:root {
  --paper: #F5F2EA;
  --ink: #182628;
  --ink-2: #405C60;
  --teal: #00766C;
  --violet: #7043AA;
  --ember: #AE432A;
  --rule: #DDD8CC;
  --sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --mono: ui-monospace, SFMono-Regular, Consolas, monospace;
  --gutter: 24px;
  --section: 56px;
}

*, *::before, *::after { box-sizing: border-box; min-width: 0; }

html { scroll-behavior: auto; overflow-x: hidden; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-x: hidden;
  overflow-wrap: break-word;
}

[hidden] { display: none !important; }

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3 { margin: 0 0 0.6em; font-weight: 650; letter-spacing: -0.02em; overflow-wrap: anywhere; }
h2 { font-size: clamp(1.375rem, 6vw, 1.75rem); line-height: 1.15; }
h3 { font-size: 1.125rem; line-height: 1.3; }
p { margin: 0 0 1em; max-width: 64ch; }
.keep { white-space: nowrap; }

a { color: var(--ink); transition: border-color 140ms ease; }
a:hover { color: var(--teal); }

:focus-visible { outline: 3px solid var(--ink); outline-offset: 3px; }
.inverse :focus-visible, .site-footer :focus-visible { outline-color: var(--paper); }

.container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

/* Skip link */
.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -200px;
  z-index: 20;
  padding: 12px 18px;
  background: var(--ink);
  color: var(--paper);
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus { top: 12px; }

/* Header */
.site-header { border-bottom: 1px solid var(--rule); }
.header-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
  padding-top: 16px;
  padding-bottom: 16px;
}
.identity { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 16px; max-width: 100%; }
.wordmark {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 0.4em;
  min-height: 44px;
  max-width: 100%;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  text-decoration: none;
}
.wordmark .ticker { font-family: var(--mono); font-weight: 500; font-size: 1rem; color: var(--ink-2); letter-spacing: 0.02em; }
.site-nav { display: flex; flex-wrap: wrap; gap: 8px; margin-left: -14px; }
.site-nav a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  text-decoration: none;
  font-weight: 600;
  border-bottom: 2px solid transparent;
}
.site-nav a:hover { border-bottom-color: var(--teal); }
.site-nav .x-btn,
.site-nav .x-btn:hover {
  margin-left: 6px;
  padding: 0;
  width: 44px;
  border: 2px solid var(--ink);
}
.site-nav .x-btn:hover { color: var(--teal); border-color: var(--teal); }

/* X button — same ink-border chrome as the rest of the page */
.x-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  width: 44px;
  min-width: 44px;
  max-width: 100%;
  padding: 0;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-decoration: none;
  line-height: 1;
}
.x-btn svg { width: 16px; height: 16px; display: block; flex: 0 0 auto; }
.x-btn:hover { color: var(--teal); border-color: var(--teal); }
.x-btn-inverse {
  border-color: var(--paper);
  background: var(--ink);
  color: var(--paper);
}
.x-btn-inverse:hover { color: var(--ink); background: var(--paper); border-color: var(--paper); }

/* Sections */
section { padding-top: var(--section); padding-bottom: var(--section); }
section:focus { outline: none; }
#schematic, #boundaries { scroll-margin-top: 32px; }

/* Hero */
.hero { display: grid; grid-template-columns: minmax(0, 1fr); gap: 32px; }
.eyebrow { font-family: var(--mono); font-size: 1rem; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-2); margin-bottom: 1rem; }
.hero h1 {
  font-size: clamp(1.625rem, 7.4vw, 2.75rem);
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.6em;
  overflow-wrap: normal;
}
.hero h1 .sentence { display: block; max-width: 100%; }
.lede { font-size: 1.125rem; line-height: 1.6; color: var(--ink-2); max-width: 56ch; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 1.5rem 0 1rem; }
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  max-width: 100%;
  padding: 10px 22px;
  border: 2px solid var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.3;
  text-decoration: none;
  text-align: center;
  cursor: pointer;
  transition: border-color 140ms ease;
}
.btn-primary { background: var(--ink); color: var(--paper); }
.btn-primary:hover { border-color: var(--teal); }
.btn-secondary { background: var(--paper); color: var(--ink); }
.btn-secondary:hover { color: var(--teal); border-color: var(--teal); }
.note { font-family: var(--mono); font-size: 1rem; color: var(--ink-2); }
.hero-art { margin: 0; }
.hero-art img { width: 100%; border: 1px solid var(--rule); }
.hero-art figcaption { font-family: var(--mono); font-size: 1rem; color: var(--ink-2); margin-top: 10px; }
.story {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--ink);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0 40px;
}
.story p { max-width: 62ch; }

/* Schematic exhibit */
.schematic { padding-top: 0; }
.panel { border: 2px solid var(--ink); background: var(--paper); padding: 12px; }
.panel-head { display: flex; flex-wrap: wrap; align-items: flex-start; justify-content: space-between; gap: 12px 24px; }
.panel-head h2 { flex: 1 1 14ch; margin-bottom: 0.3em; }
.synthetic-badge {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  min-height: 32px;
  max-width: 100%;
  padding: 2px 12px;
  border: 2px solid var(--teal);
  font-family: var(--mono);
  font-size: 1rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--ink);
}
.panel-intro { color: var(--ink-2); margin: 8px 0 12px; }

.scenario-controls { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; margin: 0 0 12px; }
.scenario-controls button {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 100%;
  min-height: 52px;
  padding: 12px 4px;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.4;
  text-align: center;
  cursor: pointer;
  transition: border-color 140ms ease;
}
.scenario-controls button::before, .scenario-controls button::after { content: none; }
.scenario-controls button:hover { border-color: var(--teal); }
.scenario-controls button .control-name {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  white-space: nowrap;
  color: var(--ink);
  opacity: 1;
}
.scenario-controls button .control-hint { display: none; color: var(--ink-2); opacity: 1; }
.scenario-controls button[aria-pressed='true'] { background: var(--ink); color: var(--paper); }
.scenario-controls button[aria-pressed='true'] .control-name { color: var(--paper); }
.scenario-controls button[aria-pressed='true'] .control-hint { color: var(--paper); opacity: 1; }
.scenario-controls button:hover .control-hint,
.scenario-controls button:active .control-hint,
.scenario-controls button:focus .control-hint,
.scenario-controls button:hover .control-name,
.scenario-controls button:active .control-name,
.scenario-controls button:focus .control-name { opacity: 1; }

.scenario-panel { border-top: 1px solid var(--ink); padding-top: 12px; }

/* Result title: deterministic two-line block below 900px */
.result-title {
  font-family: var(--mono);
  font-size: 1.125rem;
  line-height: 1.3;
  font-weight: 700;
  letter-spacing: 0;
  margin: 0;
  min-block-size: 2.6em;
  overflow-wrap: anywhere;
}
.result-title .title-part { display: block; }
.result-copy { color: var(--ink); margin: 12px 0; }

.drawing { margin: 12px 0 0; padding: 8px 0; background: var(--paper); }
.diagram { margin: 0; width: 100%; scroll-margin-bottom: 16px; }
.drawing svg { display: block; height: auto; margin-inline: auto; overflow: visible; }
.drawing .svg-wide { display: none; width: 100%; max-width: 840px; margin-inline: auto; }
.drawing .svg-narrow { display: block; width: 100%; max-width: 300px; margin-inline: auto; }
.drawing svg text {
  font-family: var(--mono);
  font-size: 18px;
  fill: #182628;
  stroke: #F5F2EA;
  stroke-width: 4px;
  paint-order: stroke fill;
  stroke-linejoin: round;
}
.drawing .svg-narrow .output-labels text { font-size: 17px; }
.drawing svg .path-labels text { font-weight: 700; }
.drawing svg .stages line { stroke: var(--ink-2); stroke-width: 1.5; stroke-dasharray: 3 6; }
.drawing svg .path-a, .drawing svg .path-b, .drawing svg .path-c {
  fill: none;
  stroke-width: 3;
  vector-effect: non-scaling-stroke;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.drawing svg .path-a { stroke: var(--teal); }
.drawing svg .path-b { stroke: var(--violet); stroke-dasharray: 12 8; }
.drawing svg .path-c { stroke: var(--ember); stroke-dasharray: 0.1 9; }
.drawing svg .nodes circle { fill: var(--ink); }

.legend { list-style: none; margin: 0 0 8px; padding: 0; display: flex; flex-wrap: wrap; gap: 8px 24px; }
.legend li { display: inline-flex; align-items: center; gap: 12px; min-height: 28px; max-width: 100%; }
.sample { display: inline-block; flex: 0 0 auto; width: 44px; border-top-width: 4px; border-top-style: solid; }
.sample-a { border-top-color: var(--teal); border-top-style: solid; }
.sample-b { border-top-color: var(--violet); border-top-style: dashed; }
.sample-c { border-top-color: var(--ember); border-top-style: dotted; }
.legend-note { color: var(--ink-2); font-size: 1rem; margin-bottom: 12px; }
.mapping-notes { margin-top: 12px; border-top: 1px solid var(--ink); }
.mapping-notes summary {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 8px 4px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.mapping-notes summary::-webkit-details-marker { display: none; }
.mapping-notes summary::before { content: '+'; flex: 0 0 auto; font-family: var(--mono); font-size: 1.25rem; width: 24px; }
.mapping-notes[open] summary::before { content: '\2212'; }
.notes-body { padding: 4px 4px 12px 28px; }
.notes-body p { margin: 0; }

/* Grammar */
.grammar { border-top: 1px solid var(--rule); }
.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: minmax(0, 1fr); gap: 32px; }
.step { border-top: 2px solid var(--ink); padding-top: 16px; }
.step-number { font-family: var(--mono); font-size: 2rem; line-height: 1; font-weight: 500; color: var(--ink-2); margin-bottom: 0.5rem; }
.step h3 { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; }
.step-sample { width: 56px; }

/* Boundaries */
.boundaries {
  background: var(--ink);
  color: var(--paper);
  border-top: 6px solid var(--teal);
}
.boundaries h2 { color: var(--paper); }
.boundaries p { color: var(--rule); }
.boundaries-status { font-family: var(--mono); font-size: 1rem; color: var(--paper); margin-bottom: 2rem; }
.blocks { display: grid; grid-template-columns: minmax(0, 1fr); gap: 28px; }
.block { border-top: 1px solid var(--paper); padding-top: 16px; }
.block h3 { color: var(--paper); font-family: var(--mono); letter-spacing: 0.02em; }

/* Footer */
.site-footer { background: var(--ink); color: var(--paper); border-top: 1px solid var(--ink-2); }
.footer-inner { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 32px; padding-top: 24px; padding-bottom: 24px; }
.footer-inner p { margin: 0; color: var(--paper); }
.footer-brand { font-weight: 700; }
.footer-status { font-family: var(--mono); font-size: 1rem; color: var(--rule); }
.footer-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}
.back-to-top {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  color: var(--paper);
  border: 2px solid var(--paper);
  text-decoration: none;
  font-weight: 600;
}
.back-to-top:hover { color: var(--ink); background: var(--paper); }

/* 404 */
.not-found { min-height: 60vh; }

/* Responsive */
@media (min-width: 760px) {
  :root { --gutter: 56px; --section: 96px; }
  h2 { font-size: clamp(1.375rem, 2.5vw, 2.125rem); }
  .header-inner { flex-direction: row; flex-wrap: wrap; align-items: center; gap: 12px 24px; }
  .site-nav { margin-left: auto; }
  .hero { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(24px, 3vw, 48px); align-items: center; }
  .hero h1 { font-size: clamp(1.75rem, 3.1vw, 2.75rem); }
  .story { grid-template-columns: repeat(2, minmax(0, 1fr)); margin-top: 72px; }
  .panel { padding: 40px; }
  .panel-head h2 { flex-basis: 16ch; margin-bottom: 0.6em; }
  .panel-intro { margin: 0 0 1.25rem; }
  .scenario-controls { gap: 12px; margin: 0 0 1.5rem; }
  .scenario-controls button {
    align-items: flex-start;
    justify-content: flex-start;
    min-height: 44px;
    padding: 14px 16px;
    text-align: left;
    overflow-wrap: anywhere;
  }
  .scenario-controls button .control-name { font-size: 1.0625rem; letter-spacing: 0; white-space: normal; }
  .scenario-controls button .control-hint { display: block; }
  .scenario-panel { padding-top: 20px; }
  .drawing { margin-top: 16px; padding: 16px; border: 1px solid var(--rule); }
  .result-copy { margin: 16px 0; }
  .mapping-notes { margin-top: 20px; }
  .steps { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 40px; }
  .blocks { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 32px 48px; }
}

@media (min-width: 900px) {
  .result-title { font-size: 1.25rem; min-block-size: 0; margin: 0; }
  .result-title .title-part { display: inline; }
  .drawing .svg-wide { display: block; }
  .drawing .svg-narrow { display: none; }
}

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

/* Tablet diagram refinement: preserve mobile and desktop geometry. */
@media (min-width: 700px) and (max-width: 899.98px) {
  .drawing .svg-narrow { width: 100%; max-width: 360px; height: auto; margin-inline: auto; }
}

/* The footer keeps the X profile link available on narrow screens. */
@media (max-width: 599px) { .site-nav .x-btn { display: none; } }

.footer-actions { flex-wrap: wrap; max-width: 100%; justify-content: flex-end; }