strong { font-family: var(--serif); font-size: clamp(1.4rem,2.4vw,2.1rem); line-height: 1.15; }
.machine-end:first-child::after { content: '→'; position: absolute; right: -1.1rem; top: 50%; width: 2.2rem; height: 2.2rem; display: grid; place-items: center; border-radius: 50%; background: var(--ink); color: var(--paper); z-index: 2; }
.machine-core { background: var(--category); color: #fff; }
.machine-core::after { content: '→'; position: absolute; right: -1.1rem; top: 50%; width: 2.2rem; height: 2.2rem; display: grid; place-items: center; border-radius: 50%; background: #fff; color: var(--category); z-index: 2; }
.machine-core ol { display: grid; gap: .5rem; margin: 0; padding: 0; list-style: none; }
.machine-core li { display: grid; grid-template-columns: 1.7rem 1fr; gap: .55rem; align-items: center; font-weight: 750; }
.machine-core li span { width: 1.55rem; height: 1.55rem; display: grid; place-items: center; border: 1px solid rgba(255,255,255,.55); border-radius: 50%; font-size: .68rem; }
.before-after { display: grid; grid-template-columns: 1fr 1fr; margin: 4rem 0; border: 1px solid var(--line); }
.before-after article { min-height: 210px; padding: 1.6rem; background: var(--paper-2); }
.before-after article + article { background: var(--card); border-left: 1px solid var(--line); box-shadow: inset 7px 0 0 var(--category); }
.before-after span { display: inline-block; margin-bottom: 1rem; font-size: .7rem; font-weight: 850; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.before-after article + article span { color: var(--category); }
.before-after p { max-width: 44ch; font-family: var(--serif); font-size: 1.3rem; line-height: 1.45; }
.story-lab { margin-top: 5rem; }
.story-lab > h3 { max-width: 28ch; font-size: clamp(1.8rem,2.6vw,2.7rem); }
.story-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 1rem; margin-top: 2rem; counter-reset: story; }
.story-grid article { min-height: 330px; padding: 1.4rem; display: flex; flex-direction: column; align-items: start; background: var(--card); border: 1px solid var(--line); position: relative; overflow: hidden; }
.story-grid article::before { content: ''; position: absolute; right: -2rem; top: -2rem; width: 7rem; height: 7rem; border-radius: 50%; background: color-mix(in srgb, var(--category) 13%, transparent); }
.story-number { width: 2.4rem; height: 2.4rem; display: grid; place-items: center; margin-bottom: 2rem; border-radius: 50% 50% 50% 12%; background: var(--ink); color: var(--paper); font-family: var(--serif); font-size: 1.2rem; transform: rotate(-6deg); }
.story-grid article > p { font-family: var(--serif); font-size: 1.25rem; line-height: 1.4; }
.story-grid article > button { margin-top: auto; border-radius: 0; background: transparent; color: var(--ink); border-color: var(--category); }
.story-answer { position: absolute; inset: 0; padding: 1.5rem; display: flex; flex-direction: column; justify-content: center; background: var(--category); color: #fff; z-index: 2; }
.story-answer[hidden] { display: none; }
.story-answer span { font-size: .68rem; font-weight: 850; letter-spacing: .11em; text-transform: uppercase; opacity: .8; }
.story-answer p { margin-top: .8rem; font-family: var(--serif); font-size: 1.3rem; line-height: 1.45; }
.story-grid button[aria-expanded="true"] { position: relative; z-index: 3; color: #fff; border-color: rgba(255,255,255,.7); }
.primer-footer { margin-top: 1rem; padding: 1.4rem; display: flex; justify-content: space-between; gap: 2rem; align-items: center; background: var(--ink); color: var(--paper); }
.primer-footer p { margin: .25rem 0 0; max-width: 60ch; }
.primer-footer a { flex: none; padding: .65rem .9rem; border: 1px solid currentColor; font-weight: 800; text-decoration: none; }
.lesson-grid { display: grid; grid-template-columns: 3fr 9fr; gap: 4rem; align-items: start; }
.lesson-toc { position: sticky; top: 1rem; padding: 3rem 0; }
.lesson-toc nav { display: grid; margin-top: 1rem; }
.lesson-toc a { padding: .45rem 0; color: var(--muted); text-decoration: none; border-bottom: 1px solid var(--line); }
.lesson-toc a[aria-current="page"] { padding-left: .7rem; color: var(--ink); border-left: 4px solid var(--category); background: color-mix(in srgb, var(--category) 8%, transparent); font-weight: 850; }
.lesson-body { max-width: 850px; }
.lesson-body section { padding: 6rem 0; border-bottom: 1px solid var(--line); scroll-margin-top: 2rem; }
.lesson-focus .lesson-body > section { min-height: 58vh; }
.lesson-focus .lesson-body > section[hidden] { display: none; }
.lesson-chapter-controls { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 1rem; padding: 1.4rem 0 5rem; border-top: 1px solid var(--line); }
.lesson-chapter-controls button { justify-self: start; background: transparent; color: var(--ink); border-color: var(--line); }
.lesson-chapter-controls button:last-child { justify-self: end; background: var(--category); color: #fff; border-color: var(--category); }
.lesson-chapter-controls button:disabled { opacity: .28; cursor: not-allowed; }
.lesson-chapter-controls span { color: var(--muted); font-size: .72rem; font-weight: 850; letter-spacing: .08em; text-transform: uppercase; white-space: nowrap; }
.lesson-body p, .lesson-body li { max-width: 70ch; }
.lesson-body h3 { margin-top: 2.4rem; }
.concept-list { display: grid; grid-template-columns: 1fr 1fr; gap: .7rem; padding: 0; list-style: none; }
.concept-list li { padding: .8rem; border-left: 3px solid var(--category); background: var(--card); }
.concept-intro { max-width: 62ch; margin-bottom: 1.5rem; color: var(--muted); }
.concept-explainer { max-width: 780px; border-top: 1px solid var(--line); }
.concept-item { display: grid; grid-template-columns: 1.5rem 1fr; gap: .65rem; padding: 1rem 0; border-bottom: 1px solid var(--line); }
.concept-marker { color: var(--category); font-family: var(--serif); font-size: 1.65rem; font-weight: 800; line-height: 1.1; }
.concept-item h4 { display: inline; color: var(--ink); }
.concept-item p { display: inline; margin: 0 0 0 .25rem; color: var(--muted); line-height: 1.55; }
.steps { list-style: none; padding: 0; counter-reset: step; }
.steps li { display: grid; grid-template-columns: 3rem 1fr; gap: 1rem; padding: 1.2rem 0; border-top: 1px solid var(--line); }
.steps li > span { color: var(--category); font-family: var(--serif); font-size: 1.5rem; }
.worked-example { margin: 1.5rem 0 2rem; padding: 2rem; background: var(--card); border: 1px solid var(--line); border-left: 6px solid var(--category); }
.case-label { display: inline-block; color: var(--ink); }
.deep-dive-intro { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 2rem; }
.deep-progress { min-width: 8rem; padding-left: 1rem; border-left: 4px solid var(--category); }
.deep-progress strong, .deep-progress span { display: block; }
.deep-progress strong { font-family: var(--serif); font-size: 1.4rem; }
.deep-progress span { color: var(--muted); font-size: .72rem; text-transform: uppercase; letter-spacing: .08em; }
.deep-tabs { display: grid; grid-template-columns: repeat(4,1fr); margin-top: 2.2rem; border: 1px solid var(--line); border-bottom: 0; }
.deep-tabs button { border: 0; border-right: 1px solid var(--line); border-radius: 0; background: var(--paper-2); color: var(--muted); padding: .85rem .55rem; font-size: .78rem; }
.deep-tabs button:last-child { border-right: 0; }
.deep-tabs button[aria-selected="true"] { background: var(--category); color: #fff; }
.deep-panel { padding: 2rem; background: var(--card); border: 1px solid var(--line); min-height: 420px; }
.deep-panel[hidden] { display: none; }
.deep-panel > button { margin-top: 1.5rem; }
.deep-concepts { display: grid; grid-template-columns: repeat(2,1fr); gap: .75rem; margin-top: 1.5rem; }
.deep-concepts article { min-height: 150px; padding: 1rem; border: 1px solid var(--line); background: var(--paper); }
.deep-concepts article > span { color: var(--category); font-family: var(--serif); font-size: 1.4rem; }
.deep-concepts h4 { margin: .4rem 0; font-family: var(--serif); font-size: 1.15rem; }
.trace-case { margin: 1.2rem 0; padding: 1.2rem; border-left: 4px solid var(--category); background: var(--paper-2); }
.reasoning-trace { list-style: none; padding: 0; }
.reasoning-trace li { display: grid; grid-template-columns: 2.7rem 1fr; gap: .8rem; padding: .8rem 0; border-top: 1px solid var(--line); }
.reasoning-trace li > span { color: var(--category); font-family: var(--serif); font-size: 1.25rem; }
.reasoning-trace p { margin: .15rem 0; }
.reasoning-trace small { color: var(--muted); }
.stress-choices { display: grid; gap: .6rem; margin: 1.4rem 0; }
.stress-choices button { border: 1px solid var(--line); border-radius: 0; background: var(--paper); color: var(--ink); text-align: left; font-weight: 650; }
.stress-choices button[aria-pressed="true"] { border-color: var(--category); box-shadow: inset 5px 0 0 var(--category); }
.stress-result { padding: 1rem; background: color-mix(in srgb, var(--category) 12%, var(--paper)); border: 1px solid var(--category); }
.stress-result span, .stress-result strong { display: block; }
.stress-result span { color: var(--muted); font-size: .72rem; text-transform: uppercase; letter-spacing: .08em; }
.deep-handoff { margin-top: 1.5rem; padding: 1.2rem; display: flex; justify-content: space-between; gap: 1rem; align-items: center; background: var(--ink); color: var(--paper); }
.deep-handoff p { margin: 0; }
.deep-handoff a { flex: none; font-weight: 800; }
.problem-workbench { margin: 2rem 0 3rem; padding: 2rem; background: var(--card); border: 2px solid var(--ink); box-shadow: 10px 10px 0 color-mix(in srgb, var(--category) 38%, transparent); }
.workbench-header { display: flex; justify-content: space-between; gap: 1rem; align-items: start; padding-bottom: 1rem; border-bottom: 1px solid var(--line); }
.workbench-header h3 { font-size: clamp(1.7rem,3vw,2.5rem); }
.local-badge { flex: none; padding: .3rem .55rem; border: 1px solid var(--category); color: var(--category); font-size: .68rem; font-weight: 800; text-transform: uppercase; letter-spacing: .08em; }
.problem-workbench label { font-size: .76rem; font-weight: 800; }
.problem-workbench input, .problem-workbench select, .problem-workbench textarea { width: 100%; display: block; margin-top: .4rem; padding: .75rem; border: 1px solid var(--line); border-radius: 0; background: var(--paper); color: var(--ink); }
.problem-workbench textarea { resize: vertical; }
.problem-field { display: block; margin: 1.5rem 0; }
.problem-field textarea { font-family: var(--serif); font-size: 1.05rem; line-height: 1.5; }
.problem-field small { display: block; margin-top: .35rem; color: var(--muted); font-weight: 400; }
.workbench-context { display: grid; grid-template-columns: 1fr 1fr; gap: .8rem; }
.workbench-context .wide, .workbench-numbers { grid-column: 1/-1; }
.workbench-numbers { display: grid; grid-template-columns: repeat(4,1fr); gap: .7rem; padding: .9rem; border: 1px solid var(--line); background: var(--paper-2); }
.workbench-numbers.three { grid-template-columns: repeat(3,1fr); }
.workbench-numbers.five { grid-template-columns: repeat(5,1fr); }
.workbench-actions { display: flex; gap: .6rem; margin-top: 1rem; }
.workbench-error { margin-top: .8rem; padding: .65rem; border-left: 4px solid #ad483a; background: color-mix(in srgb, #ad483a 12%, var(--paper)); }
.workbench-result { scroll-margin-top: 1rem; margin-top: 2rem; padding-top: 1.5rem; border-top: 6px solid var(--category); }
.workbench-result[hidden] { display: none; }
.result-heading { display: flex; justify-content: space-between; gap: 1rem; align-items: center; }
.result-heading .eyebrow { margin: 0; }
.result-score { float: right; width: 10rem; margin: 0 0 1rem 1rem; padding: 1rem; text-align: right; background: var(--ink); color: var(--paper); }
.result-score span, .result-score strong { display: block; }
.result-score span { font-size: .65rem; text-transform: uppercase; letter-spacing: .08em; }
.result-score strong { font-family: var(--serif); font-size: 2.2rem; }
.result-sections { clear: both; display: grid; grid-template-columns: repeat(2,1fr); gap: .75rem; margin-top: 1.3rem; }
.result-sections article { padding: 1rem; border: 1px solid var(--line); background: var(--paper); }
.result-sections h4 { margin: 0 0 .6rem; font-family: var(--serif); font-size: 1.15rem; }
.result-sections ul { margin: 0; padding-left: 1.1rem; }
.result-sections li { margin-bottom: .35rem; }
.result-caveat { clear: both; margin-top: 1rem; padding: .8rem; color: var(--muted); border: 1px dashed var(--line); font-size: .82rem; }
.mechanics-title { margin-top: 4rem !important; }
.tool-card { margin: 1.5rem 0; padding: 1.5rem; background: var(--card); border: 1px solid var(--line); }
.tool-card textarea { width: 100%; margin: .6rem 0; padding: .8rem; border: 1px solid var(--line); background: var(--paper); color: var(--ink); }
.tool-actions { display: flex; gap: .6rem; }
.field-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: .7rem; }
.field-row label { font-size: .75rem; font-weight: 800; }
.field-row input, .field-row select { width: 100%; display: block; margin-top: .35rem; padding: .6rem; border: 1px solid var(--line); background: var(--paper); color: var(--ink); }
.calculator output { display: block; margin-top: 1.3rem; font-family: var(--serif); font-size: 1.5rem; }
.template { margin-top: 1rem; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 1rem 0; }
.template summary { cursor: pointer; font-weight: 800; }
.template pre { white-space: pre-wrap; padding: 1rem; background: var(--card); border: 1px solid var(--line); }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; }
.confused, .takeaways { margin: 2rem 0; padding: 1.4rem; background: var(--paper-2); border: 1px solid var(--line); }
.checklist { padding: 0; list-style: none; }
.checklist label { display: flex; gap: .6rem; align-items: start; padding: .55rem 0; }
.quiz fieldset { margin: 1.2rem 0; padding: 1rem; border: 1px solid var(--line); }
.quiz legend { font-family: var(--serif); font-size: 1.15rem; font-weight: 700; }
.quiz fieldset > label { display: block; padding: .35rem; }
.quiz-explanation { padding: .65rem; margin-top: .6rem; background: var(--paper-2); }
.quiz .correct { border-color: #2e7a4b; }.quiz .incorrect { border-color: #ad483a; }
.quiz output { display: block; padding: 1rem 0; font-weight: 800; }
.sources-list li { margin-bottom: 1.4rem; }
.sources-list span { display: block; color: var(--muted); font-size: .78rem; }
.lesson-nav { display: grid; grid-template-columns: 1fr 1fr; margin-top: 3rem; border: 1px solid var(--line); }
.lesson-nav a { padding: 1.5rem; background: var(--card); text-decoration: none; font-family: var(--serif); font-size: 1.2rem; }
.lesson-nav a + a { text-align: right; border-left: 1px solid var(--line); }
.lesson-nav span { display: block; font-family: var(--sans); color: var(--muted); font-size: .7rem; text-transform: uppercase; letter-spacing: .1em; }

/* Supporting pages */
.page-hero { padding: 7rem 0 4rem; border-bottom: 1px solid var(--line); }
.page-hero h1 { font-size: clamp(2.8rem, 5.5vw, 5.4rem); }
.page-hero .dek { max-width: 55rem; }
.page-section { padding: 4rem 0; }
.comparison-picker { display: grid; grid-template-columns: repeat(4,1fr); gap: .7rem; margin: 2rem 0; }
.comparison-picker select { width: 100%; padding: .8rem; background: var(--card); color: var(--ink); border: 1px solid var(--line); }
.table-scroll { overflow-x: auto; }
.compare-table { width: 100%; border-collapse: collapse; background: var(--card); }
.compare-table th, .compare-table td { min-width: 12rem; padding: .8rem; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.compare-table th:first-child { min-width: 10rem; }
.path-grid, .case-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 1rem; }
.path-card, .case-card { padding: 1.4rem; background: var(--card); border: 1px solid var(--line); }
.path-card ol { padding-left: 1.2rem; }
.glossary-list { columns: 2; column-gap: 3rem; }
.glossary-list > div { break-inside: avoid; padding: 1.2rem 0; border-top: 1px solid var(--line); }
.glossary-list dt { font-family: var(--serif); font-weight: 800; font-size: 1.25rem; }
.glossary-list dd { margin: .4rem 0; color: var(--muted); }
.source-directory article { padding: 1rem 0; border-top: 1px solid var(--line); }
.toast { position: fixed; right: 1rem; bottom: 1rem; max-width: 22rem; padding: .8rem 1rem; background: var(--ink); color: var(--paper); box-shadow: var(--shadow); transform: translateY(160%); transition: transform .2s ease; z-index: 20; }
.toast.show { transform: none; }

/* Motion explains structure, then gets out of the way. */
@keyframes atlas-rise { from { opacity: 0; transform: translateY(18px); } to { opacity: 1; transform: none; } }
@keyframes chapter-in { from { opacity: 0; transform: translateX(12px); } to { opacity: 1; transform: none; } }
@keyframes diamond-breathe { 0% { opacity: .35; transform: rotate(45deg) scale(.78); } 65% { opacity: 1; transform: rotate(45deg) scale(1.04); } 100% { opacity: 1; transform: rotate(45deg) scale(1); } }
@keyframes diagram-pop { from { opacity: 0; transform: scale(.78); } to { opacity: 1; transform: scale(1); } }
@keyframes diagram-fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes bar-grow { from { transform: scaleX(0); } to { transform: scaleX(1); } }
.motion-ready { opacity: 0; transform: translateY(18px); }
.motion-ready.in-view { animation: atlas-rise .55s cubic-bezier(.2,.75,.25,1) forwards; animation-delay: calc(var(--i, 0) * 55ms); }
.lesson-focus .lesson-body > section:not([hidden]) { animation: chapter-in .32s ease-out; }
.lesson-visual.in-view .diamonds > div { animation: diamond-breathe .75s cubic-bezier(.2,.8,.25,1) both; }
.lesson-visual.in-view .diamonds > div + div { animation-delay: .25s; }
.tree-visual.motion-ready .tree-node, .tree-visual.motion-ready .tree-row { opacity: 0; }
.tree-visual.in-view .tree-node, .tree-visual.in-view .tree-row { animation: atlas-rise .42s ease-out forwards; }
.tree-visual.in-view .tree-row:nth-of-type(2) { animation-delay: .12s; }.tree-visual.in-view .tree-row:nth-of-type(3) { animation-delay: .24s; }.tree-visual.in-view .tree-row:nth-of-type(4) { animation-delay: .36s; }
.funnel-visual.motion-ready li { opacity: 0; transform: translateY(-10px); }
.funnel-visual.in-view li { animation: atlas-rise .4s ease-out forwards; animation-delay: calc((var(--i, 0) + 1) * 90ms); }
.funnel-visual.in-view li:nth-child(1) { --i:0; }.funnel-visual.in-view li:nth-child(2) { --i:1; }.funnel-visual.in-view li:nth-child(3) { --i:2; }.funnel-visual.in-view li:nth-child(4) { --i:3; }.funnel-visual.in-view li:nth-child(5) { --i:4; }
.okr-visual.motion-ready .kr-list i::after { transform: scaleX(0); transform-origin: left; }
.okr-visual.in-view .kr-list i::after { animation: bar-grow .8s .25s ease-out forwards; transform-origin: left; }
.sprint-visual.motion-ready li, .heuristic-visual.motion-ready .scan-mark { opacity: 0; }
.sprint-visual.in-view li { animation: diagram-fade .38s ease-out forwards; }
.heuristic-visual.in-view .scan-mark { animation: diagram-pop .38s ease-out forwards; }
.sprint-visual.in-view li:nth-child(2), .heuristic-visual.in-view .mark-two { animation-delay: .12s; }.sprint-visual.in-view li:nth-child(3), .heuristic-visual.in-view .mark-three { animation-delay: .24s; }.sprint-visual.in-view li:nth-child(4) { animation-delay: .36s; }
.framework-card, .path-card, .case-card { transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.framework-card:hover, .path-card:hover, .case-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: var(--category, var(--ink)); }

@media (max-width: 1100px) {
  .atlas-hero { min-height: 520px; gap: 2rem; }
  .framework-grid { grid-template-columns: repeat(2,1fr); }
  .lesson-hero { min-height: 0; grid-template-columns: 1.08fr .92fr; gap: 2rem; }
  .lesson-visual { min-height: 350px; padding: 1.5rem; }
  .lesson-primer { display: block; padding: 5rem 0; }
  .primer-title { max-width: 760px; margin-bottom: 2rem; }
  .framework-machine { margin: 2rem 0; }
  .lesson-grid { grid-template-columns: 220px minmax(0,1fr); gap: 2rem; }
  .path-grid, .case-grid { grid-template-columns: repeat(2,1fr); }
}

@media (max-width: 900px) {
  .atlas-hero, .lesson-hero, .discovery-head { grid-template-columns: 1fr; }
  .atlas-hero { padding-top: 4rem; }.atlas-compass { max-width: 520px; margin: auto; width: 100%; }
  .framework-grid { grid-template-columns: repeat(2,1fr); }
  .filters, .comparison-picker { grid-template-columns: repeat(2,1fr); }
  .lesson-grid { grid-template-columns: 1fr; }
  .lesson-focus .lesson-toc { display: block; position: sticky; top: 0; z-index: 8; margin: 0 calc(50% - 50vw); padding: .55rem max(1rem, calc(50vw - 50%)); overflow-x: auto; background: color-mix(in srgb, var(--paper) 94%, transparent); border-block: 1px solid var(--line); backdrop-filter: blur(12px); }
  .lesson-focus .lesson-toc > strong { display: none; }
  .lesson-focus .lesson-toc nav { display: flex; min-width: max-content; gap: .35rem; margin: 0; }
  .lesson-focus .lesson-toc a { padding: .5rem .7rem; border: 1px solid var(--line); background: var(--paper); }
  .lesson-focus .lesson-toc a[aria-current="page"] { padding-left: .7rem; border: 1px solid var(--category); }
  .lesson-visual { max-width: 640px; width: 100%; margin: auto; }
  .lesson-primer { display: block; }
  .primer-title { margin-bottom: 2rem; }
  .framework-machine { margin: 2rem 0; }
  .path-grid, .case-grid { grid-template-columns: repeat(2,1fr); }
  .story-grid { grid-template-columns: 1fr; }.story-grid article { min-height: 260px; }
}

@media (max-width: 820px) {
  .site-header { min-height: 64px; }
  .nav-toggle { display: block; }
  .site-header nav { display: none; position: absolute; z-index: 10; left: 1rem; right: 1rem; top: 64px; padding: 1rem; background: var(--card); border: 1px solid var(--line); box-shadow: var(--shadow); flex-direction: column; align-items: stretch; }
  .site-header nav.open { display: flex; }
  .site-header nav a { min-height: 44px; display: flex; align-items: center; }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }
  h1, .lesson-title h1, .page-hero h1 { font-size: clamp(2.35rem, 12vw, 3.1rem); letter-spacing: -.035em; }
  h2 { font-size: clamp(1.65rem, 8vw, 2.15rem); }
  h3 { font-size: 1.25rem; }
  .dek, .lead { font-size: 1.15rem; }
  .atlas-hero { min-height: 0; padding: 3.5rem 0 3rem; }.atlas-hero h1 .script { margin-left: .3em; }.atlas-compass { font-size: .85rem; }.compass-label { font-size: .58rem; }
  .framework-grid, .filters, .comparison-picker, .path-grid, .case-grid, .field-row, .concept-list, .split, .deep-concepts, .workbench-context, .workbench-numbers, .workbench-numbers.three, .workbench-numbers.five, .result-sections, .framework-machine, .before-after { grid-template-columns: 1fr; }
  .framework-card { min-height: 270px; }.framework-card::before { margin-bottom: 1.5rem; }
  .lesson-hero { padding: 2.5rem 0 3rem; gap: 2rem; }.lesson-visual { min-height: 285px; padding: 1rem; }
  .hero-actions > * { flex: 1 1 100%; justify-content: center; text-align: center; }
  .primer-title h2 { font-size: 2rem; }
  .sprint-visual li { transform: rotate(var(--a)) translateX(6.2rem) rotate(calc(-1 * var(--a))); }
  .kr-list > div { grid-template-columns: 2.4rem 1fr 5.5rem; }
  .canvas-visual { grid-template-columns: 1fr; }.canvas-visual i { transform: rotate(90deg); text-align: center; }
  .lesson-chapter-controls { grid-template-columns: 1fr 1fr; }
  .lesson-chapter-controls span { grid-column: 1 / -1; grid-row: 1; text-align: center; }
  .lesson-body section { min-height: 0; padding: 3rem 0; }.lesson-primer { padding: 3.5rem 0; }.machine-end, .machine-core { min-height: 160px; padding: 1.2rem; }.machine-end:first-child::after, .machine-core::after { content: '↓'; right: 50%; top: auto; bottom: -1.1rem; transform: translateX(50%); }.before-after { margin: 2.5rem 0; }.before-after article { min-height: 0; }.before-after article + article { border-left: 0; border-top: 1px solid var(--line); box-shadow: inset 0 7px 0 var(--category); }.story-lab { margin-top: 3rem; }.story-grid article { min-height: 230px; }.primer-footer { align-items: start; flex-direction: column; }.worked-example { padding: 1.2rem; }.deep-tabs { grid-template-columns: 1fr 1fr; }.deep-tabs button:nth-child(2) { border-right: 0; }.deep-tabs button:nth-child(-n+2) { border-bottom: 1px solid var(--line); }.deep-panel, .problem-workbench { padding: 1.1rem; }.deep-dive-intro { grid-template-columns: 1fr; }.deep-progress { margin: 0; }.workbench-header { display: grid; }.result-score { float: none; width: 100%; margin: 0 0 1rem; text-align: left; }.deep-handoff { align-items: start; flex-direction: column; }
  .concept-item { grid-template-columns: 1.2rem 1fr; padding: .9rem 0; }.concept-marker { font-size: 1.4rem; }.concept-item h4, .concept-item p { display: block; }.concept-item p { margin: .25rem 0 0; }
  .page-hero { padding: 4rem 0 2.5rem; }.page-section { padding: 3rem 0; }
  .glossary-list { columns: 1; }.lesson-nav { grid-template-columns: 1fr; }.lesson-nav a + a { border-left: 0; border-top: 1px solid var(--line); text-align: left; }
  .site-footer { grid-template-columns: 1fr; }.site-footer nav { flex-wrap: wrap; }
}

@media (max-width: 420px) {
  .brand { font-size: .92rem; }.brand-mark { width: 30px; height: 30px; }
  .meta-row { gap: .35rem; }.meta-row span { font-size: .66rem; }
  .lesson-visual figcaption { margin-top: 1.2rem; }
  .sprint-visual li { width: 3.8rem; transform: rotate(var(--a)) translateX(5.1rem) rotate(calc(-1 * var(--a))); }
  .mock-window { width: 100%; }.mark-three { right: 6.2rem; }
}

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

@media print {
  body { background: white; color: black; font-size: 11pt; }.site-header, .site-footer, .lesson-toc, .hero-actions, .tool-card, .problem-workbench, .quiz button, .toast, .lesson-chapter-controls { display: none !important; }main { max-width: none; padding: 0; }.lesson-hero { min-height: 0; grid-template-columns: 1fr 1fr; padding: 1cm 0; }.lesson-visual { min-height: 7cm; box-shadow: none; }.lesson-grid { display: block; }.lesson-body { max-width: none; }.lesson-body section, .lesson-body section[hidden] { display: block !important; padding: .7cm 0; break-inside: avoid; }.lesson-nav { display: none; }a { text-decoration: none; }
}