:root {
  --primary: #2563eb;
  --primary-dark: #1e40af;
  --secondary: #7c3aed;
  --accent: #10b981;
  --light: #f9fafb;
  --dark: #111827;
  --gray: #6b7280;
  --border: #e5e7eb;
  --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.02);
  --radius: 1rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  color: var(--dark);
  background-color: white;
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Navigation */
.navbar {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 50;
  padding: 0.75rem 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--dark);
  text-decoration: none;
}

.logo i {
  color: var(--primary);
}

.logo-highlight {
  color: var(--primary);
}

.nav-menu {
  display: flex;
  gap: 2rem;
}

.nav-link {
  text-decoration: none;
  color: var(--gray);
  font-weight: 500;
  transition: color 0.2s;
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--dark);
  cursor: pointer;
}

/* Hero */
.hero {
  padding: 4rem 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #e0e7ff;
  color: var(--primary-dark);
  padding: 0.5rem 1rem;
  border-radius: 2rem;
  font-weight: 500;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
}

.highlight {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-text {
  font-size: 1.1rem;
  color: var(--gray);
  margin-bottom: 2rem;
}

.hero-stats {
  display: flex;
  gap: 2rem;
  margin-bottom: 2rem;
}

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

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

.stat-label {
  font-size: 0.9rem;
  color: var(--gray);
}

.hero-cta {
  display: flex;
  gap: 1rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 0.5rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.btn-outline {
  border: 2px solid var(--border);
  color: var(--dark);
}

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

.hero-image img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.image-credit {
  font-size: 0.75rem;
  color: var(--gray);
  margin-top: 0.25rem;
  text-align: right;
}

/* Sections */
.section {
  padding: 5rem 0;
}

.bg-light {
  background-color: var(--light);
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  font-size: 2.2rem;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--gray);
}

/* What is section */
.content-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
}

.text-card {
  background: white;
  padding: 2rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.info-box {
  display: flex;
  gap: 1rem;
  background: #fef3c7;
  padding: 1rem;
  border-radius: 0.5rem;
  margin-top: 1.5rem;
}

.info-box i {
  color: #d97706;
  font-size: 1.2rem;
}

.feature-grid {
  display: grid;
  gap: 1rem;
}

.feature-item {
  background: white;
  padding: 1.5rem;
  border-radius: 0.75rem;
  border: 1px solid var(--border);
  text-align: center;
}

.feature-icon {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

/* Steps */
.steps-wrapper {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.step-block {
  display: flex;
  align-items: start;
  gap: 1rem;
}

.step-num {
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 1.2rem;
  margin-bottom: 0.25rem;
}

.step-content p {
  color: var(--gray);
  font-size: 0.95rem;
}

.image-break img {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  border-radius: var(--radius);
}

/* Comparison table */
.table-responsive {
  overflow-x: auto;
  margin: 2rem 0;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: white;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.comparison-table th {
  background: var(--light);
  padding: 1rem;
  text-align: left;
  font-weight: 600;
}

.comparison-table td {
  padding: 1rem;
  border-bottom: 1px solid var(--border);
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.badge {
  background: var(--accent);
  color: white;
  font-size: 0.7rem;
  padding: 0.2rem 0.5rem;
  border-radius: 1rem;
  margin-left: 0.5rem;
}

.table-note {
  font-size: 0.9rem;
  color: var(--gray);
}

/* Guide grid */
.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.guide-item {
  background: white;
  padding: 1.5rem;
  border-radius: 0.75rem;
  border: 1px solid var(--border);
  position: relative;
}

.guide-number {
  position: absolute;
  top: -0.5rem;
  left: -0.5rem;
  width: 2rem;
  height: 2rem;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
}

.guide-item h3 {
  margin-top: 0.5rem;
  margin-bottom: 0.5rem;
}

.tip-box {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: #d1fae5;
  padding: 1.5rem;
  border-radius: 0.75rem;
}

.tip-box i {
  color: var(--accent);
  font-size: 1.5rem;
}

/* FAQ */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  margin-bottom: 1rem;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  background: white;
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: none;
  cursor: pointer;
  font-weight: 600;
  color: var(--dark);
  transition: background 0.2s;
}

.faq-question:hover {
  background: var(--light);
}

.faq-question i {
  transition: transform 0.3s;
}

.faq-item.open .faq-question i {
  transform: rotate(180deg);
}

.faq-answer {
  padding: 0 1.25rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

.faq-item.open .faq-answer {
  padding-bottom: 1.25rem;
  max-height: 300px;
}

.faq-answer p {
  color: var(--gray);
}

/* Footer */
.footer {
  background: var(--dark);
  color: #9ca3af;
  padding: 4rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
  text-decoration: none;
  margin-bottom: 1rem;
}

.footer-links h4, .footer-disclaimer h4 {
  color: white;
  margin-bottom: 1rem;
}

.footer-links a {
  display: block;
  color: #9ca3af;
  text-decoration: none;
  margin-bottom: 0.5rem;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

.footer-disclaimer p {
  font-size: 0.9rem;
  line-height: 1.5;
}

.footer-bottom {
  border-top: 1px solid #374151;
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

.footer-bottom a {
  color: #9ca3af;
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-menu {
      display: none;
      flex-direction: column;
      position: absolute;
      top: 100%;
      left: 0;
      width: 100%;
      background: white;
      padding: 1rem;
      border-bottom: 1px solid var(--border);
      box-shadow: var(--shadow);
  }

  .nav-menu.show {
      display: flex;
  }

  .mobile-toggle {
      display: block;
  }

  .hero-grid {
      grid-template-columns: 1fr;
      gap: 2rem;
  }

  .hero h1 {
      font-size: 2.2rem;
  }

  .content-grid {
      grid-template-columns: 1fr;
  }

  .footer-grid {
      grid-template-columns: 1fr;
      gap: 2rem;
  }

  .footer-bottom {
      flex-direction: column;
      gap: 1rem;
      text-align: center;
  }
}
/* Author Section */
.author-section {
  background: var(--light);
  padding: 3rem 0;
}

.author-card {
  display: flex;
  gap: 2rem;
  background: white;
  padding: 2rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  max-width: 800px;
  margin: 0 auto;
}

.author-avatar i {
  font-size: 5rem;
  color: var(--primary);
}

.author-info h3 {
  margin-bottom: 0.5rem;
}

.author-name {
  color: var(--primary-dark);
  margin-bottom: 1rem;
}

.author-disclaimer {
  font-size: 0.9rem;
  color: var(--gray);
  margin-top: 1rem;
  font-style: italic;
}

/* External links */
.step-content a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.step-content a:hover {
  color: var(--primary-dark);
}

@media (max-width: 640px) {
  .author-card {
      flex-direction: column;
      text-align: center;
  }
}