*, *::before, *::after { box-sizing: border-box; }
:root { --bg: #f5f4f1; --fg: #1a1a1a; --muted: #66645f; --line: #d8d6d0; --accent: #526e54; --page-width: 1200px; --page-padding: 80px; }
html { scroll-behavior: smooth; scroll-padding-top: 36px; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: 'Figtree', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-underline-offset: 4px; text-decoration-thickness: 1px; }
a:hover { text-decoration-color: var(--accent); }
a:focus-visible, button:focus-visible, [tabindex]:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
::selection { background: #dce4d6; color: var(--fg); }
.site-nav, .page, .site-footer { max-width: var(--page-width); margin: 0 auto; padding-left: var(--page-padding); padding-right: var(--page-padding); }
.site-nav { display: flex; align-items: center; justify-content: space-between; gap: 32px; padding-top: 34px; padding-bottom: 34px; }
.brand { display: inline-flex; align-items: center; gap: 16px; text-decoration: none; }
.brand-icon { display: block; width: 60px; height: 60px; border-radius: 14px; box-shadow: 5px 5px 0 var(--fg); }
.wordmark { font-size: 16px; font-weight: 700; letter-spacing: .05em; }
.nav-links { display: flex; gap: 48px; flex-wrap: wrap; }
.nav-links a { color: var(--muted); font-size: 14px; white-space: nowrap; text-decoration: none; transition: color 160ms ease; }
.nav-links a:hover, .nav-links a[aria-current] { color: var(--fg); }
.nav-links a[aria-current] { text-decoration: underline; text-underline-offset: 7px; }
.guide-hero { display: grid; grid-template-columns: 1.35fr 1fr; align-items: start; gap: 70px; padding: 96px 0 88px; }
.eyebrow, .section-number { margin: 0 0 24px; color: var(--muted); font-size: 11px; font-weight: 500; line-height: 1.5; letter-spacing: .12em; text-transform: uppercase; }
h1 { margin: 0 0 24px; font-size: clamp(40px, 4.7vw, 61px); font-weight: 500; line-height: 1.07; letter-spacing: -.045em; }
.hero-intro { margin: 0; color: var(--muted); font-size: 17px; line-height: 1.7; }
.image-source-note { margin: 19px 0 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.quick-start { padding-bottom: 3px; }
.quick-start .eyebrow { margin-bottom: 16px; }
.quick-start a { display: grid; grid-template-columns: 22px 1fr 14px; align-items: baseline; gap: 12px; padding: 17px 0; border-top: 1px solid var(--line); text-decoration: none; font-size: 15px; transition: color 160ms ease; }
.quick-start a:last-child { border-bottom: 1px solid var(--line); }
.quick-start a:hover { color: var(--accent); }
.quick-start small { display: block; margin-top: 6px; color: var(--muted); font-size: 12px; line-height: 1.5; }
.step-number { color: var(--muted); font-size: 11px; font-variant-numeric: tabular-nums; }
.guide-layout { display: grid; grid-template-columns: 200px minmax(0, 1fr); gap: 80px; border-top: 1px solid var(--line); }
.guide-toc { position: sticky; top: 36px; padding: 44px 0 24px; }
.guide-toc .eyebrow { margin-bottom: 19px; }
.guide-toc a { display: flex; gap: 12px; padding: 9px 0; color: var(--muted); font-size: 13px; text-decoration: none; line-height: 1.4; }
.guide-toc a span { font-size: 10px; line-height: 1.8; font-variant-numeric: tabular-nums; }
.guide-toc a:hover, .guide-toc a[aria-current] { color: var(--fg); }
.guide-toc a[aria-current] { font-weight: 600; }
.guide-toc a[aria-current] span { color: var(--accent); }
.guide-toc .toc-help { margin-top: 22px; padding-top: 23px; border-top: 1px solid var(--line); }
.guide-section { padding: 55px 0 58px; border-bottom: 1px solid var(--line); scroll-margin-top: 12px; }
.guide-section:first-child { padding-top: 44px; }
.section-number { margin-bottom: 14px; }
h2 { margin: 0 0 23px; font-size: clamp(26px, 2.7vw, 33px); font-weight: 500; line-height: 1.2; letter-spacing: -.03em; }
h3 { margin: 32px 0 10px; font-size: 17px; line-height: 1.4; font-weight: 500; letter-spacing: -.015em; }
.guide-section p, .guide-help p:not(.eyebrow) { margin: 0 0 18px; color: var(--muted); font-size: 15px; line-height: 1.8; }
strong { color: var(--fg); font-weight: 500; }
.steps { margin: 25px 0; padding: 0; list-style: none; counter-reset: steps; }
.steps li { position: relative; padding: 0 0 0 34px; margin-bottom: 19px; color: var(--muted); font-size: 15px; line-height: 1.8; counter-increment: steps; }
.steps li::before { content: counter(steps, decimal-leading-zero); position: absolute; top: 3px; left: 0; font-size: 11px; color: var(--accent); font-variant-numeric: tabular-nums; }
.guide-section .note { margin: 27px 0 0; padding: 0 0 0 17px; border-left: 2px solid #9cae94; font-size: 13px; line-height: 1.85; }
kbd { display: inline-block; font: inherit; font-size: 12px; line-height: 1.5; padding: 1px 5px; border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 3px; color: var(--fg); white-space: nowrap; vertical-align: baseline; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .86em; padding: 1px 4px; color: var(--fg); background: #e9e7e2; }
.detail-pair, .mode-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px; margin: 30px 0; }
.detail-pair h3 { margin-top: 0; }
.detail-pair p, .mode-pair p { font-size: 14px; margin-bottom: 0; }
.detail-pair p + p { margin-top: 12px; }
.mode-pair { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 24px 0; }
.mode-pair h3 { margin-top: 13px; }
.mode-symbol { display: block; width: 24px; height: 28px; font-size: 23px; line-height: 28px; }
.settings-list { margin: 24px 0 0; }
.settings-list > div { display: grid; grid-template-columns: 136px 1fr; gap: 20px; padding: 16px 0; border-top: 1px solid var(--line); font-size: 14px; line-height: 1.8; }
dt { font-weight: 500; }
dd { margin: 0; color: var(--muted); }
.shortcut-table { width: 100%; border-collapse: collapse; margin: 26px 0 0; text-align: left; font-size: 14px; }
.shortcut-table th, .shortcut-table td { padding: 14px 0; border-bottom: 1px solid var(--line); font-weight: 400; line-height: 1.8; }
.shortcut-table thead th { color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: .08em; }
.shortcut-table td, .shortcut-table thead th:last-child { text-align: right; padding-left: 16px; }
.shortcut-table th[scope="row"] { width: 45%; }
.timeline-example { margin: 34px 0 36px; border: 1px solid var(--line); padding: 24px; }
.timeline-caption { display: flex; justify-content: space-between; gap: 20px; margin-bottom: 24px; font-size: 13px; }
.timeline-caption span:last-child { color: var(--muted); font-size: 11px; white-space: nowrap; }
.timeline-drawing { position: relative; height: 235px; margin-right: 2px; }
.hour { position: absolute; width: 100%; height: 1px; padding-right: 5px; color: var(--muted); font-size: 10px; line-height: 1; font-variant-numeric: tabular-nums; }
.hour::after { content: ''; position: absolute; left: 49px; right: 0; top: 4px; border-top: 1px solid #e0ded8; }
.hour-eight { top: 0; }.hour-nine { top: 100px; }.hour-ten { top: 200px; }
.example-block { position: absolute; left: 53px; right: 0; padding: 8px 10px; font-size: 12px; line-height: 1.3; border-left: 2px solid currentColor; }
.example-block span { display: block; }
.example-block small { display: block; margin-top: 4px; font-size: 10px; }
.read-block { top: 5px; height: 50px; background: #e4e8dc; color: #45563c; }
.write-block { top: 105px; right: 34%; height: 96px; background: #dfe6e9; color: #405b70; }
.walk-block { top: 179px; left: 70%; height: 50px; background: #ece0d1; color: #795e3c; }
.example-now { position: absolute; top: 154px; left: 47px; right: 0; height: 1px; background: var(--accent); }
.example-now::after { content: ''; position: absolute; left: 0; top: -3px; width: 2px; height: 7px; background: var(--accent); }
.example-now span { position: absolute; right: 100%; top: -7px; padding: 2px 4px; background: var(--accent); color: #fff; font-size: 10px; font-variant-numeric: tabular-nums; }
figcaption { color: var(--muted); font-size: 12px; line-height: 1.7; margin-top: 13px; }
.guide-figure { margin: 32px 0; }
.guide-image { display: block; text-decoration: none; cursor: zoom-in; border: 1px solid var(--line); background: #fff; }
.image-viewport { display: block; position: relative; overflow: hidden; width: 100%; }
.image-viewport img { display: block; width: 100%; height: auto; }
.image-overview { aspect-ratio: 8 / 5; }
/* Existing demo frames contain a fictional desktop around the actual app.
   Show only the native 600 px Nook panel without modifying the source image. */
.image-app { aspect-ratio: 600 / 440; }
.image-app img.source-desktop { position: absolute; width: 288%; max-width: none; left: -188%; top: 0; }
.image-review { aspect-ratio: 600 / 480; }
.image-focus { aspect-ratio: 600 / 710; }
.image-settings { aspect-ratio: 600 / 740; }
.image-sound { aspect-ratio: 600 / 240; }
.image-sound img { position: absolute; bottom: 0; left: 0; }
.enlarge-label { display: block; border-top: 1px solid var(--line); padding: 9px 12px; color: var(--muted); background: var(--bg); text-align: right; font-size: 11px; }
.guide-image:hover .enlarge-label { color: var(--fg); }
.image-viewer { width: min(980px, calc(100vw - 36px)); max-width: none; max-height: calc(100dvh - 36px); padding: 20px; border: 1px solid var(--line); color: var(--fg); background: var(--bg); }
.image-viewer::backdrop { background: rgb(26 26 26 / .65); }
.image-viewer-header { display: flex; justify-content: space-between; align-items: center; gap: 20px; }
.image-viewer-header h2 { margin: 0; font-size: 18px; letter-spacing: -.015em; }
.image-viewer-close { display: flex; align-items: center; gap: 16px; flex-shrink: 0; padding: 9px 12px; border: 1px solid var(--line); font: inherit; font-size: 13px; background: transparent; color: inherit; cursor: pointer; }
.image-viewer-close:hover { background: #e9e7e2; }
.image-viewer > p { color: var(--muted); font-size: 12px; line-height: 1.6; margin: 14px 0; }
.image-viewer-scroll { max-height: calc(100dvh - 170px); overflow: auto; overscroll-behavior: contain; border: 1px solid var(--line); background: #fff; }
.image-viewer-content { width: 100%; }
.image-viewer-content .image-viewport { min-width: 600px; }
.image-viewer-content .image-overview { min-width: 1200px; }
html.image-viewer-open { overflow: hidden; }
.guide-help { padding: 58px 0 92px; }
.guide-help .eyebrow { margin-bottom: 16px; }
.text-link { display: inline-flex; gap: 16px; padding: 10px 0; font-size: 14px; }
.site-footer { display: flex; justify-content: space-between; gap: 24px; padding-top: 26px; padding-bottom: 32px; border-top: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.site-footer div { display: flex; flex-wrap: wrap; gap: 25px; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
.skip-link { position: absolute; left: 24px; top: -100px; z-index: 5; padding: 12px; background: var(--fg); color: var(--bg); }
.skip-link:focus { top: 12px; }
@media (max-width: 1050px) {
    .nav-links { gap: 16px 24px; }
}
@media (max-width: 1000px) {
    :root { --page-padding: 40px; }
    .guide-layout { grid-template-columns: 176px minmax(0, 1fr); gap: 40px; }
    .guide-hero { gap: 36px; }
}
@media (max-width: 760px) {
    :root { --page-padding: 28px; }
    .site-nav { align-items: flex-start; flex-direction: column; gap: 28px; padding-top: 24px; padding-bottom: 24px; }
    .brand-icon { width: 52px; height: 52px; border-radius: 12px; }
    .nav-links { gap: 24px; }
    .guide-hero { grid-template-columns: 1fr; gap: 40px; padding: 56px 0 48px; }
    h1 { font-size: clamp(39px, 7vw, 54px); }
    .quick-start { max-width: 460px; }
    .guide-layout { grid-template-columns: minmax(0, 1fr); gap: 0; }
    .guide-toc { position: static; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 18px; padding: 28px 0; border-bottom: 1px solid var(--line); }
    .guide-toc .eyebrow { grid-column: 1 / -1; margin-bottom: 12px; }
    .guide-toc a { padding: 9px 0; gap: 8px; font-size: 12px; }
    .guide-toc .toc-help { display: none; }
    .guide-section, .guide-section:first-child { padding: 42px 0; }
    .site-footer { flex-direction: column; }
}
@media (max-width: 430px) {
    :root { --page-padding: 22px; }
    .nav-links { gap: 10px; }
    .nav-links a { font-size: 12px; }
    .detail-pair { grid-template-columns: 1fr; gap: 23px; }
    .mode-pair { gap: 20px; }
    .settings-list > div { grid-template-columns: 1fr; gap: 3px; }
    .timeline-example { padding: 17px 13px; }
    .timeline-caption { flex-direction: column; gap: 6px; }
    .shortcut-table { font-size: 12px; }
    .shortcut-table td { padding-left: 8px; }
    kbd { font-size: 11px; padding-left: 4px; padding-right: 4px; }
    .image-viewer { width: calc(100vw - 20px); max-height: calc(100dvh - 20px); padding: 14px; }
    .image-viewer-header h2 { font-size: 15px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* Native desktop Sync component captures, using fictional account state. */
.sync-guide-figure .guide-image { max-width: 360px; }

.guide-illustration { display: block; width: 100%; max-width: 460px; height: auto; margin-top: 26px; }