:root{
  --bg:#f7f8fa;--card:#fff;--text:#1d2433;--muted:#687386;
  --line:#e5e9ef;--blue:#225de6;--blue2:#eef4ff;--green:#137a55;
}
*{box-sizing:border-box}html{scroll-behavior:smooth}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans JP","Hiragino Kaku Gothic ProN",Meiryo,sans-serif;background:var(--bg);color:var(--text);line-height:1.85}
a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}
.wrap{max-width:1040px;margin:auto;padding:0 20px}
header{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.header{min-height:66px;display:flex;align-items:center;justify-content:space-between;gap:24px}
.logo{font-size:19px;font-weight:800;color:var(--text)}
nav{display:flex;gap:16px;font-size:14px;flex-wrap:wrap}
.hero{padding:62px 0 38px;background:linear-gradient(180deg,#fff,#f7f8fa)}
.hero h1{font-size:40px;line-height:1.35;margin:8px 0 14px;letter-spacing:-.02em}
.hero p{max-width:760px;color:var(--muted);font-size:17px}
.badge{display:inline-block;background:var(--blue2);color:var(--blue);font-size:13px;font-weight:700;border-radius:999px;padding:5px 11px}
.section{padding:34px 0}
.section h2{font-size:28px;margin:0 0 18px}
.grid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.card{background:#fff;border:1px solid var(--line);border-radius:14px;padding:21px}
.card h3{font-size:19px;line-height:1.5;margin:0 0 8px}
.card p{color:var(--muted);margin:0 0 10px;font-size:14px}
.card .num{font-size:12px;color:var(--green);font-weight:800}
.article{max-width:820px;margin:auto;padding:36px 20px 60px}
.breadcrumbs{font-size:13px;color:var(--muted);margin-bottom:18px}
.article h1{font-size:34px;line-height:1.4;margin:0 0 18px}
.article h2{font-size:25px;line-height:1.5;margin:42px 0 14px;padding-bottom:8px;border-bottom:2px solid var(--line)}
.article h3{font-size:19px;margin:28px 0 8px}
.lead{font-size:17px}
.answer{background:var(--blue2);border-left:4px solid var(--blue);padding:17px 18px;border-radius:8px;margin:24px 0}
.note{background:#fff8dc;border:1px solid #eadb9a;border-radius:10px;padding:15px 17px;margin:22px 0}
.source{font-size:13px;color:var(--muted);word-break:break-all}
table{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);margin:18px 0}
th,td{padding:12px 13px;border-bottom:1px solid var(--line);vertical-align:top;text-align:left}
th{background:#f2f5f8}
ul,ol{padding-left:1.5em}
.related{background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px;margin-top:36px}
.related strong{display:block;margin-bottom:8px}
footer{background:#fff;border-top:1px solid var(--line);padding:30px 0;color:var(--muted);font-size:13px}
.small{font-size:13px;color:var(--muted)}
@media(max-width:720px){
 .grid{grid-template-columns:1fr}.hero h1{font-size:31px}.article h1{font-size:29px}
 .header{align-items:flex-start;flex-direction:column;padding:14px 0}
 table{font-size:14px}
}
.affiliate-box{
  background:#fff;
  border:2px solid #dfe7ff;
  border-radius:14px;
  padding:20px;
  margin:28px 0;
}
.affiliate-box strong{
  display:block;
  font-size:19px;
  margin-bottom:8px;
}
.affiliate-box ul{
  margin:12px 0 6px;
}
.affiliate-box li{
  margin:8px 0;
}