@import url("https://fonts.googleapis.com/css2?family=Inter+Tight:wght@400;500;600;700&family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,500;0,8..60,600;1,8..60,400&family=IBM+Plex+Mono:wght@400;500;600&display=swap");

:root {
  color-scheme: light;
  --paper: #fbfaf6;
  --paper-2: #f3f1ea;
  --paper-3: #e9e6dd;
  --ink: #1a1814;
  --ink-2: #3b3731;
  --ink-3: #6a6258;
  --muted: #8c8376;
  --rule: #d8cfbd;
  --rule-2: #c2b9a6;
  --accent: oklch(0.62 0.13 65);
  --accent-soft: oklch(0.94 0.05 70);
  --known: oklch(0.55 0.09 145);
  --c-dunno: #d8cfbd;
  --c-fuzzy: oklch(0.8 0.08 50);
  --c-gist: oklch(0.68 0.1 90);
  --c-solid: oklch(0.55 0.09 145);
  --c-eek: oklch(0.58 0.15 25);
  --serif: "Source Serif 4", Georgia, serif;
  --sans: "Inter Tight", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --shadow-sm: 0 1px 0 rgba(40, 30, 10, 0.04), 0 1px 2px rgba(40, 30, 10, 0.04);
  --shadow-md: 0 1px 0 rgba(40, 30, 10, 0.06), 0 16px 38px -26px rgba(40, 30, 10, 0.32);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
}

.skip-link {
  position: absolute;
  left: 16px;
  top: 12px;
  z-index: 10;
  transform: translateY(-140%);
  border: 1px solid var(--rule-2);
  border-radius: 8px;
  background: var(--paper);
  padding: 8px 12px;
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid rgba(216, 207, 189, 0.78);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  padding: 18px clamp(20px, 5vw, 64px);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--serif);
  font-size: 25px;
  font-style: italic;
  line-height: 1;
}

.brand-name,
.brand-line {
  display: block;
}

.brand-name {
  font-family: var(--serif);
  font-size: 22px;
  line-height: 1;
}

.brand-line {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.02em;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 24px);
  color: var(--ink-3);
  font-family: var(--mono);
  font-size: 12px;
}

.nav a {
  text-decoration: none;
}

.nav a[aria-current="true"] {
  color: var(--ink);
}

.nav-app {
  border: 1px solid var(--rule-2);
  border-radius: 8px;
  padding: 8px 12px;
  background: var(--paper);
  box-shadow: var(--shadow-sm);
}

main {
  overflow: hidden;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(360px, 1fr);
  gap: clamp(36px, 7vw, 96px);
  align-items: center;
  min-height: calc(100svh - 74px);
  padding: clamp(48px, 8vw, 104px) clamp(20px, 7vw, 104px);
}

.eyebrow,
.section-label,
.mono {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1,
h2 {
  font-family: var(--serif);
  font-weight: 500;
  letter-spacing: 0;
}

h1 {
  max-width: 780px;
  margin-top: 12px;
  font-size: clamp(56px, 9vw, 116px);
  line-height: 0.94;
}

.lede {
  max-width: 700px;
  margin-top: 28px;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: clamp(24px, 3vw, 36px);
  line-height: 1.18;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  border: 1px solid var(--rule-2);
  border-radius: 8px;
  background: var(--paper);
  padding: 10px 16px;
  box-shadow: var(--shadow-sm);
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}

.button.primary {
  border-color: var(--ink);
  background: var(--ink);
  color: var(--paper);
}

.example-file {
  position: relative;
  min-height: 480px;
  width: 100%;
  max-width: 460px;
  margin-inline: auto;
}

.file-stack {
  position: relative;
  min-height: 438px;
  perspective: 1200px;
}

.product-card {
  position: absolute;
  inset: 0;
  border: 1px solid var(--rule);
  border-radius: 10px;
  background: var(--paper);
  box-shadow: var(--shadow-md);
  padding: clamp(22px, 4vw, 34px);
  transform-origin: 50% 110%;
  transition:
    opacity 420ms ease,
    transform 520ms cubic-bezier(0.22, 1, 0.36, 1);
  will-change: transform, opacity;
}

.product-card[data-position="front"] {
  z-index: 3;
  opacity: 1;
  transform: translate3d(0, 0, 0) rotate(0deg);
}

.product-card[data-position="middle"] {
  z-index: 2;
  opacity: 0.76;
  transform: translate3d(18px, -18px, -42px) rotate(2.6deg);
}

.product-card[data-position="back"] {
  z-index: 1;
  opacity: 0.52;
  transform: translate3d(34px, -34px, -82px) rotate(5deg);
}

.file-stack.is-rotating .product-card[data-position="front"] {
  opacity: 0;
  transform: translate3d(-34px, 34px, 40px) rotate(-7deg);
}

.file-next {
  position: absolute;
  right: 10px;
  bottom: 26px;
  border: 1px solid var(--rule-2);
  border-radius: 999px;
  background: var(--paper);
  padding: 7px 10px;
  box-shadow: var(--shadow-sm);
  color: var(--ink-3);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.confidence {
  display: inline-flex;
  gap: 4px;
}

.dot {
  width: 9px;
  height: 9px;
  border: 1.2px solid var(--rule-2);
  border-radius: 50%;
}

.dot.filled {
  border-color: var(--known);
  background: var(--known);
}

.dot.warm {
  border-color: var(--accent);
  background: var(--accent);
}

.dot.gold {
  border-color: var(--c-gist);
  background: var(--c-gist);
}

.dot.quiet {
  border-color: var(--c-dunno);
  background: var(--c-dunno);
}

.product-card h2 {
  margin-top: 28px;
  font-size: clamp(36px, 5vw, 54px);
  line-height: 1;
}

.product-card p {
  margin-top: 16px;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: 21px;
  line-height: 1.35;
}

.note {
  margin-top: 28px;
  border-top: 1px solid var(--rule);
  padding-top: 20px;
}

.note p {
  margin-top: 8px;
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.45;
}

.band {
  display: grid;
  grid-template-columns: minmax(140px, 260px) minmax(0, 860px);
  gap: clamp(22px, 5vw, 72px);
  border-top: 1px solid var(--rule);
  padding: clamp(56px, 9vw, 108px) clamp(20px, 7vw, 104px);
}

.band.problem {
  background: var(--paper-2);
}

.band.philosophy {
  background: var(--paper);
}

.section-body h2,
.split h2,
.closing h2 {
  font-size: clamp(38px, 5vw, 72px);
  line-height: 1.02;
}

.section-body > p,
.split .section-body p {
  max-width: 790px;
  margin-top: 22px;
  color: var(--ink-2);
  font-family: var(--serif);
  font-size: clamp(22px, 2.4vw, 31px);
  line-height: 1.22;
}

.split .section-body p.small-note {
  max-width: 700px;
  border-left: 2px solid var(--rule-2);
  padding-left: 16px;
  color: var(--ink-3);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.45;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 34px;
  border: 1px solid var(--rule);
  background: var(--rule);
}

.feature-grid article {
  min-height: 210px;
  background: var(--paper);
  padding: 28px;
}

.feature-grid h3 {
  font-family: var(--serif);
  font-size: 30px;
  font-weight: 500;
  line-height: 1.05;
}

.feature-grid p {
  margin-top: 14px;
  color: var(--ink-3);
  font-size: 17px;
}

.confidence-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.confidence-list li {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper) 82%, white);
  padding: 5px 9px 5px 7px;
  color: var(--ink-2);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.02em;
}

.level {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--rule-2);
}

.level.solid {
  background: var(--c-solid);
}

.level.gist {
  background: var(--c-gist);
}

.level.fuzzy {
  background: var(--c-fuzzy);
}

.level.dunno {
  border: 1px solid var(--rule-2);
  background: var(--c-dunno);
}

.level.eek {
  background: var(--c-eek);
  box-shadow: 0 0 0 2px color-mix(in oklch, var(--c-eek) 20%, transparent);
}

.split {
  grid-template-columns: minmax(260px, 430px) minmax(0, 760px);
  background: var(--paper-2);
}

.split .section-label {
  display: block;
  margin-bottom: 16px;
}

.closing {
  display: grid;
  justify-items: start;
  gap: 26px;
  border-top: 1px solid var(--rule);
  padding: clamp(64px, 10vw, 126px) clamp(20px, 16vw, 260px);
  text-align: left;
}

.closing h2 {
  max-width: 980px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  border-top: 1px solid var(--rule);
  padding: 26px clamp(20px, 5vw, 64px);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 12px;
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 3px;
  }

  .hero,
  .band,
  .split {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .example-file,
  .file-stack {
    min-height: 470px;
    max-width: 620px;
  }
}

@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

  .site-header {
    padding: 14px 16px;
  }

  .brand-line {
    display: none;
  }

  .hero {
    padding: 42px 16px 56px;
  }

  h1 {
    font-size: 54px;
  }

  .lede {
    font-size: 24px;
  }

  .hero-actions,
  .button {
    width: 100%;
  }

  .band,
  .split,
  .closing {
    padding: 52px 16px;
  }

  .section-body h2,
  .split h2,
  .closing h2 {
    font-size: 38px;
  }

  .section-body > p,
  .split .section-body p {
    font-size: 22px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-grid article {
    min-height: auto;
    padding: 22px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    padding: 24px 16px;
  }
}