:root {
  --paper: #f5f5f7;
  --white: #fff;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #d2d2d7;
  --blue: #06c;
  --radius: 18px;
  --shell: min(1120px, calc(100% - 48px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Helvetica Neue", Arial, sans-serif; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
.section-shell { width: var(--shell); margin: 0 auto; }
.site-header { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; height: 68px; padding: 0 max(24px, calc((100% - 1120px) / 2)); border-bottom: 1px solid rgba(210,210,215,.76); background: rgba(245,245,247,.84); backdrop-filter: saturate(180%) blur(18px); }
.brand, nav, .header-link { display: flex; align-items: center; }
.brand { gap: 10px; font-size: 15px; font-weight: 600; letter-spacing: -.01em; }
.brand-mark { display: grid; place-items: center; width: 24px; height: 24px; border-radius: 7px; color: #fff; background: var(--ink); font-size: 12px; }
nav { gap: 28px; margin-left: auto; margin-right: 34px; color: var(--muted); font-size: 13px; }
nav a:hover, .header-link:hover, .text-link:hover { color: var(--blue); }
.header-link { gap: 6px; color: var(--blue); font-size: 13px; }
.hero { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 80px; align-items: end; min-height: 650px; padding: 112px 0 120px; }
.eyebrow, .section-kicker { margin: 0 0 22px; color: var(--muted); font-size: 11px; font-weight: 600; letter-spacing: .14em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
h1 { max-width: 780px; margin-bottom: 30px; font-size: clamp(48px, 7vw, 86px); line-height: .98; letter-spacing: -.065em; font-weight: 650; }
h1 span { color: var(--muted); }
.hero-lede { max-width: 520px; margin-bottom: 38px; color: var(--muted); font-size: 19px; line-height: 1.55; letter-spacing: -.02em; }
.hero-actions { display: flex; align-items: center; gap: 24px; }
.button { display: inline-flex; align-items: center; gap: 10px; min-height: 46px; padding: 0 20px; border-radius: 999px; font-size: 14px; font-weight: 600; transition: transform .2s ease, background .2s ease; }
.button:hover { transform: translateY(-2px); }
.button-dark { color: #fff; background: var(--ink); }
.button-dark:hover { background: #000; }
.text-link { color: var(--blue); font-size: 14px; font-weight: 600; }
.hero-note { padding: 22px 0 6px; border-top: 1px solid var(--ink); }
.note-index { margin-bottom: 64px; color: var(--blue); font-size: 13px; font-weight: 600; }
.hero-note p { margin-bottom: 12px; color: var(--muted); font-size: 13px; }
.hero-note strong { display: block; margin-bottom: 20px; font-size: 21px; line-height: 1.3; letter-spacing: -.04em; }
.hero-note span { display: block; color: var(--muted); font-size: 13px; line-height: 1.5; }
.statement, .saving, .workflow, .inputs, .boundaries, .use, .footer-cta { padding: 120px 0; border-top: 1px solid var(--line); }
h2 { max-width: 790px; margin-bottom: 46px; font-size: clamp(36px, 5.2vw, 64px); line-height: 1.02; letter-spacing: -.06em; font-weight: 620; }
.statement-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 70px; max-width: 850px; margin-left: auto; }
.statement-grid p { color: var(--muted); font-size: 18px; line-height: 1.65; letter-spacing: -.025em; }
.conclusion { padding-bottom: 120px; }
.conclusion-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 70px; padding: 28px 0; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--line); }
.conclusion-label { display: block; margin-bottom: 18px; color: var(--blue); font-size: 12px; font-weight: 600; }
.conclusion h3 { max-width: 560px; margin: 0; font-size: 28px; line-height: 1.2; }
.conclusion p { max-width: 420px; margin: 0; color: var(--muted); font-size: 17px; line-height: 1.55; }
.saving { display: grid; grid-template-columns: 1fr 1.05fr; gap: 90px; }
.saving h2 { margin-bottom: 0; }
.compare-list { border-top: 1px solid var(--ink); }
.compare-row { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; padding: 17px 0; border-bottom: 1px solid var(--line); font-size: 14px; line-height: 1.45; }
.compare-head { color: var(--muted); font-size: 12px; font-weight: 600; }
.compare-row span:last-child { color: var(--blue); }
.workflow h2 { margin-bottom: 64px; }
.workflow-list { max-width: 860px; margin: 0 0 0 auto; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.workflow-list li { display: grid; grid-template-columns: 72px 1fr; gap: 30px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.workflow-list li > span { color: var(--blue); font-size: 13px; font-weight: 600; }
.workflow-list strong { display: block; margin-bottom: 8px; font-size: 18px; letter-spacing: -.025em; }
.workflow-list p { max-width: 600px; margin: 0; color: var(--muted); font-size: 15px; line-height: 1.55; }
.input-output-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 72px; }
h3 { margin-bottom: 24px; font-size: 22px; letter-spacing: -.04em; }
.plain-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.plain-list li { display: flex; justify-content: space-between; gap: 20px; padding: 17px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
.plain-list small { color: var(--muted); font-size: 13px; text-align: right; }
.feedback, .evidence, .actions, .topics, .checklist { padding: 120px 0; border-top: 1px solid var(--line); }
.table-wrap { overflow-x: auto; border-top: 1px solid var(--ink); }
table { width: 100%; min-width: 700px; border-collapse: collapse; text-align: left; font-size: 14px; }
th, td { padding: 17px 16px 17px 0; border-bottom: 1px solid var(--line); vertical-align: top; line-height: 1.45; }
th { color: var(--muted); font-size: 12px; font-weight: 600; }
td:first-child { color: var(--blue); font-weight: 600; }
.empty-note { margin: 18px 0 0; color: var(--muted); font-size: 13px; line-height: 1.6; }
.evidence-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.evidence-grid h3 { margin-bottom: 14px; font-size: 18px; }
.evidence-grid p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.6; }
.metric-strip { display: flex; flex-wrap: wrap; gap: 10px 28px; margin-top: 58px; padding: 16px 0; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.metric-strip strong { color: var(--ink); font-weight: 600; }
.topic-card { padding: 28px 0; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--line); }
.topic-title { display: flex; gap: 22px; align-items: baseline; }
.topic-title span { color: var(--blue); font-size: 13px; font-weight: 600; }
.topic-title h3 { margin: 0; font-size: 28px; }
.topic-details { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 60px; margin: 30px 0 0 44px; }
.topic-details p { margin: 0; padding: 13px 0; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 14px; line-height: 1.55; }
.topic-details b { display: block; margin-bottom: 4px; color: var(--ink); font-size: 12px; }
.check-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 60px; max-width: 850px; margin: 0 0 0 auto; padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.check-grid li { padding: 16px 0 16px 26px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: 14px; position: relative; }
.check-grid li::before { content: "✓"; position: absolute; left: 0; color: var(--blue); font-weight: 700; }
.boundaries { background: var(--ink); color: #fff; width: 100%; padding-left: max(24px, calc((100% - 1120px) / 2)); padding-right: max(24px, calc((100% - 1120px) / 2)); }
.boundaries .section-kicker { color: #a1a1a6; }
.boundary-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 72px; max-width: 900px; }
.boundary-column h3 { padding-bottom: 18px; border-bottom: 1px solid #48484a; }
.boundary-column ul { margin: 0; padding: 0; list-style: none; }
.boundary-column li { padding: 13px 0; border-bottom: 1px solid #333335; font-size: 16px; }
.boundary-column-muted { color: #a1a1a6; }
.use-panel { max-width: 780px; margin: 0 auto; }
.use-panel h2 { margin-bottom: 34px; }
pre { margin: 0 0 24px; padding: 26px 28px; overflow-x: auto; border-radius: var(--radius); color: #e8e8ed; background: #1d1d1f; font: 14px/1.7 ui-monospace, SFMono-Regular, Menlo, monospace; }
.use-footnote { max-width: 600px; margin: 0; color: var(--muted); font-size: 13px; line-height: 1.6; }
.footer-cta { padding-bottom: 96px; }
.footer-cta h2 { margin-bottom: 34px; }
.site-footer { display: flex; justify-content: space-between; padding-top: 22px; padding-bottom: 28px; color: var(--muted); font-size: 12px; }
@media (max-width: 760px) {
  :root { --shell: min(100% - 36px, 600px); }
  .site-header { height: 60px; padding: 0 18px; }
  nav { display: none; }
  .header-link { font-size: 12px; }
  .hero { display: block; min-height: auto; padding: 82px 0 88px; }
  h1 { font-size: clamp(47px, 14vw, 68px); }
  .hero-lede { font-size: 17px; }
  .hero-note { margin-top: 80px; }
  .note-index { margin-bottom: 34px; }
  .statement, .saving, .workflow, .inputs, .boundaries, .use, .footer-cta, .feedback, .evidence, .actions, .topics, .checklist { padding: 82px 0; }
  h2 { font-size: clamp(36px, 11vw, 54px); }
  .statement-grid, .saving, .input-output-grid, .boundary-grid { display: block; }
  .statement-grid p + p { margin-top: 22px; }
  .saving .compare-list { margin-top: 54px; }
  .compare-row { gap: 14px; font-size: 13px; }
  .workflow-list { margin-top: 0; }
  .workflow-list li { grid-template-columns: 42px 1fr; gap: 14px; }
  .input-output-grid > div + div { margin-top: 58px; }
  .conclusion { padding-bottom: 82px; }
  .conclusion-grid, .evidence-grid, .topic-details, .check-grid { display: block; }
  .conclusion-grid > div + div, .evidence-grid > div + div { margin-top: 30px; }
  .topic-title h3 { font-size: 23px; }
  .topic-details { margin-left: 0; }
  .check-grid li { padding-left: 24px; }
  .boundary-column + .boundary-column { margin-top: 54px; }
  .plain-list li { display: block; }
  .plain-list small { display: block; margin-top: 6px; text-align: left; }
  .site-footer { display: block; }
  .site-footer span { display: block; }
  .site-footer span + span { margin-top: 8px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .button { transition: none; } }