:root {
  --bg: #f4f2ee;
  --panel: #ffffff;
  --ink: #1d1c1a;
  --muted: #6b665f;
  --grid: #d8d3cb;
  --accent: #c2410c;
  --orbit: #3b4a6b;
  --view: #fbfaf8;
  --equilibrium: #0f766e;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101114;
    --panel: #181a1f;
    --ink: #e8e6e1;
    --muted: #9a958c;
    --grid: #2d3038;
    --accent: #fb923c;
    --orbit: #8ea2cf;
    --view: #0b0c0f;
    --equilibrium: #5eead4;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 system-ui, -apple-system, 'Segoe UI', sans-serif;
}

header,
main,
footer {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 16px;
}

header h1 {
  margin: 20px 0 4px;
  font-size: 28px;
  letter-spacing: 0.02em;
}

.subtitle {
  margin: 0 0 16px;
  max-width: 76ch;
  color: var(--muted);
}

main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 20px;
  align-items: start;
}

.canvas-wrap {
  position: relative;
  aspect-ratio: 4 / 3;
  background: var(--view);
  border: 1px solid var(--grid);
  border-radius: 8px;
  overflow: hidden;
}

#view {
  display: block;
  width: 100%;
  height: 100%;
  cursor: grab;
  touch-action: none;
}

#view:active {
  cursor: grabbing;
}

#view:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

.overlay {
  position: absolute;
  left: 12px;
  right: 12px;
  top: 12px;
  margin: 0;
  padding: 8px 12px;
  border-radius: 6px;
  background: var(--panel);
  border: 1px solid var(--accent);
}

.status {
  margin: 8px 0 0;
  font-variant-numeric: tabular-nums;
}

.hint,
.note,
figcaption {
  color: var(--muted);
  font-size: 13px;
}

.charts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 8px 0 20px;
}

figure {
  margin: 0;
}

#level-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
}

#level-row[hidden] {
  display: none;
}

figure.wide {
  grid-column: 1 / -1;
}

figure.wide canvas {
  aspect-ratio: 3 / 1;
  cursor: crosshair;
}

.charts canvas {
  display: block;
  width: 100%;
  aspect-ratio: 3 / 2;
  border: 1px solid var(--grid);
  border-radius: 6px;
}

.panel fieldset {
  margin: 0 0 14px;
  padding: 10px 12px 12px;
  border: 1px solid var(--grid);
  border-radius: 8px;
  background: var(--panel);
}

legend {
  padding: 0 4px;
  font-weight: 600;
}

.panel label {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  margin-top: 8px;
  font-size: 14px;
}

.panel label.check {
  justify-content: flex-start;
  align-items: center;
}

input[type='range'],
select {
  width: 100%;
}

input[type='range'] {
  accent-color: var(--accent);
}

select,
button {
  font: inherit;
  color: inherit;
  background: var(--bg);
  border: 1px solid var(--grid);
  border-radius: 6px;
  padding: 4px 8px;
}

#map-axis,
#map-mode,
#sweep-key {
  width: auto;
  padding: 0 4px;
  font-size: 13px;
}

button {
  cursor: pointer;
}

button:hover {
  border-color: var(--accent);
}

#reset-params {
  margin-top: 10px;
}

.row {
  display: flex;
  gap: 8px;
  margin-top: 10px;
  flex-wrap: wrap;
}

.row button {
  flex: 1;
  white-space: nowrap;
}

.equations {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
  font-family: ui-monospace, 'Cascadia Mono', Consolas, monospace;
  font-size: 13px;
}

output {
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.readouts {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 10px;
  margin: 0;
  font-size: 14px;
}

.readouts dt {
  color: var(--muted);
}

.readouts dd {
  margin: 0;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

footer {
  margin: 12px auto 24px;
  color: var(--muted);
  font-size: 13px;
}

a {
  color: var(--accent);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

@media (max-width: 860px) {
  main {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .charts {
    grid-template-columns: 1fr;
  }

  figure.wide canvas {
    aspect-ratio: 3 / 2;
  }
}