:root {
  color-scheme: light;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  line-height: 1.5;
  --primary: #1f4f8b;
  --primary-dark: #173b68;
  --success: #2e7d32;
  --danger: #c62828;
  --muted: #667085;
  --border: #d0d5dd;
  --bg: #f8fafc;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: #1d2939;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 32px 20px 48px;
}

header {
  margin-bottom: 24px;
}

h1 {
  margin: 0 0 8px;
  font-size: 32px;
}

.subtitle {
  margin: 0;
  color: var(--muted);
}

.source {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
  font-style: italic;
}

.status {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-weight: 600;
  margin-bottom: 16px;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

#question-number {
  margin: 0 0 8px;
  font-size: 20px;
  color: var(--primary);
}

#question-text {
  margin: 0 0 20px;
  font-size: 18px;
}

.options {
  display: grid;
  gap: 12px;
  margin-bottom: 20px;
}

.option {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #fff;
  transition: border 0.2s ease, background 0.2s ease;
}

.option input {
  margin-top: 4px;
}

.option.correct {
  border-color: rgba(46, 125, 50, 0.6);
  background: rgba(46, 125, 50, 0.08);
}

.option.incorrect {
  border-color: rgba(198, 40, 40, 0.6);
  background: rgba(198, 40, 40, 0.08);
}

.feedback {
  min-height: 48px;
  font-weight: 600;
  margin-bottom: 16px;
}

.feedback.success {
  color: var(--success);
}

.feedback.error {
  color: var(--danger);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

button {
  border: none;
  border-radius: 10px;
  padding: 10px 18px;
  font-size: 16px;
  cursor: pointer;
  background: var(--primary);
  color: #fff;
  transition: background 0.2s ease;
}

button:hover:not(:disabled) {
  background: var(--primary-dark);
}

button.secondary {
  background: #e2e8f0;
  color: #1d2939;
}

button.secondary:hover:not(:disabled) {
  background: #cbd5f5;
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.6;
}

.summary {
  font-size: 18px;
  font-weight: 600;
}

.selection-buttons {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.selection-btn {
  width: 100%;
  padding: 16px;
  font-size: 18px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.selection-btn:hover {
  background: var(--primary-dark);
}