* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #1b1d22;
  color: #e6e8ee;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

#canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
}

#panel {
  position: fixed;
  top: 16px;
  left: 16px;
  width: 280px;
  padding: 18px;
  border-radius: 14px;
  background: rgba(28, 30, 36, 0.82);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
  user-select: none;
  transition: padding 0.2s ease;
}

#panel.collapsed {
  padding-bottom: 14px;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 14px;
}

#panel.collapsed .panel-header {
  margin-bottom: 0;
}

#panel h1 {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.2px;
  color: #aeb6ff;
}

#panel-toggle {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  padding: 0;
  border-radius: 8px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #2c3140;
  color: #aeb6ff;
  font-size: 18px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s;
}

#panel-toggle:hover {
  background: #353c4e;
}

.panel-body {
  overflow: hidden;
  transition: opacity 0.2s ease;
}

#panel.collapsed .panel-body {
  display: none;
}

.row {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 14px;
  font-size: 12.5px;
}

.row span {
  display: flex;
  justify-content: space-between;
  color: #c2c6d2;
}

.row b {
  color: #8ad0ff;
  font-variant-numeric: tabular-nums;
}

.row.checkbox {
  flex-direction: row;
  align-items: center;
  gap: 9px;
  cursor: pointer;
}

.row.checkbox span {
  color: #e6e8ee;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 4px;
  background: #3a3f4b;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: #7c8cff;
  cursor: pointer;
  border: 2px solid #1b1d22;
}

input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: #7c8cff;
  cursor: pointer;
}

.buttons {
  flex-direction: row;
}

button {
  flex: 1;
  padding: 8px 10px;
  border-radius: 9px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #2c3140;
  color: #e6e8ee;
  font-size: 12.5px;
  cursor: pointer;
  transition: background 0.15s;
}

button:hover {
  background: #353c4e;
}

.hint {
  font-size: 11px;
  color: #777e8c;
  margin-top: 4px;
}

#stats {
  font-size: 11px;
  color: #5f6675;
  margin-top: 8px;
  font-variant-numeric: tabular-nums;
}