:root{--ink:#1d2a30;--muted:#566369;--line:#d6dde0;--bg:#f6f8f8;--card:#fff;--brand:#2b5b6e;--brand-dark:#1c3f4d;--accent:#d9822b;--radius:12px}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.75 -apple-system,BlinkMacSystemFont,"Hiragino Sans","Hiragino Kaku Gothic ProN","Noto Sans JP","Yu Gothic UI","Segoe UI",Roboto,sans-serif}
:lang(ja){line-break:strict;overflow-wrap:anywhere}
a{color:var(--brand)}
a:hover{color:var(--brand-dark)}
.wrap{max-width:980px;margin:0 auto;padding:0 18px}
.skip{position:absolute;left:-999px}.skip:focus{left:12px;top:12px;background:#fff;padding:8px;z-index:9}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.top{background:#fff;border-bottom:1px solid var(--line)}
.top-in{display:flex;flex-wrap:wrap;align-items:center;gap:6px 18px;padding-top:10px;padding-bottom:10px}
.brand{display:flex;align-items:center;gap:8px;font-weight:700;color:var(--ink);text-decoration:none;margin-right:auto}
.lang{font-size:14px;border:1px solid var(--line);border-radius:999px;padding:2px 12px;text-decoration:none}
.nav{display:flex;flex-wrap:wrap;gap:4px 16px;font-size:15px;width:100%}
.nav a{text-decoration:none;padding:2px 0}
.nav a[aria-current="page"]{font-weight:700;color:var(--ink);border-bottom:2px solid var(--accent)}
h1{font-size:clamp(26px,4.6vw,38px);line-height:1.35;margin:32px 0 12px;letter-spacing:-.01em}
h2{font-size:23px;line-height:1.4;margin:48px 0 12px;padding-left:12px;border-left:4px solid var(--accent)}
h3{font-size:18px;line-height:1.45;margin:24px 0 6px}
.lead{font-size:17px;color:var(--muted);max-width:760px}
.tool{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:22px;margin-top:20px;box-shadow:0 1px 2px rgba(0,0,0,.04)}
fieldset{border:0;margin:0 0 18px;padding:0}
legend{font-weight:700;font-size:17px;margin-bottom:8px;padding:0}
.f{display:flex;flex-direction:column;gap:4px;font-size:14px;font-weight:600}
.f small{font-weight:400;color:var(--muted);font-size:13px;line-height:1.5}
input,select,button{font:inherit;font-size:16px}
input,select{border:1px solid #b9c4c8;border-radius:8px;padding:8px 10px;background:#fff;color:var(--ink);min-height:44px;width:100%}
input:focus,select:focus,button:focus-visible{outline:3px solid #f2c48d;outline-offset:1px}
.dates{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}
.dates legend{grid-column:1/-1}
.period{grid-column:1/-1;margin:0;color:var(--brand);font-weight:700}
.opts{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px}
.hint{margin:0 0 10px;color:var(--muted);font-size:14px}
.line{position:relative;display:grid;grid-template-columns:2fr 1fr 1.5fr;gap:10px 12px;border:1px solid var(--line);border-radius:10px;padding:14px 44px 14px 14px;margin-bottom:10px;background:#fbfcfc}
.line .wide{grid-column:span 1}
.line .pair{display:flex;gap:8px}
.line .pair label{display:flex;align-items:center;gap:4px;font-weight:400}
.line .pair input{width:5.5em}
.line[data-custom="no"] .custom-only{display:none}
.line[data-dep="no"] .dep-only,.line[data-dep="no"] .age-only,.line[data-dep="no"] .value-only{display:none}
.line:not([data-start="age"]) .age-only{display:none}
.line:not([data-start="value"]) .value-only{display:none}
.rm{position:absolute;top:8px;right:8px;width:32px;height:32px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--muted);cursor:pointer;line-height:1}
.btn{display:inline-block;background:var(--brand);color:#fff;border:1px solid var(--brand);text-decoration:none;font-weight:700;border-radius:10px;padding:10px 16px;cursor:pointer;min-height:44px}
.btn:hover{background:var(--brand-dark);color:#fff}
.btn.ghost{background:#fff;color:var(--brand)}
.btn.ghost:hover{background:#eef4f6}
.actions{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.result{margin-top:8px;border-top:1px dashed var(--line);padding-top:4px}
.result h2{margin-top:20px}
.msg{background:#fff6ea;border:1px solid #f0d3ae;border-radius:8px;padding:10px 12px;margin:8px 0}
.sum .big{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 14px;margin:8px 0}
.sum .big strong{font-size:30px;color:var(--brand)}
.sum p{margin:4px 0}
.caveat{font-size:14px;color:var(--muted);background:var(--bg);border-radius:8px;padding:10px 12px}
.tablewrap{overflow-x:auto;-webkit-overflow-scrolling:touch}
table{border-collapse:collapse;width:100%;background:#fff;font-size:15px}
th,td{text-align:left;padding:9px 10px;border-bottom:1px solid var(--line);vertical-align:top}
thead th{background:#eaf1f3;font-size:14px;white-space:nowrap}
.res td.num,.res tfoot td.num{font-weight:700;color:var(--brand)}
.res tr.note td{font-size:13px;color:var(--muted);border-bottom-style:dashed;padding-top:2px}
.res tfoot th,.res tfoot td{font-weight:700;border-top:2px solid var(--line)}
.data.split td{font-size:14px}
.formula{background:#fff;border:1px solid var(--line);border-left:4px solid var(--brand);border-radius:8px;padding:12px 14px;font-weight:600}
blockquote{margin:16px 0;padding:12px 16px;background:#fff;border-left:4px solid #9fb5bd;border-radius:0 8px 8px 0}
blockquote cite{display:block;font-style:normal;font-size:13px;margin-top:6px;color:var(--muted)}
.cite{white-space:nowrap}
.steps{padding-left:1.4em}
.steps li{margin-bottom:8px}
.qa{border-top:1px solid var(--line);padding:14px 0}
.qa h3{margin:0;font-size:17px}
.qa p{margin:6px 0 0}
.sources{font-size:14px;color:var(--muted);padding-left:1.2em}
.article{max-width:780px}
.related ul{padding-left:1.2em}
.foot{margin-top:64px;border-top:1px solid var(--line);background:#fff;font-size:14px;color:var(--muted);padding:24px 0}
.foot-links{display:flex;flex-wrap:wrap;gap:8px 18px;margin-bottom:8px}
.ad-slot{margin:32px auto;max-width:100%;clear:both}
.ad-slot ins.adsbygoogle[data-ad-status="unfilled"]{display:none!important}
.ad-slot:has(ins[data-ad-status="filled"])::before{content:"Advertisement";display:block;font-size:11px;letter-spacing:.04em;color:#888;margin-bottom:4px;text-align:center}
html:lang(ja) .ad-slot:has(ins[data-ad-status="filled"])::before{content:"広告"}
@media (max-width:720px){
  h2{font-size:20px;margin-top:40px}
  .tool{padding:14px;margin-left:-6px;margin-right:-6px}
  .line{grid-template-columns:1fr;padding:12px 44px 12px 12px}
  .res thead{display:none}
  .res,.res tbody,.res tfoot,.res tr,.res th,.res td{display:block;width:100%}
  .res tr{border-bottom:1px solid var(--line);padding:6px 0}
  .res th,.res td{border:0;padding:2px 4px}
  .res td[data-h]::before{content:attr(data-h) ": ";color:var(--muted);font-size:13px}
  .res td:empty{display:none}
  .sum .big strong{font-size:26px}
}
@media print{
  .top,.foot,.ad-slot,.no-print,#calc,.lead,main>section:not(.tool),.related,.skip{display:none!important}
  body{background:#fff;font-size:12px}
  .tool{border:0;box-shadow:none;padding:0}
  .result{border:0}
  h1{font-size:20px;margin:0 0 8px}
}