:root {
  --fg: #111;
  --muted: #6b7280;
  --bg: #fff;
  --accent: #5b3df5;
  --accent-fg: #fff;
  --card: #f7f7f8;
  --border: #e5e7eb;
  --code-bg: #f1f1f3;
  --max: 960px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
  color: var(--fg);
  background: var(--bg);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

code {
  background: var(--code-bg);
  padding: 1px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  font-family: "SFMono-Regular", Menlo, Consolas, monospace;
}

.nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.brand { font-weight: 700; font-size: 18px; }
.brand a { color: inherit; }
.nav nav { display: flex; gap: 20px; flex-wrap: wrap; }
.nav nav a { color: var(--muted); }
.nav nav a:hover { color: var(--fg); text-decoration: none; }

main { max-width: var(--max); margin: 0 auto; padding: 24px; }

.installed {
  padding: 56px 32px 40px;
  text-align: center;
  background: linear-gradient(135deg, #f3f0ff, #ece8fb);
  border-radius: 16px;
  margin: 16px 0;
}
.installed h1 { font-size: clamp(26px, 4vw, 36px); margin: 0 0 16px; }
.installed .lede { max-width: 560px; margin: 0 auto 24px; color: #374151; }

.hero { padding: 60px 0 40px; text-align: center; }
.hero h1 {
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1.2;
  margin: 0 0 16px;
  letter-spacing: -0.02em;
}
.hero .lede {
  max-width: 640px;
  margin: 0 auto 28px;
  color: #374151;
  font-size: 17px;
}
.cta {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-fg);
  padding: 14px 28px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 16px;
}
.cta:hover { text-decoration: none; opacity: 0.92; }
.cta-note { color: var(--muted); font-size: 14px; margin-top: 12px; }

.benefits {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
  margin: 40px 0;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
}
.card h3 { margin: 0 0 8px; font-size: 17px; }
.card p { margin: 0; color: #374151; font-size: 15px; }

.how, .faq { margin: 56px 0; }
.how h2, .faq h2 { font-size: 24px; margin-bottom: 16px; letter-spacing: -0.01em; }
.how ol { padding-left: 20px; }
.how li { margin: 6px 0; }
.how .muted { color: var(--muted); margin-top: 16px; font-size: 14px; }

.faq details {
  border-top: 1px solid var(--border);
  padding: 16px 0;
}
.faq details:last-of-type { border-bottom: 1px solid var(--border); }
.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--muted); font-size: 20px; }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 12px 0 0; color: #374151; }

.doc h1 { font-size: 32px; margin-top: 40px; }
.doc h2 { font-size: 20px; margin-top: 36px; }
.doc h3 { font-size: 17px; margin-top: 24px; }
.doc p, .doc li { color: #374151; }
.doc .muted { color: var(--muted); font-size: 14px; }

footer {
  border-top: 1px solid var(--border);
  margin-top: 80px;
  padding: 24px;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}
footer a { color: var(--muted); }
footer a:hover { color: var(--fg); }