/* Archlens site: "The Drawing Set". No build step. */

:root {
  --paper: #F2EEE4;
  --paper-2: #E9E4D8;
  --paper-3: #F8F6F0;
  --ink: #16130F;
  --ink-2: #5A5247;
  --ink-3: #8C8476;
  --rule: rgba(22, 19, 15, .2);
  --rule-strong: rgba(22, 19, 15, .55);
  --grid-minor: rgba(22, 19, 15, .045);
  --grid-major: rgba(22, 19, 15, .085);
  --stale: #E8431A;
  --stale-text: #B8320D;
  --stale-wash: rgba(232, 67, 26, .1);
  --synced: #1F5BD8;
  --synced-wash: rgba(31, 91, 216, .09);
  --hatch: rgba(22, 19, 15, .35);
  --stamp-blend: multiply;
  --f-display: "Big Shoulders Display", "Arial Narrow", "Roboto Condensed", sans-serif;
  --f-sans: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
  --f-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --gutter: clamp(16px, 3.2vw, 48px);
  --frame-pad: clamp(18px, 3.6vw, 56px);
  --topbar-h: 52px;
  /* motion: one easing and duration scale for every transition on the site */
  --ease-out: cubic-bezier(.2, .7, .2, 1);
  --ease-io: cubic-bezier(.45, .05, .3, 1);
  --ease-snap: cubic-bezier(.2, .9, .25, 1.15);
  --d-1: 140ms;
  --d-2: 260ms;
  --d-3: 520ms;
  --d-4: 1100ms;
  --stagger: 70ms;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0B1C33;
    --paper-2: #10284A;
    --paper-3: #0D2140;
    --ink: #D7E9F2;
    --ink-2: #9FC0D6;
    --ink-3: #6B90AE;
    --rule: rgba(160, 205, 230, .26);
    --rule-strong: rgba(190, 225, 245, .6);
    --grid-minor: rgba(140, 200, 235, .06);
    --grid-major: rgba(140, 200, 235, .12);
    --stale: #FF6B3D;
    --stale-text: #FF7A50;
    --stale-wash: rgba(255, 107, 61, .14);
    --synced: #7DB4FF;
    --synced-wash: rgba(125, 180, 255, .13);
    --hatch: rgba(190, 225, 245, .45);
    --stamp-blend: screen;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0B1C33;
  --paper-2: #10284A;
  --paper-3: #0D2140;
  --ink: #D7E9F2;
  --ink-2: #9FC0D6;
  --ink-3: #6B90AE;
  --rule: rgba(160, 205, 230, .26);
  --rule-strong: rgba(190, 225, 245, .6);
  --grid-minor: rgba(140, 200, 235, .06);
  --grid-major: rgba(140, 200, 235, .12);
  --stale: #FF6B3D;
  --stale-text: #FF7A50;
  --stale-wash: rgba(255, 107, 61, .14);
  --synced: #7DB4FF;
  --synced-wash: rgba(125, 180, 255, .13);
  --hatch: rgba(190, 225, 245, .45);
  --stamp-blend: screen;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 12px); }
body {
  margin: 0;
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px),
    linear-gradient(var(--grid-minor) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-minor) 1px, transparent 1px);
  background-size: 120px 120px, 120px 120px, 24px 24px, 24px 24px;
  background-position: -1px -1px;
  color: var(--ink);
  font: 400 17px/1.58 var(--f-sans);
  overflow-x: hidden;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
code, pre, kbd { font-family: var(--f-mono); }
code { font-size: .86em; overflow-wrap: anywhere; }
p, li, dd { overflow-wrap: break-word; }
:focus-visible { outline: 2px solid var(--synced); outline-offset: 3px; }
::selection { background: var(--ink); color: var(--paper); }

.vh, .skip:not(:focus) {
  position: absolute !important; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}
.skip { position: fixed; top: 8px; left: 8px; z-index: 50; background: var(--ink); color: var(--paper); padding: 8px 14px; font: 500 14px var(--f-mono); }

/* ---------- labels & type ---------- */
.label, .kicker, .panel-head, .title-block b, .fb-cell > b, .detail-head, .sheet-name, .small-caps {
  font-family: var(--f-mono);
  text-transform: uppercase;
  letter-spacing: .08em;
}
.label { font-size: 12px; font-weight: 600; margin: 0 0 14px; color: var(--ink); display: flex; align-items: center; gap: 10px; }
.label::after { content: ""; flex: 1; height: 1px; background: var(--rule); }
h1, h2, .stat-n, .speed-big, .callout-big, .fb-word, .sheet-no, .stamp-word, .brand-word {
  font-family: var(--f-display);
}
h2 {
  font-size: clamp(2.3rem, 5.4vw, 4.9rem);
  font-weight: 800;
  line-height: .92;
  letter-spacing: -.005em;
  text-transform: uppercase;
  margin: 0 0 22px;
  text-wrap: balance;
}
h3 { font-size: 1.05rem; }
.lede { font-size: clamp(1.02rem, 1.4vw, 1.2rem); line-height: 1.55; max-width: 62ch; margin: 0; color: var(--ink); }
.small { font-size: 14px; line-height: 1.55; color: var(--ink-2); max-width: 70ch; }
.small a, .fineprint a { color: var(--ink); }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  height: var(--topbar-h);
  display: flex; align-items: stretch;
  background: var(--paper);
  border-bottom: 1.5px solid var(--ink);
}
.brand {
  display: flex; align-items: center; gap: 10px;
  padding: 0 18px 0 var(--gutter);
  text-decoration: none;
  border-right: 1px solid var(--rule-strong);
  flex: none;
}
.brand-mark { width: 26px; height: 26px; fill: none; stroke: var(--ink); stroke-width: 2.2; }
.brand-mark .brand-arrow { fill: var(--stale); stroke: none; }
.brand-word { font-size: 25px; font-weight: 800; text-transform: uppercase; letter-spacing: .02em; line-height: 1; }
.brand-rev { font: 500 11px var(--f-mono); letter-spacing: .06em; color: var(--ink-2); text-transform: uppercase; }
.sheet-nav { flex: 1; min-width: 0; overflow-x: auto; scrollbar-width: none; }
.sheet-nav::-webkit-scrollbar { display: none; }
.sheet-nav ol { list-style: none; margin: 0; padding: 0; display: flex; height: 100%; }
.sheet-nav li { display: flex; }
.sheet-nav a {
  display: flex; flex-direction: column; justify-content: center;
  padding: 0 14px; text-decoration: none; position: relative;
  border-right: 1px solid var(--rule);
  white-space: nowrap;
}
.sheet-nav .no { font: 600 12.5px var(--f-mono); letter-spacing: .04em; }
.sheet-nav .nm { font: 400 11px var(--f-mono); color: var(--ink-2); text-transform: uppercase; letter-spacing: .06em; }
.sheet-nav a:hover { background: var(--paper-2); }
.sheet-nav a[aria-current="location"] { background: var(--ink); color: var(--paper); }
.sheet-nav a[aria-current="location"] .nm { color: inherit; opacity: .8; }
.topbar-tools { display: flex; align-items: stretch; flex: none; }
.theme-toggle, .gh {
  display: flex; align-items: center; gap: 8px;
  padding: 0 16px;
  background: none; border: 0; border-left: 1px solid var(--rule-strong);
  color: var(--ink); font: 500 12px var(--f-mono); text-transform: uppercase; letter-spacing: .06em;
  cursor: pointer; text-decoration: none;
}
.theme-toggle svg { width: 18px; height: 18px; fill: none; stroke: var(--ink); stroke-width: 1.6; }
.theme-toggle svg path { fill: var(--ink); stroke: none; }
.gh { padding-right: var(--gutter); }
.theme-toggle:hover, .gh:hover { background: var(--paper-2); }

/* ---------- sheets ---------- */
main { padding: 34px var(--gutter) 0; }
.sheet { max-width: 1380px; margin: 0 auto 64px; position: relative; }
.frame {
  position: relative;
  border: 2px solid var(--ink);
  outline: 1px solid var(--ink);
  outline-offset: 5px;
  padding: var(--frame-pad);
  padding-bottom: 0;
  background: color-mix(in srgb, var(--paper) 72%, transparent);
}
.zones {
  position: absolute; left: 0; right: 0; top: -26px; height: 16px;
  display: grid; grid-template-columns: repeat(6, 1fr);
  font: 500 10.5px var(--f-mono); color: var(--ink-3);
  pointer-events: none;
}
.zones span { text-align: center; border-left: 1px solid var(--rule); line-height: 16px; }
.zones span:first-child { border-left: 0; }

.sheet-head {
  display: grid; grid-template-columns: minmax(0, 3fr) minmax(0, 9fr); gap: 0 clamp(20px, 3vw, 48px);
  margin-bottom: clamp(32px, 4.5vw, 64px);
}
.sheet-id { margin: 0; display: flex; flex-direction: column; gap: 6px; padding-top: 6px; }
.sheet-no {
  font-size: clamp(3rem, 7vw, 6.4rem); font-weight: 900; line-height: .8;
  color: transparent; -webkit-text-stroke: 1.5px var(--ink);
  letter-spacing: .01em;
}
.sheet-name { font-size: 12px; font-weight: 600; color: var(--ink-2); border-top: 1.5px solid var(--ink); padding-top: 8px; max-width: 220px; }
.sheet-heading { min-width: 0; }

/* title block */
.title-block {
  display: grid; grid-template-columns: 1.3fr 1.5fr .9fr .8fr;
  width: min(560px, calc(100% + 2 * var(--frame-pad)));
  margin: clamp(40px, 5vw, 72px) calc(-1 * var(--frame-pad)) 0 auto;
  border-top: 1.5px solid var(--ink); border-left: 1.5px solid var(--ink);
  font-size: 13px; line-height: 1.25;
}
.title-block > div { padding: 6px 10px 7px; border-right: 1px solid var(--rule-strong); border-bottom: 1px solid var(--rule-strong); min-width: 0; }
.title-block > div:nth-child(4), .title-block > div:last-child { border-right: 0; }
.title-block > div:nth-last-child(-n+3) { border-bottom: 0; }
.title-block b { display: block; font-size: 9.5px; font-weight: 500; color: var(--ink-2); margin-bottom: 2px; }
.title-block i { font: normal 900 21px/1 var(--f-display); letter-spacing: .02em; }
.title-block .tb-wide { grid-column: span 2; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  min-height: 46px; padding: 10px 18px;
  border: 1.5px solid var(--ink); background: var(--paper); color: var(--ink);
  font: 600 14px/1.2 var(--f-mono); letter-spacing: .02em; text-decoration: none;
  cursor: pointer; border-radius: 0;
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform var(--d-1) var(--ease-out), box-shadow var(--d-1) var(--ease-out), background-color var(--d-1);
}
.btn:hover { transform: translate(-1px, -1px); box-shadow: 5px 5px 0 var(--ink); text-decoration: none; }
.btn:active { transform: translate(3px, 3px); box-shadow: 1px 1px 0 var(--ink); }
.btn-ink { background: var(--ink); color: var(--paper); }
.btn-ghost { box-shadow: none; border-style: dashed; }
.btn-ghost:hover { box-shadow: none; transform: none; background: var(--paper-2); }
.btn[disabled] { opacity: .42; cursor: not-allowed; box-shadow: none; transform: none; }
.btn-ref { font-weight: 400; font-size: 11px; opacity: .75; text-transform: uppercase; letter-spacing: .08em; }
.btn-key {
  display: inline-grid; place-items: center; width: 22px; height: 22px; border-radius: 50%;
  border: 1.5px solid currentColor; font-size: 11.5px; line-height: 1;
}

/* ---------- cover ---------- */
.cover {
  display: grid; grid-template-columns: minmax(0, 8.4fr) minmax(0, 3.6fr);
  grid-template-areas: "kicker kicker" "title side" "body side";
  grid-template-rows: auto auto 1fr;
  gap: 0 clamp(24px, 4vw, 64px);
  margin-bottom: clamp(40px, 6vw, 80px);
}
.kicker { grid-area: kicker; margin: 0 0 18px; font-size: 12px; color: var(--ink-2); display: flex; flex-wrap: wrap; gap: 6px 12px; align-items: center; }
.kicker-no { background: var(--ink); color: var(--paper); padding: 3px 8px; font-weight: 600; }
.cover-title {
  grid-area: title;
  font-size: clamp(3.3rem, 9.6vw, 9.6rem);
  font-weight: 800; line-height: .86; letter-spacing: -.01em; text-transform: uppercase;
  margin: 0 0 clamp(26px, 3.5vw, 44px);
}
.cloud-word { position: relative; display: inline-block; white-space: nowrap; color: var(--synced); }
.delta {
  position: relative; isolation: isolate;
  display: inline-grid; place-items: end center;
  width: 2em; height: 1.75em; padding-bottom: .2em; margin-left: .35em;
  font: 600 clamp(12px, 1.2vw, 17px)/1 var(--f-mono); letter-spacing: 0;
  vertical-align: top; color: var(--stale-text);
}
.delta::before, .delta::after { content: ""; position: absolute; clip-path: polygon(50% 0, 100% 100%, 0 100%); }
.delta::before { inset: 0; background: var(--stale); z-index: -2; }
.delta::after { inset: 3.4px 2.4px 1.8px; background: var(--paper); z-index: -1; }
.cover-body { grid-area: body; }
.cover-body .lede { font-size: clamp(1.08rem, 1.55vw, 1.32rem); }
.cta { display: flex; flex-wrap: wrap; gap: 18px 22px; margin-top: 30px; }
.cover-side { grid-area: side; align-self: start; display: grid; gap: 34px; padding-top: 8px; }
.general-notes, .sheet-index { border-left: 1.5px solid var(--ink); padding-left: 20px; }
.sheet-index ol { list-style: none; margin: 0; padding: 0; }
.sheet-index a { display: grid; grid-template-columns: 64px 1fr; gap: 8px; padding: 7px 0; border-bottom: 1px solid var(--rule); text-decoration: none; font-size: 14.5px; }
.sheet-index a span { font: 600 12.5px/1.6 var(--f-mono); }
.sheet-index a:hover { background: var(--paper-2); }
.general-notes ol { margin: 0; padding-left: 1.3em; font-size: 14.5px; line-height: 1.5; color: var(--ink-2); }
.general-notes li { margin-bottom: 8px; padding-left: 4px; }
.general-notes li::marker { font: 600 12px var(--f-mono); color: var(--ink); }

/* revision clouds (drawn by script) */
.cloud { position: absolute; pointer-events: none; overflow: visible; fill: none; stroke: var(--stale); stroke-width: 1.8; stroke-linejoin: round; z-index: 1; }
.cloud.is-blue { stroke: var(--synced); }

/* ---------- details & panels ---------- */
.detail { margin: 0; }
.detail-head {
  display: flex; align-items: center; flex-wrap: wrap; gap: 8px 14px;
  font-size: 12px; margin-bottom: 16px; color: var(--ink);
}
.detail-title { font-weight: 600; }
.detail-note { color: var(--ink-2); text-transform: none; letter-spacing: 0; font-size: 12.5px; }
.detail-note::before { content: "— "; }
.bubble {
  display: inline-grid; grid-template-rows: 1fr 1fr; width: 46px; height: 46px; border-radius: 50%;
  border: 1.5px solid var(--ink); text-align: center; font: 600 11px/1 var(--f-mono); overflow: hidden; flex: none;
}
.bubble span { display: grid; place-items: center; }
.bubble span:first-child { border-bottom: 1.5px solid var(--ink); padding-top: 4px; font-size: 13px; }
.bubble span:last-child { font-size: 9px; padding-bottom: 4px; letter-spacing: 0; }

.coupling { border-top: 1.5px solid var(--ink); padding-top: 22px; }
.coupling-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) 54px minmax(0, 1fr);
  grid-template-areas: "code coupler doc" "map map map";
  gap: 22px 0;
}
.panel { border: 1.5px solid var(--ink); background: var(--paper-3); min-width: 0; position: relative; }
.panel-code { grid-area: code; }
.panel-doc { grid-area: doc; }
.panel-map { grid-area: map; }
.panel-head {
  display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 12px;
  margin: 0; padding: 8px 12px; border-bottom: 1px solid var(--rule-strong);
  font-size: 11px; color: var(--ink-2);
}
.panel-kind { color: var(--ink); font-weight: 600; }
.panel-path { text-transform: none; letter-spacing: 0; font-size: 12px; color: var(--ink); overflow-wrap: anywhere; }
.panel-meta { margin-left: auto; }

.code { margin: 0; padding: 12px 0 14px; overflow-x: auto; font-size: 12.6px; line-height: 1.62; white-space: normal; tab-size: 4; }
.code .l { display: block; white-space: pre; padding: 0 14px 0 0; }
.code .l::before {
  content: attr(data-n); display: inline-block; width: 44px; padding-right: 14px; margin-right: 4px;
  text-align: right; color: var(--ink-3); border-right: 1px solid var(--rule);
}
.code .k { font-weight: 600; }
.code .f { font-weight: 600; text-decoration: underline; text-decoration-color: var(--rule-strong); text-underline-offset: 3px; }
.code .s { color: var(--ink-2); }
.code .n { color: var(--synced); font-weight: 600; }
.hot { display: block; position: relative; }
.hot-old, .hot-new { display: block; }
.js .hot { cursor: pointer; }
.js .hot:not(.is-done) .hot-old { background: var(--synced-wash); outline: 1px dashed var(--synced); outline-offset: -1px; }
.js .hot:not(.is-done):hover .hot-old { background: color-mix(in srgb, var(--synced) 18%, transparent); }
.hot-tag {
  position: absolute; right: 10px; top: 50%; transform: translateY(-50%);
  font: 600 10px var(--f-mono); text-transform: uppercase; letter-spacing: .08em;
  background: var(--synced); color: var(--paper); padding: 3px 7px;
}
.hot.is-done .hot-tag { display: none; }
.hot.is-edited .hot-old .l { text-decoration: line-through; text-decoration-color: var(--stale); color: var(--ink-3); background: var(--stale-wash); }
.hot.is-edited .hot-old .l::before { content: "−" attr(data-n); color: var(--stale-text); }
.hot.is-edited .hot-new .l { background: var(--synced-wash); }
.hot.is-edited .hot-new .l::before { content: "+" attr(data-n); color: var(--synced); font-weight: 600; }

.coupler { grid-area: coupler; position: relative; display: flex; align-items: center; justify-content: center; }
.coupler-line {
  position: absolute; left: 6px; right: 6px; top: 50%; height: 0; border-top: 1.5px solid var(--ink);
}
.coupler-line::before, .coupler-line::after {
  content: ""; position: absolute; top: -5px; width: 9px; height: 9px; border-radius: 50%; background: var(--ink);
}
.coupler-line::before { left: -4px; }
.coupler-line::after { right: -4px; }
.coupler-label {
  position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%) rotate(-90deg) translateX(50%) translateY(-14px);
  transform-origin: center;
  white-space: nowrap; font: 500 10.5px var(--f-mono); text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2);
}
.panel-doc { display: flex; flex-direction: column; }
.coupler-svg { position: absolute; left: 0; top: 0; overflow: visible; pointer-events: none; }
.coupler-svg path { fill: none; stroke: var(--ink); stroke-width: 1.5; transition: stroke var(--d-2); }
.coupler-svg circle { fill: var(--ink); transition: fill var(--d-2); }
.coupler.has-leader .coupler-line { display: none; }
.coupler.has-leader .coupler-label { top: var(--label-y, 50%); left: var(--label-x, 50%); transform: translate(-50%, -50%) rotate(-90deg) translateY(-12px); }
.coupling[data-state="stale"] .coupler-svg path { stroke: var(--stale); }
.coupling[data-state="stale"] .coupler-svg circle { fill: var(--stale); }
.coupling[data-state="updated"] .coupler-svg path { stroke: var(--synced); }
.coupling[data-state="updated"] .coupler-svg circle { fill: var(--synced); }
.doc { padding: 18px 18px 20px; }
.doc-title { font: 600 1.2rem/1.25 var(--f-sans); margin: 0 0 12px; padding-right: 196px; min-height: 64px; }
.doc p { margin: 0 0 14px; font-size: 14.5px; line-height: 1.55; color: var(--ink-2); }
.doc-table { width: 100%; border-collapse: collapse; font-size: 13px; line-height: 1.35; }
.doc-table th, .doc-table td { text-align: left; padding: 7px 8px; border-bottom: 1px solid var(--rule); vertical-align: top; }
.doc-table th { font: 600 10.5px var(--f-mono); text-transform: uppercase; letter-spacing: .05em; color: var(--ink-2); border-bottom: 1.5px solid var(--ink); }
.doc-table td:first-child { font-family: var(--f-mono); width: 2.5em; }
.row-hot td { background: transparent; transition: background-color var(--d-2) var(--ease-out); }
.coupling[data-state="stale"] .row-hot td { background: var(--stale-wash); }
.coupling[data-state="updated"] .row-hot td { background: var(--synced-wash); }
.redline { position: relative; display: inline; }
.redline-old { transition: color var(--d-2); }
.redline.is-struck .redline-old {
  color: var(--stale-text);
  text-decoration: line-through; text-decoration-thickness: 2px; text-decoration-color: var(--stale);
}
.redline-new { display: block; color: var(--synced); font-weight: 600; min-height: 0; }
.redline-new:empty { display: none; }
.is-typing::after { content: "▍"; animation: caret .8s steps(1) infinite; margin-left: 1px; }
@keyframes caret { 50% { opacity: 0; } }

/* rubber stamp */
.stamp {
  position: absolute; top: 50px; right: 16px; z-index: 2;
  display: grid; justify-items: center; gap: 2px;
  padding: 6px 12px 7px;
  border: 3px solid currentColor; border-radius: 5px;
  box-shadow: inset 0 0 0 2px var(--paper-3), inset 0 0 0 3.5px currentColor;
  color: var(--synced);
  transform: rotate(-7deg);
  mix-blend-mode: var(--stamp-blend);
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' seed='7'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -2.6 0 0 0 2.35'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' seed='7'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -2.6 0 0 0 2.35'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  pointer-events: none;
}
.stamp-word { font-size: 38px; font-weight: 900; line-height: .9; text-transform: uppercase; letter-spacing: .08em; }
.stamp-sub { font: 600 9px var(--f-mono); text-transform: uppercase; letter-spacing: .1em; }
.stamp[data-state="stale"] { color: var(--stale); }
.stamp.is-slam { animation: slam var(--d-3) var(--ease-snap) both; }
@keyframes slam {
  0% { transform: scale(2.3) rotate(-15deg); opacity: 0; }
  55% { transform: scale(.94) rotate(-6deg); opacity: 1; }
  75% { transform: scale(1.03) rotate(-7.4deg); }
  100% { transform: scale(1) rotate(-7deg); opacity: 1; }
}
.panel-doc.is-hit { animation: thud var(--d-2) var(--ease-out); }
@keyframes thud { 30% { translate: 0 3px; } }

/* page map */
.map {
  margin: 0; padding: 14px 16px 6px; font-size: 12px; line-height: 1.6;
  white-space: pre-wrap; overflow-wrap: anywhere; color: var(--ink-2);
}
.map-h { color: var(--ink); font-weight: 600; }
.map-focus { color: var(--ink); background: linear-gradient(transparent 62%, var(--synced-wash) 62%); }
.map-flag { color: var(--stale-text); font-weight: 600; }
.map-flag.is-new { animation: flagIn var(--d-3) var(--ease-out) both; }
@keyframes flagIn { from { opacity: 0; } to { opacity: 1; } }
#map-count.is-stale { color: var(--stale-text); font-weight: 600; }

/* dimension lines */
.dimline { position: relative; margin: 6px 16px 18px; height: 54px; }
.dimline .dim { position: absolute; left: 0; height: 0; border-top: 1.5px solid var(--ink); }
.dimline .dim::before, .dimline .dim::after {
  content: ""; position: absolute; top: -7px; width: 1.5px; height: 13px; background: var(--ink); transform: rotate(45deg);
}
.dimline .dim::before { left: 0; }
.dimline .dim::after { right: 0; }
.dim-budget { top: 16px; width: 100%; border-top-style: solid; }
.dim-used { top: 42px; width: calc(var(--used) / var(--max) * 100%); border-top-width: 3px !important; transition: width var(--d-3) var(--ease-out); }
.dimline .dim-used::before, .dimline .dim-used::after { top: -8px; }
.dim-text {
  position: absolute; bottom: 3px; left: 50%; transform: translateX(-50%);
  white-space: nowrap; font: 500 11.5px var(--f-mono); background: var(--paper-3); padding: 0 6px; color: var(--ink);
}
.dim-budget .dim-text { left: auto; right: 0; transform: none; }
.dim-used .dim-text { left: 0; transform: none; font-weight: 600; }
.coupling[data-state="stale"] .dim-used { border-top-color: var(--stale); }
.coupling[data-state="stale"] .dim-used .dim-text { color: var(--stale-text); }

.coupling-controls { margin-top: 26px; }
.controls-row { display: flex; flex-wrap: wrap; gap: 14px 18px; align-items: center; }
.log {
  margin: 18px 0 0; padding: 10px 14px; min-height: 46px;
  border-left: 3px solid var(--ink); background: var(--paper-2);
  font: 13px/1.55 var(--f-mono); color: var(--ink); max-width: 100%;
  overflow-wrap: anywhere;
}
.log-sub { display: block; margin-top: 8px; padding-top: 8px; border-top: 1px dashed var(--rule-strong); color: var(--ink-2); }
.log-k { display: inline-block; font-weight: 600; text-transform: uppercase; letter-spacing: .06em; font-size: 11px; margin-right: 10px; padding: 1px 6px; border: 1px solid currentColor; }
.log.is-stale { border-left-color: var(--stale); }
.log.is-stale .log-k { color: var(--stale-text); }
.log.is-synced { border-left-color: var(--synced); }
.log.is-synced .log-k { color: var(--synced); }
.fineprint { font-size: 13px; color: var(--ink-2); margin: 14px 0 0; max-width: 80ch; }

/* ---------- A-101 ---------- */
.schedule-wrap { margin-bottom: clamp(40px, 5vw, 64px); }
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; max-width: 100%; }
.schedule { width: 100%; border-collapse: collapse; border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); min-width: 560px; }
.schedule-measured { min-width: 760px; }
.schedule th, .schedule td { text-align: left; vertical-align: top; padding: 14px 16px 15px 0; border-bottom: 1px solid var(--rule); }
.schedule thead th { font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); padding-top: 10px; padding-bottom: 10px; border-bottom: 1.5px solid var(--ink); }
.schedule tbody th { font: 600 1.1rem/1.3 var(--f-sans); width: 34%; padding-right: 28px; }
.schedule td { font-size: 16px; color: var(--ink-2); }
.schedule .mark { font: 900 1.6rem/1 var(--f-display); color: var(--ink); width: 64px; }
.schedule-measured tbody th { width: 26%; }
.schedule .measured { font: 400 13px/1.45 var(--f-mono); color: var(--ink); width: 22%; }
.schedule .measured b { font-weight: 600; }
.schedule-compact th, .schedule-compact td { padding: 10px 14px 11px 0; font-size: 14.5px; line-height: 1.45; }
.schedule-compact tbody th { font: 600 14.5px/1.4 var(--f-sans); width: auto; }
.schedule-compact.commands tbody th { white-space: nowrap; }
.schedule-compact.commands td:last-child { white-space: nowrap; font-family: var(--f-mono); font-size: 12.5px; }
.split { display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 36px clamp(28px, 4vw, 64px); align-items: start; }
.split-even { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
.tree { margin: 0; padding: 18px 20px; border: 1.5px solid var(--ink); background: var(--paper-3); font-size: 12.8px; line-height: 1.75; overflow-x: auto; }
.tree span { color: var(--ink-2); }
.split-notes p { margin: 0 0 16px; color: var(--ink-2); max-width: 54ch; }
.split-notes .note-strong { color: var(--ink); font-weight: 600; border-left: 3px solid var(--stale); padding-left: 14px; }

/* ---------- A-201 loop ---------- */
.loop { display: grid; grid-template-columns: minmax(0, 8fr) minmax(0, 4fr); gap: 28px clamp(28px, 3.5vw, 56px); align-items: start; margin-bottom: clamp(40px, 5vw, 64px); }
.loop-figure { margin: 0; }
.loop-svg { width: 100%; height: auto; overflow: visible; }
.loop-tall { display: none; max-width: 420px; margin: 0 auto; }
.loop-svg .ln { fill: none; stroke: var(--ink); stroke-width: 1.6; stroke-linecap: square; }
.loop-svg .ln.thin { stroke-width: .9; }
.loop-svg .box { fill: var(--paper-3); }
.loop-svg .head { fill: var(--ink); }
.loop-svg text { fill: var(--ink); }
.loop-svg .t-title { font: 800 30px var(--f-display); text-transform: uppercase; letter-spacing: .02em; }
.loop-svg .t-mono { font: 400 13px var(--f-mono); fill: var(--ink-2); }
.loop-svg .legend .t-mono { font-size: 13.5px; }
.loop-svg .t-edge { font: 500 13px var(--f-mono); fill: var(--ink); paint-order: stroke; stroke: var(--paper); stroke-width: 6px; stroke-linejoin: round; }
.loop-svg .t-dim { font: 600 13px var(--f-mono); paint-order: stroke; stroke: var(--paper); stroke-width: 6px; }
.loop-svg .dimg .ln { stroke: var(--stale); }
.loop-svg .t-dim { fill: var(--stale-text); }
.bubble-svg { cursor: pointer; outline: none; }
.bubble-svg circle { fill: var(--paper); stroke: var(--ink); stroke-width: 1.6; transition: fill var(--d-1), stroke var(--d-1); }
.bubble-svg text { font: 600 14px var(--f-mono); fill: var(--ink); pointer-events: none; transition: fill var(--d-1); }
.bubble-svg:hover circle, .bubble-svg.is-active circle { fill: var(--ink); }
.bubble-svg:hover text, .bubble-svg.is-active text { fill: var(--paper); }
.bubble-svg:focus-visible circle { stroke: var(--synced); stroke-width: 4; }
.node .box, .node .ln { transition: stroke var(--d-1), fill var(--d-1); }
.node.is-active .ln { stroke: var(--synced); }
.node.is-active .box { fill: var(--synced-wash); }
.keyed-notes ol { margin: 0; padding: 0; list-style: none; counter-reset: kn; }
.keyed-notes li {
  counter-increment: kn; position: relative; padding: 12px 0 13px 44px; border-bottom: 1px solid var(--rule);
  font-size: 14.5px; line-height: 1.5; color: var(--ink-2); transition: background-color var(--d-1), color var(--d-1);
}
.keyed-notes li::before {
  content: counter(kn); position: absolute; left: 0; top: 11px; width: 28px; height: 28px; border-radius: 50%;
  border: 1.5px solid var(--ink); display: grid; place-items: center; font: 600 12.5px var(--f-mono); color: var(--ink);
}
.keyed-notes li b { color: var(--ink); }
.keyed-notes li.is-active { background: var(--synced-wash); color: var(--ink); }
.keyed-notes li.is-active::before { background: var(--ink); color: var(--paper); }

.js .loop.is-armed .ln { stroke-dasharray: 1; stroke-dashoffset: 1; }
.js .loop.is-armed text, .js .loop.is-armed .head, .js .loop.is-armed .bubble-svg { opacity: 0; }
.js .loop.is-drawn .ln { stroke-dashoffset: 0; transition: stroke-dashoffset var(--d-4) var(--ease-io), stroke var(--d-1); }
.js .loop.is-drawn .edges .ln { transition-delay: calc(var(--d-4) / 2); }
.js .loop.is-drawn .legend .ln { transition-delay: calc(var(--d-4) * .7); }
.js .loop.is-drawn text, .js .loop.is-drawn .head, .js .loop.is-drawn .bubble-svg { opacity: 1; transition: opacity var(--d-3) var(--ease-out) var(--d-4); }

.where { margin-bottom: clamp(40px, 5vw, 64px); }

.dims { position: relative; padding-bottom: 26px; }
.dim-row { display: grid; grid-template-columns: minmax(0, 150px) minmax(0, 1fr); gap: 14px; align-items: center; padding: 8px 0; border-bottom: 1px solid var(--rule); }
.dim-k { margin: 0; font-size: 13px; line-height: 1.3; }
.dim-k b { display: block; font-weight: 600; }
.dim-k span { color: var(--ink-2); font-size: 12px; }
.dim-track { position: relative; height: 40px; }
.dims .dim { position: absolute; top: 24px; left: calc(var(--from) / var(--max) * 100%); width: calc((var(--to) - var(--from)) / var(--max) * 100%); min-width: 2px; height: 0; border-top: 2px solid var(--ink); }
.dims .dim::before, .dims .dim::after { content: ""; position: absolute; top: -7px; width: 1.5px; height: 12px; background: var(--ink); transform: rotate(45deg); }
.dims .dim::before { left: 0; }
.dims .dim::after { right: 0; }
.dims .dim-ext { border-top: 1px dashed var(--ink-3); }
.dims .dim-ext::before { display: none; }
.dims .dim-ext::after { background: var(--ink-3); }
.dim-row-key .dim:not(.dim-ext) { border-top-color: var(--synced); border-top-width: 3px; }
.dim-row-key .dim-ext { border-top-color: var(--synced); }
.dim-v { position: absolute; top: 2px; font: 500 11.5px var(--f-mono); white-space: nowrap; color: var(--ink); left: calc(var(--at) / var(--max) * 100%); }
.dim-axis { position: absolute; left: 164px; right: 0; bottom: 0; height: 20px; font: 400 10.5px var(--f-mono); color: var(--ink-3); white-space: nowrap; }
.nowrap { white-space: nowrap; }
.dim-axis span { position: absolute; left: calc(var(--at) / var(--max) * 100%); transform: translateX(-50%); top: 4px; }
.dim-axis span:first-child { transform: none; }
.dim-axis span:last-child { transform: translateX(-100%); }

/* ---------- A-301 evidence ---------- */
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); margin-bottom: clamp(40px, 5vw, 64px); }
.stat { padding: 18px clamp(14px, 2vw, 26px) 22px; border-left: 1px solid var(--rule-strong); min-width: 0; }
.stat:first-child { border-left: 0; padding-left: 0; }
.stat-n { margin: 0; font-size: clamp(5rem, 11vw, 10rem); font-weight: 900; line-height: .8; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.stat-n span { font-size: .45em; font-weight: 800; vertical-align: .9em; margin-left: .04em; }
.stat-l { margin: 10px 0 18px; font: 600 12px var(--f-mono); text-transform: uppercase; letter-spacing: .07em; }
.cmp { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: 6px 10px; align-items: center; font: 400 11.5px var(--f-mono); }
.cmp-k { color: var(--ink-2); white-space: nowrap; }
.cmp-v { text-align: right; white-space: nowrap; }
.cmp-bar { position: relative; height: 10px; border-top: 1.5px solid var(--ink); margin-top: 5px; }
.cmp-bar::before, .cmp-bar::after { content: ""; position: absolute; top: -6px; width: 1.5px; height: 11px; background: var(--ink); transform: rotate(45deg); }
.cmp-bar::before { left: 0; }
.cmp-bar::after { right: 0; }
.cmp-part { border-top: 0; }
.cmp-part::before { display: none; }
.cmp-part::after { display: none; }
.cmp-part {
  background:
    linear-gradient(var(--ink), var(--ink)) left top / calc(var(--r) * 100%) 4px no-repeat,
    repeating-linear-gradient(-45deg, var(--hatch) 0 1px, transparent 1px 5px) calc(var(--r) * 100%) 0 / calc((1 - var(--r)) * 100% + 1px) 10px no-repeat;
  height: 10px; margin-top: 0;
}

.ci { margin: 0; }
.ci figcaption .small { margin: -6px 0 18px; }
.ci-plot { position: relative; padding-bottom: 28px; }
.ci-row { display: grid; grid-template-columns: 112px minmax(0, 1fr) 112px; gap: 14px; align-items: center; height: 46px; border-bottom: 1px solid var(--rule); }
.ci-k { font: 500 12px var(--f-mono); color: var(--ink-2); }
.ci-key .ci-k { color: var(--ink); font-weight: 600; }
.ci-v { font: 600 15px var(--f-sans); text-align: right; white-space: nowrap; }
.ci-v small { font: 400 12px var(--f-mono); color: var(--ink-2); }
.ci-track { position: relative; height: 100%; background: repeating-linear-gradient(90deg, var(--rule) 0 1px, transparent 1px calc(100% / 6)); }
.ci-range {
  position: absolute; top: 50%; height: 0; border-top: 1.5px solid var(--ink-2);
  left: calc((var(--a) - var(--lo)) / (var(--hi) - var(--lo)) * 100%);
  width: calc((var(--b) - var(--a)) / (var(--hi) - var(--lo)) * 100%);
}
.ci-range::before, .ci-range::after { content: ""; position: absolute; top: -7px; width: 1.5px; height: 13px; background: var(--ink-2); transform: rotate(45deg); }
.ci-range::before { left: 0; }
.ci-range::after { right: 0; }
.ci-key .ci-range { border-top: 3px solid var(--synced); top: calc(50% - 1px); }
.ci-key .ci-range::before, .ci-key .ci-range::after { background: var(--synced); width: 2px; }
.ci-pt {
  position: absolute; top: 50%; width: 11px; height: 11px; background: var(--paper); border: 2px solid var(--ink);
  left: calc((var(--p) - var(--lo)) / (var(--hi) - var(--lo)) * 100%); transform: translate(-50%, -50%) rotate(45deg);
}
.ci-key .ci-pt { background: var(--synced); border-color: var(--paper); box-shadow: 0 0 0 1.5px var(--synced); }
.ci-axis { position: absolute; left: 126px; right: 126px; bottom: 0; height: 20px; font: 400 10.5px var(--f-mono); color: var(--ink-3); }
.ci-axis span { position: absolute; top: 6px; left: calc((var(--p) - 70) / 30 * 100%); transform: translateX(-50%); }
.callout-nomap { border: 1.5px solid var(--ink); padding: 22px 24px; background: var(--paper-3); }
.callout-nomap .label { margin-bottom: 4px; }
.callout-big { margin: 0 0 12px; font-size: clamp(2.6rem, 4.6vw, 4rem); font-weight: 800; line-height: .9; text-transform: uppercase; }
.callout-nomap p:last-child { margin: 0; font-size: 15px; color: var(--ink-2); }

.data-table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 760px; border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); }
.data-table th, .data-table td { padding: 9px 12px 9px 0; text-align: right; border-bottom: 1px solid var(--rule); white-space: nowrap; font-variant-numeric: tabular-nums; }
.data-table th:first-child, .data-table td:first-child { text-align: left; }
.data-table thead th { font: 600 10.5px var(--f-mono); text-transform: uppercase; letter-spacing: .06em; color: var(--ink-2); border-bottom: 1.5px solid var(--ink); white-space: normal; vertical-align: bottom; }
.data-table tbody th { font: 500 13px var(--f-mono); }
.data-table .row-key th, .data-table .row-key td { font-weight: 600; background: var(--synced-wash); }
.split + .label, .stats + .split { margin-top: 0; }
.ci + .callout-nomap { align-self: center; }
section .split + h3.label { margin-top: clamp(40px, 5vw, 60px); }
.more { margin: 16px 0 0; }
.more summary { cursor: pointer; font: 600 12px var(--f-mono); text-transform: uppercase; letter-spacing: .07em; padding: 8px 0; width: fit-content; }
.more summary:hover { text-decoration: underline; }
.more[open] summary { margin-bottom: 8px; }
.more .small { margin-top: 10px; }
.redline-split { margin-top: clamp(48px, 6vw, 80px); }
.redline-note { position: relative; padding: 24px 26px 22px; border: 1.5px dashed var(--stale); background: var(--stale-wash); }
.redline-tag { margin: 0 0 6px; display: flex; align-items: center; gap: 10px; font: 600 11.5px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--stale-text); }
.delta-inline { font-size: 11px; width: 24px; height: 21px; margin: 0; vertical-align: middle; }
.delta-inline::after { background: var(--paper-3); }
.redline-note h3 { font: 800 clamp(1.8rem, 3vw, 2.5rem)/.95 var(--f-display); text-transform: uppercase; margin: 0 0 14px; }
.redline-note p, .redline-note li { font-size: 15.5px; color: var(--ink); }
.redline-note ol { padding-left: 1.3em; margin: 0 0 14px; }
.redline-note li { margin-bottom: 8px; }
del { text-decoration: line-through; text-decoration-color: var(--stale); text-decoration-thickness: 2px; color: var(--stale-text); }
ins { text-decoration: none; background: linear-gradient(transparent 58%, var(--synced-wash) 58%); color: var(--synced); font-weight: 600; }
.redline-moral { font-weight: 600; border-top: 1px solid var(--stale); padding-top: 12px; margin: 0; }
.speed-big { margin: 0 0 8px; font-size: clamp(4.4rem, 9vw, 8rem); font-weight: 900; line-height: .85; }
.speed-big span { letter-spacing: -.02em; }
.speed-bars { margin: 18px 0 10px; }
.speed-row { display: grid; grid-template-columns: 150px minmax(0, 1fr) 54px; gap: 12px; align-items: center; height: 36px; }
.speed-k { font: 500 12px var(--f-mono); color: var(--ink-2); }
.speed-v { font: 600 13px var(--f-mono); text-align: right; }
.speed-track { position: relative; height: 12px; }
.speed-bar { position: absolute; left: 0; top: 0; height: 12px; width: max(4px, calc(var(--v) / var(--max) * 100%)); background: var(--ink); }
.speed-old .speed-bar { background: repeating-linear-gradient(-45deg, var(--hatch) 0 1.5px, transparent 1.5px 6px); border: 1px solid var(--ink-3); }
.speed-old .speed-k, .speed-old .speed-v { text-decoration: line-through; text-decoration-color: var(--stale); color: var(--ink-2); }
.limits { margin-top: clamp(40px, 5vw, 64px); margin-bottom: 30px; }
.limits ol { margin: 0; padding-left: 1.4em; columns: 2 320px; column-gap: 48px; }
.limits li { margin: 0 0 10px; color: var(--ink-2); break-inside: avoid; font-size: 15.5px; }
.limits li::marker { font: 600 12px var(--f-mono); color: var(--ink); }

.code-block { position: relative; border: 1.5px solid var(--ink); background: var(--paper-3); margin: 0 0 14px; max-width: 100%; }
.code-block pre { margin: 0; padding: 14px 16px; overflow-x: auto; font-size: 13px; line-height: 1.6; }
.code-block code { font-size: inherit; overflow-wrap: normal; }
.copy {
  position: absolute; top: 0; right: 0;
  border: 0; border-left: 1px solid var(--rule-strong); border-bottom: 1px solid var(--rule-strong);
  background: var(--paper-2); color: var(--ink);
  font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .07em;
  padding: 7px 11px; cursor: pointer;
}
.copy:hover { background: var(--ink); color: var(--paper); }
.copy.is-done { background: var(--synced); color: var(--paper); }
.js .code-block pre { padding-right: 84px; }

/* ---------- S-401 ---------- */
.survey-flag { display: inline-flex; flex-wrap: wrap; margin: 0 0 18px; border: 2px solid var(--stale); color: var(--stale-text); font: 600 12px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; transform: rotate(-1.2deg); }
.survey-flag span { padding: 6px 12px; }
.survey-flag span + span { border-left: 2px solid var(--stale); }
.survey { min-width: 1040px; }
.survey-notes { margin-top: clamp(32px, 4vw, 48px); }
.survey-notes p { margin: 0; color: var(--ink-2); max-width: 60ch; font-size: 15.5px; }
.survey th, .survey td { text-align: left; white-space: normal; vertical-align: top; padding: 14px 18px 14px 0; font-size: 14.5px; line-height: 1.45; }
.survey tbody th { font: 600 15px/1.3 var(--f-sans); width: 14%; }
.survey tbody th a { display: inline-block; margin-bottom: 2px; }
.survey tbody th small { display: block; font: 400 11.5px var(--f-mono); color: var(--ink-2); text-transform: uppercase; letter-spacing: .05em; margin-top: 3px; }
.survey td { color: var(--ink-2); }
.survey .is-self th, .survey .is-self td { background: var(--synced-wash); color: var(--ink); }
.survey .is-self th { box-shadow: inset 4px 0 0 var(--synced); padding-left: 14px; }

/* ---------- A-501 learn ---------- */
.learn { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.learn-modes dl { margin: 0; }
.learn-modes dl > div { padding: 12px 0 13px; border-bottom: 1px solid var(--rule); }
.learn-modes dl > div:first-child { border-top: 2px solid var(--ink); }
.learn-modes dt code { font-size: 13px; font-weight: 600; }
.learn-modes dd { margin: 5px 0 0; font-size: 14.5px; color: var(--ink-2); }
.quiz { margin: 0; border: 1.5px solid var(--ink); background: var(--paper-3); padding: 18px clamp(16px, 2.4vw, 26px) 22px; }
.illustration-flag { margin: -4px 0 16px; display: inline-block; font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--stale-text); border: 1.5px dashed var(--stale); padding: 4px 9px; }
.transcript { font-size: 15px; }
.turn { position: relative; padding-left: 92px; margin: 0 0 16px; }
.who { position: absolute; left: 0; top: 2px; font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); width: 80px; border-top: 1.5px solid var(--ink); padding-top: 4px; }
.turn-you code { font-size: 14px; background: var(--paper-2); padding: 3px 8px; }
.q-count { margin: 0 0 4px; font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); }
.q { margin: 0 0 14px; font-weight: 500; font-size: 16px; line-height: 1.5; }
.choices { display: grid; gap: 8px; margin: 0 0 14px; padding: 0; list-style: none; }
.choice {
  display: grid; grid-template-columns: 30px minmax(0, 1fr); gap: 10px; align-items: center; width: 100%;
  text-align: left; padding: 9px 12px; background: var(--paper); color: var(--ink);
  border: 1.5px solid var(--rule-strong); font: 400 15px/1.35 var(--f-sans); cursor: pointer;
}
.choice:hover:not([disabled]) { border-color: var(--ink); background: var(--paper-2); }
.choice-key { display: grid; place-items: center; width: 26px; height: 26px; border: 1.5px solid var(--ink); border-radius: 50%; font: 600 12px var(--f-mono); }
.choice[disabled] { cursor: default; }
.choice.is-right { border-color: var(--synced); background: var(--synced-wash); }
.choice.is-right .choice-key { background: var(--synced); border-color: var(--synced); color: var(--paper); }
.choice.is-wrong { border-color: var(--stale); background: var(--stale-wash); }
.choice.is-wrong .choice-key { background: var(--stale); border-color: var(--stale); color: var(--paper); }
.choices-static { margin: 0 0 12px; padding-left: 1.6em; }
.choices-static li { margin-bottom: 4px; }
.grade { border-left: 3px solid var(--synced); padding: 4px 0 4px 14px; margin: 0 0 14px; font-size: 15px; }
.grade.is-wrong { border-left-color: var(--stale); }
.grade p { margin: 0 0 8px; }
.grade-mark { font: 600 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; padding: 2px 7px; border: 1.5px solid currentColor; margin-right: 8px; }
.grade .grade-mark { color: var(--synced); }
.grade.is-wrong .grade-mark { color: var(--stale-text); }
.cite { font: 400 12.5px/1.6 var(--f-mono); color: var(--ink-2); }
.cite a { color: var(--ink); }
.static-answer summary { cursor: pointer; font: 600 12px var(--f-mono); text-transform: uppercase; letter-spacing: .06em; }
.static-answer p { font-size: 15px; }

/* ---------- I-601 install ---------- */
.tabs { margin-bottom: clamp(40px, 5vw, 64px); }
.tablist { display: flex; border-bottom: 2px solid var(--ink); overflow-x: auto; scrollbar-width: none; }
.tablist::-webkit-scrollbar { display: none; }
.tablist [role="tab"] {
  display: flex; align-items: baseline; gap: 10px; flex: none;
  padding: 12px 20px 11px; background: transparent; color: var(--ink);
  border: 1.5px solid var(--ink); border-bottom: 0; margin-right: -1.5px;
  font: 600 15px var(--f-sans); cursor: pointer;
}
.tablist [role="tab"]:hover { background: var(--paper-2); }
.tablist [role="tab"][aria-selected="true"] { background: var(--ink); color: var(--paper); }
.tab-no { font: 500 11px var(--f-mono); opacity: .7; }
.tabpanel { padding: 24px 0 0; max-width: 900px; }
.tabpanel + .tabpanel { border-top: 1px solid var(--rule); margin-top: 28px; }
.js .tabpanel + .tabpanel { border-top: 0; margin-top: 0; }
.tabpanel-title { font: 800 1.9rem/1 var(--f-display); text-transform: uppercase; margin: 0 0 12px; }
.tabpanel p { max-width: 72ch; }
.tabpanel:focus-visible { outline-offset: 8px; }
.prompt { margin: 0 0 16px; padding: 10px 16px; border-left: 3px solid var(--ink); background: var(--paper-2); font-style: italic; }
.trust ul { margin: 0; padding-left: 1.2em; columns: 2 320px; column-gap: 48px; }
.trust li { margin-bottom: 10px; color: var(--ink-2); font-size: 15px; break-inside: avoid; }

/* ---------- revisions, terminal, modes, trial ---------- */
.revisions { border-left: 1.5px solid var(--ink); padding-left: 20px; }
.rev-table { width: 100%; border-collapse: collapse; font-size: 13.5px; line-height: 1.4; }
.rev-table th, .rev-table td { text-align: left; vertical-align: top; padding: 7px 8px 8px 0; border-bottom: 1px solid var(--rule); }
.rev-table thead th { font: 600 10px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); padding-top: 0; }
.rev-table tbody th { font: 600 12.5px var(--f-mono); white-space: nowrap; }
.rev-table td:nth-child(2) { font: 400 12px var(--f-mono); white-space: nowrap; color: var(--ink-2); }
.rev-table td:last-child { color: var(--ink-2); padding-right: 0; }
.rev { vertical-align: -3px; }
.label .delta-inline { flex: none; }

.tree-k { margin: 18px 0 8px; font: 500 12.5px var(--f-mono); color: var(--ink-2); display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; }
.tree-k:first-of-type { margin-top: 0; }
.tree-k code { color: var(--ink); font-weight: 600; }
.tree i { font-style: normal; color: var(--ink-3); }

.term { border: 1.5px solid var(--ink); background: var(--paper-3); min-width: 0; }
.term-bar { display: flex; align-items: center; gap: 10px; margin: 0; padding: 6px 6px 6px 12px; min-height: 34px; background: var(--ink); color: var(--paper); font: 500 11px var(--f-mono); text-transform: uppercase; letter-spacing: .08em; }
.term-replay { margin-left: auto; padding: 3px 9px; border: 1px solid currentColor; background: none; color: inherit; font: inherit; letter-spacing: inherit; text-transform: inherit; cursor: pointer; transition: background-color var(--d-1), color var(--d-1); }
.term-replay:hover { background: var(--paper); color: var(--ink); }
.term-replay:focus-visible { outline-color: var(--paper); outline-offset: 2px; }
.term-body { margin: 0; padding: 12px 14px 14px; font-size: 12px; line-height: 1.6; white-space: normal; color: var(--ink-2); }
.t-ln { display: block; white-space: pre-wrap; overflow-wrap: anywhere; padding-left: 2ch; text-indent: -2ch; transition: opacity var(--d-2) var(--ease-out); }
.t-cmd { color: var(--ink); font-weight: 600; }
.t-cmd + .t-ln:not(.t-cmd) { margin-top: 2px; }
.t-ln + .t-cmd { margin-top: 10px; }
.t-cont { padding-left: 6ch; }
.t-ps { color: var(--synced); }
.t-stale { color: var(--stale-text); font-weight: 600; }
.t-review { color: var(--synced); font-weight: 600; }
.term.is-armed .t-ln:not(.is-on) { opacity: 0; }
.term-detail .fineprint { margin-top: 10px; }

.modes { margin-bottom: clamp(40px, 5vw, 64px); }
.modes .schedule-compact td:last-child { font-size: 13.5px; }
.tl { margin: 0; }
.tl-row { display: grid; grid-template-columns: 76px minmax(0, 1fr); gap: 12px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--rule); }
.tl-row:first-of-type { border-top: 2px solid var(--ink); }
.tl-k { margin: 0; font-size: 13px; }
.tl-key .tl-k code { font-weight: 600; }
.tl-track { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.tl-track li { font: 500 11.5px/1 var(--f-mono); padding: 6px 8px; border: 1px solid var(--rule-strong); background: var(--paper-3); }
.tl-track .tl-up { border-color: var(--synced); background: var(--synced-wash); color: var(--synced); font-weight: 600; }
.tl-track .tl-hold { border: 1.5px dashed var(--stale); color: var(--stale-text); font-weight: 600; }
.tl-track .tl-commit { background: var(--ink); border-color: var(--ink); color: var(--paper); }

.stat-kv { margin: 14px 0 0; font: 400 12px/1.55 var(--f-mono); color: var(--ink-2); }
.stat-kv b { color: var(--ink); font-weight: 600; }
.noise { margin: 0; }
.noise-row { display: grid; grid-template-columns: 104px minmax(0, 1fr); gap: 6px 14px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--rule); }
.noise-row:first-of-type { border-top: 2px solid var(--ink); }
.noise-k { margin: 0; font: 500 12px var(--f-mono); color: var(--ink-2); }
.noise-strip { position: relative; height: 26px; }
.noise-old { background: repeating-linear-gradient(90deg, var(--ink-3) 0 1px, transparent 1px calc(100% / 407)); }
.noise-hit { position: absolute; top: -5px; bottom: -5px; left: 62%; width: 2px; background: var(--stale); }
.noise-new { display: flex; align-items: stretch; gap: 7px; }
.noise-new > i { width: 2px; background: var(--ink); }
.noise-info { display: flex; align-items: center; margin-left: 10px; padding: 0 8px; border: 1px dashed var(--ink-3); font: 500 10.5px var(--f-mono); color: var(--ink-2); white-space: nowrap; }
.noise-v { grid-column: 2; margin: 0; font: 400 12.5px/1.45 var(--f-mono); color: var(--ink); }
.noise-v code { white-space: nowrap; }
.trial-notes { margin-top: clamp(40px, 5vw, 64px); }
.trial-notes ul { margin: 0; padding-left: 1.2em; columns: 2 320px; column-gap: 48px; }
.trial-notes li { margin-bottom: 10px; color: var(--ink-2); font-size: 15.5px; break-inside: avoid; }
.trial-runs td:nth-child(2), .trial-runs td:nth-child(3) { font-family: var(--f-mono); font-size: 13px; white-space: nowrap; color: var(--ink); }
.trial-runs tbody th { width: 28%; }
.trial-stats .stat-n { font-size: clamp(4rem, 8vw, 7.5rem); }
.trial-stats + .label { margin-top: 0; }
.trial-notes li b { color: var(--ink); }
.finding .redline-tag { color: var(--stale-text); }
.split-term { margin-top: clamp(40px, 5vw, 64px); }
.schedule .row-key th, .schedule .row-key td { background: var(--synced-wash); color: var(--ink); }
.tl figcaption .small { margin: -6px 0 14px; }

.faq { border-top: 2px solid var(--ink); }
.faq-item { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: 6px clamp(24px, 4vw, 56px); padding: 18px 0 16px; border-bottom: 1px solid var(--rule); }
.faq-item h3 { margin: 0; font: 600 1.1rem/1.35 var(--f-sans); }
.faq-item p { margin: 0; color: var(--ink-2); font-size: 15.5px; max-width: 68ch; }
.star { margin-top: clamp(40px, 5vw, 64px); padding: clamp(20px, 3vw, 32px); border: 1.5px solid var(--ink); background: var(--paper-3); }
.star-big { margin: 0 0 10px; font: 800 clamp(1.9rem, 3.6vw, 3rem)/.95 var(--f-display); text-transform: uppercase; }
.star p { max-width: 64ch; }
.star .cta { margin-top: 18px; }

/* ---------- footer title block ---------- */
.site-foot { padding: 0 var(--gutter) 48px; }
.foot-block {
  max-width: 1380px; margin: 0 auto;
  display: grid; grid-template-columns: 2.2fr repeat(3, 1fr);
  border: 2px solid var(--ink); outline: 1px solid var(--ink); outline-offset: 5px;
  background: var(--paper);
}
.fb-cell { padding: 12px 16px 14px; border-right: 1px solid var(--rule-strong); border-bottom: 1px solid var(--rule-strong); min-width: 0; }
.fb-cell > b { display: block; font-size: 10px; font-weight: 500; color: var(--ink-2); margin-bottom: 4px; }
.fb-cell p { margin: 0; font-size: 14.5px; }
.fb-name { grid-row: span 2; }
.fb-word { font-size: clamp(3rem, 6vw, 5.4rem) !important; font-weight: 900; text-transform: uppercase; line-height: .85 !important; margin: 4px 0 10px !important; letter-spacing: .01em; }
.fb-links { grid-column: 1 / -1; }
.fb-links ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 6px 22px; font-size: 14.5px; }
.fb-legal { grid-column: 1 / -1; border-bottom: 0; }
.fb-legal p { color: var(--ink-2); font-size: 13.5px; }

/* ---------- responsive ---------- */
@media (max-width: 1300px) {
  .sheet-nav .nm { display: none; }
}
@media (max-width: 1100px) {
  .brand-rev { display: none; }
  .loop { grid-template-columns: 1fr; }
  .keyed-notes ol { columns: 2 280px; column-gap: 36px; }
  .keyed-notes li { break-inside: avoid; }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .stat:nth-child(3) { border-left: 0; padding-left: 0; }
  .stat:nth-child(-n+2) { border-bottom: 1px solid var(--rule-strong); }
}
@media (max-width: 900px) {
  .sheet-head { grid-template-columns: 1fr; }
  .sheet-id { flex-direction: row; align-items: baseline; gap: 14px; margin-bottom: 18px; }
  .sheet-name { border-top: 0; padding-top: 0; }
  .cover { grid-template-columns: 1fr; grid-template-areas: "kicker" "title" "body" "side"; grid-template-rows: none; }
  .cover-side { margin-top: 40px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
  .coupling-grid { grid-template-columns: minmax(0, 1fr); grid-template-areas: "code" "coupler" "doc" "map"; gap: 0; }
  .coupler { height: 56px; }
  .coupler-line { left: 50%; right: auto; top: 6px; bottom: 6px; height: auto; width: 0; border-top: 0; border-left: 1.5px solid var(--ink); }
  .coupler-line::before { left: -5px; top: -4px; }
  .coupler-line::after { left: -5px; right: auto; top: auto; bottom: -4px; }
  .coupler-label { transform: translateY(-50%); left: calc(50% + 14px); right: 0; white-space: normal; }
  .split, .split-even, .learn { grid-template-columns: minmax(0, 1fr); }
  .foot-block { grid-template-columns: 1fr 1fr; }
  .fb-name { grid-column: 1 / -1; grid-row: auto; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  :root { --topbar-h: 48px; }
  .brand { padding-right: 12px; gap: 8px; }
  .brand-word { font-size: 21px; }
  .sheet-nav a { padding: 0 10px; }
  .sheet-nav .no { font-size: 11.5px; }
  .theme-toggle { padding: 0 12px; }
  .theme-label { display: none; }
  .gh { display: none; }
  main { padding-top: 28px; }
  .frame { outline-offset: 3px; }
  .zones { display: none; }
  .loop-wide { display: none; }
  .loop-tall { display: block; }
  .keyed-notes ol { columns: 1; }
  .stats { grid-template-columns: minmax(0, 1fr); }
  .stat { border-left: 0 !important; padding-left: 0 !important; border-bottom: 1px solid var(--rule-strong); }
  .stat:last-child { border-bottom: 0; }
  .doc-title { padding-right: 0; }
  .hot-tag { top: -9px; right: 6px; transform: none; font-size: 9px; padding: 2px 6px; }
  .panel-doc .stamp { position: relative; top: auto; right: auto; order: 1; align-self: flex-end; margin: 16px 18px -4px 0; }
  .panel-doc .doc { order: 2; }
  .stamp-word { font-size: 30px; }
  .title-block { grid-template-columns: 1fr 1fr; width: calc(100% + 2 * var(--frame-pad)); }
  .title-block > div { border-right: 1px solid var(--rule-strong) !important; border-bottom: 1px solid var(--rule-strong) !important; }
  .title-block > div:nth-child(2n) { border-right: 0 !important; }
  .title-block > div:last-child { border-bottom: 0 !important; grid-column: span 2; }
  .dim-row { grid-template-columns: minmax(0, 1fr); gap: 2px; }
  .dim-axis { left: 0; }
  .ci-row { grid-template-columns: 84px minmax(0, 1fr) 76px; gap: 8px; }
  .ci-v small { display: block; }
  .ci-axis { left: 92px; right: 84px; }
  .ci-k { font-size: 11px; }
  .speed-row { grid-template-columns: 112px minmax(0, 1fr) 46px; gap: 8px; }
  .speed-k { font-size: 11px; }
  .turn { padding-left: 0; }
  .who { position: static; display: block; width: auto; border-top: 0; padding-top: 0; margin-bottom: 4px; }
  .foot-block { grid-template-columns: 1fr; }
  .fb-cell { border-right: 0; }
  .tablist [role="tab"] { padding: 10px 14px 9px; font-size: 14px; }
  .cta .btn { width: 100%; justify-content: center; }
  .dimline .dim-budget .dim-text { font-size: 10.5px; }
  .noise-row { grid-template-columns: minmax(0, 1fr); }
  .noise-v { grid-column: 1; }
  .term-body { padding: 10px 12px 12px; font-size: 11.5px; }
  .tl-row { grid-template-columns: minmax(0, 1fr); gap: 8px; }
  .revisions { padding-left: 14px; }
  .faq-item { grid-template-columns: minmax(0, 1fr); }
  .star .btn { width: 100%; justify-content: center; }
}

/* ---------- micro-interactions ---------- */
.sheet-nav a, .sheet-index a, .theme-toggle, .gh, .copy, .tablist [role="tab"], .choice, .more summary {
  transition: background-color var(--d-1), color var(--d-1), border-color var(--d-1), translate var(--d-1) var(--ease-out);
}
.sheet-nav a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 3px; background: var(--stale);
  transform: scaleX(0); transform-origin: left; transition: transform var(--d-2) var(--ease-out);
}
.sheet-nav a[aria-current="location"]::after { transform: scaleX(1); }
.choice:active:not([disabled]), .copy:active, .tablist [role="tab"]:active { translate: 0 1px; }
.schedule .mark { transition: translate var(--d-2) var(--ease-out), color var(--d-2); }
@media (hover: hover) {
  .schedule tbody tr, .data-table tbody tr { transition: background-color var(--d-1); }
  .schedule tbody tr:hover, .data-table tbody tr:hover { background-color: var(--grid-major); }
  .schedule tbody tr:hover .mark { translate: 4px 0; color: var(--stale-text); }
}
@keyframes rise { from { opacity: 0; translate: 0 12px; } }
.js .tabpanel:not([hidden]), .grade, .quiz-body > .q-count { animation: rise var(--d-2) var(--ease-out); }
.js .cover > * { animation: rise var(--d-3) var(--ease-out) both; }
.js .cover > :nth-child(2) { animation-delay: var(--stagger); }
.js .cover > :nth-child(3) { animation-delay: calc(var(--stagger) * 2); }
.js .cover > :nth-child(4) { animation-delay: calc(var(--stagger) * 3); }
.loop-svg .pulse path { fill: none; stroke: var(--synced); stroke-width: 3.4; stroke-linecap: round; opacity: 0; pointer-events: none; }

/* theme switch: the new sheet is laid over the old one from the toggle */
::view-transition-old(root), ::view-transition-new(root) { animation: none; mix-blend-mode: normal; }
::view-transition-new(root) { animation: sheet-over var(--d-3) var(--ease-io); }
@keyframes sheet-over {
  from { clip-path: circle(0 at var(--vt-x, 100%) var(--vt-y, 0)); }
  to { clip-path: circle(var(--vt-r, 150vmax) at var(--vt-x, 100%) var(--vt-y, 0)); }
}

/* scroll reveals: armed by main.js only for content below the fold, never without JS or with reduced motion */
.motion .rv { transition: opacity var(--d-3) var(--ease-out), translate var(--d-3) var(--ease-out); transition-delay: calc(var(--d, 0) * var(--stagger)); }
.motion .rv:not(.is-in) { opacity: 0; translate: 0 22px; }
.motion .rv [data-stagger] > * { transition: opacity var(--d-3) var(--ease-out), translate var(--d-3) var(--ease-out); transition-delay: calc((var(--d, 0) + var(--i, 0)) * var(--stagger)); }
.motion .rv:not(.is-in) [data-stagger] > * { opacity: 0; translate: 0 14px; }
.motion .rv :is(.cmp-bar, .speed-bar, .dims .dim, .ci-range, .noise-strip) { transform-origin: left center; transition: scale var(--d-4) var(--ease-io); transition-delay: calc(var(--d, 0) * var(--stagger) + var(--d-2)); }
.motion .rv:not(.is-in) :is(.cmp-bar, .speed-bar, .dims .dim, .ci-range, .noise-strip) { scale: 0 1; }
.motion .rv .ci-pt { transition: scale var(--d-2) var(--ease-snap) var(--d-4); }
.motion .rv:not(.is-in) .ci-pt { scale: 0; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; animation-delay: 0s !important; transition-duration: .001ms !important; transition-delay: 0s !important; }
  .motion .rv, .motion .rv [data-stagger] > *, .motion .rv :is(.cmp-bar, .speed-bar, .dims .dim, .ci-range, .noise-strip, .ci-pt), .term.is-armed .t-ln { opacity: 1 !important; translate: none !important; scale: none !important; }
  .loop-svg .pulse { display: none; }
  ::view-transition-group(*), ::view-transition-old(*), ::view-transition-new(*) { animation: none !important; }
}

@media print {
  .topbar, .coupling-controls, .copy, .theme-toggle, .term-replay, .loop-svg .pulse { display: none !important; }
  .motion .rv, .motion .rv [data-stagger] > *, .motion .rv :is(.cmp-bar, .speed-bar, .dims .dim, .ci-range, .noise-strip, .ci-pt), .term.is-armed .t-ln { opacity: 1 !important; translate: none !important; scale: none !important; }
  body { background: #fff; }
  .sheet { break-inside: avoid-page; }
}