:root {
  --background: #ffffff;
  --foreground: #171717;
  --muted: #f5f5f5;
  --muted-foreground: #737373;
  --primary: #0f172a;
  --primary-foreground: #f8fafc;
  --border: #e5e5e5;
  --card: #ffffff;
  --card-foreground: #171717;
}

[data-theme="dark"] {
  --background: #0a0a0a;
  --foreground: #fafafa;
  --muted: #262626;
  --muted-foreground: #a3a3a3;
  --primary: #f8fafc;
  --primary-foreground: #0f172a;
  --border: #404040;
  --card: #171717;
  --card-foreground: #fafafa;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(to bottom, var(--muted), #e5e5e5);
  color: var(--foreground);
  line-height: 1.6;
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
}

[data-theme="dark"] body {
  background: linear-gradient(to bottom, #171717, #262626);
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 2rem;
}

.particles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 10;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: all 0.3s;
}

.header.scrolled {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(12px);
  box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}

[data-theme="dark"] .header.scrolled {
  background: rgba(23, 23, 23, 0.7);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 0;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0;
  color: var(--foreground);
}

.header-actions { display: flex; align-items: center; gap: 1rem; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: 0.375rem;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.2s;
  border: 1px solid var(--border);
  background: var(--background);
  color: var(--foreground);
}

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

.btn-outline { border: 1px solid var(--border); }

.btn-lg { padding: 0.625rem 2rem; font-size: 1rem; }

.btn-star {
  border: none;
  background: linear-gradient(90deg, var(--primary), var(--primary));
  background-size: 400% 400%;
  color: var(--primary-foreground);
}

.theme-btn {
  padding: 0.5rem;
  border-radius: 9999px;
  background: var(--muted);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.theme-btn:hover { background: var(--border); }

.theme-btn .sun-icon { display: none; }
.theme-btn .moon-icon { display: block; }

[data-theme="dark"] .theme-btn .sun-icon {
  display: block;
  color: #facc15;
}

[data-theme="dark"] .theme-btn .moon-icon { display: none; }

.hero {
  padding: 15rem 0 8rem;
  text-align: center;
}

.hero-cta { display: flex; justify-content: center; margin-bottom: 2rem; }

.hero-title {
  font-size: clamp(2.25rem, 5vw, 4rem);
  font-weight: 700;
  margin: 0;
  line-height: 1.2;
  color: var(--foreground);
}

.hero-subtitle { color: var(--muted-foreground); }

.hero-desc {
  margin: 1rem 0 2rem;
  font-size: 1.125rem;
  color: var(--muted-foreground);
}

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

.section { padding: 4rem 0; }

.section-muted { background: var(--muted); }

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  text-align: center;
  margin: 0 0 3rem;
  color: var(--foreground);
}

.section-title-lg { font-size: clamp(2.25rem, 4vw, 3rem); }

.benefits-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

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

.check {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.5rem;
  height: 1.5rem;
  color: var(--primary);
  font-weight: bold;
}

.benefit h3 { font-size: 1.125rem; font-weight: 600; margin: 0 0 0.5rem; }
.benefit p { margin: 0; color: var(--muted-foreground); }

.features-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card {
  background: var(--card);
  color: var(--card-foreground);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.05);
  padding: 1.5rem;
}

.card-title { font-size: 1.125rem; font-weight: 600; margin: 0 0 1rem; }

.feature-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  color: var(--muted-foreground);
}

.check-sm { color: var(--primary); flex-shrink: 0; }

.flow-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.flow-card {
  padding: 1.5rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.05);
}

.flow-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 9999px;
  background: var(--muted);
  color: var(--muted-foreground);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: 1rem;
}

.flow-card h3 { font-size: 1.25rem; font-weight: 600; margin: 0 0 0.5rem; }
.flow-card p { margin: 0; color: var(--muted-foreground); }

.testimonial { max-width: 28rem; margin: 0 auto; }

.testimonial-card { padding: 1.5rem; }

.testimonial-header { display: flex; align-items: center; gap: 1rem; margin-bottom: 1rem; }

.avatar {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 9999px;
  background: var(--muted);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.875rem;
  flex-shrink: 0;
}

.testimonial-header h3 { font-size: 1rem; font-weight: 600; margin: 0; }

.testimonial-role { font-size: 0.875rem; color: var(--muted-foreground); margin: 0.25rem 0 0; }

.testimonial-content { color: var(--muted-foreground); margin: 0; }

.footer {
  margin-top: 5rem;
  padding: 3rem 0;
  background: var(--background);
  color: var(--foreground);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

@media (min-width: 768px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
  }
}

.footer p { margin: 0; color: var(--muted-foreground); }

.github-link {
  color: var(--foreground);
  padding: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.github-link:hover { color: var(--muted-foreground); }