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

:root {
  --color-bg: #fafafa;
  --color-surface: #ffffff;
  --color-text: #1a1a2e;
  --color-text-muted: #555;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-border: #e5e7eb;
  --font-sans: system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, "Cascadia Code", "Fira Code", monospace;
  --max-width: 64rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f0f1a;
    --color-surface: #1a1a2e;
    --color-text: #e5e5e5;
    --color-text-muted: #999;
    --color-primary: #3b82f6;
    --color-primary-hover: #60a5fa;
    --color-border: #2a2a3e;
  }
}

html {
  font-family: var(--font-sans);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  border-bottom: 1px solid var(--color-border);
  padding: 1rem 2rem;
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.nav-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
}

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

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  font-family: var(--font-mono);
}

main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem;
  width: 100%;
}

.hero {
  padding: 6rem 0 4rem;
  text-align: center;
}

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

.subtitle {
  font-size: 1.25rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
}

.description {
  max-width: 36rem;
  margin: 0 auto 2rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

.cta {
  margin-top: 2rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: background-color 0.15s, transform 0.1s;
  cursor: pointer;
  border: none;
}

.btn:active {
  transform: scale(0.98);
}

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

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

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

@media (max-width: 640px) {
  .hero h1 {
    font-size: 2rem;
  }

  .hero {
    padding: 3rem 0 2rem;
  }
}