:root {
  --primary-color: #3498db;
  --bg-color: #f4f7f6;
  --white: #ffffff;
  --text-dark: #444444;
  --text-light: #718096;
  --accent-light: #f0f9ff;
  --border-color: #edf2f7;
  --btn-border: #e2e8f0;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Noto Sans KR', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
  line-height: 1.8;
  color: var(--text-dark);
  max-width: 900px;
  margin: 0 auto;
  padding: 20px;
  background-color: var(--bg-color);
}

.main-container {
  background: var(--white);
  padding: 40px;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  margin-top: 20px;
}

/* Quiz Header */
.quiz-header {
  text-align: center;
  margin-bottom: 30px;
}

.quiz-header h1 {
  color: var(--text-dark);
  margin-bottom: 10px;
}

.quiz-header p {
  color: var(--text-light);
}

/* Quiz Card */
.word-card {
  background: var(--white);
  border: 2px solid var(--border-color);
  padding: 40px;
  border-radius: 15px;
  text-align: center;
  margin-bottom: 30px;
  min-height: 400px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.word-text {
  font-size: 3rem;
  font-weight: 800;
  color: var(--primary-color);
  margin-bottom: 5px;
}

.phonetic {
  color: #a0aec0;
  font-size: 1.1rem;
  margin-bottom: 25px;
}

/* Options Grid */
.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 15px;
  margin-top: 20px;
}

.option-btn {
  background: var(--white);
  border: 2px solid var(--btn-border);
  padding: 18px;
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-dark);
}

.option-btn:hover {
  border-color: var(--primary-color);
  background: var(--accent-light);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(52, 152, 219, 0.1);
}

.option-btn:active {
  transform: translateY(0);
}

.result-msg {
  margin-top: 30px;
  font-weight: bold;
  font-size: 1.2rem;
  min-height: 1.5em;
}

/* Visual Learning Section */
.visual-learning-section {
  margin-top: 50px;
  padding: 25px;
  background-color: #f9f9f9;
  border-radius: 15px;
  box-shadow: inset 0 2px 5px rgba(0,0,0,0.02);
}

.visual-learning-section h3 {
  text-align: center;
  color: #2c3e50;
  margin-bottom: 10px;
  font-size: 1.5rem;
}

.visual-learning-section p {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 30px;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 25px;
  margin-top: 30px;
}

.gallery-item {
  text-align: center;
  background: white;
  padding: 15px;
  border-radius: 10px;
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
  transition: transform 0.2s;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.gallery-item:hover {
  transform: translateY(-5px);
}

.gallery-item img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  border: 1px solid #eee;
  box-shadow: 0 4px 10px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

.gallery-item span {
  display: block;
  margin-top: 10px;
  font-size: 0.95rem;
  color: #555;
  font-weight: 500;
}

/* Content Section */
.content-section {
  margin-top: 50px;
  border-top: 1px solid #eee;
  padding-top: 30px;
}

.blog-post {
  margin-bottom: 30px;
}

.blog-post h3 {
  color: #2d3748;
  border-left: 5px solid var(--primary-color);
  padding-left: 15px;
  margin-bottom: 15px;
  font-size: 1.3rem;
}

.blog-post p {
  color: #4a5568;
  font-size: 1.05rem;
}

.blog-post strong {
  color: var(--primary-color);
}

/* Footer */
.footer-links {
  text-align: center;
  margin-top: 50px;
  padding-bottom: 40px;
  font-size: 0.9rem;
  color: var(--text-light);
}

.footer-links a {
  color: var(--text-light);
  margin: 0 12px;
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--primary-color);
  text-decoration: underline;
}

@media (max-width: 600px) {
  .main-container {
    padding: 20px;
  }
  .word-card {
    padding: 30px 15px;
  }
  .word-text {
    font-size: 2.2rem;
  }
  .options-grid {
    grid-template-columns: 1fr;
  }
  .gallery-grid {
    grid-template-columns: 1fr;
    gap: 15px;
  }
  .option-btn {
    padding: 15px;
  }
}