body {
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: #0f172a;
  /* slate-900 */
  margin: 0;
  color: #e2e8f0;
  /* slate-200 */
}

header,
footer {
  background: #0b1220;
  /* darker */
  color: #e2e8f0;
  padding: 1rem;
  text-align: center;
}

.sim-warning {
  color: #f59e0b;
  font-weight: 600;
}

main {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 16px;
  padding: 16px;
  max-width: 1200px;
  margin: 0 auto;
}

.card {
  background: #111827;
  /* gray-900 */
  border: 1px solid #1f2937;
  /* gray-800 */
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
  padding: 14px;
}

.help-list {
  margin: 0;
  padding-left: 1.2rem;
  line-height: 1.5;
}

.muted {
  color: #94a3b8;
}

.auth-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 8px;
  align-items: center;
}

.auth-actions {
  display: flex;
  gap: 8px;
}

input,
select,
button {
  font-size: 0.95rem;
  padding: 8px 10px;
  border-radius: 8px;
  border: 1px solid #334155;
  background: #0b1220;
  color: #e2e8f0;
}

input::placeholder {
  color: #64748b;
}

.btn {
  cursor: pointer;
  transition: .15s ease;
}

.btn:hover {
  filter: brightness(1.1);
}

.btn-primary {
  background: #2563eb;
  border-color: #1d4ed8;
}

.btn-ghost {
  background: transparent;
  border-color: #334155;
}

.alert {
  grid-column: 1/-1;
  background: #1e293b;
  border: 1px solid #334155;
  color: #e2e8f0;
  padding: 12px;
  border-radius: 10px;
}

section h2 {
  margin: 0 0 8px;
  font-size: 1.1rem;
  color: #e5e7eb;
}

#theory-panel {
  background: #1f2937;
}

.theory-box {
  font-size: 0.95rem;
  line-height: 1.5;
  max-height: 240px;
  overflow-y: auto;
  padding: 0.5rem;
}

.theory-box p {
  margin: 0 0 0.6rem;
}

#metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.metric {
  background: #0b2942;
  border: 1px solid #12345622;
  border-radius: 6px;
  padding: 6px 10px;
  min-width: 120px;
  text-align: center;
}

#logs {
  background: #0b1220;
  color: #06d6a0;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  height: 200px;
  overflow-y: auto;
  border-radius: 6px;
  padding: 8px;
  border: 1px solid #1f2937;
}

#controls label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin: 4px 8px 4px 0;
}

#controls input[type="range"] {
  width: 140px;
}

#metrics-graph {
  display: block;
  margin: 8px auto 0;
  background: #0b1220;
  border: 1px solid #1f2937;
  border-radius: 8px;
}

/* Quiz styles */
#quiz-panel {
  background: #102a17;
}

#quiz {
  font-size: 0.95em;
  line-height: 1.4;
}

.quiz-block {
  border: 1px solid #14532d;
  background: #0b2314;
  padding: 10px;
  margin-bottom: 10px;
  border-radius: 8px;
}

.quiz-block h3 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.quiz-options label {
  display: block;
  cursor: pointer;
  margin: 4px 0;
}

.quiz-feedback {
  font-weight: 600;
  margin-top: 6px;
}

.quiz-correct {
  color: #22c55e;
}

.quiz-wrong {
  color: #ef4444;
}

/* Layout fixes for login/auth */
* {
  box-sizing: border-box;
}

.auth-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 8px;
  align-items: center;
}

.auth-grid input {
  width: 100%;
}

.auth-actions,
#auth-status {
  grid-column: 1 / -1;
}

/* End layout fixes */