:root {
  --bg: #fafafa;
  --surface: #ffffff;
  --ink: #111827;
  --muted: #6b7280;
  --faint: #9ca3af;
  --line: #e5e7eb;
  --accent: #1f2937;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

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

body {
  background: var(--bg);
  color: var(--ink);
  font: 18px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(250, 250, 250, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  gap: 10px;
  align-items: center;
  text-decoration: none;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.nav-links {
  display: flex;
  gap: 24px;
  font-size: 16px;
  color: var(--muted);
}

.nav-links a {
  text-decoration: none;
  transition: color 0.15s;
}

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

.nav-sibling {
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  color: var(--faint);
  transition: all 0.15s;
}

.nav-sibling:hover {
  color: var(--ink);
  border-color: var(--ink);
  background: var(--surface);
}

.lang-toggle {
  padding: 4px 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s;
}

.lang-toggle:hover {
  color: var(--ink);
  border-color: var(--ink);
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 32px;
}

.hero {
  display: flex;
  align-items: center;
  gap: 64px;
  padding: 72px 0 56px;
}

.hero-text {
  flex: 1 1 auto;
  min-width: 0;
}

.hero-brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.hero-brand h1 {
  font-size: 44px;
  font-weight: 750;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.hero-tagline {
  margin-top: 12px;
  font-size: 22px;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: -0.01em;
}

.hero p {
  margin-top: 16px;
  max-width: 460px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.preview {
  flex: 0 0 auto;
  width: 380px;
  border-radius: 12px;
  border: 1px solid var(--line);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

.hero-buttons {
  display: flex;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-block;
  padding: 14px 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  transition: background 0.15s;
}

.button:hover { background: #0f172a; }

.button.secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

.button.secondary:hover {
  background: var(--surface);
  border-color: var(--ink);
}

.features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  padding: 56px 0;
  border-top: 1px solid var(--line);
}

.feature {
  text-align: center;
}

.feature-icon {
  display: block;
  font-size: 32px;
  margin-bottom: 10px;
  color: var(--muted);
}

.feature h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 6px;
}

.feature p {
  font-size: 15px;
  color: var(--muted);
  line-height: 1.5;
}

.install {
  padding: 56px 0;
  border-top: 1px solid var(--line);
}

.install h2 {
  font-size: 28px;
  font-weight: 750;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.install ol {
  padding-left: 20px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.install em {
  font-style: normal;
  color: var(--faint);
}

.dev {
  padding: 56px 0;
  border-top: 1px solid var(--line);
}

.dev h2 {
  font-size: 28px;
  font-weight: 750;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
}

.dev ol {
  padding-left: 20px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.dev code {
  font-family: var(--mono);
  font-size: 15px;
  padding: 2px 6px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--ink);
}

.id-hint {
  margin-top: 24px;
  padding: 18px 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.id-hint p {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 8px;
}

.id-hint code {
  display: block;
  font-family: var(--mono);
  font-size: 14px;
  color: var(--muted);
  word-break: break-all;
}

.id-hint code strong {
  color: var(--ink);
}

@media (max-width: 768px) {
  .hero { flex-direction: column; gap: 36px; padding: 48px 0 36px; }
  .hero-brand h1 { font-size: 32px; }
  .preview { width: 100%; max-width: 320px; }
  .features { grid-template-columns: 1fr; gap: 32px; }
  .nav-links { gap: 16px; }
}