:root {
  color-scheme: dark;
}
body {
  font-family: system-ui, -apple-system, sans-serif;
  margin: 0;
  padding: 24px;
  background: #0f1220;
  color: #e8ebf7;
}
.shell-container {
  max-width: 560px;
  margin: 0 auto;
}
h1, h2 {
  margin: 0 0 16px 0;
}
button {
  display: inline-block;
  padding: 10px 16px;
  margin: 6px 6px 0 0;
  background: #2d3459;
  color: #e8ebf7;
  border: 1px solid #444c7a;
  border-radius: 6px;
  cursor: pointer;
  font: inherit;
}
button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
button:hover:not(:disabled) {
  background: #3a4270;
}
.level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
  margin-top: 12px;
}
.level-card {
  padding: 24px 12px;
  text-align: center;
}
.actions {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
pre {
  background: #1a1e35;
  padding: 12px;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 12px;
  line-height: 1.4;
}
.shell-note {
  font-size: 13px;
  color: #9aa0c8;
  margin-top: 8px;
}