@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Plus+Jakarta+Sans:wght@600;700;800&display=swap');

:root {
  --ink-950: #030812;
  --ink-900: #071425;
  --ink-850: #0b1a2e;
  --ink-800: #10223a;
  --ink-700: #1c3451;
  --paper: #f5f7fb;
  --paper-soft: #e9eef6;
  --muted: #91a1b8;
  --muted-dark: #64748a;
  --line: rgba(145, 169, 201, 0.2);
  --line-strong: rgba(145, 169, 201, 0.36);
  --blue: #4f8cff;
  --blue-deep: #2d66ee;
  --cyan: #32d8d0;
  --green: #36d995;
  --amber: #f2b84b;
  --red: #f06f7f;
  --shadow-soft: 0 32px 80px rgba(1, 8, 20, 0.28);
  --shadow-hard: 7px 7px 0 rgba(2, 11, 24, 0.18);
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-sm: 10px;
  --shell: 1200px;
  --header-h: 74px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
section[id] { scroll-margin-top: calc(var(--header-h) + 18px); }

body {
  margin: 0;
  min-width: 320px;
  background: var(--paper);
  color: var(--ink-900);
  font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}
body.menu-open { overflow: hidden; }

h1, h2, h3, .brand-copy strong, .section-number, .volume-title strong {
  font-family: "Plus Jakarta Sans", "Inter", system-ui, sans-serif;
}

button, input, a { font: inherit; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
svg { width: 1em; height: 1em; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }

::selection { background: rgba(79, 140, 255, 0.25); }

:where(a, button, input):focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}

.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: 999;
  top: 12px;
  left: 12px;
  transform: translateY(-150%);
  background: #fff;
  color: var(--ink-900);
  padding: 10px 14px;
  border-radius: 8px;
  box-shadow: var(--shadow-soft);
  transition: transform 180ms ease;
}
.skip-link:focus { transform: translateY(0); }

.shell { width: min(calc(100% - 40px), var(--shell)); margin-inline: auto; }

/* Site Header */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-h);
  background: rgba(245, 247, 251, 0.86);
  backdrop-filter: blur(18px) saturate(1.2);
  -webkit-backdrop-filter: blur(18px) saturate(1.2);
  border-bottom: 1px solid rgba(7, 20, 37, 0.08);
  transition: box-shadow 200ms ease, background 200ms ease;
}
.site-header.is-scrolled { background: rgba(245, 247, 251, 0.96); box-shadow: 0 10px 30px rgba(5, 18, 35, 0.08); }
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; min-width: max-content; }
.brand img { border-radius: 11px; box-shadow: 0 8px 20px rgba(36, 100, 238, 0.2); }
.brand-copy { display: grid; line-height: 1.02; }
.brand-copy strong { font-size: 1rem; letter-spacing: -0.02em; }
.brand-copy span { color: var(--muted-dark); font-size: 0.66rem; letter-spacing: 0.13em; text-transform: uppercase; margin-top: 4px; }
.desktop-nav { display: flex; align-items: center; gap: 24px; margin-left: auto; }
.desktop-nav a { color: #405069; font-size: 0.86rem; font-weight: 700; position: relative; }
.desktop-nav a::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -8px; height: 2px; background: var(--blue); transition: right 180ms ease; }
.desktop-nav a:hover::after { right: 0; }
.header-actions { display: flex; align-items: center; gap: 14px; }
.menu-button { display: none; width: 48px; height: 48px; border: 1px solid rgba(7,20,37,.12); border-radius: 12px; background: transparent; padding: 14px 11px; cursor: pointer; }
.menu-button span:not(.sr-only) { display: block; height: 2px; background: currentColor; margin: 5px 0; transition: transform 180ms ease; }
.mobile-nav { display: none; }

/* Buttons */
.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 0 20px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-weight: 800;
  font-size: 0.9rem;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease, border-color 180ms ease;
  touch-action: manipulation;
}
.button:hover { transform: translateY(-2px); }
.button:active { transform: translateY(0) scale(0.98); }
.button-small { min-height: 44px; padding-inline: 16px; font-size: 0.82rem; }
.button-primary { color: #fff; background: linear-gradient(135deg, var(--blue), var(--blue-deep)); box-shadow: 0 12px 26px rgba(45, 102, 238, 0.24); }
.button-primary:hover { box-shadow: 0 16px 34px rgba(45, 102, 238, 0.32); }
.button-quiet { background: rgba(255,255,255,.78); border-color: rgba(7,20,37,.14); color: var(--ink-900); }
.button-disabled { cursor: default; user-select: none; box-shadow: 0 10px 24px rgba(45, 102, 238, 0.18); }
.button-disabled:hover, .button-disabled:active { transform: none; box-shadow: 0 10px 24px rgba(45, 102, 238, 0.18); }
.play-mark { width: 25px; height: 25px; border-radius: 50%; display: grid; place-items: center; background: var(--ink-900); color: white; font-size: .56rem; padding-left: 2px; }

/* Hero Section */
.hero {
  min-height: 880px;
  padding: calc(var(--header-h) + 96px) 0 40px;
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(rgba(7,20,37,.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(7,20,37,.035) 1px, transparent 1px),
    radial-gradient(circle at 79% 34%, rgba(50,216,208,.10), transparent 28%),
    radial-gradient(circle at 75% 20%, rgba(79,140,255,.12), transparent 24%),
    var(--paper);
  background-size: 40px 40px, 40px 40px, auto, auto, auto;
}
.hero::before {
  content: "ERUDITE / MEMORY INSTRUMENT";
  position: absolute;
  left: 26px;
  top: 48%;
  transform: rotate(-90deg) translateX(-50%);
  transform-origin: left top;
  font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace;
  font-size: .62rem;
  letter-spacing: .18em;
  color: rgba(7,20,37,.26);
}
.hero-grid { display: grid; grid-template-columns: 0.94fr 1.06fr; gap: 76px; align-items: center; }
.hero-copy { padding-top: 18px; }
.eyebrow { margin: 0 0 22px; display: flex; align-items: center; gap: 11px; color: #4e6077; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .72rem; font-weight: 600; letter-spacing: .16em; text-transform: uppercase; }
.eyebrow span { width: 32px; height: 1px; background: currentColor; }
.eyebrow-light { color: #91a8c4; }
.hero h1, .section h2, .final-cta h2 {
  margin: 0;
  font-size: clamp(3.2rem, 6.4vw, 6.2rem);
  line-height: .98;
  letter-spacing: -0.055em;
  font-weight: 800;
}
h1 em, h2 em { color: var(--blue-deep); font-style: normal; }
.hero-lede { max-width: 620px; margin: 28px 0 0; color: #52637a; font-size: 1.08rem; line-height: 1.8; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.trust-line { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 24px; color: #65768c; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .7rem; letter-spacing: .06em; text-transform: uppercase; }
.trust-line span { display: inline-flex; align-items: center; gap: 9px; }
.trust-line span:not(:first-child)::before { content: ""; width: 4px; height: 4px; border-radius: 50%; background: var(--blue); }

/* Interactive Flashcard Study Console */
.hero-console-wrap { position: relative; padding: 48px 10px 26px 42px; }
.study-console {
  position: relative;
  z-index: 2;
  border-radius: 32px;
  padding: 24px;
  color: white;
  background:
    linear-gradient(180deg, rgba(255,255,255,.055), transparent 38%),
    var(--ink-900);
  border: 1px solid rgba(126,163,207,.28);
  box-shadow: 0 50px 110px rgba(3,11,22,.34), inset 0 1px 0 rgba(255,255,255,.06);
}
.study-console::before {
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid rgba(135,167,208,.08);
  border-radius: 23px;
  pointer-events: none;
}
.console-label { position: absolute; z-index: 3; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; letter-spacing: .14em; color: #455970; }
.console-label::after { content: ""; display: inline-block; height: 1px; width: 42px; vertical-align: middle; margin-left: 10px; background: currentColor; }
.console-label-a { top: 8px; left: 0; }
.console-label-b { right: -32px; top: 165px; transform: rotate(90deg); }
.console-label-c { bottom: 0; left: 112px; }
.console-topline { position: relative; z-index: 1; display: flex; align-items: start; justify-content: space-between; gap: 20px; padding-bottom: 16px; }
.console-topline > div:first-child { display: grid; gap: 2px; }
.micro-label { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; color: #6f87a5; font-size: .62rem; font-weight: 600; letter-spacing: .14em; }
.console-topline strong { font-size: .98rem; }
.console-counter { min-width: 84px; text-align: right; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .92rem; color: #b7c9dd; }
.console-counter i { font-style: normal; opacity: .42; margin-inline: 4px; }
.mode-switch { display: grid; grid-template-columns: 1fr 1fr; padding: 5px; background: #0a1a2f; border: 1px solid rgba(145,169,201,.16); border-radius: 12px; }
.mode-switch button { min-height: 44px; border: 0; border-radius: 8px; background: transparent; color: #7890ad; font-size: .78rem; font-weight: 800; cursor: pointer; touch-action: manipulation; }
.mode-switch button.is-active { background: #172d49; color: #fff; box-shadow: inset 0 0 0 1px rgba(126,163,207,.18); }
.flashcard { perspective: 1200px; position: relative; width: 100%; min-height: 310px; margin-top: 17px; padding: 0; background: transparent; border: 0; cursor: pointer; transform-style: preserve-3d; touch-action: manipulation; }
.flashcard-face { position: absolute; inset: 0; backface-visibility: hidden; -webkit-backface-visibility: hidden; border-radius: 22px; border: 1px solid rgba(125,159,202,.25); display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 32px 24px; background:
  radial-gradient(circle at 84% 28%, rgba(50,216,208,.16), transparent 26%),
  linear-gradient(145deg, #11233b, #0d1d32);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.04);
  transition: transform 520ms cubic-bezier(.2,.7,.1,1);
}
.flashcard-front { transform: rotateY(0); }
.flashcard-back { transform: rotateY(180deg); }
.flashcard.is-flipped .flashcard-front { transform: rotateY(-180deg); }
.flashcard.is-flipped .flashcard-back { transform: rotateY(0); }
.card-kicker { color: #56ddb3; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .65rem; letter-spacing: .18em; margin-bottom: 18px; }
.flashcard strong { max-width: 430px; color: #f4f8ff; font-size: clamp(1.2rem, 2vw, 1.65rem); line-height: 1.45; text-align: center; }
.flashcard-back p { max-width: 410px; text-align: center; color: #8fa3bc; font-size: .85rem; margin: 12px 0 0; }
.flip-hint { margin-top: 22px; color: #627894; font-size: .7rem; font-weight: 700; }
.normal-controls { display: grid; grid-template-columns: auto 1fr auto; gap: 14px; align-items: center; margin-top: 17px; }
.normal-controls button { border: 0; background: transparent; color: #93a6bd; font-size: .76rem; font-weight: 800; padding: 10px 8px; min-height: 44px; cursor: pointer; touch-action: manipulation; }
.progress-track { height: 6px; border-radius: 999px; background: #1c3049; overflow: hidden; }
.progress-track span { display: block; height: 100%; background: var(--blue); border-radius: inherit; transition: width 200ms ease; }
.rating-controls { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; margin-top: 17px; }
.rating-controls button { min-width: 0; min-height: 60px; border-radius: 12px; background: #10243b; border: 1px solid rgba(145,169,201,.18); color: #dce8f7; cursor: pointer; display: grid; place-content: center; gap: 2px; transition: background 160ms ease, border-color 160ms ease, transform 160ms ease; touch-action: manipulation; }
.rating-controls button:hover { transform: translateY(-2px); }
.rating-controls button:active { transform: scale(0.96); }
.rating-controls button:nth-child(1):hover { border-color: var(--red); background: rgba(240,111,127,.12); }
.rating-controls button:nth-child(2):hover { border-color: var(--amber); background: rgba(242,184,75,.12); }
.rating-controls button:nth-child(3):hover { border-color: var(--green); background: rgba(54,217,149,.12); }
.rating-controls button:nth-child(4):hover { border-color: #54bde7; background: rgba(84,189,231,.12); }
.rating-controls span { font-size: .75rem; font-weight: 800; }
.rating-controls strong { color: #7f93ac; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; }
.console-footnote { display: flex; justify-content: space-between; align-items: center; gap: 18px; margin-top: 18px; color: #7288a4; font-size: .68rem; font-weight: 700; }
.console-status { display: inline-flex; align-items: center; gap: 8px; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; letter-spacing: .08em; }
.console-status i { width: 7px; height: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px rgba(54,217,149,.1); }
.hero-index { margin-top: 76px; display: flex; justify-content: space-between; border-top: 1px solid rgba(7,20,37,.13); padding-top: 16px; color: #75859a; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; letter-spacing: .12em; }

/* Sections Common */
.section { position: relative; padding: 130px 0; overflow: hidden; }
.section-number { font-size: 5.5rem; font-weight: 800; line-height: 1; color: rgba(7,20,37,.075); letter-spacing: -.08em; margin-bottom: -20px; }
.section-grid { display: grid; grid-template-columns: .74fr 1.26fr; gap: 88px; align-items: start; }
.section-intro { position: sticky; top: calc(var(--header-h) + 46px); }
.section h2 { font-size: clamp(2.7rem, 4.8vw, 4.8rem); }
.section h2 em { display: block; }
.section-intro > p:not(.eyebrow), .wide-heading > p, .analytics-copy > p:not(.eyebrow), .ai-copy > p:not(.eyebrow), .privacy-copy > p:not(.eyebrow) { color: #5d6d82; font-size: 1rem; line-height: 1.8; margin: 24px 0 0; }
.arrow-link { margin-top: 28px; display: inline-flex; align-items: center; gap: 12px; font-weight: 800; font-size: .86rem; }
.arrow-link span { color: var(--blue); transition: transform 180ms ease; }
.arrow-link:hover span { transform: translateX(5px); }

/* Section 00: Android Screenshots Showcase */
.section-screens {
  color: #f4f8ff;
  background:
    radial-gradient(circle at 12% 8%, rgba(79,140,255,.17), transparent 27%),
    radial-gradient(circle at 87% 40%, rgba(50,216,208,.10), transparent 24%),
    var(--ink-900);
}
.screens-heading { display: grid; grid-template-columns: .58fr 1.12fr .72fr; gap: 38px; align-items: end; }
.screens-heading .section-number { color: rgba(255,255,255,.08); }
.screens-heading .eyebrow { color: #8fa6c1; margin-bottom: 0; }
.screens-heading h2 { font-size: clamp(2.8rem, 4.8vw, 4.8rem); }
.screens-heading h2 em { color: #7da5ff; }
.screens-heading > p { color: #8fa4bc; margin: 0; line-height: 1.8; }

.showcase-tabs { display: flex; gap: 10px; margin-top: 48px; border-bottom: 1px solid rgba(145,169,201,.18); padding-bottom: 16px; overflow-x: auto; scrollbar-width: none; }
.showcase-tabs::-webkit-scrollbar { display: none; }
.showcase-tab { min-height: 44px; padding: 0 16px; border: 1px solid rgba(145,169,201,.18); border-radius: 10px; background: rgba(11,26,46,.6); color: #8ea3bd; font-size: .82rem; font-weight: 700; cursor: pointer; display: inline-flex; align-items: center; gap: 8px; transition: background 180ms ease, border-color 180ms ease, color 180ms ease; white-space: nowrap; touch-action: manipulation; }
.showcase-tab span { color: #58718f; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .68rem; }
.showcase-tab.is-active { background: rgba(79,140,255,.18); border-color: var(--blue); color: white; }
.showcase-tab.is-active span { color: var(--cyan); }

.android-showcase-wrap { position: relative; margin-top: 36px; }
.android-frame-glow { position: absolute; inset: -40px; background: radial-gradient(circle at 50% 50%, rgba(79,140,255,.15), transparent 70%); pointer-events: none; }
.screen-gallery { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; position: relative; z-index: 2; }
.screen-shot { min-width: 0; margin: 0; transition: opacity 300ms ease, transform 300ms ease; }
.phone-frame {
  position: relative;
  aspect-ratio: 9 / 18.5;
  padding: 8px;
  overflow: hidden;
  border: 1.5px solid rgba(145,169,201,.32);
  border-radius: 34px;
  background: #020914;
  box-shadow: 0 32px 70px rgba(0,0,0,.45), inset 0 1px 0 rgba(255,255,255,.1);
}
.phone-statusbar { position: absolute; top: 0; left: 0; right: 0; height: 28px; z-index: 10; display: flex; align-items: center; justify-content: space-between; padding: 0 18px; color: rgba(255,255,255,.8); font-size: .6rem; font-weight: 700; pointer-events: none; }
.phone-notch { width: 12px; height: 12px; border-radius: 50%; background: #000; border: 1px solid rgba(255,255,255,.15); }
.phone-icons { display: flex; gap: 4px; font-size: .55rem; }
.phone-icons i::before { content: "●"; opacity: .7; }
.phone-frame img { width: 100%; height: 100%; border-radius: 26px; object-fit: cover; }
.screen-shot figcaption { display: grid; gap: 4px; margin-top: 18px; }
.screen-shot figcaption > span { color: #55708f; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .6rem; letter-spacing: .08em; }
.screen-shot figcaption strong { font-size: .88rem; color: #fff; }
.screen-shot figcaption small { color: #7289a4; font-size: .72rem; line-height: 1.55; }
.swipe-dots { display: none; justify-content: center; gap: 8px; margin-top: 18px; }
.swipe-dots span { width: 8px; height: 8px; border-radius: 50%; background: rgba(145,169,201,.25); transition: background 180ms ease, width 180ms ease; }
.swipe-dots span.is-active { width: 22px; border-radius: 999px; background: var(--blue); }
.screen-proof { display: flex; align-items: center; justify-content: center; gap: 10px; margin: 48px 0 0; color: #7890ad; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .61rem; letter-spacing: .07em; text-transform: uppercase; }
.screen-proof span { width: 7px; height: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 6px rgba(54,217,149,.08); }

/* Section 01: Engine Instrument */
.section-engine { background: #fff; }
.engine-instrument { border: 1px solid rgba(7,20,37,.13); border-radius: var(--radius-lg); padding: 34px; background: #f8fafc; box-shadow: 0 24px 70px rgba(11,31,55,.08); }
.instrument-header { display: flex; justify-content: space-between; align-items: start; gap: 20px; border-bottom: 1px solid rgba(7,20,37,.1); padding-bottom: 24px; }
.instrument-header > div:first-child { display: grid; gap: 6px; }
.instrument-header strong { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: 2.4rem; letter-spacing: -.06em; }
.instrument-status { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; letter-spacing: .12em; color: #1d8f68; border: 1px solid rgba(29,143,104,.28); background: rgba(54,217,149,.08); border-radius: 6px; padding: 7px 9px; }
.retention-scale { margin-top: 32px; }
.retention-scale input { width: 100%; height: 32px; appearance: none; -webkit-appearance: none; background: transparent; cursor: pointer; touch-action: manipulation; }
.retention-scale input::-webkit-slider-runnable-track { height: 6px; border-radius: 999px; background: linear-gradient(90deg, var(--blue) 0 var(--retention-progress, 66.6%), #dfe6ef var(--retention-progress, 66.6%) 100%); }
.retention-scale input::-moz-range-track { height: 6px; border-radius: 999px; background: #dfe6ef; }
.retention-scale input::-moz-range-progress { height: 6px; border-radius: 999px; background: var(--blue); }
.retention-scale input::-webkit-slider-thumb { appearance: none; -webkit-appearance: none; width: 26px; height: 26px; border-radius: 50%; margin-top: -10px; background: #fff; border: 6px solid var(--blue); box-shadow: 0 4px 14px rgba(45,102,238,.35); }
.retention-scale input::-moz-range-thumb { width: 16px; height: 16px; border-radius: 50%; background: #fff; border: 6px solid var(--blue); box-shadow: 0 4px 14px rgba(45,102,238,.35); }
.scale-labels { display: flex; justify-content: space-between; margin-top: 8px; color: #8291a5; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .64rem; }
.state-rail { display: grid; grid-template-columns: auto 1fr auto 1fr auto 1fr auto; align-items: center; margin: 42px 0; }
.state-node { min-width: 90px; display: grid; justify-items: center; gap: 3px; text-align: center; }
.state-node i { width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center; font-style: normal; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .6rem; border: 1px solid #cfd9e5; background: #fff; color: #708097; }
.state-node strong { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .64rem; letter-spacing: .08em; }
.state-node span { color: #8190a3; font-size: .64rem; }
.state-node.is-active i { color: white; background: var(--blue); border-color: var(--blue); box-shadow: 0 0 0 6px rgba(79,140,255,.12); }
.state-line { height: 1px; background: #d4dde8; position: relative; }
.state-line::after { content: ""; position: absolute; right: -1px; top: -3px; width: 7px; height: 7px; border-top: 1px solid #aebdce; border-right: 1px solid #aebdce; transform: rotate(45deg); }
.engine-readouts { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid rgba(7,20,37,.1); border-radius: 16px; overflow: hidden; background: white; }
.engine-readouts article { padding: 22px; display: grid; gap: 2px; }
.engine-readouts article + article { border-left: 1px solid rgba(7,20,37,.1); }
.engine-readouts span { color: #718197; font-size: .68rem; font-weight: 700; }
.engine-readouts strong { font-size: 1.2rem; letter-spacing: -.03em; }
.engine-readouts small { color: #96a3b3; font-size: .63rem; }
.instrument-note { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 20px; color: #708096; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .58rem; letter-spacing: .06em; }
.instrument-note span { display: inline-flex; align-items: center; gap: 8px; }
.instrument-note span::before { content: "+"; color: var(--blue); }

/* Section 02: Card Workshop Specimen Board */
.section-cards { background: var(--paper); }
.wide-heading { display: grid; grid-template-columns: .72fr 1.15fr .7fr; gap: 48px; align-items: end; margin-bottom: 62px; }
.wide-heading h2 { font-size: clamp(2.8rem, 4.7vw, 4.8rem); }
.wide-heading h2 em { display: block; }
.wide-heading > p { margin: 0 0 6px; }
.specimen-board { display: grid; grid-template-columns: repeat(12, 1fr); gap: 18px; align-items: stretch; }
.specimen { position: relative; border: 1px solid rgba(7,20,37,.14); background: #fff; border-radius: 18px; padding: 20px; min-height: 260px; box-shadow: var(--shadow-hard); overflow: hidden; }
.specimen header, .specimen footer { position: relative; z-index: 2; display: flex; align-items: center; justify-content: space-between; gap: 16px; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; }
.specimen header { color: #596a80; font-size: .61rem; letter-spacing: .08em; }
.specimen header i { color: var(--blue); font-style: normal; font-size: .9rem; }
.specimen footer { position: absolute; left: 20px; right: 20px; bottom: 17px; justify-content: flex-start; color: #8996a7; font-size: .59rem; line-height: 1.45; }
.specimen-basic { grid-column: span 4; }
.specimen-cloze { grid-column: span 4; }
.specimen-occlusion { grid-column: span 4; }
.specimen-math { grid-column: span 5; }
.specimen-media { grid-column: span 3; }
.specimen-html { grid-column: span 4; }
.mini-card-stack { position: relative; height: 145px; margin-top: 26px; }
.mini-card { position: absolute; inset: 0; border-radius: 14px; border: 1px solid rgba(7,20,37,.16); display: grid; place-items: center; padding: 20px; text-align: center; font-weight: 800; }
.mini-card.rear { transform: rotate(-5deg) translate(-8px, 9px); background: #e8fff7; color: #126e52; }
.mini-card.front { transform: rotate(3deg) translate(9px, -3px); background: #0d1c30; color: #f3f7ff; box-shadow: 0 16px 28px rgba(7,20,37,.18); }
.specimen-cloze p { margin: 44px 8px 0; color: #27384d; font-size: 1.08rem; line-height: 1.8; font-weight: 600; }
.specimen-cloze mark { background: #e2ebff; color: #1c55c2; padding: 2px 5px; border-bottom: 2px solid #5a8dff; border-radius: 4px; }
.occlusion-diagram { position: relative; height: 175px; margin-top: 14px; color: #47647f; }
.occlusion-diagram svg { width: 100%; height: 100%; }
.mask { position: absolute; min-width: 48px; min-height: 32px; border-radius: 6px; border: 2px solid #94b9ff; background: #2f6fe9; color: white; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .64rem; font-weight: 700; box-shadow: 0 8px 16px rgba(45,102,238,.25); cursor: pointer; touch-action: manipulation; }
.mask-one { left: 39%; top: 40%; }
.mask-two { right: 12%; top: 62%; }
.mask-three { left: 9%; top: 68%; }
.mask.is-revealed { width: auto; min-width: 88px; padding-inline: 8px; background: #e8f2ff; color: #184ea9; }
.mask-answer { position: absolute; right: 8px; top: 18px; border: 1px solid rgba(7,20,37,.12); background: rgba(255,255,255,.92); border-radius: 7px; padding: 6px 8px; color: #5d6f86; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .56rem; }
.formula-card { margin: 30px 0 0; padding: 24px; border-left: 3px solid var(--blue); background: #f2f6fc; display: grid; gap: 11px; border-radius: 0 10px 10px 0; }
.formula-card > span { color: #74849a; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; }
.formula-card strong { color: #162b44; font-family: Georgia, serif; font-size: 1.45rem; font-weight: 400; letter-spacing: -.03em; }
.formula-card small { color: #8b98a9; }
.media-wave { height: 90px; margin: 30px 0 18px; display: flex; align-items: center; justify-content: center; gap: 6px; }
.media-wave span { width: 5px; border-radius: 4px; background: linear-gradient(var(--cyan), var(--blue)); animation: wave 1.8s ease-in-out infinite; }
.media-wave span:nth-child(1), .media-wave span:nth-child(9) { height: 24px; }
.media-wave span:nth-child(2), .media-wave span:nth-child(8) { height: 44px; animation-delay: -1.4s; }
.media-wave span:nth-child(3), .media-wave span:nth-child(7) { height: 68px; animation-delay: -.8s; }
.media-wave span:nth-child(4), .media-wave span:nth-child(6) { height: 48px; animation-delay: -1.1s; }
.media-wave span:nth-child(5) { height: 80px; animation-delay: -.4s; }
@keyframes wave { 0%,100% { transform: scaleY(.7); opacity: .7; } 50% { transform: scaleY(1.06); opacity: 1; } }
.media-control { width: 100%; min-height: 48px; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 10px; border: 1px solid rgba(7,20,37,.12); border-radius: 10px; background: #f4f7fb; padding: 0 12px; color: #53657b; font-size: .66rem; }
.media-control i { width: 28px; height: 28px; display: grid; place-items: center; background: var(--ink-900); color: white; font-style: normal; border-radius: 50%; font-size: .55rem; }
.media-control span { text-align: left; font-weight: 700; }
.media-control b { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .58rem; }
.comparison-table-mini { margin-top: 27px; border: 1px solid rgba(7,20,37,.12); border-radius: 10px; overflow: hidden; }
.comparison-table-mini div { display: grid; grid-template-columns: .8fr 1fr 1fr; }
.comparison-table-mini div + div { border-top: 1px solid rgba(7,20,37,.1); }
.comparison-table-mini span, .comparison-table-mini b { padding: 9px 10px; font-size: .62rem; }
.comparison-table-mini span { color: #75859a; background: #f2f5f9; }
.comparison-table-mini b { border-left: 1px solid rgba(7,20,37,.1); font-weight: 700; color: #2f4258; }
.feature-rail { display: flex; justify-content: center; flex-wrap: wrap; margin-top: 60px; border-top: 1px solid rgba(7,20,37,.12); border-bottom: 1px solid rgba(7,20,37,.12); }
.feature-rail span { padding: 14px 22px; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; letter-spacing: .06em; color: #637389; }
.feature-rail span + span { border-left: 1px solid rgba(7,20,37,.1); }

/* Section: Comparison Matrix */
.section-comparison { background: #ffffff; }
.comparison-board { margin-top: 40px; border-radius: 24px; border: 1px solid rgba(7,20,37,.12); background: #f8fafc; overflow: hidden; box-shadow: 0 20px 60px rgba(7,20,37,.06); }
.comparison-table-full { display: grid; grid-template-columns: 1fr; }
.table-header, .table-row { display: grid; grid-template-columns: 1.4fr 1.2fr 1fr 1fr; align-items: center; padding: 18px 24px; }
.table-header { background: #0d1d32; color: white; border-bottom: 1px solid rgba(255,255,255,.1); font-weight: 700; font-size: .88rem; }
.col-erudite { display: flex; align-items: center; gap: 8px; color: var(--cyan); font-weight: 800; }
.table-row { border-bottom: 1px solid rgba(7,20,37,.08); font-size: .88rem; }
.table-row:last-child { border-bottom: 0; }
.col-feature { font-weight: 600; color: #23354d; }
.highlight-cell { font-weight: 700; color: #0d1d32; }
.check-icon { color: #169b6b; font-weight: 800; }
.badge { display: inline-block; padding: 4px 10px; border-radius: 6px; font-size: .74rem; font-weight: 700; }
.badge-success { background: rgba(54,217,149,.15); color: #0f8056; }
.badge-free { background: rgba(79,140,255,.15); color: #1d58cd; }

/* Section 04: AI Workbench & Prompt Builder */
.section-ai { color: white; background:
  linear-gradient(rgba(120,158,204,.05) 1px, transparent 1px),
  linear-gradient(90deg, rgba(120,158,204,.05) 1px, transparent 1px),
  var(--ink-900);
  background-size: 36px 36px;
}
.ai-layout { display: grid; grid-template-columns: .72fr 1.28fr; gap: 70px; align-items: start; }
.ai-copy .section-number { color: rgba(255,255,255,.08); }
.ai-copy h2 { font-size: clamp(2.9rem, 4.8vw, 4.8rem); }
.ai-copy h2 em { color: #7da5ff; }
.ai-copy > p:not(.eyebrow) { color: #91a6be; }

.ai-generator-widget { margin-top: 36px; padding: 20px; border-radius: 18px; background: rgba(13,29,50,.85); border: 1px solid rgba(145,169,201,.22); }
.widget-title { display: block; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .62rem; color: #7890ad; letter-spacing: .12em; margin-bottom: 12px; }
.widget-options { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.prompt-chip { min-height: 40px; padding: 0 14px; border-radius: 8px; border: 1px solid rgba(145,169,201,.2); background: rgba(7,20,37,.6); color: #8fa4be; font-size: .76rem; font-weight: 700; cursor: pointer; touch-action: manipulation; }
.prompt-chip.is-selected { background: var(--blue); border-color: var(--blue); color: white; }
.prompt-output-box { position: relative; border-radius: 10px; background: #061120; border: 1px solid rgba(145,169,201,.18); padding: 14px; }
.prompt-output-box pre { margin: 0; white-space: pre-wrap; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .72rem; color: #a9c2e0; line-height: 1.6; }
.prompt-output-box button { margin-top: 10px; }

.ai-workbench { position: relative; min-height: 560px; display: grid; grid-template-columns: 1fr 60px 1fr 60px 1fr; align-items: center; border: 1px solid rgba(145,169,201,.2); border-radius: 26px; padding: 30px; background: rgba(6,18,35,.78); box-shadow: 0 45px 100px rgba(0,0,0,.28); overflow: hidden; }
.workbench-grid { position: absolute; inset: 0; background: radial-gradient(circle, rgba(132,163,199,.16) 1px, transparent 1.5px); background-size: 20px 20px; opacity: .35; }
.workflow-stage { position: relative; z-index: 2; min-width: 0; min-height: 330px; border: 1px solid rgba(138,169,207,.2); border-radius: 16px; padding: 17px; background: #0d1d32; box-shadow: inset 0 1px 0 rgba(255,255,255,.04); }
.stage-top { display: flex; justify-content: space-between; align-items: center; padding-bottom: 14px; margin-bottom: 16px; border-bottom: 1px solid rgba(138,169,207,.14); }
.stage-top span { color: #57708e; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .58rem; }
.stage-top strong { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .64rem; letter-spacing: .1em; }
.option { display: flex; align-items: center; gap: 10px; min-height: 42px; padding: 0 11px; border: 1px solid rgba(138,169,207,.13); border-radius: 8px; color: #8196b0; font-size: .68rem; font-weight: 700; }
.option + .option { margin-top: 8px; }
.option i { width: 10px; height: 10px; border-radius: 50%; border: 1px solid #617894; }
.option.is-selected { color: white; border-color: var(--blue); background: rgba(79,140,255,.09); }
.option.is-selected i { border-color: var(--blue); box-shadow: inset 0 0 0 3px #0d1d32; background: var(--blue); }
.workflow-connector { position: relative; z-index: 2; display: grid; place-items: center; color: #6f84a0; }
.workflow-connector::before, .workflow-connector::after { content: ""; position: absolute; left: 2px; right: 2px; height: 1px; background: rgba(125,157,196,.26); }
.workflow-connector::after { right: 4px; left: auto; width: 8px; height: 8px; border-top: 1px solid rgba(125,157,196,.4); border-right: 1px solid rgba(125,157,196,.4); transform: rotate(45deg); }
.workflow-connector span { transform: rotate(-90deg); width: 140px; text-align: center; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .51rem; letter-spacing: .08em; background: #071425; }
.external-boundary { display: inline-block; margin-bottom: 20px; border: 1px dashed rgba(242,184,75,.44); color: var(--amber); padding: 5px 7px; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .5rem; letter-spacing: .08em; }
.prompt-lines { display: grid; gap: 8px; }
.prompt-lines i { display: block; height: 6px; background: #223650; border-radius: 999px; }
.prompt-lines i:nth-child(2) { width: 88%; }
.prompt-lines i:nth-child(3) { width: 65%; }
.prompt-lines i:nth-child(4) { width: 94%; }
.prompt-lines i:nth-child(5) { width: 72%; }
.provider-row { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 28px; }
.provider-row span { padding: 5px 7px; border-radius: 5px; background: #162a44; color: #8499b3; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .48rem; }
.import-file { display: grid; grid-template-columns: auto 1fr auto; gap: 10px; align-items: center; border: 1px solid rgba(79,140,255,.34); background: rgba(79,140,255,.08); border-radius: 10px; padding: 12px; }
.import-file > i { width: 34px; height: 34px; border-radius: 7px; background: var(--blue); color: white; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-style: normal; display: grid; place-items: center; font-size: .55rem; }
.import-file div { min-width: 0; display: grid; }
.import-file strong { overflow: hidden; text-overflow: ellipsis; font-size: .66rem; }
.import-file span { color: #6f86a1; font-size: .52rem; }
.import-file b { color: var(--green); }
.library-target { margin-top: 55px; padding: 16px; border-radius: 10px; background: #10243c; display: grid; gap: 4px; text-align: center; }
.library-target span { color: #6d85a2; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .5rem; letter-spacing: .1em; }
.library-target strong { color: #dce8f7; font-size: .76rem; }

/* Section 05: Analytics */
.section-analytics { background: #fff; }
.analytics-layout { display: grid; grid-template-columns: 1.24fr .76fr; gap: 70px; align-items: center; }
.analytics-panel { color: white; border-radius: 28px; padding: 28px; background:
  radial-gradient(circle at 20% 18%, rgba(79,140,255,.12), transparent 32%),
  var(--ink-900);
  border: 1px solid rgba(126,163,207,.22);
  box-shadow: 0 40px 90px rgba(7,20,37,.25);
}
.analytics-topbar { display: flex; justify-content: space-between; align-items: center; gap: 20px; }
.analytics-topbar > div:first-child { display: grid; gap: 4px; }
.analytics-topbar strong { font-size: 1rem; }
.range-switch { display: flex; gap: 3px; padding: 4px; background: #0b1b2f; border-radius: 8px; }
.range-switch span { padding: 6px 9px; color: #7188a5; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .52rem; }
.range-switch span.is-active { background: #1b3659; color: white; border-radius: 5px; }
.metric-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-top: 24px; }
.metric-row article { min-width: 0; padding: 14px; border: 1px solid rgba(129,162,202,.15); background: rgba(11,29,49,.75); border-radius: 12px; display: grid; gap: 1px; }
.metric-row span { color: #7e93ac; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .51rem; letter-spacing: .06em; text-transform: uppercase; }
.metric-row strong { font-size: 1.2rem; letter-spacing: -.04em; white-space: nowrap; }
.metric-row small { color: #6f85a0; font-size: .52rem; }
.metric-row small.warning { color: #f1818d; }
.chart-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 12px; }
.chart-grid article { min-width: 0; padding: 16px; border: 1px solid rgba(129,162,202,.15); background: rgba(7,21,38,.65); border-radius: 14px; }
.chart-grid header, .heatmap-row > div:first-child { display: flex; justify-content: space-between; gap: 15px; align-items: center; }
.chart-grid header strong, .heatmap-row strong { font-size: .7rem; }
.chart-grid header span, .heatmap-row span { color: #7086a1; font-size: .56rem; }
.bar-row { display: grid; grid-template-columns: 42px 26px 1fr; gap: 8px; align-items: center; margin-top: 12px; }
.bar-row > span, .bar-row > b { color: #8aa0ba; font-size: .53rem; }
.bar-row > b { text-align: right; color: #dce8f6; }
.bar-row > i { height: 5px; border-radius: 999px; background: #172b44; overflow: hidden; }
.bar-row > i > u { display: block; height: 100%; width: var(--bar); background: var(--blue); border-radius: inherit; }
.bar-row:nth-of-type(1) > i > u { background: var(--red); }
.bar-row:nth-of-type(2) > i > u { background: var(--amber); }
.bar-row:nth-of-type(3) > i > u { background: var(--green); }
.bar-row:nth-of-type(4) > i > u { background: var(--cyan); }
.forecast-bars { height: 112px; display: grid; grid-template-columns: repeat(7, 1fr); align-items: end; gap: 7px; margin-top: 13px; }
.forecast-bars span { position: relative; height: var(--h); background: linear-gradient(var(--blue), #315fbd); border-radius: 4px 4px 2px 2px; }
.forecast-bars i { position: absolute; top: -17px; left: 50%; transform: translateX(-50%); color: #6f86a1; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .45rem; font-style: normal; }
.forecast-labels { display: grid; grid-template-columns: repeat(7, 1fr); gap: 7px; margin-top: 7px; text-align: center; color: #60758f; font-size: .44rem; }
.heatmap-row { margin-top: 12px; padding: 16px; border: 1px solid rgba(129,162,202,.15); background: rgba(7,21,38,.65); border-radius: 14px; }
.heatmap { display: grid; grid-template-columns: repeat(14, 1fr); gap: 5px; margin-top: 12px; }
.heatmap i { aspect-ratio: 1.2; border-radius: 4px; background: #122740; }
.heatmap i.l1 { background: #1b3f70; }
.heatmap i.l2 { background: #275ba8; }
.heatmap i.l3 { background: #3b7fe3; }
.heatmap i.l4 { background: #28bdd4; }
.analytics-copy .section-number { margin-bottom: -22px; }
.analytics-copy h2 { font-size: clamp(2.8rem, 4.8vw, 4.8rem); }
.focused-review-list { margin-top: 34px; border-top: 1px solid rgba(7,20,37,.13); }
.focused-review-list article { display: grid; grid-template-columns: 1fr auto; gap: 12px 20px; align-items: center; padding: 18px 0; border-bottom: 1px solid rgba(7,20,37,.13); }
.focused-review-list article > span { display: flex; align-items: center; gap: 12px; font-weight: 800; font-size: .82rem; }
.focused-review-list article > span i { width: 27px; height: 27px; display: grid; place-items: center; border: 1px solid rgba(7,20,37,.15); border-radius: 6px; font-style: normal; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; color: #718198; font-size: .55rem; }
.focused-review-list article > strong { color: #68798f; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .65rem; }
.focused-review-list article > div { grid-column: 1 / -1; display: flex; gap: 7px; }
.preview-action { border: 1px solid rgba(7,20,37,.14); background: #fff; border-radius: 6px; padding: 6px 9px; color: #5f7187; font-size: .6rem; font-weight: 800; }
.preview-action-primary { background: var(--ink-900); color: white; border-color: var(--ink-900); }

/* Section 06: Free Starting Material (Decks) */
.section-decks { background: #eef3f8; }
.deck-heading { grid-template-columns: .72fr 1.15fr .7fr; }
.volume-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.deck-volume { position: relative; min-height: 420px; display: grid; grid-template-columns: 86px 1fr; border: 1px solid rgba(7,20,37,.15); border-radius: 18px; overflow: hidden; background: #fff; box-shadow: 10px 12px 0 rgba(7,20,37,.08); transition: transform 220ms ease, box-shadow 220ms ease; }
.deck-volume:hover { transform: translateY(-4px); box-shadow: 13px 17px 0 rgba(7,20,37,.08); }
.volume-spine { position: relative; z-index: 2; color: white; background: #17335c; display: flex; flex-direction: column; align-items: center; padding: 22px 10px; }
.volume-twelve .volume-spine { background: #0c6e76; }
.volume-spine span, .volume-spine i { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .56rem; letter-spacing: .16em; writing-mode: vertical-rl; transform: rotate(180deg); }
.volume-spine strong { margin: auto 0; font-size: 2.5rem; line-height: 1; }
.volume-spine i { font-style: normal; color: rgba(255,255,255,.65); }
.volume-cover { position: relative; z-index: 2; padding: 30px; display: flex; flex-direction: column; background:
  linear-gradient(rgba(7,20,37,.035) 1px, transparent 1px),
  linear-gradient(90deg, rgba(7,20,37,.035) 1px, transparent 1px),
  #fff;
  background-size: 24px 24px;
}
.volume-code { align-self: flex-end; color: #8391a3; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .55rem; letter-spacing: .08em; }
.volume-title { margin: 70px 0 40px; display: grid; }
.volume-title span { color: #65758a; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .7rem; letter-spacing: .12em; }
.volume-title strong { font-size: 3rem; line-height: 1; letter-spacing: -.06em; }
.volume-facts { display: flex; flex-wrap: wrap; gap: 7px; }
.volume-facts span { border: 1px solid rgba(7,20,37,.13); border-radius: 5px; padding: 6px 8px; color: #63748a; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .56rem; }
.volume-toggle { margin-top: auto; align-self: flex-start; border: 0; background: transparent; padding: 18px 0 0; font-weight: 800; font-size: .72rem; cursor: pointer; display: flex; gap: 10px; align-items: center; min-height: 44px; touch-action: manipulation; }
.volume-toggle span { width: 23px; height: 23px; border-radius: 50%; display: grid; place-items: center; background: var(--ink-900); color: white; transition: transform 200ms ease; }
.deck-volume.is-open .volume-toggle span { transform: rotate(45deg); }
.chapter-drawer { position: absolute; z-index: 1; left: 86px; right: 0; bottom: 0; padding: 20px 30px; background: #0d1d32; color: #b9c9db; transform: translateY(100%); transition: transform 260ms cubic-bezier(.2,.7,.1,1); display: grid; grid-template-columns: 1fr 1fr; gap: 7px 16px; }
.chapter-drawer span { font-size: .63rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.deck-volume.is-open .chapter-drawer { transform: translateY(0); }
.deck-total { margin-top: 52px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 24px; border-top: 1px solid rgba(7,20,37,.15); border-bottom: 1px solid rgba(7,20,37,.15); padding: 20px 0; }
.deck-total span { color: #697a90; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .65rem; }
.deck-total span:last-child { text-align: right; }
.deck-total strong { font-size: 2.1rem; letter-spacing: -.05em; }

/* Section 07: FAQ Accordion */
.section-faq { background: #ffffff; }
.faq-accordion { max-width: 900px; margin-top: 40px; display: grid; gap: 14px; }
.faq-item { border: 1px solid rgba(7,20,37,.12); border-radius: 14px; background: #f8fafc; overflow: hidden; transition: border-color 180ms ease, box-shadow 180ms ease; }
.faq-item.is-open { border-color: rgba(79,140,255,.35); box-shadow: 0 10px 30px rgba(7,20,37,.05); background: #fff; }
.faq-trigger { width: 100%; min-height: 60px; padding: 18px 24px; border: 0; background: transparent; display: flex; justify-content: space-between; align-items: center; gap: 16px; text-align: left; font-weight: 700; font-size: 1rem; color: #132438; cursor: pointer; touch-action: manipulation; }
.faq-icon { font-style: normal; font-size: 1.2rem; color: var(--blue); transition: transform 200ms ease; }
.faq-item.is-open .faq-icon { transform: rotate(45deg); }
.faq-panel { padding: 0 24px 20px; color: #58697f; font-size: .94rem; line-height: 1.7; border-top: 1px solid transparent; }
.faq-item.is-open .faq-panel { border-color: rgba(7,20,37,.06); }

/* Section 08: Privacy */
.section-privacy { color: white; background: #05101f; }
.privacy-layout { display: grid; grid-template-columns: .7fr 1.3fr; gap: 70px; align-items: center; }
.privacy-copy > p:not(.eyebrow) { color: #8fa4bc; }
.ownership-diagram { display: grid; grid-template-columns: 1fr 90px 150px 90px 1fr; align-items: center; min-height: 300px; border: 1px solid rgba(145,169,201,.18); border-radius: 24px; padding: 30px; background:
  radial-gradient(circle, rgba(135,167,208,.13) 1px, transparent 1.5px),
  rgba(9,25,44,.7);
  background-size: 18px 18px;
}
.ownership-source { display: grid; gap: 9px; }
.ownership-source span { padding: 10px; border: 1px solid rgba(145,169,201,.2); border-radius: 7px; background: #0d2037; color: #91a6bf; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .56rem; letter-spacing: .08em; text-align: center; }
.ownership-flow { display: grid; justify-items: center; gap: 10px; }
.ownership-flow i { width: 100%; height: 1px; background: rgba(125,157,196,.35); position: relative; }
.ownership-flow i::after { content: ""; position: absolute; right: 0; top: -3px; width: 7px; height: 7px; border-top: 1px solid rgba(125,157,196,.55); border-right: 1px solid rgba(125,157,196,.55); transform: rotate(45deg); }
.ownership-flow b { color: #7188a4; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .47rem; letter-spacing: .08em; }
.ownership-core { aspect-ratio: 1; border-radius: 50%; background: linear-gradient(145deg, #1e5ecf, #1748a0); box-shadow: 0 0 0 12px rgba(79,140,255,.08), 0 20px 50px rgba(0,0,0,.28); display: grid; place-content: center; text-align: center; }
.ownership-core span, .ownership-core small { font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .48rem; letter-spacing: .1em; color: #a9c5ff; }
.ownership-core strong { font-size: 1.4rem; }
.ownership-output { min-height: 104px; border: 1px solid rgba(50,216,208,.28); background: rgba(50,216,208,.06); border-radius: 12px; display: grid; place-content: center; gap: 3px; text-align: center; }
.ownership-output span { color: #62c9c4; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .5rem; letter-spacing: .08em; }
.ownership-output strong { font-size: .76rem; }
.privacy-guarantees { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid rgba(145,169,201,.18); border-bottom: 1px solid rgba(145,169,201,.18); }
.privacy-guarantees article { padding: 22px 24px; display: grid; gap: 3px; }
.privacy-guarantees article + article { border-left: 1px solid rgba(145,169,201,.18); }
.privacy-guarantees i { color: #55708f; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .55rem; font-style: normal; }
.privacy-guarantees strong { font-size: .82rem; }
.privacy-guarantees span { color: #7f94ad; font-size: .67rem; }
.privacy-note { grid-column: 1 / -1; color: #667d99; font-size: .64rem; margin: 0; }
.privacy-note a { color: #a9c5ff; font-weight: 800; text-decoration: underline; text-underline-offset: 3px; }

/* Final CTA */
.final-cta { padding: 130px 0; text-align: center; background: var(--paper); }
.final-cta-inner { max-width: 900px; }
.final-cta img { margin: 0 auto 28px; border-radius: 25px; box-shadow: 0 22px 45px rgba(45,102,238,.22); }
.final-cta .eyebrow { justify-content: center; }
.final-cta h2 { font-size: clamp(3.2rem, 6vw, 6.2rem); }
.final-cta p:not(.eyebrow) { max-width: 650px; margin: 25px auto 0; color: #607087; }
.final-actions, .final-cta .trust-line { justify-content: center; }

/* Mobile Floating Quick-Dock (<620px Android screens) */
.mobile-quick-dock {
  position: fixed;
  bottom: 16px;
  left: 14px;
  right: 14px;
  z-index: 95;
  background: rgba(7, 20, 37, 0.94);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(145, 169, 201, 0.25);
  border-radius: 18px;
  padding: 10px 14px;
  box-shadow: 0 14px 40px rgba(0,0,0,.4);
  transform: translateY(150%);
  transition: transform 300ms cubic-bezier(.2,.7,.1,1);
  display: none;
}
.mobile-quick-dock.is-visible { transform: translateY(0); }
.dock-content { display: flex; align-items: center; justify-content: space-between; gap: 12px; color: white; }
.dock-info { display: flex; align-items: center; gap: 10px; }
.dock-info img { border-radius: 6px; }
.dock-info span { font-size: .78rem; color: #b7c9dd; }
.dock-info strong { color: white; }

/* Site Footer */
.site-footer { color: #b0c0d2; background: #020914; padding: 70px 0 22px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr .8fr .8fr .8fr; gap: 50px; }
.footer-brand .brand-copy strong { color: white; }
.footer-brand p { max-width: 290px; color: #6f849f; font-size: .72rem; margin-top: 18px; }
.publisher-line { display: inline-block; margin-top: 13px; color: #7187a1; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .57rem; letter-spacing: .06em; text-transform: uppercase; }
.footer-grid > div:not(.footer-brand):not(.build-status) { display: grid; align-content: start; gap: 10px; }
.footer-grid > div > strong { color: white; font-size: .72rem; margin-bottom: 4px; }
.footer-grid a { color: #7e92aa; font-size: .68rem; }
.footer-grid a:hover { color: white; }
.build-status { align-content: start; display: grid; gap: 5px; }
.build-status span { display: flex; align-items: center; gap: 8px; color: #6f86a1; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .55rem; letter-spacing: .08em; text-transform: uppercase; }
.build-status span i { width: 7px; height: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 5px rgba(54,217,149,.08); }
.build-status strong { color: white; font-size: .82rem; }
.build-status small { color: #5d718b; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .55rem; }
.footer-bottom { display: flex; justify-content: space-between; gap: 20px; border-top: 1px solid rgba(145,169,201,.13); margin-top: 54px; padding-top: 20px; color: #52667f; font-family: ui-monospace, "Cascadia Code", "SFMono-Regular", Consolas, monospace; font-size: .55rem; letter-spacing: .05em; }

/* Legal Page Styling (privacy.html) */
.legal-page { background: var(--paper); }
.legal-content { padding-top: calc(var(--header-h) + 60px); padding-bottom: 90px; max-width: 860px; }
.legal-header h1 { font-size: clamp(2.5rem, 5vw, 4rem); margin: 10px 0; }
.legal-subtitle { color: #68798f; font-size: .88rem; font-weight: 600; margin-bottom: 40px; }
.legal-article section { margin-bottom: 38px; }
.legal-article h2 { font-size: 1.5rem; margin: 0 0 14px; color: var(--ink-900); }
.legal-article p { color: #4e6077; font-size: 1.02rem; line-height: 1.8; margin: 0 0 14px; }
.legal-article ul { color: #4e6077; padding-left: 20px; line-height: 1.8; }
.legal-article li { margin-bottom: 8px; }

[data-reveal] { opacity: 0; transform: translateY(24px); transition: opacity 700ms ease, transform 700ms cubic-bezier(.2,.7,.1,1); }
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }

/* Responsive Media Queries (Mobile & Android Optimized) */
@media (max-width: 1080px) {
  .desktop-nav { gap: 18px; }
  .desktop-nav a { font-size: .78rem; }
  .hero-grid { gap: 38px; }
  .hero h1 { font-size: clamp(3.2rem, 6.2vw, 5.2rem); }
  .section-grid, .ai-layout, .analytics-layout, .privacy-layout { gap: 44px; }
  .wide-heading { grid-template-columns: .62fr 1.3fr; }
  .wide-heading > p { grid-column: 2; }
  .screens-heading { grid-template-columns: .55fr 1.45fr; }
  .screens-heading > p { grid-column: 2; }
  .specimen-basic, .specimen-cloze, .specimen-occlusion { grid-column: span 6; }
  .specimen-math, .specimen-media, .specimen-html { grid-column: span 6; margin-top: 0; transform: none; }
  .table-header, .table-row { grid-template-columns: 1.2fr 1fr 1fr 1fr; font-size: .8rem; padding: 14px 18px; }
  .ai-workbench { grid-template-columns: 1fr; gap: 12px; min-height: 0; }
  .workflow-stage { min-height: auto; }
  .workflow-connector { min-height: 42px; }
  .workflow-connector::before, .workflow-connector::after { left: 50%; right: auto; top: 0; bottom: 0; width: 1px; height: auto; }
  .workflow-connector::after { top: auto; bottom: 3px; width: 7px; height: 7px; transform: rotate(135deg); }
  .workflow-connector span { transform: none; width: auto; padding: 3px 8px; }
  .library-target { margin-top: 24px; }
  .ownership-diagram { grid-template-columns: 1fr 55px 124px 55px 1fr; padding: 20px; }
}

@media (max-width: 860px) {
  :root { --header-h: 68px; }
  .desktop-nav { display: none; }
  .menu-button { display: block; }
  .mobile-nav { position: fixed; inset: var(--header-h) 0 auto; display: grid; padding: 18px 20px 24px; background: rgba(245,247,251,.98); border-bottom: 1px solid rgba(7,20,37,.1); transform: translateY(-120%); transition: transform 220ms ease; box-shadow: 0 20px 40px rgba(0,0,0,.1); }
  .mobile-nav.is-open { transform: translateY(0); }
  .mobile-nav a { padding: 14px 0; border-bottom: 1px solid rgba(7,20,37,.08); font-weight: 800; font-size: .9rem; }
  .hero { min-height: 0; padding-top: calc(var(--header-h) + 60px); }
  .hero::before { display: none; }
  .hero-grid { grid-template-columns: 1fr; }
  .hero-copy { max-width: 720px; }
  .hero-console-wrap { padding: 34px 10px 22px; }
  .console-label-a { left: 14px; }
  .console-label-b { right: -50px; }
  .console-label-c { left: 50%; transform: translateX(-50%); }
  .hero-index { margin-top: 46px; overflow-x: auto; gap: 36px; }
  .hero-index span { white-space: nowrap; }
  .section { padding: 85px 0; }
  .section-grid, .analytics-layout, .ai-layout, .privacy-layout { grid-template-columns: 1fr; }
  .section-intro { position: static; }
  .wide-heading { grid-template-columns: 1fr; gap: 16px; }
  .wide-heading > p { grid-column: auto; max-width: 640px; }
  .screens-heading { grid-template-columns: 1fr; gap: 16px; }
  .screens-heading > p { grid-column: auto; max-width: 640px; }
  .specimen-board { grid-template-columns: 1fr 1fr; }
  .specimen-basic, .specimen-cloze, .specimen-occlusion, .specimen-math, .specimen-media, .specimen-html { grid-column: auto; transform: none; margin: 0; }
  .specimen-occlusion { grid-column: 1 / -1; }
  .analytics-panel { order: 2; }
  .analytics-copy { order: 1; }
  .volume-grid { grid-template-columns: 1fr; }
  .privacy-guarantees { grid-template-columns: 1fr; }
  .privacy-guarantees article + article { border-left: 0; border-top: 1px solid rgba(145,169,201,.18); }
  .privacy-note { margin-top: -12px; }
  .footer-grid { grid-template-columns: 1.2fr 1fr 1fr; }
  .build-status { grid-column: 1 / -1; border-top: 1px solid rgba(145,169,201,.13); padding-top: 20px; }
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 24px), var(--shell)); }
  .brand-copy span { display: none; }
  .header-actions { gap: 8px; }
  .button-small { padding-inline: 12px; }
  .hero h1 { font-size: clamp(2.8rem, 13.5vw, 4.4rem); }
  .hero-lede { font-size: .96rem; }
  .hero-actions .button { width: 100%; }
  .trust-line { gap: 8px 12px; }
  .study-console { padding: 16px; border-radius: 24px; }
  .console-label { display: none; }
  .console-topline strong { max-width: 200px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
  .flashcard { min-height: 280px; }
  .flashcard-face { padding: 22px 16px; }
  .rating-controls { grid-template-columns: 1fr 1fr; }
  .section-number { font-size: 4rem; }
  .section h2, .final-cta h2 { font-size: clamp(2.4rem, 11vw, 3.8rem); }
  
  .showcase-tabs { font-size: .78rem; }
  .screen-gallery { display: flex; width: calc(100% + 14px); margin-top: 24px; overflow-x: auto; overscroll-behavior-inline: contain; scroll-snap-type: x mandatory; scrollbar-width: none; padding-bottom: 12px; }
  .screen-gallery::-webkit-scrollbar { display: none; }
  .screen-shot { flex: 0 0 min(80vw, 290px); scroll-snap-align: center; }
  .swipe-dots { display: flex; }

  .table-header, .table-row { grid-template-columns: 1.2fr 1fr 0.8fr 0.8fr; font-size: .74rem; padding: 12px 10px; }
  .comparison-board { overflow-x: auto; }
  .comparison-table-full { min-width: 520px; }

  .engine-instrument { padding: 18px; }
  .instrument-header strong { font-size: 1.9rem; }
  .state-rail { grid-template-columns: 1fr; gap: 10px; }
  .state-line { width: 1px; height: 28px; justify-self: center; }
  .state-line::after { right: -3px; top: auto; bottom: 0; transform: rotate(135deg); }
  .engine-readouts { grid-template-columns: 1fr; }
  .engine-readouts article + article { border-left: 0; border-top: 1px solid rgba(7,20,37,.1); }
  .specimen-board { grid-template-columns: 1fr; }
  .screen-proof { justify-content: flex-start; margin-top: 24px; line-height: 1.6; }
  .feature-rail { justify-content: flex-start; overflow-x: auto; flex-wrap: nowrap; }
  .feature-rail span { white-space: nowrap; }
  .ai-workbench { padding: 16px; }
  .metric-row { grid-template-columns: 1fr 1fr; }
  .chart-grid { grid-template-columns: 1fr; }
  .analytics-panel { padding: 18px; }
  .analytics-topbar { align-items: flex-start; flex-direction: column; }
  .heatmap { gap: 3px; }
  .deck-volume { grid-template-columns: 64px 1fr; }
  .chapter-drawer { left: 64px; grid-template-columns: 1fr; max-height: 158px; overflow: auto; }
  .volume-title { margin-top: 46px; }
  .volume-title strong { font-size: 2.35rem; }
  .deck-total { grid-template-columns: 1fr; text-align: center; }
  .deck-total span:last-child { text-align: center; }
  .ownership-diagram { grid-template-columns: 1fr; gap: 16px; }
  .ownership-flow { min-height: 44px; }
  .ownership-flow i { width: 1px; height: 100%; }
  .ownership-flow i::after { right: -3px; top: auto; bottom: 0; transform: rotate(135deg); }
  .ownership-core { width: 130px; justify-self: center; }
  .mobile-quick-dock { display: block; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 34px 24px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  [data-reveal] { opacity: 1; transform: none; }
}