/* =============================================================================
   skill-3d.css: the page of the 3D master skill, the flagship (2026-10-12)
   Direction: Aurora Atelier (site.css), extended. Colours come from site.css
   tokens only; this file holds no literal colour.
   Idea:    the skill is a workshop with a storeroom, so the page is a walk
            through its rooms, and every room shows its count drawn to scale.
   Grid:    "the workshop walk" on the atelier grid (12 columns, 1.5rem gutters,
            84rem container). Ten numbered plates, each with its own shape:
            a masthead, a statement over a file bar, a split, a wall of laws,
            a track of steps, a field of dots, a shelf of bars, a sum drawn in
            dots (the training, added 2026-10-13), two indexes, a screen beside
            its index, a run of commands.
   Spacing: tight .5/.75rem, default 1rem, medium 1.5/2rem, loose 3/4rem,
            section 4 to 7rem (the tiers of site.css).
   Type:    the levels of site.css: micro, small, body, title, lede, h3, h2, and
            one display size of its own for the name.
   Focus:   one focal point per screen: the name, then each plate's figure.
   Motion:  the first screen arrives once; a plate enters once; a bar grows
            once to show a share; the line of the build track follows the scroll
            because each step waits for the one before. Transform and opacity
            only. Reduced motion: everything is in place, nothing moves.
   ========================================================================== */

.h2 em, .h3 em { color: var(--g, var(--color-rust)); }
.d1 { --d: 90ms; } .d2 { --d: 230ms; } .d3 { --d: 400ms; } .d4 { --d: 560ms; }
.plate { padding-block: var(--section); scroll-margin-top: var(--topnav-h); }
.plate + .plate { border-top: 1px solid var(--color-line); }
/* glass.css makes .act a flex ROW; a plate with two .wrap blocks (the playbook) put them side by side and forced 640px on a phone. Stack them. */
.plate.act { flex-direction: column; align-items: flex-start; }

/* ---------- plate heads ---------- */
.ph { display: grid; gap: 1rem; align-content: start; }
.ph .lede { max-inline-size: 52ch; }
.ph__num { font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); text-shadow: var(--halo); }
.note { font-size: var(--t-small); line-height: 1.55; color: var(--color-ink-mute); text-shadow: var(--halo-small); max-inline-size: 64ch; }
.note a, .body a { color: var(--g, var(--color-rust)); text-underline-offset: 0.2em; text-decoration-thickness: 1px; }
.note a:hover, .body a:hover { text-decoration-thickness: 2px; }
.body { font-size: var(--t-body); line-height: 1.6; color: var(--color-ink-soft); text-shadow: var(--halo-small); max-inline-size: 60ch; }
code.k { font-family: var(--font-mono); font-size: 0.9em; color: var(--color-ink); }

/* ---------- 0. the masthead ---------- */
.m3 { min-height: calc(100svh - var(--topnav-h)); display: grid; }
.m3__grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: var(--gap); grid-template-rows: auto minmax(1.5rem, 1fr) auto auto auto; padding-block: clamp(2rem, 5vh, 4rem) 2.5rem; }
.m3__kicker { grid-column: 1 / -1; grid-row: 1; display: flex; align-items: baseline; line-height: 1.7; }
.m3__name { grid-column: 1 / -1; grid-row: 3; }
.m3__ns { display: block; font-family: var(--font-mono); font-weight: 400; font-size: var(--t-title); letter-spacing: 0.08em; color: var(--color-rust); text-shadow: var(--halo-small); margin-bottom: 0.5rem; }
.m3__word { display: block; font-family: var(--font-serif); font-weight: 400; font-size: clamp(2.5rem, 12.6vw, 13rem); line-height: 0.96; letter-spacing: -0.035em; white-space: nowrap; color: var(--color-ink); text-shadow: var(--halo); }
.m3__word .aurora-text { padding-inline-end: 0; }
.m3__kicker > span:last-child { min-width: 0; }
.m3__say { grid-column: 1 / span 6; grid-row: 4; display: grid; gap: 1.75rem; padding-top: 2rem; align-content: start; }
.m3__say .lede strong { font-weight: 600; color: var(--color-ink); }
.toc { grid-column: 8 / -1; grid-row: 4; align-self: end; padding-top: 2rem; }
.toc h2 { font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); margin-bottom: 0.5rem; }
.toc ol { list-style: none; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); grid-auto-flow: column; grid-template-rows: repeat(5, auto); column-gap: var(--gap); }
.toc a { display: grid; grid-template-columns: 2.25rem minmax(0, 1fr); align-items: baseline; min-height: 2.75rem; padding-block: 0.625rem; border-top: 1px solid var(--color-line-strong); text-decoration: none; font-family: var(--font-serif); font-size: var(--t-title); line-height: 1.2; color: var(--color-ink); text-shadow: var(--halo-small); transition: color var(--duration-fast) ease; }
.toc a i { font-family: var(--font-mono); font-style: normal; font-size: var(--t-micro); letter-spacing: 0.06em; color: var(--g); }
.toc a span { transition: transform var(--duration-normal) var(--ease-premium); }
.toc a:hover { color: var(--g); }
.toc a:hover span { transform: translateX(0.25rem); }
.strip { grid-column: 1 / -1; grid-row: 5; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 1.5rem var(--gap); margin-top: 2.5rem; }
.strip > div { display: grid; grid-template-rows: auto 1fr; gap: 0.375rem; padding-top: 0.75rem; border-top: 1px solid var(--color-line-strong); }
.strip dd { order: -1; font-family: var(--font-serif); font-weight: 400; font-size: clamp(1.75rem, 1.1rem + 1.5vw, 2.75rem); line-height: 1; letter-spacing: -0.02em; white-space: nowrap; color: var(--g); text-shadow: var(--halo); }
.strip dt { font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); }
@media (max-width: 1100px) {
  .m3 { min-height: 0; }
  .m3__grid { grid-template-rows: auto 2rem auto auto auto auto; }
  .m3__say { grid-column: 1 / -1; }
  .toc { grid-column: 1 / -1; grid-row: 5; }
  .strip { grid-row: 6; grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .m3__word { font-size: 13.6vw; }
  .m3__ns { font-size: var(--t-body); }
  .toc ol { grid-template-columns: minmax(0, 1fr); grid-auto-flow: row; grid-template-rows: none; }
  .strip { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .m3__say .btn { flex: 1 1 100%; }
}

/* ---------- I. what it is: a statement over the file bar ---------- */
.what { row-gap: 3rem; align-items: start; }
.what__head { grid-column: 1 / span 8; }
.what__say { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1.08; letter-spacing: -0.02em; color: var(--color-ink); text-shadow: var(--halo); text-wrap: balance; }
.what__say em { font-style: italic; color: var(--g); }
.what__facts { grid-column: 10 / -1; display: grid; }
.what__facts > div { display: grid; gap: 0.25rem; padding: 0.875rem 0; border-top: 1px solid var(--color-line-strong); }
.what__facts dd { order: -1; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.05; color: var(--g); text-shadow: var(--halo); }
.what__facts dt { font-size: var(--t-small); color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.scale { grid-column: 1 / -1; display: grid; gap: 1rem; }
.scale__bar { display: flex; height: clamp(3rem, 2rem + 3vw, 5rem); border-radius: 999px; overflow: hidden; border: 1px solid var(--color-line-strong); background: var(--glass-fill); }
.scale__bar span { display: block; flex: var(--n) 1 0; min-width: 3px; background: var(--c); transform-origin: left center; }
.scale__bar span + span { border-left: 2px solid var(--color-paper); }
.scale__key { list-style: none; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 0 var(--gap); }
.scale__key li { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 0 0.625rem; align-items: baseline; padding: 0.875rem 0; border-top: 1px solid var(--color-line-strong); }
.scale__key i { width: 0.75rem; height: 0.75rem; border-radius: 50%; background: var(--c); align-self: center; }
.scale__key b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.1; color: var(--color-ink); text-shadow: var(--halo); }
.scale__key span { grid-column: 2; font-size: var(--t-small); color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.scale__key li:nth-child(-n+2) b { font-size: var(--t-h2); }
@media (prefers-reduced-motion: no-preference) {
  html.js .grow .scale__bar span { transform: scaleX(0); transition: transform 900ms var(--ease-premium); transition-delay: calc(var(--i) * 90ms); }
  html.js .grow.in .scale__bar span { transform: none; }
}
@media (max-width: 1100px) { .what__head, .what__facts { grid-column: 1 / -1; } .what__facts { grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: var(--gap); } .scale__key { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

/* ---------- II. it never works alone: the split ---------- */
.pairs { row-gap: 3rem; align-items: start; }
.pairs__head { grid-column: 1 / span 5; position: sticky; top: calc(var(--topnav-h) + 2rem); }
.split { grid-column: 7 / -1; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.split > div { display: grid; gap: 0.5rem; align-content: start; padding: 1.75rem 2rem; }
.split > div + div { border-left: 1px solid var(--color-line); }
.split h3 { font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--g); }
.split b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.15; color: var(--color-ink); overflow-wrap: anywhere; }
.split p { font-size: var(--t-body); line-height: 1.55; color: var(--color-ink-soft); }
.split a { color: var(--g); text-underline-offset: 0.2em; }
.who { grid-column: 7 / -1; width: 100%; border-collapse: collapse; }
.who caption { text-align: left; padding-bottom: 0.75rem; font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.14em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.who th, .who td { text-align: left; vertical-align: top; padding: 0.875rem 1rem 0.875rem 0; border-top: 1px solid var(--color-line-strong); font-size: var(--t-small); line-height: 1.5; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.who thead th { font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-ink-mute); }
.who tbody th { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); }
.who td b { font-family: var(--font-mono); font-weight: 500; color: var(--g); white-space: nowrap; }
.who a { color: inherit; text-underline-offset: 0.2em; }
.else { grid-column: 1 / -1; padding: 2rem 2.5rem; display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: 1.5rem var(--gap); align-items: start; }
.else__lead { grid-column: 1 / span 4; display: grid; gap: 0.75rem; }
.else__lead h3 { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.15; color: var(--color-ink); }
.else__lead p { font-size: var(--t-body); color: var(--color-ink-soft); }
.else ul { grid-column: 6 / -1; list-style: none; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 2.5rem; }
.else li { display: grid; gap: 0.125rem; padding: 0.75rem 0; border-bottom: 1px solid var(--color-line); font-size: var(--t-small); line-height: 1.5; color: var(--color-ink-soft); }
.else li a { display: inline-flex; align-items: center; min-height: 1.75rem; justify-self: start; font-family: var(--font-mono); font-size: var(--t-small); font-weight: 500; color: var(--g); text-underline-offset: 0.2em; }
@media (max-width: 1100px) {
  .pairs__head, .split, .who, .else__lead, .else ul { grid-column: 1 / -1; }
  .pairs__head { position: static; }
}
@media (max-width: 700px) {
  .split { grid-template-columns: minmax(0, 1fr); }
  .split > div { padding: 1.25rem; }
  .split > div + div { border-left: 0; border-top: 1px solid var(--color-line); }
  .who thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .who tr { display: grid; padding: 0.875rem 0; border-top: 1px solid var(--color-line-strong); }
  .who th, .who td { border-top: 0; padding: 0.125rem 0; }
  .else { padding: 1.25rem; }
  .else ul { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- III. the laws: a wall of fifteen, no cards ---------- */
.laws__head { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: var(--gap); row-gap: 1rem; align-items: end; margin-bottom: 3rem; }
.laws__head .ph { grid-column: 1 / span 7; }
.laws__head .note { grid-column: 9 / -1; }
.wall { list-style: none; counter-reset: law; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); grid-auto-flow: column; grid-template-rows: repeat(5, auto); column-gap: var(--gap); }
.wall li { counter-increment: law; display: grid; grid-template-columns: 3.25rem minmax(0, 1fr); column-gap: 0.75rem; align-items: baseline; align-content: start; padding: 1.125rem 0; border-top: 1px solid var(--color-line-strong); }
.wall li::before { content: counter(law, decimal-leading-zero); font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); text-shadow: var(--halo); }
.wall b { display: block; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); text-shadow: var(--halo-small); }
.wall span { display: block; grid-column: 2; margin-top: 0.25rem; font-size: var(--t-small); line-height: 1.5; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.decide { margin-top: 3rem; padding: 0.5rem 2rem; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); column-gap: var(--gap); }
.decide > div { display: grid; gap: 0.25rem; align-content: start; padding: 1.25rem 0; }
.decide dd { order: -1; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.05; color: var(--g); }
.decide dt { font-size: var(--t-small); line-height: 1.45; color: var(--color-ink-soft); }
@media (max-width: 1100px) {
  .laws__head .ph, .laws__head .note { grid-column: 1 / -1; }
  .wall { grid-template-columns: repeat(2, minmax(0, 1fr)); grid-template-rows: repeat(8, auto); }
  .decide { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 700px) {
  .wall { grid-template-columns: minmax(0, 1fr); grid-auto-flow: row; grid-template-rows: none; }
  .decide { padding: 0.25rem 1.25rem; grid-template-columns: minmax(0, 1fr); }
  .decide > div + div { border-top: 1px solid var(--color-line); }
}

/* ---------- IV. a build: the track ---------- */
.build { row-gap: 3rem; align-items: start; }
.build__head { grid-column: 1 / span 4; position: sticky; top: calc(var(--topnav-h) + 2rem); display: grid; gap: 1.5rem; }
.words { display: grid; }
.words > div { display: grid; grid-template-columns: 6.5rem minmax(0, 1fr); gap: 0.75rem; padding: 0.75rem 0; border-top: 1px solid var(--color-line-strong); font-size: var(--t-small); line-height: 1.5; text-shadow: var(--halo-small); }
.words dt { font-family: var(--font-serif); font-style: italic; font-size: var(--t-title); line-height: 1.2; color: var(--g); }
.words dd { color: var(--color-ink-soft); }
.track { grid-column: 6 / -1; position: relative; list-style: none; padding: 1rem 2rem 1rem 0; }
.track::before, .track__fill { content: ''; position: absolute; left: 2.75rem; top: 2.5rem; bottom: 2.5rem; width: 2px; margin-left: -1px; }
.track::before { background: var(--color-line-strong); }
.track__fill { width: 4px; margin-left: -2px; border-radius: 2px; background: var(--g-mark); transform-origin: top center; transform: scaleY(var(--track, 1)); pointer-events: none; }
.step { position: relative; display: grid; grid-template-columns: 5.5rem minmax(0, 1fr) minmax(0, 1fr); column-gap: 1.5rem; align-items: start; padding: 1.125rem 0; }
.step__n { position: relative; z-index: 1; justify-self: center; display: grid; place-items: center; width: 2.75rem; height: 2.75rem; border-radius: 50%; font-family: var(--font-serif); font-style: italic; font-size: var(--t-title); line-height: 1; color: var(--g); background: var(--color-paper); border: 2px solid var(--g-mark); }
.step__what { display: grid; gap: 0.25rem; }
.step__what b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); }
.step__what code { font-family: var(--font-mono); font-size: var(--t-small); color: var(--g); overflow-wrap: anywhere; }
.step__check { font-size: var(--t-small); line-height: 1.5; color: var(--color-ink-soft); padding-top: 0.25rem; }
.step__check i { display: block; font-family: var(--font-sans); font-weight: 500; font-style: normal; font-size: var(--t-micro); letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-ink-mute); }
.step--phase { padding-top: 3.75rem; }
.step__phase { position: absolute; left: 5.5rem; right: 0; top: 1rem; margin-left: 1.5rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--g-mark); font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--g); }
.step--refine { --g: var(--color-rose); --g-mark: var(--mark-rose); }
@media (max-width: 1100px) { .build__head, .track { grid-column: 1 / -1; } .build__head { position: static; } }
@media (max-width: 700px) {
  .track { padding: 0.5rem 1rem 0.5rem 0; }
  .track::before, .track__fill { left: 2.125rem; }
  .step { grid-template-columns: 4.25rem minmax(0, 1fr); column-gap: 0.5rem; }
  .step__check { grid-column: 2; }
  .step__phase { left: 4.25rem; margin-left: 0.5rem; }
}

/* ---------- V. the kitchen: fifty-two dots ---------- */
.kitchen { row-gap: 3rem; align-items: start; }
.kitchen__head { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: var(--gap); row-gap: 1rem; align-items: end; }
.kitchen__head .ph { grid-column: 1 / span 7; }
.kitchen__head .note { grid-column: 9 / -1; }
.ops { grid-column: 1 / span 7; list-style: none; padding: 1rem 2rem; }
.ops li { display: grid; grid-template-columns: 5.5rem minmax(0, 1fr) 2.5rem; column-gap: 1.25rem; align-items: center; min-height: 3.25rem; padding: 0.625rem 0; border-top: 1px solid var(--color-line); }
.ops li:first-child { border-top: 0; }
.ops__fam { font-family: var(--font-mono); font-size: var(--t-small); font-weight: 500; color: var(--color-ink); }
.ops__dots { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.ops__dots i { width: 1rem; height: 1rem; border-radius: 50%; background: var(--g-mark); }
.ops__dots i.t { background: transparent; border: 2px solid var(--g-mark); }
.ops__n { justify-self: end; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); }
.ops__ones { grid-column: 2 / -1; font-family: var(--font-mono); font-size: var(--t-micro); line-height: 1.6; color: var(--color-ink-mute); }
.ops li.ops--ones { grid-template-rows: auto auto; row-gap: 0.375rem; }
.rules { grid-column: 9 / -1; list-style: none; }
.rules li { padding: 1rem 0; border-top: 1px solid var(--color-line-strong); font-size: var(--t-body); line-height: 1.55; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.rules b { display: block; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); margin-bottom: 0.25rem; }
@media (prefers-reduced-motion: no-preference) {
  html.js .ops.reveal .ops__dots i { opacity: 0; transition: opacity 500ms ease; transition-delay: calc(var(--row, 0) * 80ms + 200ms); }
  html.js .ops.reveal.in .ops__dots i { opacity: 1; }
}
@media (max-width: 1100px) { .kitchen__head .ph, .kitchen__head .note, .ops, .rules { grid-column: 1 / -1; } }
@media (max-width: 700px) { .ops { padding: 0.5rem 1.25rem; } .ops li { grid-template-columns: 4.5rem minmax(0, 1fr) 2rem; column-gap: 0.75rem; } .ops__dots { gap: 0.375rem; } .ops__dots i { width: 0.75rem; height: 0.75rem; } }

/* ---------- VI. the library: a shelf of bars ---------- */
.lib3 { row-gap: 3rem; align-items: start; }
.lib3__head { grid-column: 1 / span 7; }
.lib3__sum { grid-column: 9 / -1; display: grid; }
.lib3__sum > div { display: grid; gap: 0.25rem; padding: 0.875rem 0; border-top: 1px solid var(--color-line-strong); }
.lib3__sum dd { order: -1; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1; color: var(--g); text-shadow: var(--halo); }
.lib3__sum dt { font-size: var(--t-small); line-height: 1.45; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.shelf { grid-column: 1 / -1; list-style: none; padding: 0.75rem 2.5rem; }
.shelf li { display: grid; grid-template-columns: 7.5rem minmax(0, 15rem) minmax(0, 1fr); column-gap: 2rem; row-gap: 0.25rem; align-items: baseline; padding: 1.125rem 0; border-top: 1px solid var(--color-line); }
.shelf li:first-child { border-top: 0; }
.shelf__n { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); text-align: right; }
.shelf__name { display: grid; gap: 0.125rem; }
.shelf__name b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); }
.shelf__name i { font-family: var(--font-mono); font-style: normal; font-size: var(--t-micro); letter-spacing: 0.04em; color: var(--color-ink-mute); }
.shelf__what { display: grid; gap: 0.625rem; font-size: var(--t-small); line-height: 1.55; color: var(--color-ink-soft); }
.shelf__bar { display: block; height: 0.5rem; border-radius: 999px; background: var(--color-line); overflow: hidden; }
.shelf__bar i { display: block; height: 100%; min-width: 3px; width: calc(var(--r) * 100%); border-radius: 999px; background: var(--g-mark); transform-origin: left center; }
@media (prefers-reduced-motion: no-preference) {
  html.js .shelf.reveal .shelf__bar i { transform: scaleX(0); transition: transform 900ms var(--ease-premium); transition-delay: calc(var(--i) * 50ms + 150ms); }
  html.js .shelf.reveal.in .shelf__bar i { transform: none; }
}
.cards { grid-column: 1 / -1; display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); column-gap: var(--gap); row-gap: 1.5rem; align-items: start; }
.cards .body { grid-column: 1 / span 5; }
.cards ul { grid-column: 7 / -1; list-style: none; display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); column-gap: var(--gap); }
.cards li { display: grid; gap: 0.25rem; padding-top: 0.75rem; border-top: 1px solid var(--color-line-strong); }
.cards li b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--color-ink); text-shadow: var(--halo); }
.cards li span { font-size: var(--t-small); color: var(--color-ink-soft); text-shadow: var(--halo-small); }
@media (max-width: 1100px) { .lib3__head, .lib3__sum, .cards .body, .cards ul { grid-column: 1 / -1; } .lib3__sum { grid-template-columns: repeat(3, minmax(0, 1fr)); column-gap: var(--gap); } }
@media (max-width: 700px) {
  .shelf { padding: 0.25rem 1.25rem; }
  .shelf li { grid-template-columns: 5.5rem minmax(0, 1fr); column-gap: 1rem; }
  .shelf__n { text-align: left; }
  .shelf__what { grid-column: 1 / -1; }
  .lib3__sum { grid-template-columns: minmax(0, 1fr); }
  .cards ul { grid-template-columns: repeat(2, minmax(0, 1fr)); row-gap: 1rem; }
}

/* ---------- VII. the training: one number, its sum drawn in dots, three trained parts and one that waits ---------- */
.tr3 { row-gap: 3rem; align-items: start; }
.tr3__head { grid-column: 1 / span 7; }
.tr3__big { grid-column: 9 / -1; align-self: end; display: grid; gap: 0.5rem; padding-top: 0.875rem; border-top: 2px solid var(--g-mark); }
.tr3__lbl { font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.tr3__n { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1; letter-spacing: -0.02em; white-space: nowrap; color: var(--g); text-shadow: var(--halo); }
.tr3__about { display: block; margin-bottom: 0.375rem; font-family: var(--font-serif); font-style: italic; font-size: var(--t-title); line-height: 1; letter-spacing: 0; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.tr3__head .body { max-inline-size: 52ch; }
.sum { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(0, 10fr) auto minmax(0, 9fr) auto minmax(0, 7fr); column-gap: 2rem; row-gap: 1.5rem; padding: 2rem 2.5rem; }
.sum__title { grid-column: 1 / -1; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.15; color: var(--color-ink); }
.sum__term { display: grid; grid-template-rows: auto 1fr auto; row-gap: 0.75rem; }
.sum__term h4 { font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--g); }
.sum__term ul { list-style: none; align-self: start; }
.sum__term li { display: grid; grid-template-columns: 6.25rem minmax(0, 1fr) 1.5rem; column-gap: 0.75rem; align-items: center; min-height: 1.75rem; border-top: 1px solid var(--color-line); }
.sum__term li:first-child { border-top: 0; }
.sum__term--one li { grid-template-columns: auto minmax(0, 1fr) 1.5rem; }
.sum__term--one .sum__dots { flex-wrap: nowrap; }
.sum__fam { font-family: var(--font-mono); font-size: var(--t-small); color: var(--color-ink); }
.sum__dots { display: flex; flex-wrap: wrap; gap: 0.375rem; }
.sum__dots i { width: 0.75rem; height: 0.75rem; border-radius: 50%; background: var(--g); } /* the text-safe plum: a dot carries a count, so it holds 3 to 1 */
.sum__c { justify-self: end; font-family: var(--font-serif); font-size: var(--t-title); line-height: 1; color: var(--color-ink-soft); }
.sum__ways { display: grid; gap: 0.25rem; padding-top: 0.75rem; border-top: 1px solid var(--color-line-strong); font-size: var(--t-small); line-height: 1.5; color: var(--color-ink-soft); }
.sum__ways b { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.05; color: var(--color-ink); }
.sum__x { align-self: center; font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1; color: var(--color-ink-mute); }
.sum__eq { grid-column: 1 / -1; display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.25rem 1rem; padding-top: 1.25rem; border-top: 2px solid var(--g-mark); }
.sum__eq i { font-family: var(--font-serif); font-style: normal; font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--color-ink-mute); }
.sum__eq b { font-family: var(--font-serif); font-weight: 400; font-size: clamp(1.25rem, 5.6vw, var(--t-h2)); line-height: 1; letter-spacing: -0.01em; white-space: nowrap; color: var(--g); }
.sum__eq span { font-size: var(--t-small); color: var(--color-ink-soft); }
.sum figcaption { grid-column: 1 / -1; text-shadow: none; max-inline-size: 96ch; }
.parts { grid-column: 1 / -1; display: grid; gap: 1.5rem; }
.parts ul { list-style: none; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 2rem var(--gap); }
.parts li { display: grid; gap: 0.5rem; align-content: start; padding-top: 0.875rem; border-top: 2px solid var(--g-mark); }
.parts__k { display: flex; align-items: center; gap: 0.5rem; font-family: var(--font-sans); font-size: var(--t-micro); font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--g); text-shadow: var(--halo-small); }
.parts__k i { width: 0.75rem; height: 0.75rem; border-radius: 50%; background: var(--g); flex-shrink: 0; }
.parts__n { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1; letter-spacing: -0.02em; color: var(--g); text-shadow: var(--halo); }
.parts__what { font-size: var(--t-body); line-height: 1.55; color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.parts__what strong { font-weight: 600; color: var(--color-ink); }
.parts__v { font-family: var(--font-mono); font-size: var(--t-micro); letter-spacing: 0.04em; color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.parts li.parts--open { border-top-style: dashed; border-top-color: var(--color-line-strong); }
.parts--open .parts__k { color: var(--color-ink-mute); }
.parts--open .parts__k i { background: transparent; border: 2px solid var(--g); }
.parts--open .parts__n { font-style: italic; color: var(--color-ink-soft); }
@media (prefers-reduced-motion: no-preference) {
  /* the dots are counted term by term, so they appear term by term, once */
  html.js .sum.reveal .sum__dots i { opacity: 0; transition: opacity 500ms ease; transition-delay: calc(var(--t, 0) * 240ms + 250ms); }
  html.js .sum.reveal.in .sum__dots i { opacity: 1; }
}
@media (max-width: 1100px) {
  .tr3__head, .tr3__big { grid-column: 1 / -1; }
  .sum { grid-template-columns: minmax(0, 1fr); }
  .sum__x { align-self: start; font-size: var(--t-h3); }
  .parts ul { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 700px) {
  .sum { padding: 1.25rem; }
  .sum__term li { grid-template-columns: 5.5rem minmax(0, 1fr) 1.5rem; }
  .parts ul { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- VIII. the playbook: two typed indexes ---------- */
.play { row-gap: 2.5rem; align-items: start; }
.play__head { grid-column: 1 / span 4; position: sticky; top: calc(var(--topnav-h) + 2rem); }
.folio { grid-column: 6 / -1; list-style: none; padding: 0.5rem 2rem; }
.folio li { display: grid; grid-template-columns: 3.5rem minmax(0, 1fr) auto; column-gap: 1rem; align-items: baseline; padding: 1.125rem 0; border-top: 1px solid var(--color-line); }
.folio li:first-child { border-top: 0; }
.folio__num { font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); }
.folio h3 { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); }
.folio p { margin-top: 0.25rem; font-size: var(--t-small); line-height: 1.55; color: var(--color-ink-soft); max-inline-size: 60ch; }
.folio__lbl { font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-ink-mute); }
.play--b { margin-top: var(--section); }
.stack { grid-column: 1 / -1; list-style: none; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: calc(var(--gap) * 2); }
.stack li { display: grid; grid-template-columns: 6rem minmax(0, 1fr); column-gap: 1rem; row-gap: 0.25rem; align-items: baseline; padding: 1rem 0; border-top: 1px solid var(--color-line-strong); text-shadow: var(--halo-small); }
.stack__lbl { font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.1em; text-transform: uppercase; color: var(--g); }
.stack__name { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); line-height: 1.25; color: var(--color-ink); }
.stack__brief { grid-column: 2; font-size: var(--t-small); line-height: 1.55; color: var(--color-ink-soft); }
.play__head--wide { grid-column: 1 / span 8; position: static; }
@media (max-width: 1100px) { .play__head, .folio, .play__head--wide { grid-column: 1 / -1; } .play__head { position: static; } }
@media (max-width: 700px) {
  .folio { padding: 0.25rem 1.25rem; }
  .folio li { grid-template-columns: 2.75rem minmax(0, 1fr); }
  .folio__lbl { grid-column: 2; }
  .stack { grid-template-columns: minmax(0, 1fr); }
  .stack li { grid-template-columns: minmax(0, 1fr); }
  .stack__brief { grid-column: 1; }
}

/* ---------- IX. the showroom: a screen beside its index ---------- */
.show { row-gap: 3rem; align-items: start; }
.show__head { grid-column: 1 / span 8; }
.show__stage { grid-column: 1 / span 7; position: sticky; top: calc(var(--topnav-h) + 1.5rem); display: grid; gap: 1.25rem; }
.screen { position: relative; aspect-ratio: 16 / 10; background: var(--code-bg); border: 1px solid var(--color-line-strong); border-radius: var(--radius-inner); overflow: hidden; box-shadow: 0 1.5rem 3.75rem -2rem var(--glass-shadow); }
.screen__chrome { position: absolute; inset: 0 0 auto 0; z-index: 2; display: flex; align-items: center; gap: 0.5rem; height: 2.5rem; padding: 0 1rem; border-bottom: 1px solid var(--code-label); background: var(--code-bg); }
.screen__chrome i { width: 0.625rem; height: 0.625rem; border-radius: 50%; background: var(--mark-rose); }
.screen__chrome i:nth-child(2) { background: var(--mark-amber); }
.screen__chrome i:nth-child(3) { background: var(--mark-green); }
.screen__url { margin-left: 0.75rem; font-family: var(--font-mono); font-size: var(--t-micro); letter-spacing: 0.04em; color: var(--code-label); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; min-width: 0; }
.screen__idle { position: absolute; inset: 2.5rem 0 0 0; display: grid; place-content: center; justify-items: center; gap: 1.25rem; padding: 1.5rem; text-align: center; color: var(--code-ink); }
.screen__idle[hidden] { display: none; }
.screen__line { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h3); line-height: 1.3; max-inline-size: 24ch; }
.screen__line kbd { font-family: var(--font-mono); font-size: 0.8em; padding: 0.1em 0.5em; border: 1px solid var(--code-label); border-radius: 0.375rem; }
.screen__play { display: inline-flex; align-items: center; gap: 0.75rem; min-height: 3rem; padding: 0 1.75rem; font-family: var(--font-sans); font-weight: 500; font-size: 0.8125rem; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase; color: var(--code-bg); background: var(--code-arg); border: 1px solid var(--code-arg); border-radius: 999px; cursor: pointer; transition: background-color var(--duration-normal) ease, border-color var(--duration-normal) ease, transform 100ms ease; }
.screen__play:hover { background: var(--code-ink); border-color: var(--code-ink); }
.screen__play:active { transform: scale(0.97); }
.screen__play:focus-visible { outline-color: var(--code-ink); }
.screen__play svg { width: 0.875rem; height: 0.875rem; }
.screen__note { font-size: var(--t-small); line-height: 1.5; color: var(--code-label); max-inline-size: 38ch; }
.screen__frame { position: absolute; inset: 2.5rem 0 0 0; width: 100%; height: calc(100% - 2.5rem); border: 0; background: var(--code-bg); }
.screen__frame[hidden] { display: none; }
.cap { display: grid; grid-template-columns: minmax(0, 1fr) auto; column-gap: 1.5rem; row-gap: 0.5rem; align-items: start; }
.cap__meta { grid-column: 1 / -1; display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.25rem 0.875rem; }
.cap__no { font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-h3); line-height: 1; color: var(--g); text-shadow: var(--halo); }
.cap__cat { font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.12em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.cap__count { margin-left: auto; font-family: var(--font-mono); font-size: var(--t-small); color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.cap__count b { font-weight: 500; color: var(--color-ink); }
.cap__name { font-family: var(--font-serif); font-weight: 400; font-size: var(--t-h2); line-height: 1.05; letter-spacing: -0.015em; color: var(--color-ink); text-shadow: var(--halo); }
.cap__line { grid-column: 1; font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-lede); line-height: 1.5; color: var(--color-ink-soft); text-shadow: var(--halo-small); max-inline-size: 52ch; min-height: 3em; }
.cap__ctl { grid-column: 2; grid-row: 2 / span 2; display: flex; gap: 0.5rem; align-self: start; }
.cap__nav { display: grid; place-items: center; width: 3rem; height: 3rem; color: var(--color-ink); background: var(--glass-fill); border: 1px solid var(--color-ink); border-radius: 50%; cursor: pointer; transition: background-color var(--duration-normal) ease, color var(--duration-normal) ease, transform 100ms ease; }
.cap__nav:hover { background: var(--color-ink); color: var(--color-paper); }
.cap__nav:active { transform: scale(0.95); }
.cap__nav svg { width: 1.25rem; height: 1.25rem; }
.cap .btn { grid-column: 1 / -1; justify-self: start; margin-top: 0.5rem; }
.cap .btn svg { width: 0.875rem; height: 0.875rem; }
html:not(.js) .show__stage { display: none; }
html:not(.js) .tpls { grid-column: 1 / -1; }
.tpls { grid-column: 9 / -1; display: grid; gap: 1.75rem; }
.tpls__grp h3 { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--g-mark); font-family: var(--font-serif); font-weight: 400; font-size: var(--t-title); color: var(--color-ink); text-shadow: var(--halo-small); }
.tpls__grp h3 em { font-style: italic; color: var(--g); }
.tpls__grp h3 .num { font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-ink-mute); }
.tpls__grp ul { list-style: none; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: var(--gap); }
.tpls a { display: grid; grid-template-columns: 2.25rem minmax(0, 1fr); align-items: baseline; min-height: 2.75rem; padding-block: 0.625rem; border-bottom: 1px solid var(--color-line); text-decoration: none; font-family: var(--font-serif); font-size: var(--t-title); line-height: 1.2; color: var(--color-ink); text-shadow: var(--halo-small); cursor: pointer; transition: color var(--duration-fast) ease; }
.tpls a i { font-family: var(--font-mono); font-style: normal; font-size: var(--t-micro); color: var(--color-ink-mute); }
.tpls a:hover { color: var(--g); }
.tpls a[aria-pressed="true"] { color: var(--g); border-bottom: 2px solid var(--g-mark); font-style: italic; }
.tpls a[aria-pressed="true"] i { color: var(--g); }
.tpls__foot { font-size: var(--t-small); color: var(--color-ink-mute); text-shadow: var(--halo-small); }
.tpls__foot a { display: inline; min-height: 0; padding: 0; border: 0; font-family: inherit; font-size: inherit; color: var(--g); text-decoration: underline; text-underline-offset: 0.2em; }
@media (max-width: 1100px) { .show__head, .show__stage, .tpls { grid-column: 1 / -1; } .show__stage { position: static; } }
@media (max-width: 700px) {
  .screen { aspect-ratio: 4 / 5; }
  .cap { grid-template-columns: minmax(0, 1fr); }
  .cap__ctl { grid-column: 1; grid-row: auto; }
  .cap__line { min-height: 0; }
}

/* ---------- X. install ---------- */
.inst { row-gap: 2.5rem; align-items: start; }
.inst__lead { grid-column: 1 / span 5; display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.5rem; }
.inst__steps { list-style: none; counter-reset: step; display: grid; }
.inst__steps li { counter-increment: step; display: grid; grid-template-columns: 2.5rem minmax(0, 1fr); gap: 1rem; padding: 0.875rem 0; border-top: 1px solid var(--color-line-strong); color: var(--color-ink-soft); text-shadow: var(--halo-small); }
.inst__steps li::before { content: counter(step); font-family: var(--font-serif); font-style: italic; font-size: var(--t-h3); line-height: 1; color: var(--g); }
.inst__cmds { grid-column: 7 / -1; display: grid; grid-template-columns: minmax(0, 1fr); gap: 1rem; }
@media (max-width: 1100px) { .inst__lead, .inst__cmds { grid-column: 1 / -1; } }
@media (max-width: 560px) { .inst .cmd { grid-template-columns: minmax(0, 1fr); } .inst .cmd__copy { justify-self: start; } }
.foot__back { display: inline-flex; align-items: center; min-height: 2.75rem; margin-top: 0.5rem; font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.12em; text-transform: uppercase; }

/* ---------- the chapter marker: where you are, wide screens only ---------- */
.here { display: none; }
@media (min-width: 1700px) {
  html.js .here { position: fixed; left: 1.25rem; bottom: 1.25rem; z-index: 50; display: grid; gap: 0.125rem; pointer-events: none; font-family: var(--font-sans); font-weight: 500; font-size: var(--t-micro); letter-spacing: 0.12em; text-transform: uppercase; color: var(--color-ink-mute); text-shadow: var(--halo-small); opacity: 0; transition: opacity var(--duration-slow) ease; }
  html.js .here.is-on { opacity: 1; }
  .here b { font-family: var(--font-serif); font-style: italic; font-weight: 400; font-size: var(--t-h3); line-height: 1; letter-spacing: 0; text-transform: none; color: var(--color-ink); }
}

@media (forced-colors: active) {
  .scale__bar span, .shelf__bar i, .ops__dots i, .sum__dots i, .parts__k i, .track__fill { background: CanvasText; forced-color-adjust: none; }
  .ops__dots i.t, .parts--open .parts__k i { background: Canvas; border-color: CanvasText; }
}
@media print { .here, .show__stage { display: none; } }
.m3__kicker .dot { align-self: flex-start; margin-top: 0.45em; }