:root {
  --bg: #F6F8FA; --surface: #FFFFFF; --ink: #0F172A; --ink-sub: #475569;
  --navy: #0F172A; --navy2: #1E293B; --on-navy: #F8FAFC; --on-navy-sub: #CBD5E1;
  --green: #0E9F6E; --green-bright: #34D399; --line: rgba(15,23,42,.1);
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0B1120; --surface: #111827; --ink: #F1F5F9; --ink-sub: #94A3B8;
    --navy: #030712; --navy2: #0F172A; --green: #34D399; --line: rgba(241,245,249,.12); }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  line-height: 1.8; font-size: 16px; }
a { color: var(--green); }
.container { max-width: 1040px; margin: 0 auto; padding: 0 20px; }
.nav { background: var(--navy); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; min-height: 60px; gap: 12px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--on-navy); text-decoration: none; font-weight: 700; font-size: 18px; }
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.nav-links { display: flex; gap: 18px; flex-wrap: wrap; }
.nav-links a { color: var(--on-navy-sub); text-decoration: none; font-size: 15px; }
.hero { background: linear-gradient(180deg, var(--navy2), var(--navy)); color: var(--on-navy); padding: 48px 0 64px; }
.hero-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: center; }
.hero h1 { font-size: clamp(28px, 5vw, 44px); line-height: 1.35; margin: 0 0 16px; }
.hero h1 em { font-style: normal; color: var(--green-bright); }
.hero .lead { color: var(--on-navy-sub); font-size: 17px; margin: 0 0 24px; }
.hero-shot img { width: 100%; max-width: 320px; display: block; margin: 0 auto; border-radius: 32px; box-shadow: 0 20px 50px rgba(0,0,0,.45); }
.badge-soon { display: inline-block; background: var(--green-bright); color: #052e22; font-weight: 700; padding: 10px 18px; border-radius: 999px; }
.hero-note { color: var(--on-navy-sub); font-size: 14px; margin-left: 12px; }
.section { padding: 56px 0; }
.section-label { display: inline-block; color: var(--green); font-weight: 700; font-size: 14px; letter-spacing: .05em; }
h2 { font-size: clamp(22px, 3.4vw, 30px); line-height: 1.45; margin: 6px 0 16px; }
.feature { display: grid; grid-template-columns: 1fr 300px; gap: 40px; align-items: center; padding: 36px 0; border-top: 1px solid var(--line); }
.feature:nth-of-type(even) { grid-template-columns: 300px 1fr; }
.feature:nth-of-type(even) > img { order: -1; }
.feature img { width: 100%; border-radius: 28px; box-shadow: 0 12px 30px rgba(0,0,0,.18); }
.desc { color: var(--ink-sub); }
.rules { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; margin: 20px 0; padding: 0; list-style: none; }
.rules li { background: var(--surface); border-radius: 14px; padding: 14px 16px; border: 1px solid var(--line); }
.rules b { display: block; }
.plus { background: var(--surface); border-radius: 20px; padding: 28px; border: 1px solid var(--line); }
.plus ul { padding-left: 1.2em; }
.note { font-size: 14px; color: var(--ink-sub); }
.footer { background: var(--navy); color: var(--on-navy-sub); padding: 32px 0; margin-top: 40px; font-size: 14px; }
.footer a { color: var(--on-navy); margin-right: 16px; }
.doc { max-width: 760px; margin: 0 auto; padding: 32px 20px 24px; }
.doc h1 { font-size: 30px; margin: 12px 0 4px; }
.doc h2 { font-size: 20px; margin-top: 32px; }
.updated { color: var(--ink-sub); font-size: 14px; }
.callout { background: var(--surface); border-left: 6px solid var(--green); padding: 14px 18px; border-radius: 10px; margin: 20px 0; }
.back-home { text-decoration: none; font-size: 14px; }
details { background: var(--surface); border-radius: 12px; padding: 12px 16px; margin: 10px 0; border: 1px solid var(--line); }
summary { font-weight: 700; cursor: pointer; }
@media (max-width: 760px) {
  .hero-grid, .feature, .feature:nth-of-type(even) { grid-template-columns: 1fr; }
  .feature:nth-of-type(even) > img { order: 0; }
  .feature img { max-width: 300px; margin: 0 auto; display: block; }
  .hero-note { display: block; margin: 10px 0 0; }
}