:root {
  --color-bg: #ffffff;
  --color-text: #1a1a2e;
  --color-text-muted: #555;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-surface: #f8fafc;
  --color-border: #e2e8f0;
  --color-nav-bg: rgba(255, 255, 255, 0.95);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f172a;
    --color-text: #e2e8f0;
    --color-text-muted: #94a3b8;
    --color-primary: #3b82f6;
    --color-primary-hover: #60a5fa;
    --color-surface: #1e293b;
    --color-border: #334155;
    --color-nav-bg: rgba(15, 23, 42, 0.95);
  }
}

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

body {
  font-family: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

/* Nav */

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
}

header {
  position: sticky;
  top: 0;
  background: var(--color-nav-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border);
  z-index: 10;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.25rem;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-weight: 500;
}

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

/* Hero */

.hero {
  text-align: center;
  padding: 6rem 1.5rem 4rem;
  max-width: 720px;
  margin: 0 auto;
}

.hero-logo {
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.tagline {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* Buttons */

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: background 0.15s, color 0.15s;
}

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

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

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

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

/* Features */

.features {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
}

.feature {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 0.75rem;
  padding: 1.5rem;
}

.feature h2 {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
}

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

/* CTA */

.cta {
  text-align: center;
  padding: 4rem 1.5rem;
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.cta h2 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.cta p {
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
}

/* Footer */

footer {
  text-align: center;
  padding: 2rem 1.5rem;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--color-border);
}

footer a {
  color: var(--color-text-muted);
}

footer a:hover {
  color: var(--color-primary);
}