:root{--text:#262a2d;--muted:#5f666b;--accent:#9d3f61;--accent2:#2f6f7f;--line:#dfe7e8;--soft:#f6fafb;--warm:#fff8f5}
*{box-sizing:border-box}
html{font-family:-apple-system,BlinkMacSystemFont,'Hiragino Kaku Gothic ProN','Yu Gothic',Meiryo,sans-serif;color:var(--text);line-height:1.85;background:#fff}
body{margin:0;background:linear-gradient(180deg,#fff 0,#f6fafb 55%,#fff8f5 100%)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.inner{max-width:1080px;margin:auto;padding:18px clamp(16px,4vw,38px)}
.site-header{border-bottom:1px solid var(--line);background:rgba(255,255,255,.96);position:sticky;top:0;z-index:2}
.header-row{display:flex;justify-content:space-between;gap:18px;align-items:center}
.brand{font-weight:800;color:var(--text);font-size:20px;white-space:nowrap}
.nav{display:flex;gap:10px;flex-wrap:wrap;justify-content:flex-end}
.nav a{font-size:13px;color:var(--muted)}
.breadcrumb{font-size:13px;color:var(--muted);margin:8px 0 18px}
.breadcrumb a{color:var(--muted)}
.hero{padding:34px 0 30px;border-bottom:1px solid var(--line)}
.eyebrow{font-size:14px;color:var(--accent2);font-weight:700;margin:0 0 8px}
h1{font-size:clamp(28px,5vw,44px);line-height:1.28;margin:0 0 14px;letter-spacing:0}
.lead{font-size:18px;color:var(--muted);max-width:850px;margin:0}
.content{display:grid;gap:24px;margin-top:28px}
h2{font-size:23px;line-height:1.35;margin:0 0 10px;border-left:4px solid var(--accent2);padding-left:12px;letter-spacing:0}
p{margin:0 0 14px}
section{min-width:0}
.related-block{background:var(--soft);border:1px solid var(--line);border-radius:8px;padding:18px}
.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.card{display:block;background:#fff;border:1px solid var(--line);border-radius:8px;padding:14px;min-width:0}
.card strong{display:block;color:var(--text);font-size:15px;line-height:1.5}
.card span{display:block;color:var(--muted);font-size:13px;margin-top:4px}
details{background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px 14px;margin-bottom:10px}
summary{font-weight:700;cursor:pointer}
details p{color:var(--muted);margin-top:8px}
.site-footer{border-top:1px solid var(--line);background:#fff;padding:24px clamp(16px,4vw,36px);color:var(--muted);font-size:13px;text-align:center}
@media(max-width:780px){.header-row{display:block}.nav{justify-content:flex-start;margin-top:8px}.cards{grid-template-columns:1fr}h1{font-size:30px}.lead{font-size:16px}h2{font-size:21px}}