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

:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2235;
  --bg-card-hover: #1f2b42;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-blue-dark: #2563eb;
  --accent-gold: #f59e0b;
  --accent-gold-dark: #d97706;
  --accent-green: #10b981;
  --accent-red: #ef4444;
  --border-color: #1e293b;
  --gradient-primary: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --gradient-gold: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.3);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: all 0.3s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(10, 14, 23, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
}

.logo-icon {
  font-size: 28px;
}

.logo-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: var(--transition);
}

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

.lang-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 6px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
}

.lang-toggle:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-blue);
}

/* Hero */
.hero {
  padding: 140px 0 100px;
  background: radial-gradient(ellipse at top, rgba(59, 130, 246, 0.15) 0%, transparent 60%);
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-text h1 {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
}

.highlight {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  margin-bottom: 48px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 28px;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(59, 130, 246, 0.5);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-blue);
}

.apple-icon {
  width: 20px;
  height: 20px;
}

.hero-stats {
  display: flex;
  gap: 40px;
}

.stat {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 32px;
  font-weight: 800;
  background: var(--gradient-gold);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 14px;
  color: var(--text-muted);
}

/* Phone Mockup */
.phone-mockup {
  background: var(--bg-card);
  border-radius: 40px;
  padding: 12px;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border: 1px solid var(--border-color);
}

.phone-screen {
  background: var(--bg-secondary);
  border-radius: 30px;
  padding: 24px 20px;
  overflow: hidden;
}

.calc-display {
  background: #0d1117;
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
  text-align: right;
}

.calc-display-label {
  font-size: 12px;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.calc-display-value {
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 32px;
  font-weight: 700;
  color: var(--accent-gold);
}

.calc-keys {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.calc-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.calc-key {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px 0;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  text-align: center;
}

.calc-key.func {
  background: #1e3a5f;
  color: #93c5fd;
}

.calc-key.num {
  background: #1f2937;
  color: var(--text-primary);
}

.calc-key.op {
  background: #451a03;
  color: var(--accent-gold);
}

/* Section Common */
.section-title {
  font-size: 36px;
  font-weight: 800;
  text-align: center;
  margin-bottom: 16px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 18px;
  margin-bottom: 48px;
}

section {
  padding: 100px 0;
}

/* Pain Points */
.pain-points {
  background: var(--bg-secondary);
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.pain-card {
  display: flex;
  gap: 20px;
  background: var(--bg-card);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.pain-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-4px);
}

.pain-icon {
  font-size: 40px;
  flex-shrink: 0;
}

.pain-text h3 {
  font-size: 18px;
  margin-bottom: 8px;
  color: var(--accent-red);
}

.pain-text p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Features */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.feature-card {
  background: var(--bg-card);
  padding: 28px 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: var(--transition);
  position: relative;
}

.feature-card:hover {
  border-color: var(--accent-blue);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.feature-card.featured {
  background: linear-gradient(135deg, var(--bg-card) 0%, rgba(59, 130, 246, 0.1) 100%);
  border-color: rgba(59, 130, 246, 0.3);
}

.feature-icon {
  font-size: 40px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
}

.feature-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--gradient-primary);
  color: white;
  font-size: 11px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 20px;
}

/* Accuracy */
.accuracy {
  background: var(--bg-secondary);
}

.accuracy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.accuracy-card {
  background: var(--bg-card);
  padding: 32px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  text-align: center;
}

.accuracy-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.accuracy-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.accuracy-card p {
  color: var(--text-secondary);
  font-size: 14px;
}

.accuracy-example {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 36px;
  border: 1px solid var(--border-color);
}

.accuracy-example h3 {
  font-size: 22px;
  margin-bottom: 24px;
  text-align: center;
}

.example-table {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.example-input h4,
.example-output h4 {
  font-size: 16px;
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.example-table table {
  width: 100%;
  border-collapse: collapse;
}

.example-table td {
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-color);
  font-size: 14px;
}

.example-table td:first-child {
  font-weight: 600;
  color: var(--text-secondary);
}

.example-table td:last-child {
  font-family: 'SF Mono', 'Fira Code', monospace;
  color: var(--accent-gold);
}

.pass {
  color: var(--accent-green) !important;
}

/* Compare */
.compare-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
}

.compare-table th,
.compare-table td {
  padding: 16px 24px;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.compare-table th {
  background: var(--bg-secondary);
  font-size: 15px;
  font-weight: 700;
}

.compare-table th:first-child,
.compare-table td:first-child {
  text-align: left;
  font-weight: 600;
}

.compare-table td {
  font-size: 14px;
}

.yes {
  color: var(--accent-green);
}

.no {
  color: var(--accent-red);
}

.maybe {
  color: var(--accent-gold);
}

.ours {
  background: rgba(59, 130, 246, 0.1);
}

.highlight {
  background: rgba(16, 185, 129, 0.1);
  font-weight: 600;
}

/* Audience */
.audience {
  background: var(--bg-secondary);
}

.audience-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.audience-card {
  background: var(--bg-card);
  padding: 36px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  text-align: center;
  transition: var(--transition);
}

.audience-card:hover {
  border-color: var(--accent-gold);
  transform: translateY(-4px);
}

.audience-icon {
  font-size: 56px;
  margin-bottom: 20px;
}

.audience-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.audience-card p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* CTA */
.cta {
  text-align: center;
  background: radial-gradient(ellipse at center, rgba(59, 130, 246, 0.2) 0%, transparent 70%);
}

.cta h2 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta p {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 36px;
}

.btn-large {
  padding: 18px 36px;
  font-size: 18px;
}

/* FAQ */
.faq {
  background: var(--bg-secondary);
}

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

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius);
  margin-bottom: 12px;
  border: 1px solid var(--border-color);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 24px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
  transition: var(--transition);
}

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

.faq-arrow {
  transition: var(--transition);
  color: var(--text-muted);
}

.faq-item.active .faq-arrow {
  transform: rotate(180deg);
}

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

.faq-item.active .faq-answer {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.7;
}

/* Footer */
.footer {
  padding: 40px 0;
  border-top: 1px solid var(--border-color);
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 700;
}

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

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--accent-blue);
}

.footer-copy {
  color: var(--text-muted);
  font-size: 13px;
}

/* Responsive */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

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

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

  .hero-image {
    display: none;
  }

  .feature-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links a:not(.lang-toggle) {
    display: none;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero-text h1 {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 16px;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .hero-stats {
    flex-wrap: wrap;
    gap: 24px;
  }

  .section-title {
    font-size: 28px;
  }

  section {
    padding: 60px 0;
  }

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

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .example-table {
    grid-template-columns: 1fr;
  }

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

  .cta h2 {
    font-size: 28px;
  }
}

@media (max-width: 480px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .stat-number {
    font-size: 24px;
  }
}