:root {
  --demo-max-width: 1000px;
}

#orbit-svg {
  width: 100%;
  height: auto;
  display: block;
}

/* Smooth transitions for orbit changes */
#orbit-path {
  transition: all 0.3s ease-out;
}

#planet {
  transition: r 0.2s ease-out;
}

.control-card {
  transition: opacity 0.2s ease;
}

/* Layout */
.readout-panel {
  grid-template-columns: repeat(4, 1fr);
}

.controls-grid {
  grid-template-columns: 1fr 1fr;
}

/* Unit toggle */
.unit-toggle {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

/* Timeline */
.timeline-panel {
  background: rgba(18, 18, 31, 0.92);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.timeline-track {
  position: relative;
  height: 24px;
  background: var(--space-medium);
  border-radius: var(--border-radius-sm);
  cursor: pointer;
}

.timeline-progress {
  position: absolute;
  height: 100%;
  background: var(--cosmic-teal);
  border-radius: var(--border-radius-sm) 0 0 var(--border-radius-sm);
  opacity: 0.3;
}

.timeline-handle {
  position: absolute;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 16px;
  height: 16px;
  background: var(--stellar-amber);
  border-radius: 50%;
  cursor: grab;
}

.timeline-markers {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

/* Animation controls layout (buttons styled via demo-legacy.css) */
.animation-controls {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(18, 18, 31, 0.92);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  margin-bottom: var(--space-md);
}

.speed-control {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-left: auto;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.speed-control select {
  padding: 6px 10px;
  min-height: 44px;
  background: var(--space-light);
  border: 1px solid var(--border-color);
  border-radius: 9999px;
  color: var(--text-primary);
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  font-size: var(--font-size-sm);
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

/* Overlays */
.overlays-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-md);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-color);
}

.overlay-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  cursor: pointer;
}

.overlay-toggle input {
  accent-color: var(--cosmic-teal);
}

/* Insight box */
.insight-box {
  background: rgba(18, 18, 31, 0.92);
  border-left: 4px solid var(--stellar-amber);
  padding: var(--space-md);
  border-radius: 0 var(--border-radius-md) var(--border-radius-md) 0;
  font-size: var(--font-size-md);
  line-height: var(--line-height-normal);
}

.insight-box.kepler-mode .newton-content,
.insight-box.newton-mode .kepler-content {
  display: none;
}

.insight-box h4 {
  margin: 0 0 var(--space-sm) 0;
  color: var(--stellar-amber);
  font-size: var(--font-size-sm);
}

/* Formula styling for KaTeX */
.insight-box .formula {
  margin: var(--space-sm) 0;
  padding: var(--space-sm) 0;
}

.insight-box .formula .katex {
  font-size: 1.1em;
  color: var(--cosmic-teal);
}

#newton-values {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

#newton-velocity-formula,
#newton-accel-formula {
  color: var(--cosmic-teal);
}

/* Model note (student-facing) */
.model-note {
  background: rgba(18, 18, 31, 0.9);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.5rem 0.75rem;
  margin: 0.75rem 0 1rem 0;
  color: var(--text-secondary);
  font-size: 0.8rem;
  line-height: 1.4;
}

.model-note summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text-secondary);
}

.model-note p {
  margin: 0.5rem 0 0 0;
  color: var(--text-muted);
}

/* Newton-mode specific */
.newton-only {
  display: none;
}

body.newton-mode .newton-only {
  display: block;
}

body.newton-mode .kepler-only {
  opacity: 0.5;
}

/* Responsive */
@media (max-width: 700px) {
  .readout-panel {
    grid-template-columns: repeat(2, 1fr);
  }

  .controls-grid {
    grid-template-columns: 1fr;
  }

  .demo-content {
    padding: 1rem;
  }
}

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}