body.page-red-black-trees .eyebrow {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.86rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.rb-invariant-list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.rb-invariant-list li {
  display: grid;
  grid-template-columns: 34px 1fr;
  align-items: center;
  gap: 12px;
  padding: 11px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.rb-invariant-list li > span {
  display: inline-flex;
  width: 28px;
  height: 28px;
  align-items: center;
  justify-content: center;
  border: 2px solid #b63535;
  border-radius: 50%;
  background: #2a2929;
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
}

.rb-invariant-list p {
  margin: 0;
}

.rb-visualizer {
  overflow: hidden;
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.rb-toolbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 22px;
  padding: 16px 18px;
  border-bottom: 1px solid var(--line);
}

.rb-input-group {
  display: grid;
  grid-template-columns: 105px auto;
  gap: 6px;
}

.rb-input-group label,
.rb-presets > span {
  grid-column: 1 / -1;
  margin-bottom: 1px;
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.rb-input-group input {
  width: 105px;
  min-height: 41px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}

.rb-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: flex-end;
}

.rb-presets > span {
  width: 100%;
  text-align: right;
}

.rb-visualizer button {
  min-height: 39px;
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--panel-alt);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  font-size: 0.88rem;
  font-weight: 650;
}

.rb-visualizer button:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.rb-visualizer button:focus-visible,
.rb-visualizer input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.rb-visualizer button:disabled {
  cursor: not-allowed;
  opacity: 0.38;
}

.rb-canvas-scroll {
  overflow: auto;
  height: 470px;
  background-color: var(--panel-alt);
  background-image: radial-gradient(circle, color-mix(in srgb, var(--line) 72%, transparent) 1px, transparent 1px);
  background-size: 18px 18px;
}

.rb-canvas-scroll svg {
  display: block;
  margin: 0 auto;
}

.rb-edge {
  stroke: color-mix(in srgb, var(--muted) 72%, var(--line));
  stroke-width: 2;
}

.rb-node circle {
  stroke-width: 2;
}

.rb-node text {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 14px;
  font-weight: 700;
}

.rb-node--black circle {
  fill: #292929;
  stroke: #111;
}

.rb-node--black text,
:root[data-theme="dark"] .rb-node--black text {
  fill: #fff;
}

.rb-node--red circle {
  fill: #b83f3a;
  stroke: #852c29;
}

.rb-node--red text,
:root[data-theme="dark"] .rb-node--red text {
  fill: #fff;
}

.rb-node.is-changed circle {
  stroke: #e4a12e;
  stroke-width: 5;
}

.rb-node.is-current circle {
  filter: drop-shadow(0 0 5px color-mix(in srgb, var(--accent) 75%, transparent));
  stroke: var(--accent);
  stroke-width: 5;
}

.rb-empty-label {
  fill: var(--muted);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 15px;
}

.rb-status {
  display: flex;
  min-height: 82px;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  padding: 12px 18px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.rb-status div > span {
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.rb-status p {
  margin: 2px 0 0;
  font-weight: 650;
}

.rb-status > span {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 0.82rem;
  font-variant-numeric: tabular-nums;
}

.rb-transport {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 18px;
  border-bottom: 1px solid var(--line);
}

.rb-transport-buttons {
  display: flex;
  gap: 5px;
}

.rb-visualizer .rb-play {
  min-width: 105px;
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg);
}

.rb-visualizer .rb-play:hover:not(:disabled) {
  background: color-mix(in srgb, var(--accent) 86%, var(--text));
  color: var(--bg);
}

.rb-speed {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-right: auto;
  font-size: 0.82rem;
  font-weight: 700;
}

.rb-speed input {
  width: 100px;
  accent-color: var(--accent);
}

.rb-speed output {
  min-width: 34px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.rb-metrics {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  margin: 0;
  border-bottom: 1px solid var(--line);
}

.rb-metrics div {
  padding: 9px 11px;
  border-right: 1px solid var(--line);
  text-align: center;
}

.rb-metrics div:last-child {
  border-right: 0;
}

.rb-metrics dt {
  color: var(--muted);
  font-size: 0.71rem;
}

.rb-metrics dd {
  margin: 1px 0 0;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.rb-checks {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  padding: 10px 18px;
  border-bottom: 1px solid var(--line);
}

.rb-checks span {
  padding: 3px 8px;
  border: 1px solid color-mix(in srgb, #27834f 38%, var(--line));
  border-radius: 999px;
  background: color-mix(in srgb, #27834f 8%, var(--panel));
  color: color-mix(in srgb, #27834f 82%, var(--text));
  font-size: 0.73rem;
  font-weight: 700;
}

:root[data-theme="dark"] .rb-checks span {
  color: #96d7ae;
}

.rb-checks span.is-failing {
  border-color: color-mix(in srgb, #b83f3a 45%, var(--line));
  background: color-mix(in srgb, #b83f3a 10%, var(--panel));
  color: #a6312d;
}

:root[data-theme="dark"] .rb-checks span.is-failing {
  color: #ffaaa4;
}

.rb-code {
  overflow-x: auto;
  background: var(--code);
}

.rb-code ol {
  min-width: max-content;
  margin: 0;
  padding: 12px 0 12px 48px;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  font-size: 0.82rem;
}

.rb-code li {
  padding: 2px 18px 2px 8px;
  border-left: 3px solid transparent;
  color: var(--muted);
}

.rb-code li.is-current {
  border-left-color: var(--accent);
  background: var(--accent-soft);
  color: var(--text);
}

.rb-code code {
  padding: 0;
  background: transparent;
}

.rb-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 13px;
  padding: 9px 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.74rem;
}

.rb-legend span {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.rb-swatch {
  width: 13px;
  height: 13px;
  border: 2px solid var(--line);
  border-radius: 50%;
}

.rb-swatch--red { border-color: #852c29; background: #b83f3a; }
.rb-swatch--black { border-color: #111; background: #292929; }
.rb-swatch--current { border-color: var(--accent); background: var(--accent-soft); }
.rb-swatch--changed { border: 4px solid #e4a12e; background: var(--panel); }

.rb-case-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  margin: 16px 0;
}

.rb-case-grid article {
  padding: 17px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
}

.rb-case-grid article > span {
  color: var(--accent);
  font-size: 0.74rem;
  font-weight: 750;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.rb-case-grid h4 {
  margin: 7px 0;
}

.rb-case-grid p {
  margin: 0;
  color: var(--muted);
}

@media (max-width: 820px) {
  .rb-toolbar {
    align-items: stretch;
    flex-direction: column;
  }

  .rb-presets {
    justify-content: flex-start;
  }

  .rb-presets > span {
    text-align: left;
  }

  .rb-transport {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .rb-speed {
    margin-right: 0;
  }

  .rb-case-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .rb-toolbar,
  .rb-status,
  .rb-transport,
  .rb-checks {
    padding-right: 12px;
    padding-left: 12px;
  }

  .rb-input-group {
    grid-template-columns: 1fr;
  }

  .rb-input-group label,
  .rb-input-group input {
    grid-column: 1;
    width: 100%;
  }

  .rb-presets button {
    flex: 1;
  }

  .rb-canvas-scroll {
    height: 370px;
  }

  .rb-status {
    min-height: 108px;
    flex-direction: column;
    gap: 5px;
  }

  .rb-transport {
    flex-direction: column;
  }

  .rb-transport-buttons {
    width: 100%;
  }

  .rb-transport-buttons button {
    flex: 1;
  }

  .rb-play {
    min-width: 43px !important;
  }

  .rb-play span {
    display: none;
  }

  .rb-metrics {
    grid-template-columns: repeat(2, 1fr);
  }

  .rb-metrics div:nth-child(even) {
    border-right: 0;
  }

  .rb-metrics div:nth-child(-n + 4) {
    border-bottom: 1px solid var(--line);
  }

  .rb-metrics div:last-child {
    grid-column: 1 / -1;
  }
}

@media print {
  .rb-toolbar,
  .rb-transport {
    display: none;
  }

  .rb-canvas-scroll {
    height: 360px;
  }
}