:root {
  color-scheme: light;
  --paper: #f8f4eb;
  --paper-light: #fffdf8;
  --paper-deep: #eee8db;
  --ink: #233536;
  --muted: #5b6864;
  --accent: #b36c4e;
  --accent-dark: #85472f;
  --line: #d9d8c9;
  --focus: #174f59;
  --serif: Georgia, 'Times New Roman', serif;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-family: var(--sans);
  background: var(--paper);
  color: var(--ink);
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 2rem; }
body { margin: 0; font-size: 1rem; line-height: 1.65; }
body.dialog-open { overflow: hidden; }
img, svg { display: block; max-width: 100%; }
img { height: auto; }
figure { margin: 0; }
button, input, select, textarea { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
a { color: inherit; text-underline-offset: .22em; text-decoration-thickness: 1px; }
a:hover { color: var(--accent-dark); }
button:focus-visible,
a:focus-visible,
summary:focus-visible { outline: 3px solid var(--focus); outline-offset: 5px; }
h1, h2, h3, p, ul, ol { margin-top: 0; }
h1, h2, h3 { text-wrap: balance; }
h1, h2 { font-family: var(--serif); font-weight: 400; }
h1 { font-size: clamp(2.7rem, 5.6vw, 5.5rem); line-height: 1.025; letter-spacing: -.055em; }
h2 { font-size: clamp(2rem, 3.5vw, 3.2rem); line-height: 1.14; letter-spacing: -.035em; }
h3 { font-size: 1.13rem; line-height: 1.4; font-weight: 650; }
p { margin-bottom: 1.2rem; }
li + li { margin-top: .55rem; }
[id] { scroll-margin-top: 2rem; }
.wrapper { width: min(100% - 4rem, 1160px); margin-inline: auto; }
.skip-link {
  position: fixed;
  z-index: 100;
  left: 1rem;
  top: 1rem;
  padding: .75rem 1rem;
  background: var(--ink);
  color: #fff;
  transform: translateY(-180%);
}
.skip-link:focus { transform: translateY(0); }
.site-header { border-bottom: 1px solid var(--line); }
.header-inner { display: flex; align-items: center; gap: 2rem; min-height: 100px; }
.brand { display: inline-flex; align-items: center; gap: .7rem; text-decoration: none; flex: 0 0 auto; }
.brand-icon { width: 38px; height: 38px; color: var(--accent); }
.brand-name { font-family: var(--serif); font-size: 1.8rem; letter-spacing: -.055em; line-height: 1.1; }
.brand:hover { color: var(--ink); }
.primary-nav { display: flex; align-items: center; justify-content: center; gap: 1.85rem; margin-left: auto; font-size: .875rem; }
.primary-nav a { display: inline-flex; align-items: center; min-height: 44px; text-decoration: none; }
.primary-nav a:hover { text-decoration: underline; }
.primary-nav a[aria-current='page'] { text-decoration: underline; text-decoration-color: var(--accent); }
.lang-switch { display: inline-flex; align-items: center; justify-content: center; gap: .4rem; min-height: 44px; padding: .35rem .85rem; border: 1px solid var(--line); border-radius: 2px; font-size: .8rem; line-height: 1.3; text-decoration: none; white-space: nowrap; }
.lang-switch:hover { border-color: var(--accent); }
.nav-toggle { display: none; min-width: 44px; min-height: 44px; border: 1px solid var(--line); background: transparent; color: var(--ink); padding: .5rem .7rem; font-size: .8rem; }
.local-tag { display: inline-block; color: var(--muted); font-size: .65rem; font-weight: 600; line-height: 1.4; letter-spacing: .09em; text-transform: uppercase; }
.draft-notice { display: flex; align-items: flex-start; gap: .7rem; padding-block: .9rem; color: #655640; font-size: .9375rem; line-height: 1.65; border-bottom: 1px solid var(--line); }
.draft-notice p { margin: 0; }
.draft-notice strong { font-weight: 650; }
.draft-notice .local-tag { margin-right: .7rem; }
.notice-icon { flex: 0 0 auto; display: grid; place-items: center; width: 18px; height: 18px; margin-top: .15rem; border: 1px solid #938268; border-radius: 50%; font-family: var(--serif); font-size: .8rem; line-height: 1; }
.eyebrow { margin-bottom: 1.05rem; color: var(--accent-dark); font-size: .7rem; font-weight: 700; line-height: 1.5; letter-spacing: .14em; text-transform: uppercase; }
.home-hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 4.4rem; align-items: center; padding-top: 4.2rem; padding-bottom: 4.7rem; }
.hero-copy { padding-block: 1rem; }
.hero-copy h1 { max-width: 10.5ch; margin-bottom: 1.5rem; }
.hero-lead { max-width: 36ch; margin-bottom: 1.8rem; color: var(--muted); font-size: 1.06rem; line-height: 1.8; }
.actions { display: flex; align-items: center; flex-wrap: wrap; gap: .75rem 1.2rem; }
.button { display: inline-flex; justify-content: center; align-items: center; gap: .6rem; min-height: 50px; padding: .8rem 1.25rem; border: 1px solid var(--ink); border-radius: 2px; font-size: .81rem; font-weight: 600; line-height: 1.45; text-decoration: none; transition: background-color 150ms, color 150ms, border-color 150ms; }
.button.primary { background: var(--ink); color: var(--paper-light); }
.button.primary:hover { background: #3d5150; border-color: #3d5150; }
.button.secondary { background: transparent; color: var(--ink); border-color: var(--line); }
.button.secondary:hover { border-color: var(--ink); background: var(--paper-deep); }
.hero-art { position: relative; padding: 1.5rem 1.5rem 1rem; border: 1px solid var(--line); background: var(--paper-light); }
.hero-art::before { content: ''; position: absolute; top: .75rem; left: .75rem; right: .75rem; bottom: .75rem; pointer-events: none; border: 1px solid #e9e5d9; }
.hero-art img { width: 100%; aspect-ratio: 1.08; object-fit: contain; }
.art-note { position: relative; display: block; padding: .4rem .75rem .3rem; color: var(--muted); text-align: center; font-size: .72rem; line-height: 1.6; }
.hero-meta { display: flex; align-items: center; flex-wrap: wrap; gap: .65rem 1.3rem; margin-top: 1.55rem; color: var(--muted); font-size: .72rem; }
.hero-meta span { display: inline-flex; align-items: center; gap: .5rem; }
.hero-meta span::before { content: ''; width: 4px; height: 4px; background: var(--accent); border-radius: 50%; }
.section-heading { display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: 1rem; margin-bottom: 1.6rem; }
.section-heading h2 { margin: 0; }
.section-heading > p { max-width: 38ch; margin: 0; color: var(--muted); font-size: .85rem; }
.section-heading > .eyebrow { flex-basis: 100%; max-width: none; color: var(--accent-dark); font-size: .7rem; margin-bottom: -.55rem; }
.tutorial-feature { display: grid; grid-template-columns: 1fr 1fr; background: var(--paper-light); border: 1px solid var(--line); }
.feature-image { display: grid; place-items: center; padding: 2.4rem; background: var(--paper-deep); }
.feature-image img { width: 100%; max-width: 390px; aspect-ratio: 1.1; object-fit: contain; }
.feature-copy { align-self: center; padding: 2.5rem 3rem; }
.feature-copy .eyebrow { margin-bottom: .8rem; }
.feature-copy h2, .feature-copy h3 { margin-bottom: 1.2rem; font-family: var(--serif); font-size: clamp(2rem, 3.5vw, 3.2rem); line-height: 1.14; letter-spacing: -.035em; font-weight: 400; }
.feature-copy > p { color: var(--muted); font-size: .975rem; }
.details-list { display: flex; flex-wrap: wrap; gap: .4rem 1rem; padding: 0; list-style: none; margin-bottom: 1.5rem; color: var(--muted); font-size: .9375rem; }
.details-list li { margin: 0; }
.how-section { padding-top: 5rem; padding-bottom: 4.8rem; }
.how-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 2.5rem; padding-top: 1.4rem; }
.how-grid article { padding-top: 1.2rem; border-top: 1px solid var(--line); }
.how-number { display: block; margin-bottom: 1.1rem; font-family: var(--serif); color: var(--accent); font-size: 1.5rem; line-height: 1; }
.how-grid h3 { margin-bottom: .6rem; font-size: .95rem; }
.how-grid p { max-width: 32ch; margin: 0; font-size: .975rem; color: var(--muted); }
.paper-strip { display: flex; align-items: center; gap: 1.6rem; padding: 1.6rem 2rem; background: var(--paper-deep); border: 1px solid var(--line); }
.paper-swatch { flex: 0 0 auto; width: 43px; height: 43px; background: var(--accent); transform: rotate(-10deg); box-shadow: 7px 6px 0 #d3b28c; }
.paper-strip h2, .paper-strip h3 { margin-bottom: .25rem; font-family: var(--serif); font-weight: 400; font-size: 1.6rem; letter-spacing: -.025em; }
.paper-strip p { margin: 0; color: var(--muted); font-size: .975rem; }
.paper-strip > a { display: inline-flex; align-items: center; min-height: 44px; flex-shrink: 0; margin-left: auto; font-size: .8rem; }
.site-footer { margin-top: 5rem; border-top: 1px solid var(--line); }
.footer-inner { display: grid; grid-template-columns: 1fr auto; gap: 1rem 3rem; padding-block: 2.3rem 1.6rem; }
.footer-brand .brand-name { font-size: 1.45rem; }
.footer-brand > p { max-width: 43ch; margin: .45rem 0 0; color: var(--muted); font-size: .9375rem; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: flex-end; align-content: flex-start; gap: .1rem 1.2rem; font-size: .76rem; }
.footer-links a { display: inline-flex; align-items: center; min-height: 44px; }
.credit { grid-column: 1 / -1; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .9375rem; line-height: 1.8; }
.credit p { margin: 0; }

/* A direct language choice is the only page at the local root. */
.language-page { min-height: 55vh; padding-block: 5rem 3rem; }
.language-page main > .brand { margin-bottom: 3rem; }
.language-page .draft-notice { margin-top: 2.2rem; }
.language-page h1 { max-width: 17ch; margin-bottom: 1.5rem; font-size: clamp(2.6rem, 5vw, 4.6rem); }
.language-page > p { max-width: 60ch; color: var(--muted); }
.language-cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1.5rem; margin-top: 2.3rem; }
.language-card { display: block; padding: 2rem; border: 1px solid var(--line); background: var(--paper-light); text-decoration: none; }
.language-card:hover { border-color: var(--accent); }
.language-card h2 { margin-bottom: .6rem; }
.language-card p { margin-bottom: 0; color: var(--muted); font-size: .9rem; }
.language-card > span:first-child { display: block; margin-bottom: .8rem; color: var(--accent-dark); font-size: .75rem; letter-spacing: .12em; font-weight: 700; }
.language-card > strong { display: block; font-family: var(--serif); font-size: 2.7rem; line-height: 1.1; letter-spacing: -.04em; font-weight: 400; }
.language-card > span:last-child { display: flex; align-items: center; min-height: 44px; margin-top: 1.3rem; color: var(--accent-dark); font-size: .9375rem; }

/* Tutorial pages keep the paper orientation and the action/result pair prominent. */
.breadcrumb { display: flex; align-items: center; flex-wrap: wrap; gap: .2rem .55rem; padding-top: 1.1rem; color: var(--muted); font-size: .72rem; }
.breadcrumb a { display: inline-flex; align-items: center; min-height: 44px; }
.tutorial-hero { display: grid; grid-template-columns: 1.5fr 1fr; gap: 3.8rem; align-items: center; padding-block: 1.8rem 3.4rem; }
.tutorial-heading h1 { max-width: 16ch; margin-bottom: 1.3rem; font-size: clamp(2.7rem, 4.8vw, 4.5rem); }
.tutorial-heading > p { max-width: 48ch; color: var(--muted); font-size: .96rem; line-height: 1.8; }
.tutorial-facts { display: flex; flex-wrap: wrap; gap: .5rem 1.2rem; padding-top: .5rem; color: var(--muted); font-size: .74rem; }
.tutorial-facts span { display: inline-flex; align-items: center; gap: .5rem; }
.tutorial-facts span + span::before { content: ''; display: inline-block; height: 12px; width: 1px; margin-right: .2rem; background: var(--line); }
.tutorial-cover { padding: 1.25rem; background: var(--paper-light); border: 1px solid var(--line); }
.tutorial-cover img { width: 100%; max-height: 325px; aspect-ratio: 1.1; object-fit: contain; }
.tutorial-cover figcaption { margin-top: .4rem; color: var(--muted); text-align: center; font-size: .7rem; }
.tutorial-layout { display: grid; grid-template-columns: 205px minmax(0, 1fr); gap: 3.4rem; align-items: start; border-top: 1px solid var(--line); padding-top: 2.6rem; }
.tutorial-index { position: sticky; top: 2rem; font-size: .78rem; }
.tutorial-index details { padding-bottom: 1rem; }
.tutorial-index details > a { display: flex; align-items: center; min-height: 44px; padding-block: .55rem; color: var(--muted); line-height: 1.5; text-decoration: none; }
.tutorial-index details > a:hover { color: var(--accent-dark); text-decoration: underline; }
.tutorial-index summary { display: flex; align-items: center; justify-content: space-between; min-height: 44px; cursor: pointer; color: var(--ink); font-size: .68rem; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; list-style: none; }
.tutorial-index summary::-webkit-details-marker { display: none; }
.tutorial-index summary::after { content: '+'; font-size: 1.1rem; font-weight: 400; }
.tutorial-index details[open] summary::after { content: '−'; }
.step-nav { padding: .75rem 0 0; margin: 0; list-style: none; }
.step-nav li { margin: 0; border-bottom: 1px solid var(--line); }
.step-nav a { display: flex; align-items: baseline; gap: .65rem; min-height: 44px; padding: .65rem .55rem .65rem 0; color: var(--muted); font-size: .8125rem; line-height: 1.5; text-decoration: none; }
.step-nav a > span:first-child { flex: 0 0 1.25rem; color: var(--accent-dark); font-family: var(--serif); font-size: .9rem; font-variant-numeric: tabular-nums; }
.step-nav a:hover, .step-nav a[aria-current='step'], .step-nav a.is-active { color: var(--accent-dark); }
.step-nav a[aria-current='step'], .step-nav a.is-active { box-shadow: inset 2px 0 0 var(--accent); padding-left: .65rem; }
.tutorial-body { min-width: 0; }
.tutorial-body h2 { margin-bottom: 1.25rem; font-size: 2.2rem; }
.tutorial-body > section { margin-bottom: 3.8rem; }
.tutorial-body p, .tutorial-body li { font-size: .975rem; }
.materials-grid { display: grid; grid-template-columns: 1.25fr 1fr; gap: 2rem; margin-bottom: 1.75rem; }
.material-list { margin-bottom: 0; padding-left: 1.15rem; }
.material-list li { padding-left: .25rem; }
.material-list li::marker { color: var(--accent); }
.paper-note { align-self: start; padding: 1.2rem 1.35rem; background: var(--paper-deep); border-left: 2px solid var(--accent); color: var(--muted); font-size: .9375rem; }
.paper-note .paper-swatch { display: block; width: 30px; height: 30px; margin: .25rem 0 1.4rem .2rem; box-shadow: 6px 5px 0 #d3b28c; }
.paper-note h3 { margin-bottom: .5rem; font-size: .9rem; color: var(--ink); }
.paper-note p { margin-bottom: .8rem; font-size: .9375rem; }
.paper-note p:last-child { margin-bottom: 0; }
.diagram-legend { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .7rem 1.5rem; list-style: none; margin: 1.75rem 0 1.4rem; padding: 1rem 0; border-block: 1px solid var(--line); }
.diagram-legend li { display: flex; align-items: baseline; gap: .75rem; margin: 0; color: var(--muted); font-size: .9375rem; }
.diagram-legend strong { color: var(--ink); font-weight: 600; }
.legend-mark { display: inline-block; position: relative; flex: 0 0 27px; width: 27px; align-self: center; }
.legend-mark.dash { border-top: 2px dashed var(--ink); }
.legend-mark.thin { border-top: 1px solid var(--muted); }
.legend-mark.arrow { height: 15px; border: 1.5px solid var(--accent-dark); border-right: none; border-bottom: none; border-radius: 70% 0 0 0; }
.legend-mark.arrow::after { content: ''; position: absolute; width: 6px; height: 6px; right: 0; top: -4px; border-right: 1.5px solid var(--accent-dark); border-top: 1.5px solid var(--accent-dark); transform: rotate(45deg); }
.legend-mark.dots::before { content: 'A · B'; font-family: var(--serif); font-size: .8rem; color: var(--accent-dark); white-space: nowrap; }
.orientation-note { padding: 1rem 1.25rem; background: var(--paper-light); border: 1px solid var(--line); color: var(--muted); font-size: .9375rem !important; }
.orientation-note p { margin-bottom: 0; }
#steps > h2 { margin-bottom: 2rem; }
.fold-step { padding-top: .2rem; padding-bottom: 2.8rem; margin-bottom: 2.8rem; border-bottom: 1px solid var(--line); }
.fold-step:last-child { margin-bottom: 0; }
.step-title { display: flex; align-items: center; gap: .8rem; margin-bottom: 1rem; }
.step-number { display: grid; place-items: center; flex: 0 0 auto; width: 35px; height: 35px; border-radius: 50%; border: 1px solid var(--accent); color: var(--accent-dark); font-family: var(--serif); font-size: 1.1rem; line-height: 1; }
.step-title h3 { margin-bottom: 0; font-family: var(--serif); font-size: 1.65rem; font-weight: 400; letter-spacing: -.025em; line-height: 1.3; }
.step-instruction { max-width: 73ch; margin-bottom: .85rem; }
.step-orientation { margin-bottom: 1.4rem; padding-left: 1rem; border-left: 2px solid var(--line); color: var(--muted); font-size: .9375rem !important; }
.diagram-pair { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1rem; margin-bottom: 1.25rem; }
.diagram-pair.single { grid-template-columns: minmax(0, 1fr); max-width: 490px; }
.diagram-card { overflow: hidden; background: var(--paper-light); border: 1px solid var(--line); }
.diagram-card > a { display: block; padding: .6rem; background: #fffdf7; cursor: zoom-in; }
.diagram-card > a:hover { background: #f1ecde; }
.diagram-card > a:focus-visible { outline-offset: -5px; }
.diagram-card img { width: 100%; aspect-ratio: 1.14; object-fit: contain; }
.diagram-card figcaption { min-height: 78px; padding: .8rem 1rem; border-top: 1px solid var(--line); }
.diagram-card figcaption strong { display: block; margin-bottom: .2rem; color: var(--accent-dark); font-size: .64rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
.diagram-card figcaption > span { display: flex; align-items: center; gap: .4rem; color: var(--muted); font-size: .9375rem; line-height: 1.55; }
.step-result { padding: .9rem 1.15rem; background: var(--paper-deep); color: #45564e; font-size: .975rem; line-height: 1.75; }
.step-result p { margin: 0; font-size: inherit; }
.step-result strong { font-weight: 650; color: var(--ink); }
.checks-section { padding: 1.8rem 2rem; background: var(--paper-deep); }
.checks-section h2 { font-size: 2rem; }
.checks-list { padding-left: 1.15rem; margin-bottom: 0; }
.checks-list li { padding-left: .3rem; font-size: .975rem; }
.checks-list li::marker { color: var(--accent-dark); }
.final-section { padding-bottom: .7rem; }
.final-section > img, .final-section > figure { width: 100%; max-width: 480px; margin: 1.6rem auto; }
.source-credit { padding-top: 1.7rem; border-top: 1px solid var(--line); color: var(--muted); }
.source-credit h2 { font-family: var(--sans); font-size: .85rem; font-weight: 650; letter-spacing: 0; }
.source-credit p { font-size: .9375rem; line-height: 1.85; }
.source-credit a { overflow-wrap: anywhere; }
.step-pager { display: flex; justify-content: space-between; flex-wrap: wrap; gap: .5rem 1rem; margin-top: 1rem; font-size: .75rem; }
.prev-next { display: inline-flex; align-items: center; min-height: 44px; padding: .5rem 0; }
.prev-next + .prev-next { margin-left: auto; text-align: right; }
#image-dialog { width: min(960px, calc(100% - 2rem)); max-height: calc(100dvh - 2rem); padding: 1rem; overflow: auto; border: 1px solid var(--line); background: var(--paper-light); color: var(--ink); }
#image-dialog::backdrop { background: rgb(20 35 35 / .7); }
.dialog-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: .5rem; }
.dialog-toolbar h2 { margin: 0; font-size: 1.3rem; letter-spacing: -.02em; }
.dialog-toolbar button { min-height: 44px; padding: .5rem 1rem; background: var(--ink); border: 1px solid var(--ink); border-radius: 2px; color: #fff; font-size: .8rem; }
#image-dialog > img { display: block; width: 100%; max-height: 68dvh; object-fit: contain; margin-inline: auto; }
.dialog-caption { max-width: 75ch; margin: .8rem auto .3rem; color: var(--muted); font-size: .9375rem; line-height: 1.7; }

@media (min-width: 1440px) {
  .home-hero { gap: 5.5rem; padding-top: 5rem; padding-bottom: 5.2rem; }
}

@media (max-width: 1000px) {
  .header-inner { gap: 1.2rem; }
  .primary-nav { gap: 1.2rem; }
  .brand-name { font-size: 1.65rem; }
  .home-hero { gap: 2.5rem; }
  .hero-copy h1 { font-size: 4.4rem; }
  .feature-copy { padding: 2rem; }
  .tutorial-layout { grid-template-columns: 170px minmax(0, 1fr); gap: 2rem; }
  .tutorial-hero { gap: 2.5rem; }
  .materials-grid { grid-template-columns: 1fr; gap: 1.25rem; }
  .paper-note { max-width: none; }
}

@media (max-width: 850px) {
  .wrapper { width: min(100% - 2.5rem, 600px); }
  .header-inner { flex-wrap: wrap; gap: .45rem .8rem; min-height: 83px; padding-block: .8rem; }
  .brand { gap: .55rem; margin-right: auto; }
  .brand-icon { width: 31px; height: 31px; }
  .brand-name { font-size: 1.6rem; }
  .lang-switch { padding-inline: .65rem; font-size: .73rem; }
  .primary-nav { order: 4; flex-basis: 100%; justify-content: flex-start; margin: 0; padding-top: .25rem; gap: 1.5rem; }
  .primary-nav a { font-size: .8rem; }
  .js .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .js .primary-nav { display: none; }
  .js .site-header.nav-open .primary-nav { display: flex; }
  .header-inner > .local-tag { order: 5; width: 100%; }
  .draft-notice { gap: .6rem; padding-block: .8rem; font-size: .9375rem; }
  .home-hero { grid-template-columns: 1fr; gap: 2.2rem; padding-block: 2.6rem 3rem; }
  .hero-copy { padding: 0; }
  .hero-copy h1 { max-width: 12ch; margin-bottom: 1.2rem; font-size: clamp(3.2rem, 9.3vw, 4.8rem); }
  .hero-lead { max-width: 45ch; font-size: 1rem; margin-bottom: 1.4rem; }
  .eyebrow { margin-bottom: .8rem; font-size: .65rem; }
  .hero-meta { margin-top: 1.3rem; }
  .hero-art { width: 100%; max-width: 460px; margin-inline: auto; padding: 1rem; }
  .hero-art img { max-height: 360px; aspect-ratio: 1.15; }
  .art-note { font-size: .68rem; }
  .section-heading { display: block; margin-bottom: 1.25rem; }
  .section-heading h2 { font-size: 2.2rem; }
  .section-heading > p { margin-top: .65rem; }
  .tutorial-feature { grid-template-columns: 1fr; }
  .feature-image { padding: 1.5rem; }
  .feature-image img { width: 80%; max-width: 320px; max-height: 290px; }
  .feature-copy { padding: 1.7rem; }
  .feature-copy h2, .feature-copy h3 { font-size: 2.15rem; }
  .how-section { padding-block: 3rem; }
  .how-grid { grid-template-columns: 1fr; gap: 1.6rem; padding-top: .5rem; }
  .how-grid article { display: grid; grid-template-columns: 28px 1fr; gap: 0 1rem; }
  .how-number { grid-row: 1 / 3; margin-top: .2rem; font-size: 1.35rem; }
  .how-grid h3 { grid-column: 2; }
  .how-grid p { grid-column: 2; max-width: 48ch; }
  .paper-strip { flex-wrap: wrap; padding: 1.3rem; gap: 1rem 1.4rem; }
  .paper-strip > div:not(.paper-swatch) { flex: 1; min-width: 0; }
  .paper-strip h2, .paper-strip h3 { font-size: 1.4rem; }
  .paper-strip > a { flex-basis: 100%; margin-left: 0; }
  .paper-swatch { width: 33px; height: 33px; box-shadow: 6px 5px 0 #d3b28c; }
  .site-footer { margin-top: 3rem; }
  .footer-inner { grid-template-columns: 1fr; padding-top: 1.8rem; gap: 1rem; }
  .footer-links { justify-content: flex-start; }
  .credit { padding-top: .9rem; }
  .language-page { padding-top: 2.7rem; }
  .language-page h1 { font-size: 3.1rem; }
  .language-cards { grid-template-columns: 1fr; gap: 1rem; margin-top: 1.8rem; }
  .language-card { padding: 1.5rem; }
  .language-card h2 { font-size: 2rem; }
  .breadcrumb { padding-top: .65rem; font-size: .68rem; }
  .tutorial-hero { grid-template-columns: 1fr; gap: 1.5rem; padding-block: 1.4rem 2rem; }
  .tutorial-heading h1 { max-width: 16ch; font-size: clamp(2.7rem, 8.3vw, 3.7rem); }
  .tutorial-heading > p { font-size: .93rem; margin-bottom: .8rem; }
  .tutorial-facts { gap: .4rem .9rem; font-size: .7rem; }
  .tutorial-cover { max-width: 400px; width: 100%; margin-inline: auto; padding: .8rem; }
  .tutorial-cover img { max-height: 250px; aspect-ratio: 1.4; }
  .tutorial-layout { grid-template-columns: 1fr; gap: 1.8rem; padding-top: 1.2rem; }
  .tutorial-index { position: static; padding: .3rem 1rem; border: 1px solid var(--line); background: var(--paper-light); }
  .tutorial-index details { padding-bottom: 0; }
  .tutorial-index details[open] { padding-bottom: .8rem; }
  .tutorial-index summary { font-size: .67rem; }
  .step-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 0 1rem; padding-top: 0; }
  .step-nav a { font-size: .8125rem; }
  .tutorial-body h2 { font-size: 2rem; }
  .tutorial-body > section { margin-bottom: 2.8rem; }
  .tutorial-body p, .tutorial-body li { font-size: .975rem; }
  .materials-grid { gap: 1rem; margin-bottom: 1.4rem; }
  .paper-note { padding: 1rem 1.1rem; }
  .diagram-legend { gap: .65rem 1.1rem; margin-top: 1.4rem; }
  .diagram-legend li { font-size: .9375rem; }
  .orientation-note { padding: .9rem 1rem; font-size: .9375rem !important; }
  .fold-step { padding-bottom: 2rem; margin-bottom: 2rem; }
  .step-title { gap: .7rem; }
  .step-number { width: 32px; height: 32px; font-size: 1rem; }
  .step-title h3 { font-size: 1.5rem; }
  .step-orientation { font-size: .9375rem !important; }
  .diagram-pair { gap: .75rem; }
  .diagram-card > a { padding: .3rem; }
  .diagram-card figcaption { min-height: 78px; padding: .65rem .75rem; }
  .diagram-card figcaption strong { font-size: .59rem; }
  .diagram-card figcaption > span { font-size: .9375rem; }
  .step-result { padding: .85rem 1rem; font-size: .975rem; }
  .checks-section { padding: 1.4rem; }
  .checks-section h2 { font-size: 1.85rem; }
  .checks-list li { font-size: .975rem; }
  .source-credit p { font-size: .9375rem; }
}

@media (max-width: 420px) {
  .wrapper { width: calc(100% - 2rem); }
  .header-inner { gap: .3rem .45rem; }
  .brand { gap: .4rem; }
  .brand-name { font-size: 1.4rem; }
  .brand-icon { width: 27px; height: 27px; }
  .nav-toggle { padding-inline: .5rem; font-size: .7rem; }
  .lang-switch { padding-inline: .5rem; font-size: .69rem; }
  .home-hero { padding-top: 2.2rem; }
  .hero-copy h1 { font-size: 3.1rem; }
  .hero-lead { font-size: .95rem; }
  .actions { gap: .6rem; }
  .button { font-size: .76rem; padding-inline: 1rem; }
  .hero-meta { gap: .5rem .9rem; font-size: .68rem; }
  .feature-copy { padding: 1.3rem; }
  .feature-copy h2, .feature-copy h3 { font-size: 2rem; }
  .tutorial-heading h1 { font-size: 2.7rem; }
  .tutorial-facts span + span::before { display: none; }
  .step-nav { grid-template-columns: 1fr; }
  .diagram-pair { grid-template-columns: 1fr; gap: .9rem; }
  .diagram-card img { max-height: 310px; }
  .diagram-card figcaption { min-height: 0; padding: .7rem .9rem; }
  .diagram-card figcaption strong { font-size: .62rem; }
  .diagram-card figcaption > span { font-size: .9375rem; }
  .diagram-legend { grid-template-columns: 1fr; gap: .5rem; }
  .checks-section { padding: 1.15rem; }
  #image-dialog { width: calc(100% - 1rem); padding: .6rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}

@media print {
  :root { --paper: #fff; --paper-light: #fff; --paper-deep: #f3f3ee; }
  body { font-size: 10pt; }
  .wrapper { width: 100%; }
  .skip-link, .primary-nav, .nav-toggle, .lang-switch, .tutorial-index, .step-pager, .site-footer, #image-dialog { display: none !important; }
  .header-inner { min-height: auto; padding-bottom: 1rem; }
  .brand-name { font-size: 20pt; }
  .local-tag { display: none; }
  .draft-notice { font-size: 9pt; }
  .tutorial-hero { gap: 1rem; padding-block: 1rem; }
  .tutorial-heading h1 { font-size: 28pt; }
  .tutorial-cover img { max-height: 160px; }
  .tutorial-layout { display: block; padding-top: 1rem; }
  .tutorial-body h2 { font-size: 20pt; }
  .tutorial-body p, .tutorial-body li { font-size: 10pt; }
  .fold-step { break-inside: avoid; page-break-inside: avoid; margin-bottom: 1rem; padding-bottom: 1rem; }
  .step-title h3 { font-size: 17pt; }
  .diagram-pair { grid-template-columns: 1fr 1fr; max-width: 580px; }
  .diagram-card img { max-height: 210px; }
  .diagram-card figcaption { min-height: auto; }
  .diagram-card figcaption > span { font-size: 8pt; }
  .source-credit { break-inside: avoid; }
}

/* Additional materials and catalogue styles are concatenated by the generator. */

/* Materials and exploration extend the retained cream, ink and terracotta design. */
[hidden] { display: none !important; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip-path: inset(50%); white-space: nowrap; border: 0; }
select:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
.primary-nav { gap: 1.2rem; }
.catalogue-section { padding-top: 4.8rem; }
.catalogue-intro { max-width: 68ch; color: var(--muted); }
.catalogue-note, .shopping-disclosure { padding: 1rem 1.2rem; background: var(--paper-deep); border-left: 2px solid var(--accent); color: #45564e; font-size: .9rem; }
.catalogue-filters { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)) auto; gap: 1rem; align-items: end; padding-block: 1rem; }
.catalogue-filter { display: grid; gap: .45rem; min-width: 0; font-size: .85rem; }
.catalogue-filter > span { font-weight: 650; }
.catalogue-filter select { width: 100%; min-height: 50px; padding: .6rem; border: 1px solid var(--line); background: var(--paper-light); color: var(--ink); border-radius: 2px; }
.catalogue-count { margin-top: .5rem; font-size: .85rem; color: var(--muted); }
.catalogue-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 1.2rem; }
.catalogue-card { min-width: 0; border: 1px solid var(--line); background: var(--paper-light); }
.catalogue-art { height: 105px; display: grid; place-items: center; background: var(--paper-deep); overflow: hidden; }
.catalogue-art.has-cover { display: block; height: 190px; padding: .8rem; }
.catalogue-art.has-cover img { width: 100%; height: 100%; min-height: 0; object-fit: contain; }
.legend-mark.dots.boat::before { content: '≋'; font-size: 1.4rem; }
.legend-mark.dots.box::before { content: '+'; font-size: 1.4rem; }
.legend-mark.dots.butterfly::before { content: 'O'; }
.legend-mark.dots.plane::before { content: 'M · A'; }
.legend-mark.dots.modular { flex-basis: 56px; width: 56px; }
.legend-mark.dots.modular::before { content: 'A–F / T–P'; font-size: .75rem; white-space: nowrap; }
.legend-mark.dots.star { flex-basis: 76px; width: 76px; }
.legend-mark.dots.star::before { content: '01–30 / T–P'; font-size: .7rem; white-space: nowrap; }
.related-tutorials { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: .6rem 1.5rem; }
@media (min-width: 851px) { .tutorial-index { max-height: calc(100dvh - 4rem); overflow-y: auto; overscroll-behavior: contain; padding-right: .5rem; } }
@media (max-width: 420px) { .related-tutorials { grid-template-columns: 1fr; } }
.catalogue-art .paper-swatch { width: 40px; height: 40px; }
.catalogue-art.cat, .catalogue-art.flower, .catalogue-art.modular { background: #e1e8df; }
.catalogue-art.boat, .catalogue-art.plane { background: #e0e9ec; }
.catalogue-art.heart, .catalogue-art.garland { background: #eee0d8; }
.catalogue-art.dragon { background: #e2dfe7; }
.catalogue-art.plane .paper-swatch, .catalogue-art.boat .paper-swatch { clip-path: polygon(0 0,100% 40%,25% 100%,35% 50%); transform: rotate(12deg); }
.catalogue-art.heart .paper-swatch { transform: rotate(45deg); width: 32px; height: 32px; }
.catalogue-art.modular .paper-swatch { transform: rotate(45deg); background: #71816e; }
.catalogue-art.dog .paper-swatch { clip-path: polygon(0 0,50% 20%,100% 0,85% 85%,50% 100%,15% 85%); width: 62px; height: 54px; transform: none; }
.catalogue-card-body { padding: 1.3rem; }
.catalogue-card h3 { font-family: var(--serif); font-size: 1.7rem; font-weight: 400; letter-spacing: -.03em; }
.catalogue-card p { font-size: .9rem; color: var(--muted); }
.catalogue-card .catalogue-status { color: var(--accent-dark); font-size: .65rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }
.catalogue-card .catalogue-meta { margin-bottom: .4rem; font-size: .78rem; }
.catalogue-label { font-weight: 650; }
.catalogue-card .button { margin-top: 1rem; }
.catalogue-guide { margin-top: 1.5rem; }
.catalogue-guide > a { flex-shrink: 1; max-width: 24rem; }
.catalogue-empty { padding: 1.5rem; border: 1px solid var(--line); }
.guide-hero { padding-block: 2rem 2.5rem; max-width: 850px; margin-inline: auto; }
.guide-hero h1 { font-size: clamp(2.7rem,5vw,4.8rem); max-width: 20ch; margin-bottom: 1.4rem; }
.guide-hero .hero-lead { max-width: 62ch; }
.paper-comparison { border: 1px solid var(--line); background: var(--paper-light); padding: 1.5rem; }
.paper-samples { display: flex; justify-content: center; align-items: center; gap: 2.4rem; min-height: 150px; }
.paper-samples > span { display: block; width: 88px; height: 88px; box-shadow: 6px 7px 0 #e4dccb; }
.sample-front { background: var(--accent); transform: rotate(-8deg); }
.sample-back { background: #e9dfc9; transform: rotate(5deg); border: 1px solid #c8bea5; }
.sample-fold { background: linear-gradient(135deg,var(--accent) 50%,#e9dfc9 50%); transform: rotate(-4deg); }
.paper-comparison figcaption { color: var(--muted); max-width: 72ch; margin: 1rem auto 0; font-size: .85rem; text-align: center; }
.guide-layout { display: grid; grid-template-columns: 230px minmax(0,1fr); gap: 4rem; padding-top: 1rem; }
.guide-index { align-self: start; position: sticky; top: 1.5rem; padding: 1.2rem; border: 1px solid var(--line); background: var(--paper-light); }
.guide-index summary { cursor: pointer; font-weight: 650; }
.guide-index ol { padding-left: 1.2rem; margin-top: 1rem; }
.guide-index a { display: inline-block; padding-block: .35rem; font-size: .85rem; line-height: 1.6; }
.guide-body { min-width: 0; max-width: 760px; }
.guide-body > h2 { margin-top: 3rem; font-size: clamp(1.8rem,3vw,2.5rem); }
.guide-body > h2:first-of-type { margin-top: 2rem; }
.guide-body > h3 { margin-top: 1.8rem; }
.guide-body p, .guide-body li { font-size: 1rem; line-height: 1.85; }
.guide-body a { overflow-wrap: anywhere; }
.related-guide { background: var(--paper-deep); padding: 1.6rem; margin-block: 3rem; }
.related-guide h2 { font-size: 2rem; }
.related-guide p:last-child { margin: 1rem 0 0; }
.home-shopping { padding-top: 4rem; }
.shopping-section { padding-top: 2rem; border-top: 1px solid var(--line); }
.shopping-section > p { max-width: 80ch; }
.shopping-section h2 { max-width: 22ch; }
.shopping-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 1rem; margin-block: 1.5rem; }
.home-shopping .shopping-grid { grid-template-columns: repeat(3,minmax(0,1fr)); }
.shopping-card { border: 1px solid var(--line); background: var(--paper-light); padding: 1.3rem; }
.shopping-card h3 { font-family: var(--serif); font-size: 1.5rem; font-weight: 400; }
.shopping-card p { font-size: .9rem; color: var(--muted); margin-bottom: 0; }
.shopping-icon { display: block; font-size: 2.3rem; line-height: 1.2; color: var(--accent); margin-bottom: .7rem; }
.market-choice { display: flex; flex-wrap: wrap; gap: .6rem; padding: 1rem 0; border: 0; margin: 0; }
.market-choice legend { font-size: .9rem; font-weight: 650; }
.market-link { display: inline-flex; align-items: center; min-height: 44px; padding: .5rem .8rem; border: 1px solid var(--line); text-decoration: none; font-size: .85rem; }
.market-panel { padding: 1rem 1.2rem; border: 1px solid var(--line); margin-top: .7rem; }
.market-panel summary { cursor: pointer; min-height: 32px; font-weight: 650; }
.market-panel ul { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: .6rem 1.4rem; padding-left: 1rem; margin-top: 1rem; }
.market-panel li + li { margin-top: 0; }
.product-example { display: block; font-size: .8rem; color: var(--muted); margin-top: .5rem; }
.product-example a { font-size: .8rem; }
.market-panel a { display: inline-flex; align-items: center; gap: .4rem; min-height: 44px; }
.market-panel p { color: var(--muted); font-size: .85rem; margin-bottom: 0; }
@media(max-width:1000px) {
  .header-inner { gap: 1rem; }
  .primary-nav { gap: .8rem; font-size: .8rem; }
  .guide-layout { grid-template-columns: 190px minmax(0,1fr); gap: 2rem; }
  .home-shopping .shopping-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}
@media(max-width:850px) {
  .primary-nav { flex-wrap: wrap; gap: .2rem 1.2rem; }
  .catalogue-section { padding-top: 3rem; }
  .catalogue-filters { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .catalogue-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .catalogue-card-body { padding: 1rem; }
  .catalogue-guide { width: 100%; }
  .guide-layout { grid-template-columns: 1fr; gap: 1rem; }
  .guide-index { position: static; }
  .guide-index ol { columns: 2; column-gap: 2rem; }
  .guide-index li { break-inside: avoid; }
  .guide-hero { padding-block: 1.5rem; }
  .paper-samples { gap: 1.8rem; min-height: 130px; }
  .paper-samples > span { width: 65px; height: 65px; }
}
@media(max-width:500px) {
  .catalogue-filters, .catalogue-grid, .shopping-grid, .home-shopping .shopping-grid, .market-panel ul { grid-template-columns: 1fr; }
  .catalogue-art { height: 85px; }
  .guide-index ol { columns: 1; }
  .paper-comparison { padding: 1rem; }
  .paper-samples { gap: 1.2rem; min-height: 100px; }
  .paper-samples > span { width: 52px; height: 52px; }
  .guide-hero h1 { font-size: 2.7rem; }
  .related-guide { padding: 1.2rem; }
}
@media print {
  .catalogue-filters, .shopping-section, .guide-index, .home-shopping { display: none; }
  .guide-layout { display: block; }
  .guide-body { max-width: none; }
  .catalogue-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
}