:root {
  --concept-accent: #7bdff2;
  --concept-accent-rgb: 123, 223, 242;
  --concept-good: #73d49c;
  --concept-warn: #f4be63;
  --concept-bad: #f17878;
}

* { box-sizing: border-box; }

.concept-root { padding-bottom: 24px; }

.concept-root button,
.concept-root select,
.concept-root input { font: inherit; }

.concept-root button,
.concept-root select {
  min-height: 38px;
  border: 1px solid var(--demo-line);
  border-radius: 8px;
  background: #202a35;
  color: var(--demo-text);
}

.concept-root button {
  padding: 7px 12px;
  cursor: pointer;
}

.concept-root button:hover,
.concept-root button:focus-visible,
.concept-root select:hover,
.concept-root select:focus-visible {
  border-color: var(--concept-accent);
  outline: none;
}

.concept-root button.primary {
  border-color: rgba(var(--concept-accent-rgb), 0.75);
  background: rgba(var(--concept-accent-rgb), 0.15);
  color: #fff;
  font-weight: 720;
}

.concept-root button:disabled { cursor: default; opacity: 0.42; }

.concept-root input[type="range"] {
  width: 100%;
  accent-color: var(--concept-accent);
}

.concept-root code,
.concept-root .mono {
  color: var(--concept-accent);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.complexity-pill {
  display: inline-flex;
  gap: 7px;
  align-items: center;
  margin-bottom: 10px;
  padding: 5px 9px;
  border: 1px solid rgba(var(--concept-accent-rgb), 0.35);
  border-radius: 999px;
  background: rgba(var(--concept-accent-rgb), 0.08);
  color: var(--concept-accent);
  font-size: 11px;
  font-weight: 780;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.concept-workspace {
  display: grid;
  grid-template-columns: minmax(210px, 255px) minmax(360px, 1fr) minmax(210px, 255px);
  gap: 14px;
  align-items: start;
}

.concept-panel {
  min-width: 0;
  border: 1px solid var(--demo-line);
  border-radius: 12px;
  background: linear-gradient(150deg, #151d26f2, #10161df2);
  box-shadow: 0 14px 40px #0003;
}

.concept-controls,
.concept-readout { padding: 15px; }

.concept-panel h2,
.concept-panel h3 { margin: 0; }

.concept-panel h2 {
  font-size: 15px;
  font-weight: 720;
}

.concept-panel h3 {
  color: var(--demo-dim);
  font-size: 11px;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.control-stack { display: grid; gap: 9px; margin-top: 13px; }
.control-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 7px; }
.control-row.two { grid-template-columns: repeat(2, 1fr); }

.field { display: grid; gap: 6px; }
.field label,
.field-head {
  display: flex;
  justify-content: space-between;
  color: var(--demo-dim);
  font-size: 12px;
}
.field output { color: var(--concept-accent); font-family: ui-monospace, monospace; }

.concept-status {
  min-height: 38px;
  margin: 13px 0 0;
  padding: 9px 10px;
  border-left: 2px solid var(--concept-accent);
  background: rgba(var(--concept-accent-rgb), 0.06);
  color: var(--demo-dim);
  font-size: 12px;
  line-height: 1.45;
}

.concept-stage { overflow: hidden; }

.stage-head {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  min-height: 48px;
  padding: 10px 13px;
  border-bottom: 1px solid var(--demo-line);
}

.stage-head span { color: var(--demo-dim); font-size: 12px; }

.world-mount {
  position: relative;
  min-height: 420px;
  padding: 12px;
  background:
    radial-gradient(circle at 50% 40%, rgba(var(--concept-accent-rgb), 0.08), transparent 55%),
    #0a0f14;
}

.world-mount > hexlife-world,
.world-mount > hexlife-ca,
.world-mount > hexlife-grid {
  display: block;
  width: min(100%, 640px);
  margin-inline: auto;
  border-radius: 9px;
  overflow: hidden;
}

.world-mount > hexlife-world::part(overlay),
.world-mount > hexlife-world::part(reset),
.world-mount > hexlife-ca::part(overlay),
.world-mount > hexlife-grid::part(overlay) { display: none; }

.dual-worlds {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.dual-worlds figure { min-width: 0; margin: 0; }
.dual-worlds figcaption {
  padding: 7px 4px 0;
  color: var(--demo-dim);
  font-size: 11px;
  text-align: center;
}
.dual-worlds hexlife-world { display: block; width: 100%; border-radius: 8px; overflow: hidden; }
.dual-worlds hexlife-world::part(overlay),
.dual-worlds hexlife-world::part(reset) { display: none; }

.metric-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 7px;
  margin: 13px 0;
}

.metric {
  min-width: 0;
  padding: 9px;
  border: 1px solid var(--demo-line);
  border-radius: 8px;
  background: #0d131a;
}

.metric span { display: block; color: var(--demo-dim); font-size: 10px; text-transform: uppercase; }
.metric strong {
  display: block;
  margin-top: 3px;
  overflow: hidden;
  color: var(--demo-text);
  font-family: ui-monospace, monospace;
  font-size: 16px;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.trace {
  display: block;
  width: 100%;
  height: 92px;
  border: 1px solid var(--demo-line);
  border-radius: 8px;
  background: #090e13;
}

.legend { display: grid; gap: 7px; margin-top: 13px; }
.legend-item { display: flex; gap: 8px; align-items: center; color: var(--demo-dim); font-size: 11px; }
.swatch { width: 12px; height: 12px; flex: 0 0 auto; border: 1px solid #ffffff2e; border-radius: 3px; }

.concept-notes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 14px;
}

.concept-note { padding: 16px 18px; }
.concept-note p { margin: 8px 0 0; color: var(--demo-dim); font-size: 13px; line-height: 1.6; }

.concept-pager {
  display: flex;
  gap: 12px;
  justify-content: space-between;
  margin-top: 18px;
}

.concept-pager a {
  display: grid;
  gap: 3px;
  width: min(48%, 360px);
  padding: 11px 13px;
  border: 1px solid var(--demo-line);
  border-radius: 9px;
  color: var(--demo-text);
  text-decoration: none;
}
.concept-pager a:last-child { text-align: right; }
.concept-pager a:hover { border-color: var(--concept-accent); }
.concept-pager small { color: var(--demo-dim); }

.demo-library-intro { max-width: 820px; margin-bottom: 20px; color: var(--demo-dim); line-height: 1.65; }
.demo-library-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.demo-card {
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  gap: 8px;
  min-height: 210px;
  padding: 17px;
  border: 1px solid var(--demo-line);
  border-radius: 12px;
  background: linear-gradient(145deg, #151d26, #0f151c);
  color: var(--demo-text);
  text-decoration: none;
}
.demo-card:hover,
.demo-card:focus-visible { border-color: var(--card-accent, var(--demo-accent)); outline: none; transform: translateY(-1px); }
.demo-card .rank { color: var(--card-accent, var(--demo-accent)); font: 750 11px/1 ui-monospace, monospace; }
.demo-card h2 { margin: 0; font-size: 18px; }
.demo-card p { margin: 0; color: var(--demo-dim); font-size: 13px; line-height: 1.5; }
.demo-card .surface { color: var(--card-accent, var(--demo-accent)); font: 600 11px/1.4 ui-monospace, monospace; }
.reference-demos { margin-top: 28px; }
.reference-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.reference-links a { padding: 13px; border: 1px solid var(--demo-line); border-radius: 9px; color: var(--demo-link); text-decoration: none; }

.synth-keyboard { display: grid; grid-template-columns: repeat(8, 1fr); gap: 4px; margin-top: 10px; }
.synth-key { height: 34px; border-radius: 4px; background: rgba(var(--concept-accent-rgb), var(--key-level, .12)); }

@media (max-width: 1020px) {
  .concept-workspace { grid-template-columns: minmax(210px, 260px) minmax(0, 1fr); }
  .concept-readout { grid-column: 1 / -1; }
  .demo-library-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 700px) {
  .concept-workspace { grid-template-columns: 1fr; }
  .world-mount { min-height: 0; padding: 8px; }
  .concept-notes { grid-template-columns: 1fr; }
  .dual-worlds { grid-template-columns: 1fr; }
  .demo-library-grid,
  .reference-links { grid-template-columns: 1fr; }
}

@media (max-width: 430px) {
  .control-row { grid-template-columns: 1fr; }
  .control-row.two { grid-template-columns: 1fr 1fr; }
  .concept-pager { flex-direction: column; }
  .concept-pager a { width: 100%; }
  .concept-pager a:last-child { text-align: left; }
}