:root {
  --bg: #ffffff;
  --bg-soft: #f2f7fb;
  --fg: #232328;
  --fg-soft: #55555c;
  --muted: #86868c;
  --line: #e3e7ec;
  --accent: #16a2da;
  --accent-ink: #ffffff;
  --card: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #18181b;
    --bg-soft: #1f2226;
    --fg: #ececef;
    --fg-soft: #b4b4bb;
    --muted: #8a8a92;
    --line: #2e3238;
    --accent: #4cbbe8;
    --accent-ink: #0d1b24;
    --card: #202024;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.6 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }

.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }

/* Header */
.site-header { border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--fg); font-weight: 600; font-size: 17px; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; }
.nav { display: flex; gap: 20px; font-size: 15px; }
.nav a { color: var(--fg-soft); }
.nav a[aria-current="page"] { color: var(--fg); font-weight: 600; }

/* Hero */
.hero { text-align: center; padding: 72px 0 56px; background: linear-gradient(var(--bg), var(--bg-soft)); }
.hero img { width: 168px; height: 168px; }
.hero h1 { font-size: clamp(34px, 6vw, 52px); line-height: 1.1; margin: 18px 0 8px; letter-spacing: -0.02em; }
.hero .tagline { font-size: clamp(18px, 3vw, 22px); color: var(--fg-soft); margin: 0 0 28px; }
.button {
  display: inline-block; padding: 12px 24px; border-radius: 999px;
  background: var(--accent); color: var(--accent-ink); font-weight: 600;
}
.button:hover { text-decoration: none; filter: brightness(1.05); }
.button.disabled { background: var(--line); color: var(--fg-soft); cursor: default; }
.hero .note { font-size: 14px; color: var(--muted); margin-top: 14px; }

/* Sections */
section { padding: 56px 0; }
section + section { border-top: 1px solid var(--line); }
h2 { font-size: 28px; letter-spacing: -0.01em; margin: 0 0 8px; text-align: center; }
.lead { text-align: center; color: var(--fg-soft); margin: 0 auto 36px; max-width: 620px; }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 20px; }
.card h3 { margin: 0 0 6px; font-size: 17px; }
.card p { margin: 0; color: var(--fg-soft); font-size: 15px; }
.card .icon { font-size: 22px; line-height: 1; margin-bottom: 10px; display: block; }

.chips { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; }
.chip { border: 1px solid var(--line); border-radius: 999px; padding: 6px 14px; font-size: 14px; color: var(--fg-soft); background: var(--card); }

/* FAQ */
.faq { max-width: 720px; margin: 0 auto; }
.faq details { border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; margin-bottom: 10px; background: var(--card); }
.faq summary { cursor: pointer; font-weight: 600; }
.faq details p { margin: 10px 0 0; color: var(--fg-soft); }

.contact { text-align: center; }
.contact .email { font-size: 20px; font-weight: 600; }

/* Long-form pages */
.doc { max-width: 720px; margin: 0 auto; padding: 48px 16px 64px; }
.doc h1 { font-size: 34px; letter-spacing: -0.02em; margin: 0 0 4px; }
.doc h2 { text-align: left; font-size: 20px; margin: 32px 0 8px; }
.doc .meta { color: var(--muted); font-size: 14px; margin: 0 0 24px; }
.doc li { margin-bottom: 6px; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); padding: 28px 0 40px; font-size: 14px; color: var(--muted); }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; justify-content: space-between; }
.site-footer nav { display: flex; gap: 20px; }
.site-footer a { color: var(--fg-soft); }

@media (max-width: 560px) {
  .nav { gap: 14px; font-size: 14px; }
  .hero { padding: 48px 0 40px; }
  .hero img { width: 128px; height: 128px; }
  section { padding: 44px 0; }
}