:root {
  --primary: #0284c7;
  --primary-hover: #0369a1;
  --primary-light: #e0f2fe;
  --secondary: #0f172a;
  --accent: #06b6d4;
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --text-main: #1e293b;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --success: #10b981;
  --error: #ef4444;
  --radius: 12px;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.05);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.04);
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-main);
  line-height: 1.6;
  scroll-behavior: smooth;
}

.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--secondary);
  font-size: 1.25rem;
  font-weight: 700;
}

.brand-icon {
  font-size: 1.75rem;
}

.brand-name strong {
  color: var(--primary);
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--primary);
}

.nav-cta {
  display: inline-flex;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--primary);
  color: #ffffff;
}

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

.btn-secondary {
  background-color: #ffffff;
  color: var(--secondary);
  border-color: var(--border);
}

.btn-secondary:hover {
  background-color: var(--primary-light);
  border-color: var(--primary);
}

.hero-section {
  padding: 64px 0;
  background: linear-gradient(180deg, #eff6ff 0%, var(--bg-main) 100%);
}

.hero-content {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: 48px;
}

.badge {
  display: inline-block;
  background-color: var(--primary-light);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.hero-title {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--secondary);
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-stats {
  display: flex;
  gap: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.visual-card {
  background-color: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.tooth-illustration {
  width: 180px;
  height: 216px;
  margin-bottom: 16px;
}

.tooth-svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 10px 8px rgb(2 132 199 / 0.15));
}

.visual-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
}

.badge-dot {
  width: 8px;
  height: 8px;
  background-color: var(--success);
  border-radius: 50%;
}

.section {
  padding: 80px 0;
}

.section-alt {
  background-color: #f1f5f9;
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 48px;
}

.section-tag {
  display: inline-block;
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 8px;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 12px;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1rem;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.card {
  background-color: var(--bg-card);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card-icon {
  font-size: 2.2rem;
  margin-bottom: 16px;
}

.type-badge {
  display: inline-block;
  padding: 4px 10px;
  background-color: var(--primary-light);
  color: var(--primary);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 10px;
}

.card-text {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.quiz-container {
  max-width: 680px;
  margin: 0 auto;
}

.quiz-box, .quiz-result {
  background-color: var(--bg-card);
  padding: 36px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.quiz-progress {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.quiz-score-badge {
  background-color: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
  font-size: 0.85rem;
  padding: 4px 10px;
  border-radius: 6px;
}

.quiz-question {
  font-size: 1.25rem;
  color: var(--secondary);
  margin-bottom: 24px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.quiz-option-btn {
  padding: 14px 18px;
  background-color: var(--bg-main);
  border: 1px solid var(--border);
  border-radius: 8px;
  text-align: left;
  font-size: 0.95rem;
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

.quiz-option-btn:hover:not(:disabled) {
  border-color: var(--primary);
  background-color: var(--primary-light);
}

.quiz-option-btn.correct {
  background-color: #d1fae5;
  border-color: var(--success);
  color: #065f46;
  font-weight: 600;
}

.quiz-option-btn.incorrect {
  background-color: #fee2e2;
  border-color: var(--error);
  color: #991b1b;
  font-weight: 600;
}

.quiz-feedback {
  padding: 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  margin-bottom: 20px;
}

.quiz-feedback.correct {
  background-color: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.quiz-feedback.incorrect {
  background-color: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

.quiz-footer {
  display: flex;
  justify-content: flex-end;
}

.quiz-result {
  text-align: center;
}

.result-title {
  font-size: 1.75rem;
  color: var(--secondary);
  margin-bottom: 12px;
}

.result-summary {
  font-size: 1.1rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.tips-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.tip-card {
  background-color: var(--bg-card);
  padding: 32px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.tip-number {
  display: inline-block;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 12px;
}

.tip-card h4 {
  font-size: 1.15rem;
  color: var(--secondary);
  margin-bottom: 8px;
}

.tip-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.footer {
  background-color: var(--secondary);
  color: #94a3b8;
  padding: 40px 0;
  text-align: center;
  font-size: 0.9rem;
}

.footer-content p {
  margin-bottom: 6px;
}

.footer-sub {
  font-size: 0.8rem;
  color: #64748b;
}

.hidden {
  display: none !important;
}

@media (max-width: 768px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-stats {
    justify-content: center;
  }

  .nav-links, .nav-cta {
    display: none;
  }
}