body {
  font-family: sans-serif;
  background-color: var(--bg);
  color: var(--text);
  margin: 0;
  padding: 0;
}
.card {
  margin: 1em auto;
  padding: 1em;
  max-width: 600px;
  border: 1px solid #ccc;
  border-radius: 8px;
}
:root[data-theme='light'] {
  --bg: #ffffff;
  --text: #000000;
}
:root[data-theme='dark'] {
  --bg: #121212;
  --text: #ffffff;
}

.selector-panel {
  padding: 1em;
  text-align: center;
}
.button-group button {
  margin: 0.5em;
  padding: 0.5em 1em;
  font-size: 1rem;
  cursor: pointer;
}
header, footer {
  text-align: center;
  padding: 1em;
  background-color: #eee;
}
:root[data-theme='dark'] header,
:root[data-theme='dark'] footer {
  background-color: #1e1e1e;
}
.hint-console-icon {
  animation: pulse 2s infinite;
  color: orange;
}
@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.2); }
  100% { transform: scale(1); }
}