:root {
  --converter-gap: 1rem;
  --converter-bg: #ffffff;
  --converter-border: #cccccc;
  --converter-input-border: #999999;
  --converter-focus: #007acc;
}

.converter-panel button {
  font-size: 1rem;
  padding: 0.5rem;
  margin-bottom: 0.75rem;
  background-color: var(--converter-focus);
  color: #fff;
  border: none;
  border-radius: 2px;
  cursor: pointer;
}

.converter-panel button:focus {
  outline: 2px solid var(--converter-focus);
  outline-offset: 2px;
}

.unit-converter {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--converter-gap);
  padding: var(--converter-gap);
  background-color: var(--converter-bg);
}

.converter-panel {
  background-color: var(--converter-bg);
  border: 1px solid var(--converter-border);
  border-radius: 4px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
}

.converter-panel h2 {
  margin-top: 0;
}

.converter-panel label {
  font-weight: bold;
  margin-bottom: 0.5rem;
}

.converter-panel input,
.converter-panel select,
.converter-panel output {
  font-size: 1rem;
  padding: 0.5rem;
  margin-bottom: 0.75rem;
  border: 1px solid var(--converter-input-border);
  border-radius: 2px;
}

.converter-panel input:focus,
.converter-panel select:focus,
.converter-panel output:focus {
  outline: 2px solid var(--converter-focus);
  outline-offset: 2px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --converter-bg: #2a2a2a;
    --converter-border: #444444;
    --converter-input-border: #555555;
    --converter-focus: #3399ff;
  }
}