:root{
  --bg:#f7f8fb;--card:#fff;--text:#172033;--muted:#667085;--line:#e5e7eb;
  --accent:#2563eb;--accent2:#1d4ed8;--soft:#eff6ff;--good:#087f5b;
  font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI","Noto Sans JP",sans-serif
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);line-height:1.75}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.site-header{background:rgba(255,255,255,.96);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10;backdrop-filter:blur(8px)}
.header-inner,.container{max-width:1080px;margin:auto;padding-left:20px;padding-right:20px}
.header-inner{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{font-weight:900;color:var(--text);font-size:1.15rem;white-space:nowrap}
.nav{display:flex;gap:16px;flex-wrap:wrap}
.nav a{color:var(--muted);font-size:.93rem}
.hero{padding:52px 0 26px}
.hero h1{font-size:clamp(2rem,5vw,3.45rem);line-height:1.14;margin:0 0 14px;letter-spacing:-.02em}
.hero p{font-size:1.05rem;color:var(--muted);max-width:780px}
.badge{display:inline-block;background:var(--soft);color:var(--accent2);padding:5px 10px;border-radius:999px;font-size:.85rem;font-weight:800;margin-bottom:14px}
.category-title{font-size:1.35rem;margin:38px 0 14px}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;margin:16px 0 30px}
.card,.tool-box,.info-box{background:var(--card);border:1px solid var(--line);border-radius:18px;padding:22px;box-shadow:0 2px 8px rgba(15,23,42,.035)}
.card{display:flex;flex-direction:column;min-height:210px}
.card h2,.card h3{margin:0 0 8px;line-height:1.4}
.card p{color:var(--muted);margin:0 0 14px;flex:1}
.tool-link{display:inline-flex;align-items:center;gap:6px;font-weight:800}
.tool-page{padding:34px 0 60px}
.tool-page h1{font-size:clamp(1.8rem,4vw,2.7rem);line-height:1.25;margin:0 0 8px}
.lead{color:var(--muted);margin-bottom:24px}
label{font-weight:750;display:block;margin:14px 0 7px}
textarea,input,select,button{font:inherit}
textarea,input[type="text"],input[type="number"],input[type="date"],input[type="datetime-local"],select{
  width:100%;border:1px solid #cfd4dc;border-radius:12px;padding:12px;background:#fff;color:var(--text)
}
textarea{min-height:180px;resize:vertical}
.actions{display:flex;gap:10px;flex-wrap:wrap;margin:14px 0}
button,.button{
  border:0;border-radius:12px;background:var(--accent);color:#fff;padding:11px 16px;font-weight:800;cursor:pointer;display:inline-block
}
button.secondary,.button.secondary{background:#eef2f7;color:#344054}
button:hover,.button:hover{filter:brightness(.97);text-decoration:none}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:14px}
.stat{background:#f8fafc;border:1px solid var(--line);padding:14px;border-radius:14px}
.stat strong{display:block;font-size:1.35rem}
.small{font-size:.9rem;color:var(--muted)}
.notice{background:#fffbeb;border:1px solid #fde68a;padding:12px 14px;border-radius:12px}
.result{background:#f8fafc;border:1px solid var(--line);padding:16px;border-radius:14px;margin-top:14px;overflow:auto}
.result strong{font-size:1.2rem}
table{border-collapse:collapse;width:100%;background:#fff}
th,td{border:1px solid var(--line);padding:9px;text-align:left;white-space:nowrap}
.footer{border-top:1px solid var(--line);background:#fff;margin-top:50px}
.footer-inner{max-width:1080px;margin:auto;padding:28px 20px;color:var(--muted);font-size:.92rem}
.footer-links{display:flex;gap:14px;flex-wrap:wrap;margin-bottom:8px}
.section-title{margin-top:42px}
.kbd{font-family:ui-monospace,monospace;background:#eef2f7;border:1px solid #d8dee8;border-bottom-width:2px;border-radius:6px;padding:1px 6px}
.two-col{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.three-col{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.check{display:flex;align-items:center;gap:8px;margin-top:12px}
.check input{width:auto}
.inline-note{font-size:.9rem;color:var(--muted);margin-top:6px}
.pill{display:inline-block;padding:2px 8px;border-radius:999px;background:#ecfdf3;color:var(--good);font-size:.8rem;font-weight:800}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}
pre{white-space:pre-wrap;word-break:break-word}
@media(max-width:800px){
  .grid{grid-template-columns:1fr 1fr}
  .stats{grid-template-columns:repeat(2,1fr)}
  .three-col{grid-template-columns:1fr}
}
@media(max-width:600px){
  .grid,.two-col{grid-template-columns:1fr}
  .header-inner{align-items:flex-start;flex-direction:column;padding-top:14px;padding-bottom:14px}
  .hero{padding-top:34px}
}


.seo-content{margin-top:26px;display:grid;gap:18px}
.seo-content h2{margin-top:0;font-size:1.35rem}
.seo-content h3{margin:0 0 6px;font-size:1.05rem}
.example-box{background:#f8fafc;border-left:4px solid var(--accent);padding:16px 18px;border-radius:10px}
.faq-list{display:grid;gap:10px}
.faq-list details{background:#fff;border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.faq-list summary{font-weight:800;cursor:pointer}
.faq-list details p{margin:8px 0 0;color:var(--muted)}
.related-links{display:flex;flex-wrap:wrap;gap:10px}
.related-links a{background:var(--soft);padding:8px 12px;border-radius:999px;font-weight:750}
.breadcrumb{font-size:.9rem;color:var(--muted);margin-bottom:14px}