@layer reset, tokens, base, structure, components, responsive, preferences;

@layer reset {
  *, *::before, *::after { box-sizing: border-box; }
  html { -webkit-text-size-adjust: 100%; }
  body, h1, h2, h3, p, figure, dl, dd { margin: 0; }
  img { display: block; max-width: 100%; height: auto; }
  button { font: inherit; }
  [hidden] { display: none !important; }
}

@layer tokens {
  :root {
    color-scheme: light dark;
    --canvas: #ffffff;
    --ink: #16181b;
    --muted: #6c6f77;
    --bubble-muted: #555962;
    --quiet: #f3f4f6;
    --incoming: #e9eaec;
    --divider: #e1e2e5;
    --blue: #00b0f0;
    --deep-blue: #0093c8;
    --pressed-blue: #0086b8;
    --cyan: #4fcbf7;
    --blue-ink: #002a36;
    --green: #82bc23;
    --error: #f0473e;
    --surface: #ffffff;
    --focus: #002a36;
    --link: #002a36;
    --float-shadow: 0 4px 24px rgb(22 24 27 / 9%);
    --humanist: "Aptos", "Segoe UI", "Gill Sans", "Trebuchet MS", sans-serif;
  }
}

@layer base {
  html { scroll-padding-block: 24px 120px; }
  body { background: var(--canvas); color: var(--ink); font-family: var(--humanist); font-size: 18px; line-height: 1.6; }
  a { color: var(--link); text-decoration-thickness: 2px; text-underline-offset: 4px; }
  a, button { -webkit-tap-highlight-color: transparent; }
  a:hover { text-decoration-thickness: 3px; }
  a:focus-visible, button:focus-visible { outline: 3px solid var(--focus); outline-offset: 4px; }
  h1, h2, h3 { line-height: 1.12; letter-spacing: -.025em; text-wrap: balance; }
  h1 { font-size: clamp(42px, 4.5vw, 64px); font-weight: 800; max-width: 15ch; }
  h2 { font-size: 32px; font-weight: 800; max-width: 28ch; }
  h3 { font-size: 24px; font-weight: 700; }
  p { max-width: 68ch; }
  p + p { margin-block-start: 16px; }
  ul, ol { padding-inline-start: 24px; }
  li + li { margin-block-start: 12px; }
  strong { font-weight: 700; }
  button { cursor: pointer; }
  section, article, li[id] { scroll-margin-block-start: 24px; }
}

@layer structure {
  [data-role="masthead"], main, [data-role="footer"] { width: min(1136px, calc(100% - 48px)); margin-inline: auto; }
  [data-role="masthead"] { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding-block: 24px; border-block-end: 1px solid var(--divider); }
  [data-role="page-cover"] { display: grid; gap: 40px; align-items: center; padding-block: 64px 56px; }
  [data-role="page-cover"][data-illustrated] { grid-template-columns: minmax(0, 1.12fr) minmax(0, 1fr); }
  [data-role="cover-copy"] { min-width: 0; }
  [data-role="intro"] { margin-block-start: 24px; max-width: 62ch; }
  [data-role="intro"] p { font-size: 20px; line-height: 1.5; }
  [data-role="intro"] p + p { font-size: 18px; color: var(--muted); }
  [data-role="cover-art"] { align-self: stretch; display: flex; align-items: center; justify-content: center; }
  [data-role="cover-art"] img { width: 100%; border-radius: 24px; }
  [data-role="reading-layout"] { display: grid; grid-template-columns: 208px minmax(0, 1fr); gap: 64px; align-items: start; border-block-start: 1px solid var(--divider); padding-block-start: 40px; }
  [data-role="reading-column"] { width: 100%; max-width: 784px; min-width: 0; }
  [data-role="page-outline"] { position: sticky; top: 24px; display: flex; flex-direction: column; align-items: stretch; }
  [data-role="page-outline"] a { display: flex; align-items: center; min-height: 48px; font-size: 16px; line-height: 1.3; padding-block: 8px; text-decoration: none; color: var(--muted); }
  [data-role="page-outline"] a:hover { color: var(--ink); text-decoration: underline; text-decoration-color: var(--deep-blue); }
  [data-role="page-outline"] [data-role="label"] { margin-block-end: 8px; }
  [data-role="idea"] { padding-block: 8px 40px; margin-block-end: 32px; border-block-end: 1px solid var(--divider); }
  [data-role="idea"] > h2 { margin-block-end: 24px; }
  [data-role="footer"] { margin-block-start: 56px; padding-block: 32px 144px; border-block-start: 1px solid var(--divider); }
  [data-role="footer"] p { font-size: 16px; color: var(--muted); }
  [data-role="footer-links"] { display: flex; flex-wrap: wrap; gap: 8px 24px; margin-block-start: 12px; }
  [data-role="footer-links"] a { display: inline-flex; align-items: center; min-height: 48px; font-size: 16px; }
  [data-role="bottom-dock"] { position: fixed; inset-block-end: 16px; inset-inline-start: 50%; transform: translateX(-50%); width: min(736px, calc(100% - 32px)); display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 4px; z-index: 20; padding: 8px; background: var(--surface); border: 1px solid var(--divider); border-radius: 24px; box-shadow: var(--float-shadow); }
  [data-role="bottom-dock"] a { min-height: 68px; display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 4px; padding: 4px; border-radius: 16px; color: var(--muted); font-size: 16px; line-height: 1.2; font-weight: 600; text-decoration: none; }
  [data-role="bottom-dock"] a:hover { background: var(--quiet); color: var(--ink); }
  [data-role="bottom-dock"] a[aria-current="page"] { background: var(--blue); color: var(--blue-ink); }
}

@layer components {
  [data-role="skip-link"] { position: fixed; inset-block-start: 12px; inset-inline-start: 12px; transform: translateY(-180%); min-height: 48px; display: flex; align-items: center; padding: 8px 16px; z-index: 100; background: var(--surface); border: 2px solid var(--focus); border-radius: 10px; font-size: 16px; }
  [data-role="skip-link"]:focus { transform: translateY(0); }
  [data-role="home-link"] { display: flex; align-items: center; gap: 12px; min-height: 52px; text-decoration: none; }
  [data-role="home-link"] strong { display: block; font-size: 22px; line-height: 1.2; letter-spacing: -.015em; }
  [data-role="brand-subtitle"] { display: block; font-size: 16px; color: var(--muted); line-height: 1.4; }
  [data-role="notebook-mark"] { width: 44px; height: 44px; border-radius: 14px; background: var(--blue); position: relative; flex: 0 0 auto; }
  [data-role="notebook-mark"]::before, [data-role="notebook-mark"]::after { content: ""; position: absolute; border: 2px solid var(--blue-ink); border-radius: 2px; top: 11px; bottom: 11px; width: 13px; }
  [data-role="notebook-mark"]::before { left: 10px; transform: skewY(-8deg); }
  [data-role="notebook-mark"]::after { right: 10px; transform: skewY(8deg); }
  [data-role="guide-label"] { border-radius: 14px; background: var(--quiet); color: var(--ink); padding: 8px 16px; font-size: 16px; font-weight: 600; }
  [data-role="eyebrow"], [data-role="label"] { font-size: 16px; line-height: 1.4; font-weight: 600; color: var(--muted); letter-spacing: 0; }
  [data-role="eyebrow"] { margin-block-end: 16px; display: flex; align-items: center; gap: 8px; }
  [data-role="eyebrow"]::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--deep-blue); flex: 0 0 auto; }
  [data-role="hero-actions"] { display: flex; align-items: flex-start; flex-wrap: wrap; gap: 12px; margin-block-start: 28px; }
  [data-role="primary-link"], [data-role="text-link"], [data-role="source-link"] { display: inline-flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 48px; font-size: 18px; line-height: 1.4; font-weight: 700; max-width: 100%; padding: 12px 16px; border-radius: 14px; }
  [data-role="primary-link"] { background: var(--blue); color: var(--blue-ink); border-radius: 22px; text-decoration: none; padding-inline: 20px; font-size: 20px; }
  [data-role="primary-link"]:hover { background: var(--cyan); }
  [data-role="primary-link"]:active { background: var(--pressed-blue); }
  [data-role="text-link"] { padding-inline: 0; text-decoration-color: var(--deep-blue); }
  [data-role="source-link"] { margin-block-start: 20px; background: var(--quiet); text-decoration: none; }
  [data-role="source-link"]:hover { text-decoration: underline; text-decoration-color: var(--deep-blue); }
  [data-role="source-actions"] { display: flex; gap: 12px; flex-wrap: wrap; margin-block: 16px; }
  [data-role="source-actions"] [data-role="source-link"] { margin: 0; }
  [data-role="question-bubble"] { position: relative; background: var(--incoming); border-radius: 16px; padding: 20px 24px; margin-block: 24px; max-width: 64ch; }
  [data-role="question-bubble"]::after { content: ""; width: 12px; height: 12px; background: var(--incoming); position: absolute; inset-block-end: 8px; inset-inline-start: -5px; border-radius: 0 0 0 5px; }
  [data-role="question-bubble"] p:not([data-role="label"]) { font-size: 20px; line-height: 1.5; margin-block-start: 12px; }
  [data-role="question-bubble"] [data-role="label"] { color: var(--bubble-muted); }
  [data-role="route-list"] { display: grid; gap: 8px; }
  [data-role="next-note"] { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 88px; padding: 20px 24px; border: 1px solid var(--divider); border-radius: 16px; text-decoration: none; background: var(--surface); }
  [data-role="next-note"] [data-role="label"] { display: block; margin-block-end: 4px; }
  [data-role="next-note"] strong { display: block; font-size: 20px; line-height: 1.4; }
  [data-role="next-note"]:hover { border-color: var(--deep-blue); background: var(--quiet); }
  [data-role="next-arrow"] { display: grid; place-items: center; width: 40px; height: 40px; flex: 0 0 auto; border-radius: 50%; background: var(--blue); color: var(--blue-ink); font-size: 24px; }
  [data-role="reading-column"] > [data-role="next-note"] { background: var(--blue); color: var(--blue-ink); border-color: var(--blue); }
  [data-role="reading-column"] > [data-role="next-note"] [data-role="label"] { color: var(--blue-ink); }
  [data-role="reading-column"] > [data-role="next-note"] [data-role="next-arrow"] { background: var(--surface); color: var(--link); }
  [data-role="myth-grid"] { display: grid; gap: 16px; }
  [data-role="myth"] { background: var(--quiet); border-radius: 16px; padding: 24px; }
  [data-role="myth"] h3 { font-size: 22px; margin-block-end: 16px; }
  [data-role="myth-toggle"] { display: inline-flex; align-items: center; justify-content: center; min-width: 44px; min-height: 48px; font-size: 20px; font-weight: 700; padding: 10px 20px; border: 0; border-radius: 22px; background: var(--blue); color: var(--blue-ink); }
  [data-role="myth-toggle"]:hover { background: var(--cyan); }
  [data-role="myth-toggle"]:active { background: var(--pressed-blue); }
  [data-role="myth-answer"] { margin-block-start: 16px; border-block-start: 1px solid var(--divider); padding-block-start: 16px; }
  [data-role="evidence-card"] { padding: 28px; margin-block-start: 24px; border: 1px solid var(--divider); border-radius: 16px; background: var(--surface); }
  [data-role="evidence-card"] h3 { margin-block-end: 20px; }
  [data-role="evidence-card"] > [data-role="eyebrow"]::before { border-radius: 2px; }
  [data-role="evidence-limit"] { background: var(--quiet); border-radius: 10px; padding: 16px; margin-block-start: 20px; }
  [data-role="evidence-limit"] p + p { margin-block-start: 8px; }
  [data-role="search-example"] { display: flex; align-items: center; gap: 12px; border: 2px solid var(--divider); padding: 16px; border-radius: 10px; margin-block: 20px; font-size: 18px; font-weight: 600; }
  [data-role="search-symbol"] { display: block; width: 18px; height: 18px; border: 2px solid var(--muted); border-radius: 50%; position: relative; flex: 0 0 auto; margin-inline-end: 4px; }
  [data-role="search-symbol"]::after { content: ""; width: 8px; height: 2px; position: absolute; inset-block-end: -3px; inset-inline-end: -6px; background: var(--muted); transform: rotate(45deg); }
  [data-role="setting-row"] { background: var(--quiet); border-radius: 16px; padding: 24px; margin-block-end: 12px; }
  [data-role="setting-row"] h3 { margin-block-end: 12px; }
  [data-role="check-steps"] { list-style: none; padding: 0; counter-reset: none; margin: 0 0 24px; }
  [data-role="check-steps"] li { position: relative; padding: 24px 24px 24px 52px; border-inline-start: 2px solid var(--divider); margin: 0; }
  [data-role="check-steps"] li::before { content: ""; width: 18px; height: 18px; border: 5px solid var(--blue); background: var(--surface); position: absolute; inset-inline-start: -10px; inset-block-start: 30px; border-radius: 50%; }
  [data-role="check-steps"] h3 { margin-block-end: 12px; }
  [data-role="note-list"] { margin-block: 24px; }
  [data-role="note-list"] li::marker { color: var(--deep-blue); }
  [data-role="quote-sheet"] { padding: 24px; border: 1px solid var(--divider); border-radius: 16px; background: var(--quiet); margin-block-end: 24px; }
  [data-role="sheet-heading"] { display: flex; align-items: center; justify-content: space-between; padding-block-end: 16px; border-block-end: 1px solid var(--divider); }
  [data-role="paper-mark"] { width: 16px; height: 16px; background: var(--green); border-radius: 50%; }
  [data-role="quote-lines"] > div { display: grid; grid-template-columns: 136px minmax(0, 1fr); gap: 24px; border-block-end: 1px solid var(--divider); padding-block: 20px; }
  [data-role="quote-lines"] > div:last-child { border: 0; padding-block-end: 4px; }
  [data-role="quote-lines"] dt { font-weight: 700; font-size: 20px; }
  [data-role="quote-lines"] dd { font-size: 18px; }
  [data-role="dock-icon"] { width: 21px; height: 21px; position: relative; display: block; }
  [data-icon="start"] { border: 2px solid currentColor; border-radius: 4px; }
  [data-icon="start"]::after { content: ""; position: absolute; height: 13px; width: 2px; top: 2px; left: 8px; background: currentColor; }
  [data-icon="find"] { border: 2px solid currentColor; border-radius: 50%; width: 18px; height: 18px; margin: 0 3px 3px 0; }
  [data-icon="find"]::after { content: ""; position: absolute; height: 2px; width: 8px; bottom: -3px; right: -6px; transform: rotate(45deg); background: currentColor; }
  [data-icon="ask"] { border: 2px solid currentColor; border-radius: 6px; }
  [data-icon="ask"]::after { content: ""; position: absolute; width: 7px; height: 7px; border-left: 2px solid currentColor; border-bottom: 2px solid currentColor; bottom: -5px; left: 3px; background: inherit; }
  [data-icon="cost"] { border: 2px solid currentColor; border-radius: 50%; }
  [data-icon="cost"]::before, [data-icon="cost"]::after { content: ""; position: absolute; width: 8px; height: 2px; left: 5px; background: currentColor; }
  [data-icon="cost"]::before { top: 5px; }
  [data-icon="cost"]::after { bottom: 5px; }
  [data-icon="read"] { border: 2px solid currentColor; border-radius: 3px; }
  [data-icon="read"]::after { content: ""; width: 9px; height: 7px; border-top: 2px solid currentColor; border-bottom: 2px solid currentColor; position: absolute; left: 4px; top: 5px; }
  [data-icon="pause"]::before, [data-icon="pause"]::after { content: ""; width: 5px; height: 18px; position: absolute; top: 1px; background: currentColor; border-radius: 2px; }
  [data-icon="pause"]::before { left: 3px; }
  [data-icon="pause"]::after { right: 3px; }
}

@layer responsive {
  @media (max-width: 900px) {
    [data-role="reading-layout"] { grid-template-columns: 176px minmax(0, 1fr); gap: 32px; }
    [data-role="page-cover"] { gap: 24px; padding-block: 44px; }
    h1 { font-size: 48px; }
  }
  @media (max-width: 700px) {
    [data-role="masthead"], main, [data-role="footer"] { width: calc(100% - 32px); }
    [data-role="masthead"] { padding-block: 16px; gap: 8px; }
    [data-role="home-link"] { gap: 8px; }
    [data-role="home-link"] strong { font-size: 20px; }
    [data-role="guide-label"] { display: none; }
    [data-role="page-cover"], [data-role="page-cover"][data-illustrated] { grid-template-columns: minmax(0, 1fr); padding-block: 32px; gap: 24px; }
    h1 { font-size: 42px; max-width: 16ch; }
    h2 { font-size: 28px; }
    h3 { font-size: 22px; }
    [data-role="intro"] { margin-block-start: 20px; }
    [data-role="intro"] p { font-size: 20px; }
    [data-role="cover-art"] { max-width: 420px; justify-self: center; }
    [data-role="reading-layout"] { grid-template-columns: minmax(0, 1fr); gap: 24px; padding-block-start: 24px; }
    [data-role="page-outline"] { position: static; flex-direction: row; flex-wrap: wrap; gap: 4px 8px; }
    [data-role="page-outline"] [data-role="label"] { flex-basis: 100%; margin-block-end: 4px; }
    [data-role="page-outline"] a { color: var(--link); padding: 10px 12px; background: var(--quiet); border-radius: 14px; min-height: 44px; }
    [data-role="idea"] { padding-block-end: 32px; margin-block-end: 24px; }
    [data-role="hero-actions"] { flex-direction: column; gap: 8px; margin-block-start: 24px; }
    [data-role="hero-actions"] [data-role="primary-link"] { width: 100%; }
    [data-role="evidence-card"], [data-role="quote-sheet"], [data-role="myth"] { padding: 20px; }
    [data-role="question-bubble"] { padding: 20px; margin-inline-start: 4px; }
    [data-role="next-note"] { padding: 16px; gap: 12px; }
    [data-role="next-note"] strong { font-size: 20px; }
    [data-role="quote-lines"] > div { grid-template-columns: minmax(0, 1fr); gap: 8px; }
    [data-role="check-steps"] li { padding: 20px 0 24px 24px; }
    [data-role="check-steps"] li::before { inset-block-start: 24px; }
    [data-role="source-actions"] { flex-direction: column; }
    [data-role="source-link"] { width: 100%; }
    [data-role="bottom-dock"] { inset-block-end: 0; width: 100%; gap: 2px; padding: 8px 6px max(8px, env(safe-area-inset-bottom)); border-radius: 0; border-inline: 0; border-block-end: 0; }
    [data-role="bottom-dock"] a { min-height: 60px; border-radius: 14px; font-size: 16px; }
    [data-role="footer"] { margin-block-start: 40px; padding-block-end: 128px; }
    [data-role="footer-links"] { flex-direction: column; align-items: flex-start; gap: 4px; }
  }
}

@layer preferences {
  @media (prefers-color-scheme: dark) {
    :root { --canvas: #121316; --ink: #f3f4f6; --muted: #bfc2c9; --bubble-muted: #bfc2c9; --quiet: #1b1d21; --incoming: #25282d; --divider: #454951; --surface: #1b1d21; --link: #4fcbf7; --focus: #4fcbf7; --float-shadow: 0 4px 24px rgb(0 0 0 / 18%); }
    [data-role="eyebrow"]::before, [data-role="note-list"] li::marker { background: var(--cyan); color: var(--cyan); }
    [data-role="cover-art"] img { border: 1px solid var(--divider); }
  }
  @media (prefers-reduced-motion: no-preference) {
    [data-role="myth-answer"][data-revealing] { animation: reveal-note .24s cubic-bezier(.16, 1, .3, 1); }
    @keyframes reveal-note { from { opacity: .8; transform: scale(.98); transform-origin: top left; } to { opacity: 1; transform: scale(1); } }
  }
  @media (forced-colors: active) {
    [data-role="bottom-dock"] a[aria-current="page"] { outline: 2px solid Highlight; }
    [data-role="notebook-mark"], [data-role="dock-icon"] { forced-color-adjust: auto; }
  }
  @media print {
    [data-role="bottom-dock"], [data-role="page-outline"], [data-role="myth-toggle"], [data-role="footer-links"], [data-role="skip-link"] { display: none !important; }
    [data-role="myth-answer"][hidden] { display: block !important; }
    body { background: #fff; color: #16181b; font-size: 12pt; }
    [data-role="masthead"], main, [data-role="footer"] { width: 100%; }
    [data-role="reading-layout"] { display: block; }
    [data-role="footer"] { padding-block-end: 16px; }
    [data-role="evidence-card"], [data-role="question-bubble"], [data-role="myth"] { break-inside: avoid; }
  }
}