:root {
  color-scheme: dark;
  --bg: #100b19;
  --panel: rgba(36, 24, 53, 0.82);
  --line: rgba(255, 255, 255, 0.12);
  --ink: #f7f1fb;
  --muted: #c5b7cf;
  --purple: #a071ed;
  --mint: #79e2c2;
  --gold: #ffc75b;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 14% 8%, rgba(160, 113, 237, .26), transparent 30rem),
    radial-gradient(circle at 86% 76%, rgba(121, 226, 194, .12), transparent 28rem),
    linear-gradient(145deg, #100b19, #241637 62%, #100b19);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Noto Sans JP", sans-serif;
}

a { color: inherit; }
.shell { width: min(100% - 40px, 940px); margin: 0 auto; }
.nav { display: flex; align-items: center; justify-content: space-between; padding: 24px 0; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; font-weight: 900; letter-spacing: .04em; }
.brand img { width: 42px; height: 42px; border-radius: 12px; box-shadow: 0 9px 28px rgba(0,0,0,.28); }
.nav-links { display: flex; gap: 20px; color: var(--muted); font-size: 14px; font-weight: 700; }
.nav-links a { text-decoration: none; }
.nav-links a:hover { color: white; }

.hero { min-height: 68vh; display: grid; grid-template-columns: 1.18fr .82fr; gap: 48px; align-items: center; padding: 60px 0 88px; }
.eyebrow { margin: 0; color: var(--mint); font-size: 12px; font-weight: 900; letter-spacing: .22em; }
h1 { margin: 16px 0 0; font-size: clamp(48px, 8vw, 88px); line-height: .98; letter-spacing: -.05em; }
.lead { max-width: 660px; margin: 26px 0 0; color: var(--muted); font-size: 18px; line-height: 1.9; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 50px; padding: 0 22px; border-radius: 16px; text-decoration: none; font-size: 14px; font-weight: 900; }
.button.primary { color: #171020; background: var(--mint); box-shadow: 0 16px 42px rgba(121,226,194,.16); }
.button.secondary { border: 1px solid var(--line); background: rgba(255,255,255,.06); }
.app-icon { width: min(100%, 310px); justify-self: center; border-radius: 68px; box-shadow: 0 38px 100px rgba(0,0,0,.46), 0 0 80px rgba(160,113,237,.22); transform: rotate(2deg); }

.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; padding-bottom: 88px; }
.card { border: 1px solid var(--line); border-radius: 24px; background: var(--panel); padding: 24px; box-shadow: 0 20px 55px rgba(0,0,0,.16); backdrop-filter: blur(14px); }
.card small { color: var(--purple); font-weight: 900; letter-spacing: .14em; }
.card h2 { margin: 12px 0 8px; font-size: 20px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.8; }

.page { padding: 36px 0 72px; }
.back { display: inline-flex; color: var(--mint); text-decoration: none; font-size: 14px; font-weight: 800; }
.page-header { margin: 42px 0 28px; }
.page-header h1 { font-size: clamp(40px, 7vw, 62px); }
.page-header .meta { color: #a99ab6; font-size: 14px; }
.stack { display: grid; gap: 18px; }
.section h2 { margin: 0 0 14px; font-size: 21px; }
.section h3 { margin: 24px 0 8px; font-size: 16px; }
.section p, .section li { color: var(--muted); font-size: 14px; line-height: 1.9; }
.section a { color: var(--mint); font-weight: 700; text-underline-offset: 4px; }
.faq summary { cursor: pointer; list-style: none; font-weight: 900; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::before { content: "Q."; color: var(--mint); margin-right: 8px; }
.faq p { padding-top: 14px; border-top: 1px solid var(--line); }
.contact { border-color: rgba(121,226,194,.3); background: rgba(121,226,194,.09); }

footer { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 18px; padding: 28px 0 42px; border-top: 1px solid var(--line); color: #a99ab6; font-size: 12px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer-links a { text-decoration: none; }

@media (max-width: 720px) {
  .shell { width: min(100% - 28px, 940px); }
  .nav { padding-top: 16px; }
  .nav-links { gap: 12px; font-size: 12px; }
  .hero { grid-template-columns: 1fr; padding-top: 38px; text-align: center; }
  .lead { font-size: 16px; }
  .cta-row { justify-content: center; }
  .app-icon { width: 220px; order: -1; border-radius: 48px; }
  .feature-grid { grid-template-columns: 1fr; }
  .card { padding: 20px; }
}