#tree-flatten-demo {
  margin: 1.2rem auto;
  padding: 1rem;
  border: 1px solid #ddd;
  border-radius: 0.75rem;
  width: min(1200px, calc(100vw - 2rem));
  max-width: 100%;
  box-sizing: border-box;
  font-family: inherit;
  font-size: 0.96rem;
  line-height: 1.4;
}

#tree-flatten-demo h3 {
  font-size: 1.12rem;
  margin: 0 0 0.45rem;
}

#tree-flatten-demo h4 {
  font-size: 0.98rem;
}

#tree-flatten-demo h5 {
  font-size: 0.9rem;
}

#tree-flatten-demo .tfd-controls {
  margin-top: 0.8rem;
  display: grid;
  gap: 0.7rem;
}

#tree-flatten-demo label {
  display: grid;
  gap: 0.2rem;
}

#tree-flatten-demo input[type="range"] {
  width: 100%;
}

#tree-flatten-demo .tfd-summary {
  margin-top: 0.8rem;
  padding: 0.7rem;
  border: 1px solid #ececec;
  background: #fafafa;
}

#tree-flatten-demo .tfd-player {
  margin-top: 0.8rem;
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
}

#tree-flatten-demo .tfd-layout {
  margin-top: 0.8rem;
  display: grid;
  gap: 0.85rem;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  align-items: start;
}

#tree-flatten-demo .tfd-right-column {
  display: grid;
  gap: 0.85rem;
}

#tree-flatten-demo .tfd-player button {
  border: 1px solid #d1d5db;
  background: #fff;
  border-radius: 0.45rem;
  padding: 0.3rem 0.6rem;
  font-size: 0.86rem;
  cursor: pointer;
}

#tree-flatten-demo .tfd-player button:hover {
  background: #f3f4f6;
}

#tree-flatten-demo .tfd-step-label {
  font-family: monospace;
  font-size: 0.82rem;
  color: #374151;
}

#tree-flatten-demo .tfd-columns {
  display: grid;
  gap: 0.8rem;
  margin-top: 0.8rem;
}

#tree-flatten-demo .tfd-arrays {
  border: 1px solid #ececec;
  border-radius: 0.6rem;
  padding: 0.7rem;
  background: #fcfcfd;
}

#tree-flatten-demo .tfd-arrays h4 {
  margin: 0 0 0.55rem;
}

#tree-flatten-demo .tfd-array-row {
  display: grid;
  gap: 0.3rem;
  margin-top: 0.45rem;
}

#tree-flatten-demo .tfd-array-name {
  font-family: monospace;
  font-size: 0.72rem;
  font-weight: 600;
}

#tree-flatten-demo .tfd-array-values {
  font-family: monospace;
  font-size: 0.68rem;
  color: #374151;
}

#tree-flatten-demo .tfd-array-token {
  color: inherit;
}

#tree-flatten-demo .tfd-array-token-active {
  color: #1d4ed8;
  font-weight: 700;
}

#tree-flatten-demo .tfd-walkthrough {
  border: 1px solid #ececec;
  border-radius: 0.6rem;
  padding: 0.7rem;
}

#tree-flatten-demo .tfd-walkthrough h4 {
  margin: 0 0 0.45rem;
}

#tree-flatten-demo .tfd-walkthrough-code {
  margin: 0;
  padding: 0.55rem;
  border: 1px solid #e5e7eb;
  border-radius: 0.5rem;
  background: #f9fafb;
  overflow-x: auto;
  font-size: 0.82rem;
  line-height: 1.45;
}

#tree-flatten-demo .tfd-columns h4 {
  margin-bottom: 0.3rem;
}

#tree-flatten-demo .tfd-tree-card {
  border: 1px solid #ececec;
  padding: 0.95rem;
  border-radius: 0.6rem;
  background: #fff;
}

#tree-flatten-demo .tfd-ascii-tree {
  margin: 0.45rem 0 0;
  padding: 0.65rem 0.75rem;
  border: 1px solid #e5e7eb;
  border-radius: 0.5rem;
  background: #f9fafb;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 0.82rem;
  line-height: 1.45;
  white-space: pre;
  overflow-x: auto;
}

#tree-flatten-demo .tfd-ascii-line {
  color: #374151;
}

#tree-flatten-demo .tfd-ascii-taken {
  color: #1d4ed8;
  font-weight: 600;
}

#tree-flatten-demo .tfd-ascii-active {
  color: #b45309;
  font-weight: 700;
}

#tree-flatten-demo .tfd-ascii-terminal {
  color: #15803d;
  font-weight: 700;
}

#tree-flatten-demo .tfd-ascii-muted {
  color: #9ca3af;
}

#tree-flatten-demo .tfd-note {
  margin-top: 0.6rem;
  color: #444;
  font-size: 0.86rem;
}

@media (max-width: 980px) {
  #tree-flatten-demo {
    width: calc(100vw - 1rem);
  }

  #tree-flatten-demo .tfd-layout {
    grid-template-columns: 1fr;
  }
}

#tree-flatten-demo .tfd-legend {
  margin-top: 0.8rem;
  display: flex;
  column-gap: 0.8rem;
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: #444;
}

#tree-flatten-demo .tfd-legend strong {
  color: #000;
}