/* lucelang.org — the engineering-atlas frame and its diagrams. The palette,
 * typography, prose, code, tables, cards, and common controls come from
 * www/shared/core.css, loaded first on every page. */

:root {
  --prose: 58rem;
  --side: 15.5rem;
  --rail: 12.5rem;
  --zig: #365d91;
  --zig-soft: #dce6f3;
  --luce: #4f702d;
  --luce-soft: #e2ead7;
  --machine: #8b3f75;
  --machine-soft: #eedce8;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --zig: #9db9e4; --zig-soft: #283646;
    --luce: #a9c97c; --luce-soft: #2f3b29;
    --machine: #dda1cd; --machine-soft: #432f3d;
  }
}

:root[data-theme="light"] {
  --zig: #365d91; --zig-soft: #dce6f3;
  --luce: #4f702d; --luce-soft: #e2ead7;
  --machine: #8b3f75; --machine-soft: #eedce8;
}

:root[data-theme="dark"] {
  --zig: #9db9e4; --zig-soft: #283646;
  --luce: #a9c97c; --luce-soft: #2f3b29;
  --machine: #dda1cd; --machine-soft: #432f3d;
}

/* Header and search */

header.top {
  position: sticky;
  top: 0;
  z-index: 30;
  display: grid;
  grid-template-columns: minmax(12rem, 1fr) auto minmax(12rem, 1fr);
  align-items: center;
  gap: 1.35rem;
  min-height: var(--bar);
  padding: 0 clamp(1.1rem, 3vw, 2.5rem);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  border-bottom: 1px solid var(--line-strong);
  backdrop-filter: blur(10px);
}

.mark { justify-self: start; }

nav.tabs {
  display: flex;
  justify-self: center;
  gap: 1.1rem;
  min-width: 0;
  max-width: 100%;
  overflow-x: auto;
  scrollbar-width: none;
}

nav.tabs::-webkit-scrollbar { display: none; }
.tools { justify-self: end; }

.find input {
  width: 9.2rem;
  max-width: 22vw;
  padding: .34rem .5rem;
  color: var(--ink);
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: 0;
  font: inherit;
  font-size: .78rem;
}

.find input::placeholder { color: var(--ink-faint); }

#hits {
  position: absolute;
  top: calc(var(--bar) - 1px);
  right: clamp(1.1rem, 3vw, 2.5rem);
  width: min(32rem, calc(100vw - 2rem));
  max-height: 70vh;
  overflow-y: auto;
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  box-shadow: 0 .8rem 2.2rem color-mix(in srgb, var(--ink) 12%, transparent);
}

#hits a {
  display: block;
  padding: .65rem .8rem;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}

#hits a:last-child { border-bottom: 0; }
#hits a:hover, #hits a.on { background: var(--accent-soft); }
#hits b { display: block; font-size: .86rem; }
#hits em { display: block; color: var(--ink-faint); font-size: .76rem; font-style: normal; font-weight: 500; }
#hits .none { padding: .8rem; color: var(--ink-faint); font-size: .82rem; }

/* Three-column reading shell */

.shell {
  display: grid;
  grid-template-columns: var(--side) minmax(0, var(--prose)) var(--rail);
  align-items: start;
  justify-content: center;
  gap: clamp(1.7rem, 3vw, 3rem);
  max-width: 96rem;
  margin: 0 auto;
  padding: 0 1.4rem;
}

.side,
.rail {
  position: sticky;
  top: var(--bar);
  max-height: calc(100vh - var(--bar));
  overflow-y: auto;
}

.side { padding: 2.25rem 0; }
.rail { padding: 2.7rem 0; }
.side details { border: 0; }

.side summary,
.rail h2 {
  color: var(--ink-faint);
  font-size: .68rem;
  font-weight: 800;
  letter-spacing: .09em;
  text-transform: uppercase;
}

.side summary {
  margin-bottom: .65rem;
  padding-left: .65rem;
  cursor: default;
  list-style: none;
}

.side summary::before {
  content: "■";
  margin-right: .5rem;
  color: var(--accent);
  font-size: .58em;
}

.side summary::-webkit-details-marker { display: none; }
.side ul, .rail ul { margin: 0; padding: 0; list-style: none; }
.side li, .rail li { margin: 0; }

.side li a {
  display: block;
  padding: .3rem .55rem .3rem .65rem;
  color: var(--ink-soft);
  border-left: 2px solid transparent;
  font-size: .84rem;
  font-weight: 500;
  line-height: 1.4;
  text-decoration: none;
}

.side li.h3 a { padding-left: 1.4rem; font-size: .8rem; }
.side li a:hover { color: var(--ink); background: var(--paper-soft); }
.side li a.here { color: var(--ink); background: var(--accent-soft); border-left-color: var(--accent); font-weight: 800; }

.rail h2 { margin: 0 0 .7rem; padding: 0; border: 0; line-height: 1.4; }
.rail ul { border-left: 1px solid var(--line); }

.rail li a {
  display: block;
  margin-left: -1px;
  padding: .22rem .65rem;
  color: var(--ink-faint);
  border-left: 2px solid transparent;
  font-size: .77rem;
  font-weight: 500;
  line-height: 1.38;
  text-decoration: none;
}

.rail li.h3 a { padding-left: 1.2rem; font-size: .74rem; }
.rail li a:hover { color: var(--ink); }
.rail li a.on { color: var(--ink); border-left-color: var(--accent); font-weight: 800; }

main { min-width: 0; padding: 2.2rem 0 4.5rem; }
article { max-width: var(--prose); }
article > p,
article > ul,
article > ol,
article > .plain-note,
article > .honesty,
article > .decision,
article > .boundary,
article > .invariant,
article > .story-opening { max-width: 49rem; }
article > ul, article > ol { margin: 0 0 1.15rem; padding-left: 1.45rem; }

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-bottom: 1rem;
  color: var(--ink-faint);
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.crumbs a { color: var(--ink-faint); text-decoration: none; }
.crumbs a:hover { color: var(--accent); }
.crumbs span[aria-current] { color: var(--ink); }

footer {
  max-width: 96rem;
  margin: 0 auto;
  padding: 2rem 1.4rem 3rem;
  color: var(--ink-faint);
  border-top: 1px solid var(--line-strong);
  font-size: .76rem;
}

footer p { max-width: var(--prose); margin: 0 auto; }

/* Editorial hierarchy */

.lede {
  margin: -.35rem 0 2rem;
  color: var(--ink-soft);
  font-family: var(--display);
  font-size: clamp(1.2rem, 2.2vw, 1.55rem);
  line-height: 1.48;
}

.eyebrow,
.diagram-label,
.mini-label,
.owner-label {
  color: var(--accent);
  font-size: .66rem;
  font-weight: 800;
  letter-spacing: .1em;
  text-transform: uppercase;
}

body[data-root="./"] article > h1 {
  max-width: 13ch;
  font-family: var(--display);
  font-size: clamp(3rem, 7vw, 5.6rem);
  font-weight: 400;
  letter-spacing: -.025em;
  line-height: .98;
}

.atlas-intro .lede { max-width: 39rem; margin-top: .4rem; font-family: var(--face); font-size: 1.08rem; }

.story-opening {
  margin: 1.8rem 0 1.25rem;
  padding: 1.1rem 1.2rem;
  background: var(--accent-soft);
  border-left: 5px solid var(--accent);
}

.story-opening p { margin: .35rem 0 0; font-size: 1.02rem; }

.story-link {
  display: inline-block;
  padding: .65rem .85rem;
  background: var(--ink);
  color: var(--paper-raised);
  border: 1px solid var(--ink);
  text-decoration: none;
}

.story-link:hover { color: var(--ink); background: var(--accent-soft); border-color: var(--accent); }

.plain-note {
  margin: 1.5rem 0;
  padding: .9rem 1rem;
  color: var(--ink-soft);
  background: var(--paper-soft);
  border-left: 4px solid var(--line-strong);
}

.plain-note p:last-child { margin-bottom: 0; }

.route-number {
  display: block;
  margin-bottom: .7rem;
  color: var(--accent) !important;
  font-size: .68rem !important;
  font-weight: 800;
  letter-spacing: .1em;
}

.annotated-code .line {
  display: grid;
  grid-template-columns: minmax(19rem, auto) 1fr;
  gap: 1.4rem;
}

.annotated-code .line i { color: var(--ink-faint); font-style: normal; }

/* Exact compiler traces */

.trace {
  margin: 1.8rem 0 2.5rem;
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  box-shadow: .45rem .45rem 0 var(--paper-soft);
}

.trace-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.05rem;
  border-bottom: 1px solid var(--line-strong);
}

.trace-head strong { display: block; margin-top: .2rem; }
.trace-head a { flex: 0 0 auto; color: var(--ink-faint); font-size: .68rem; }

.trace-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  background: var(--line-strong);
  gap: 1px;
}

.trace-tabs button {
  min-width: 0;
  padding: .68rem .55rem;
  color: var(--ink-faint);
  background: var(--paper-soft);
  border: 0;
  border-radius: 0;
  font-family: var(--face);
  font-size: .72rem;
  font-weight: 800;
  cursor: pointer;
}

.trace-tabs button:hover,
.trace-tabs button[aria-pressed="true"] { color: var(--ink); background: var(--accent-soft); box-shadow: inset 0 -3px 0 var(--accent); }

.trace-panel { background: var(--paper-raised); }

.trace-caption {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: .85rem 1rem .75rem;
}

.trace-caption p { margin: 0; color: var(--ink-soft); font-size: .78rem; line-height: 1.55; }
.trace-caption a { flex: 0 0 auto; font-size: .68rem; }

.trace .trace-code {
  max-height: 38rem;
  margin: 0;
  overflow: auto;
  border: 0;
  border-top: 1px solid var(--line);
}

.trace .trace-code code { font-size: .74rem; line-height: 1.6; }

.decision-table {
  display: grid;
  grid-template-columns: 1fr;
  margin: 1.4rem 0;
  border: 1px solid var(--line-strong);
}

.decision-table > div {
  display: grid;
  grid-template-columns: 10rem 1fr;
  gap: 1rem;
  padding: .6rem .75rem;
  border-bottom: 1px solid var(--line);
}

.decision-table > div:last-child { border-bottom: 0; }
.decision-table b { font-size: .75rem; }
.decision-table span { color: var(--ink-soft); font-size: .78rem; }

.token-story {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin: 1.3rem 0 1.5rem;
  padding: 1rem;
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
}

.token-story span {
  display: flex;
  flex-direction: column;
  min-width: 5.5rem;
  padding: .5rem .6rem;
  border: 1px solid var(--line);
}

.token-story b { font-size: .8rem; }
.token-story small { color: var(--ink-faint); font-size: .58rem; text-transform: uppercase; }

.assembly-explainer {
  margin: 1.5rem 0;
  border-top: 1px solid var(--line-strong);
}

.asm-line {
  display: grid;
  grid-template-columns: minmax(18rem, 2fr) 3fr;
  gap: 1.2rem;
  padding: .9rem 0;
  border-bottom: 1px solid var(--line);
}

.asm-line code { align-self: start; }
.asm-line p { margin: 0; color: var(--ink-soft); font-size: .8rem; line-height: 1.55; }

.story-steps { counter-reset: story; margin: 1.5rem 0; padding: 0 !important; list-style: none; }
.story-steps li { display: grid; grid-template-columns: 2rem 1fr; column-gap: .8rem; margin: 0; padding: .75rem 0; border-bottom: 1px solid var(--line); }
.story-steps li::before { counter-increment: story; content: counter(story, decimal-leading-zero); grid-row: 1 / 3; color: var(--accent); font-size: .7rem; font-weight: 800; }
.story-steps b, .story-steps span { grid-column: 2; }
.story-steps span { color: var(--ink-soft); font-size: .8rem; }

.invariant,
.decision,
.boundary,
.honesty {
  margin: 1.6rem 0;
  padding: 1rem 1.05rem;
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
}

.invariant { border-left: 5px solid var(--accent); }
.decision { background: var(--accent-soft); border-color: var(--accent); }
.boundary { border-left: 5px solid var(--zig); }
.honesty { border-left: 5px solid var(--good); }
.invariant p:last-child, .decision p:last-child, .boundary p:last-child, .honesty p:last-child { margin-bottom: 0; }

.source-strip {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin: 1.25rem 0 1.7rem;
}

.source-link {
  display: inline-block;
  padding: .25rem .45rem;
  color: var(--ink-soft);
  background: var(--paper-soft);
  border: 1px solid var(--line);
  font-size: .7rem;
  font-weight: 700;
  line-height: 1.35;
  text-decoration: none;
}

.source-link::before { content: "↗ "; color: var(--accent); }
.source-link:hover { color: var(--ink); border-color: var(--line-strong); }

.fact-grid,
.system-grid,
.choice-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 1.5rem 0;
  padding: 1px;
  background: var(--line-strong);
}

.fact,
.system-card,
.choice {
  min-width: 0;
  padding: 1rem;
  background: var(--paper-raised);
}

a.system-card { color: var(--ink); text-decoration: none; }
a.system-card:hover { background: var(--accent-soft); }
.system-card strong, .fact strong, .choice strong { display: block; margin-bottom: .25rem; }
.system-card strong::after { content: " →"; color: var(--accent); }
.system-card span, .fact span, .choice span { display: block; color: var(--ink-soft); font-size: .84rem; line-height: 1.55; }

/* Diagram grammar */

.diagram {
  margin: 1.7rem 0 2rem;
  padding: clamp(.8rem, 2.3vw, 1.35rem);
  overflow-x: auto;
  background:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px),
    var(--paper-raised);
  background-size: 24px 24px;
  border: 1px solid var(--line-strong);
}

.diagram figcaption,
.diagram > .diagram-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin: -.1rem 0 1.1rem;
  color: var(--ink-faint);
  font-size: .72rem;
}

.diagram figcaption strong,
.diagram-head strong { color: var(--ink); font-size: .76rem; letter-spacing: .06em; text-transform: uppercase; }

.legend { display: flex; flex-wrap: wrap; gap: .65rem; margin: .6rem 0 0; color: var(--ink-faint); font-size: .68rem; }
.key::before { content: ""; display: inline-block; width: .58rem; height: .58rem; margin-right: .3rem; border: 2px solid var(--line-strong); vertical-align: -.05rem; }
.key.zig::before { border-color: var(--zig); background: var(--zig-soft); }
.key.luce::before { border-color: var(--luce); background: var(--luce-soft); }
.key.machine::before { border-color: var(--machine); background: var(--machine-soft); }

.pipeline-map {
  display: grid;
  grid-template-columns: repeat(8, minmax(7.3rem, 1fr));
  gap: .55rem;
  min-width: 68rem;
  align-items: stretch;
}

.pipeline-map a,
.flow-node,
.arch-node,
.heap-node,
.byte-box,
.layer {
  position: relative;
  display: block;
  min-width: 0;
  padding: .7rem;
  color: var(--ink);
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  text-decoration: none;
}

.pipeline-map a:not(:last-child)::after {
  content: "→";
  position: absolute;
  top: 50%;
  right: -.5rem;
  z-index: 2;
  padding: 0 .1rem;
  color: var(--accent);
  background: var(--paper-raised);
  transform: translate(50%, -50%);
}

.pipeline-map a:hover { background: var(--accent-soft); }
.pipeline-map b, .flow-node b, .arch-node b { display: block; font-size: .78rem; }
.pipeline-map small, .flow-node small, .arch-node small { display: block; margin-top: .3rem; color: var(--ink-faint); font-size: .66rem; line-height: 1.4; }
.pipeline-map .stage-no { display: block; margin-bottom: .65rem; color: var(--accent); font-size: .62rem; font-weight: 800; letter-spacing: .08em; }

.flow {
  display: flex;
  align-items: stretch;
  gap: 1.35rem;
  width: 100%;
  min-width: 0;
  padding-bottom: .2rem;
  overflow-x: auto;
}

.flow-node { flex: 0 0 9rem; width: 9rem; }
.flow-node.wide { flex-basis: 12rem; width: 12rem; }
.flow-node::after {
  content: "→";
  position: absolute;
  top: 50%;
  right: -1.35rem;
  width: 1.35rem;
  color: var(--accent);
  text-align: center;
  transform: translateY(-50%);
}
.flow-node:last-child::after { content: none; }

.fork-flow {
  display: grid;
  grid-template-columns: 10rem 3.5rem minmax(10rem, 1fr) minmax(10rem, 1fr);
  grid-template-rows: repeat(2, auto);
  gap: .8rem;
  align-items: center;
}
.fork-flow .root { grid-row: 1 / 3; }
.fork-flow .fork { grid-row: 1 / 3; color: var(--accent); font-size: 2rem; text-align: center; }

.layer-stack { display: grid; gap: .55rem; }
.layer { display: grid; grid-template-columns: 8rem 1fr; gap: .8rem; align-items: baseline; }
.layer strong { font-size: .76rem; }
.layer span { color: var(--ink-soft); font-size: .78rem; }
.layer.zig { border-left: 5px solid var(--zig); }
.layer.luce { border-left: 5px solid var(--luce); }
.layer.machine { border-left: 5px solid var(--machine); }

.owner-zig { border-color: var(--zig); background: var(--zig-soft); }
.owner-luce { border-color: var(--luce); background: var(--luce-soft); }
.owner-machine { border-color: var(--machine); background: var(--machine-soft); }

.owner-controls,
.step-controls {
  display: flex;
  flex-wrap: wrap;
  gap: .45rem;
  margin: 0 0 1rem;
}

.owner-controls button,
.step-controls button,
.demo-action {
  padding: .36rem .6rem;
  color: var(--ink-soft);
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: 0;
  font-family: var(--face);
  font-size: .7rem;
  font-weight: 800;
  letter-spacing: .04em;
  cursor: pointer;
}

.owner-controls button:hover,
.step-controls button:hover,
.demo-action:hover,
.owner-controls button[aria-pressed="true"],
.step-controls button[aria-pressed="true"] { color: var(--ink); background: var(--accent-soft); border-color: var(--accent); }

.js [data-owner].dim { opacity: .18; filter: grayscale(1); }

.token-stream { display: flex; flex-wrap: wrap; gap: .38rem; }
.token {
  display: inline-flex;
  flex-direction: column;
  gap: .18rem;
  padding: .42rem .5rem;
  color: var(--ink);
  background: var(--paper-raised);
  border: 1px solid var(--line-strong);
  font-size: .78rem;
}
.token small { color: var(--ink-faint); font-size: .56rem; letter-spacing: .07em; text-transform: uppercase; }
.token.keyword { border-color: var(--tok-keyword); }
.token.name { border-color: var(--tok-decl); }
.token.literal { border-color: var(--tok-number); }
.token.layout { border-color: var(--tok-verb); background: var(--machine-soft); }

.tree,
.tree ul { margin: 0; padding: 0; list-style: none; }
.tree ul { position: relative; margin-left: 1.2rem; padding-left: 1.2rem; border-left: 1px solid var(--line-strong); }
.tree li { position: relative; margin: .4rem 0; }
.tree ul > li::before { content: ""; position: absolute; top: .8rem; left: -1.2rem; width: .9rem; border-top: 1px solid var(--line-strong); }
.tree code { display: inline-block; border: 1px solid var(--line); }

.scope-grid,
.heap-graph,
.worker-worlds,
.artifact-stack,
.representation-grid {
  display: grid;
  gap: .75rem;
}

.scope-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.scope-grid .arch-node { min-height: 8rem; }
.arch-node strong, .heap-node strong { display: block; margin-bottom: .35rem; }
.arch-node p, .heap-node p { margin: 0; color: var(--ink-soft); font-size: .75rem; line-height: 1.5; }

.heap-graph { grid-template-columns: repeat(3, minmax(8rem, 1fr)); align-items: center; }
.heap-node { text-align: center; }
.heap-node .count { display: inline-block; margin-top: .5rem; padding: .08rem .35rem; color: var(--accent); border: 1px solid var(--accent); font-size: .65rem; font-weight: 800; }
.heap-edge { color: var(--accent); font-size: 1.2rem; text-align: center; }

.worker-worlds { grid-template-columns: 1fr 5rem 1fr; align-items: stretch; }
.world { padding: .9rem; background: var(--paper-raised); border: 1px solid var(--line-strong); }
.world h3 { margin: 0 0 .65rem; font-size: .82rem; }
.world .heap-node { margin-top: .5rem; }
.bridge { display: flex; flex-direction: column; align-items: center; justify-content: center; color: var(--accent); font-size: 1.4rem; text-align: center; }
.bridge small { color: var(--ink-faint); font-size: .6rem; letter-spacing: .05em; text-transform: uppercase; }

.byte-row { display: grid; grid-template-columns: repeat(12, minmax(1.9rem, 1fr)); min-width: 32rem; }
.byte-box { padding: .65rem .2rem; border-right: 0; font-size: .64rem; text-align: center; }
.byte-box:last-child { border-right: 1px solid var(--line-strong); }
.byte-box.tag { color: var(--accent); background: var(--accent-soft); }
.byte-box.payload { grid-column: span 11; }

.artifact-stack { grid-template-columns: 1fr; }
.artifact-layer { display: grid; grid-template-columns: 9rem 1fr; gap: .8rem; padding: .7rem .8rem; background: var(--paper-raised); border: 1px solid var(--line-strong); }
.artifact-layer strong { font-size: .74rem; }
.artifact-layer span { color: var(--ink-soft); font-size: .76rem; }

.representation-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.representation { padding: .9rem; background: var(--paper-raised); border-top: 4px solid var(--line-strong); }
.representation.value { border-color: var(--luce); }
.representation.reference { border-color: var(--zig); }
.representation.effect { border-color: var(--accent); }
.representation strong { display: block; margin-bottom: .35rem; }
.representation p { margin: 0; color: var(--ink-soft); font-size: .78rem; }

.stage-panel { padding: 1rem; background: var(--paper-raised); border: 1px solid var(--line-strong); }
.stage-panel h3 { margin-top: 0; }
.stage-panel > :last-child { margin-bottom: 0; }
.js [data-step-panel][hidden] { display: none; }

.comparison { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; margin: 1.5rem 0; padding: 1px; background: var(--line-strong); }
.comparison > div { padding: 1rem; background: var(--paper-raised); }
.comparison h3 { margin-top: 0; }
.comparison .yes h3 { color: var(--good); }
.comparison .no h3 { color: var(--bad); }

.feature-index { columns: 2 18rem; column-gap: 2rem; margin: 1rem 0; padding: 0; list-style: none; }
.feature-index li { break-inside: avoid; padding: .36rem 0; border-bottom: 1px solid var(--line-soft); font-size: .82rem; }
.feature-index a { text-decoration: none; }

.call-path { counter-reset: path; margin: 1.4rem 0; padding: 0; list-style: none; }
.call-path li { position: relative; margin: 0 0 0 1rem; padding: .7rem .7rem .7rem 2.7rem; border-left: 1px solid var(--line-strong); }
.call-path li::before { counter-increment: path; content: counter(path); position: absolute; top: .65rem; left: -1rem; width: 2rem; height: 2rem; color: var(--paper-raised); background: var(--ink); border-radius: 50%; font-size: .68rem; font-weight: 800; line-height: 2rem; text-align: center; }
.call-path li:last-child { border-left-color: transparent; }
.call-path strong { display: block; }
.call-path span { color: var(--ink-soft); font-size: .82rem; }

@keyframes pulse-stage {
  0%, 100% { box-shadow: none; }
  50% { box-shadow: 0 0 0 4px var(--accent-soft); }
}

.pipeline-map a:hover { animation: pulse-stage 1.1s ease-in-out infinite; }

/* Responsive */

@media (max-width: 82rem) {
  .shell { grid-template-columns: var(--side) minmax(0, var(--prose)); }
  .rail { display: none; }
}

@media (max-width: 72rem) {
  header.top {
    position: static;
    display: flex;
    flex-wrap: wrap;
    min-height: auto;
    row-gap: .25rem;
    padding: .65rem 1rem;
  }
  nav.tabs { order: 3; width: 100%; justify-content: flex-start; }
  .tools { margin-left: auto; }
  #hits { position: fixed; top: 4rem; right: 1rem; left: 1rem; width: auto; }
  .side, .rail { top: 0; }
}

@media (max-width: 56rem) {
  .shell { grid-template-columns: minmax(0, 1fr); gap: 0; padding: 0 1rem; }
  .side { position: static; max-height: none; padding: 1.1rem 0 0; overflow: visible; }
  .side details { padding: .55rem .65rem; background: var(--paper-soft); border: 1px solid var(--line-strong); }
  .side summary { margin: 0; cursor: pointer; }
  .side details[open] summary { margin-bottom: .45rem; }
  main { padding: 1.5rem 0 3.2rem; }
  h1 { font-size: 2.2rem; }
  h2 { margin-top: 2.7rem; }
  .find input { width: 7.8rem; max-width: none; }
  nav.seq { flex-direction: column; }
  nav.seq a { max-width: none; }
  nav.seq a.on { margin-left: 0; text-align: left; }
  .scope-grid, .representation-grid { grid-template-columns: 1fr; }
  .worker-worlds { grid-template-columns: 1fr; }
  .bridge { min-height: 4rem; transform: rotate(90deg); }
  .annotated-code .line { grid-template-columns: 1fr; gap: 0; margin-bottom: .55rem; }
}

@media (max-width: 40rem) {
  body { font-size: .94rem; }
  .tools { gap: .55rem; }
  a.cross { display: none; }
  .fact-grid, .system-grid, .choice-grid, .comparison { grid-template-columns: 1fr; }
  .layer { grid-template-columns: 1fr; gap: .2rem; }
  .heap-graph { grid-template-columns: 1fr; }
  .heap-edge { transform: rotate(90deg); }
  .artifact-layer { grid-template-columns: 1fr; gap: .2rem; }
  .diagram figcaption, .diagram-head { display: block; }
  .trace-head, .trace-caption { display: block; }
  .trace-head a, .trace-caption a { display: inline-block; margin-top: .5rem; }
  .trace-tabs { grid-template-columns: 1fr 1fr; }
  .decision-table > div, .asm-line { grid-template-columns: 1fr; gap: .2rem; }
  .token-story span { min-width: calc(50% - .25rem); }
}

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

@media print {
  header.top, .side, .rail, nav.seq, footer, button.copy, .owner-controls, .step-controls, .trace-tabs { display: none !important; }
  .shell { display: block; max-width: none; }
  article { max-width: none; }
  .diagram { break-inside: avoid; background: white; }
  [data-step-panel][hidden] { display: block !important; }
}