:root {
  --bg: #121212;
  --card: #1e1e1e;
  --gold: #ffd700;
  --pink: #ffc0cb;
  --text: #e0e0e0;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  justify-content: center;
  padding: 20px;
}

.app-container {
  width: 100%;
  max-width: 700px;
}

header {
  display: flex;
  justify-content: space-between;
  color: var(--gold);
  margin-bottom: 20px;
  font-family: monospace;
}

#quiz-card {
  background: var(--card);
  padding: 30px;
  border-radius: 12px;
  border: 1px solid #333;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

.option-btn {
  display: block;
  width: 100%;
  padding: 15px;
  margin: 10px 0;
  background: transparent;
  border: 1px solid #444;
  color: var(--text);
  text-align: left;
  cursor: pointer;
  border-radius: 6px;
  transition: 0.2s;
}

.option-btn:hover {
  background: rgba(255, 255, 255, 0.1);
}

.option-btn.selected {
  border-color: var(--pink);
  background: rgba(255, 192, 203, 0.1);
}

.nav-controls {
  display: flex;
  gap: 10px;
  margin-top: 20px;
  justify-content: center;
}

#prev-btn,
#next-btn {
  background: transparent;
  border: 1px solid var(--gold);
  color: var(--gold);
  padding: 12px 20px;
  cursor: pointer;
  border-radius: 4px;
  flex: 1; /* Makes buttons equal width */
  transition: 0.2s;
}

#prev-btn:hover,
#next-btn:hover {
  background: rgba(255, 215, 0, 0.1);
  transition: 0.2s;
}

#check-btn {
  background: var(--gold);
  color: #121212;
  border: none;
  padding: 12px 20px;
  font-weight: bold;
  cursor: pointer;
  border-radius: 4px;
  flex: 1.5; /* Makes the main action button slightly wider */
  transition: 0.2s;
}

#check-btn:hover {
  background: #e6c200;
  transition: 0.2s;
}

/* Optional: Disable the button visually if at the start */
#prev-btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.hidden {
  display: none;
}

.key-phrase-box {
  margin-top: 25px;
  padding: 15px;
  border-left: 4px solid var(--gold);
  background: rgba(255, 215, 0, 0.05);
}

.explanation-item {
  margin: 15px 0;
  font-size: 0.95em;
  line-height: 1.5;
}

.correct-text {
  color: var(--gold);
  font-weight: bold;
}
.incorrect-text {
  color: var(--pink);
}