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

:root {
  --bg: #ffffff;
  --bg-secondary: #f5f5f7;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --accent: #0071e3;
  --border: #d2d2d7;
  --max-width: 680px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-secondary: #1c1c1e;
    --text: #f5f5f7;
    --text-secondary: #98989d;
    --accent: #2997ff;
    --border: #3a3a3c;
  }
}

html { font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  padding: 2rem 1.25rem 4rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

header {
  margin-bottom: 3rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

header .app-name {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
}

header nav {
  margin-top: 0.75rem;
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

header nav a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
}

header nav a:hover { text-decoration: underline; }

h1 {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

h2 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}

p { margin-bottom: 1rem; color: var(--text); }

p + p { margin-top: 0; }

ul, ol {
  margin: 0.75rem 0 1rem 1.5rem;
}

li { margin-bottom: 0.4rem; }

a { color: var(--accent); }

.meta {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 2.5rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 2rem;
}

.card {
  background: var(--bg-secondary);
  border-radius: 12px;
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text);
  display: block;
  transition: opacity 0.15s;
}

.card:hover { opacity: 0.8; }

.card .card-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.card .card-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.04em;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-top: 0.75rem;
}

footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

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

.faq-item {
  border-top: 1px solid var(--border);
  padding: 1.25rem 0;
}

.faq-item:last-child { border-bottom: 1px solid var(--border); }

.faq-q {
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.faq-a { color: var(--text-secondary); }

.contact-box {
  background: var(--bg-secondary);
  border-radius: 12px;
  padding: 1.5rem;
  margin-top: 2rem;
}

.contact-box p { margin: 0; }

@media (max-width: 480px) {
  .hero h1 { font-size: 2.25rem; }
  h1 { font-size: 1.6rem; }
}