:root{
  --ink:#14212E; --ink2:#56646F; --ink3:#8A96A0;
  --line:#E4E9ED; --line2:#F1F4F7;
  --bg:#FFFFFF; --panel:#F7F9FB; --panel2:#FBFCFD;
  --brand:#0081D0; --brand-d:#00659F; --brand-w:#EAF5FC;
  --navy:#0F2A3F; --navy2:#16354D;
  --amber:#9A6212;
  --max:1120px; --prose:720px;
  --sp:104px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:"Hiragino Kaku Gothic ProN","Hiragino Sans","Yu Gothic Medium","Yu Gothic","Noto Sans JP",-apple-system,"Segoe UI",system-ui,sans-serif;
  font-size:16px; line-height:1.95; letter-spacing:.012em;
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
}
img,svg{max-width:100%}
a{color:var(--brand); text-decoration:none}
a:hover{color:var(--brand-d); text-decoration:underline; text-underline-offset:3px}
h1,h2,h3,h4{line-height:1.5; letter-spacing:-.005em; margin:0; font-weight:700}
p{margin:0 0 1.35em}
p:last-child{margin-bottom:0}
ul,ol{margin:0 0 1.35em; padding-left:1.5em}
li{margin:.4em 0}
hr{border:0;border-top:1px solid var(--line);margin:0}
.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-variant-numeric:tabular-nums}
.tnum{font-variant-numeric:tabular-nums}

/* ---------- layout ---------- */
.wrap{max-width:var(--max);margin:0 auto;padding:0 28px}
.prose{max-width:var(--prose)}
section.bl{padding:var(--sp) 0}
section.bl.tight{padding:64px 0}
.bl+.bl{border-top:1px solid var(--line2)}
.panel{background:var(--panel)}
.dark{background:var(--navy);color:#E9F0F5}
.dark h1,.dark h2,.dark h3{color:#fff}
.dark a{color:#8FD0F5}
.dark .eyebrow{color:#7FC6EE}
.dark .lead{color:#C3D3DE}
.dark .note{color:#93A7B5}

/* ---------- type helpers ---------- */
.eyebrow{
  display:block;font-size:12px;font-weight:700;letter-spacing:.16em;
  color:var(--brand);margin:0 0 18px;text-transform:uppercase;
}
.eyebrow.ja{letter-spacing:.1em;text-transform:none;font-size:12.5px}
.display{font-size:clamp(27px,3.9vw,41px);line-height:1.42;letter-spacing:-.02em;font-weight:700}
h1.pt{font-size:clamp(26px,3.4vw,36px);line-height:1.45;letter-spacing:-.015em}
h2.sec{font-size:clamp(21px,2.4vw,27px);line-height:1.5;margin:0 0 20px}
h3.sub{font-size:17.5px;margin:0 0 10px}
.lead{font-size:clamp(16px,1.35vw,18px);line-height:1.95;color:var(--ink2)}
.note{font-size:13.5px;line-height:1.85;color:var(--ink3)}
.hl{background:linear-gradient(transparent 62%, #CFEAFA 62%);padding:0 .05em}

/* ---------- header ---------- */
header.site{
  position:sticky;top:0;z-index:50;background:rgba(255,255,255,.93);
  backdrop-filter:saturate(1.6) blur(8px);border-bottom:1px solid var(--line);
}
.hd{display:flex;align-items:center;gap:28px;height:74px;max-width:var(--max);margin:0 auto;padding:0 28px}
.brand{display:flex;align-items:center;flex:0 0 auto;color:var(--ink)}
.brand svg{height:26px;width:auto;display:block}
.brand:hover{text-decoration:none}
nav.main{margin-left:auto;display:flex;align-items:center;gap:2px}
nav.main a{
  color:var(--ink);font-size:14.5px;font-weight:500;letter-spacing:.02em;
  padding:9px 13px;border-radius:3px;white-space:nowrap;
}
nav.main a:hover{background:var(--panel);text-decoration:none;color:var(--brand-d)}
nav.main a.on{color:var(--brand);font-weight:700}
.navcta{
  margin-left:12px;background:var(--brand);color:#fff!important;font-weight:700!important;
  padding:10px 20px!important;border-radius:3px;
}
.navcta:hover{background:var(--brand-d)!important;text-decoration:none!important}
.burger{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:3px;
  padding:8px 11px;font-size:13px;cursor:pointer;color:var(--ink)}

/* ---------- buttons ---------- */
.btn,.btn2{
  display:inline-flex;align-items:center;gap:9px;font-size:15px;font-weight:700;
  padding:15px 30px;border-radius:3px;letter-spacing:.02em;line-height:1.3;
  border:1px solid transparent;cursor:pointer;
}
.btn{background:var(--brand);color:#fff}
.btn:hover{background:var(--brand-d);color:#fff;text-decoration:none}
.btn2{background:#fff;color:var(--ink);border-color:#C9D3DA}
.btn2:hover{border-color:var(--brand);color:var(--brand);text-decoration:none}
.dark .btn2{background:transparent;color:#fff;border-color:rgba(255,255,255,.35)}
.dark .btn2:hover{border-color:#fff;color:#fff}
.btnrow{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px}
.arw::after{content:"→";font-weight:400}
.tlink{font-weight:700;font-size:14.5px;letter-spacing:.02em}
.tlink::after{content:" →";font-weight:400}

/* ---------- grids ---------- */
.g2{display:grid;grid-template-columns:repeat(2,1fr);gap:28px}
.g3{display:grid;grid-template-columns:repeat(3,1fr);gap:26px}
.g4{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.split{display:grid;grid-template-columns:1fr 1fr;gap:64px;align-items:center}
.split.n{grid-template-columns:.85fr 1.15fr}
.hold{display:grid;grid-template-columns:300px 1fr;gap:56px}

/* ---------- card ---------- */
.card{
  background:#fff;border:1px solid var(--line);border-radius:4px;padding:30px 28px;
  display:flex;flex-direction:column;transition:border-color .15s,box-shadow .15s;
}
a.card:hover{border-color:#A9C9DC;box-shadow:0 2px 14px rgba(20,33,46,.055);text-decoration:none}
a.card:hover h3{color:var(--brand-d)}
.card h3{color:var(--ink)}
.card .note,.card p{color:var(--ink2)}
.card .foot{margin-top:auto;padding-top:18px}
.ico{width:32px;height:32px;color:var(--brand);margin-bottom:16px}

/* ---------- stats ---------- */
.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:2px;background:var(--line)}
.stats.two{grid-template-columns:repeat(2,1fr)}
.stats>div{background:#fff;padding:28px 24px}
.dark .stats{background:rgba(255,255,255,.14)}
.dark .stats>div{background:var(--navy)}
.stats .n{font-size:35px;font-weight:700;line-height:1.25;letter-spacing:-.02em;font-variant-numeric:tabular-nums}
.stats .n small{font-size:16px;font-weight:700;margin-left:3px}
.stats .k{font-size:12.5px;color:var(--ink3);margin-top:6px;letter-spacing:.03em}
.dark .stats .k{color:#93A7B5}

/* ---------- price band ---------- */
.band{border:1px solid var(--line);border-radius:4px;padding:22px 24px;background:var(--panel2)}
.band .amt{font-size:29px;font-weight:700;letter-spacing:-.02em;font-variant-numeric:tabular-nums;line-height:1.3}
.band .amt small{font-size:15px;font-weight:700;margin-left:2px}
.band .cap{font-size:12.5px;color:var(--ink3);letter-spacing:.04em;margin-bottom:4px}

/* ---------- table ---------- */
table.t{width:100%;border-collapse:collapse;font-size:14.5px}
table.t th,table.t td{border-bottom:1px solid var(--line);padding:16px 14px;text-align:left;vertical-align:top}
table.t thead th{font-size:12.5px;letter-spacing:.06em;color:var(--ink3);font-weight:700;border-bottom-width:1px;padding-bottom:12px}
table.t tbody tr:hover{background:var(--panel2)}
table.t td.num{font-variant-numeric:tabular-nums;white-space:nowrap;font-weight:700}
.tscroll{overflow-x:auto}

/* ---------- steps ---------- */
ol.steps{list-style:none;padding:0;margin:0;counter-reset:s}
ol.steps>li{
  counter-increment:s;position:relative;padding:0 0 30px 62px;
}
ol.steps>li::before{
  content:counter(s,decimal-leading-zero);position:absolute;left:0;top:1px;
  font-size:13px;font-weight:700;color:var(--brand);letter-spacing:.06em;
  width:40px;padding-top:4px;
}
ol.steps>li::after{
  content:"";position:absolute;left:14px;top:30px;bottom:6px;width:1px;background:var(--line);
}
ol.steps>li:last-child{padding-bottom:0}
ol.steps>li:last-child::after{display:none}
ol.steps h3{font-size:16.5px;margin:0 0 6px}
ol.steps p{font-size:14.5px;color:var(--ink2);margin:0}

/* ---------- kv list ---------- */
dl.kv{margin:0;display:grid;grid-template-columns:190px 1fr;gap:0}
dl.kv dt,dl.kv dd{border-top:1px solid var(--line);padding:16px 0;margin:0;font-size:14.5px}
dl.kv dt{font-weight:700;color:var(--ink2);padding-right:20px}
dl.kv dd{color:var(--ink)}

/* ---------- breadcrumb ---------- */
.bc{font-size:12.5px;color:var(--ink3);padding:22px 0 0;letter-spacing:.02em}
.bc a{color:var(--ink3)}
.bc a:hover{color:var(--brand)}
.bc span{margin:0 8px;opacity:.55}

/* ---------- page head ---------- */
.phead{padding:26px 0 var(--sp)}
.phead .display,.phead h1{margin:0 0 22px}

/* ---------- chips / meta ---------- */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 18px}
.chip{font-size:12px;font-weight:700;letter-spacing:.04em;padding:5px 11px;border-radius:2px;
  background:var(--brand-w);color:var(--brand-d);border:1px solid #CDE7F7}
.chip.g{background:var(--panel);color:var(--ink2);border-color:var(--line)}
.meta{font-size:13px;color:var(--ink3);letter-spacing:.03em}

/* ---------- pull quote / callout ---------- */
.callout{border-left:2px solid var(--brand);padding:4px 0 4px 24px;margin:30px 0;color:var(--ink2);font-size:15.5px}
.box{border:1px solid var(--line);border-radius:4px;padding:26px 28px;background:var(--panel2)}
.box h3{margin:0 0 10px;font-size:16px}

/* ---------- form (mock) ---------- */
.form{max-width:640px}
.fld{margin:0 0 24px}
.fld label{display:block;font-size:14px;font-weight:700;margin:0 0 8px}
.fld .req{color:#C0392B;font-size:12px;margin-left:6px;font-weight:700}
.fld .opt{color:var(--ink3);font-size:12px;margin-left:6px;font-weight:400}
.fld input,.fld select,.fld textarea{
  width:100%;font:inherit;font-size:15px;padding:13px 14px;border:1px solid #C9D3DA;border-radius:3px;
  background:#fff;color:var(--ink);
}
.fld input:focus,.fld select,.fld textarea:focus{outline:2px solid var(--brand-w);border-color:var(--brand)}
.fld textarea{min-height:150px;resize:vertical;line-height:1.8}
.fld .hint{font-size:12.5px;color:var(--ink3);margin-top:7px}
.check{display:flex;gap:11px;align-items:flex-start;font-size:14px;line-height:1.7}
.check input{width:18px;height:18px;margin-top:3px;flex:0 0 auto}
.mockbadge{display:inline-block;font-size:11.5px;font-weight:700;letter-spacing:.06em;
  background:#FFF4E0;color:var(--amber);border:1px solid #F0DCB4;border-radius:2px;padding:4px 9px;margin-bottom:14px}

/* ---------- footer ---------- */
footer.site{background:var(--navy);color:#B9CBD8;padding:76px 0 34px;font-size:14px}
footer.site .brand{color:#fff;margin-bottom:20px}
footer.site .fh{font-size:12px;letter-spacing:.14em;color:#7C93A4;margin:0 0 16px;font-weight:700}
footer.site a{color:#CFDDE7;display:block;padding:5px 0;font-size:14px}
footer.site a:hover{color:#fff}
footer.site .fg{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:44px}
footer.site .fbot{border-top:1px solid rgba(255,255,255,.14);margin-top:56px;padding-top:26px;
  display:flex;justify-content:space-between;gap:20px;font-size:12.5px;color:#8AA1B1;flex-wrap:wrap}
footer.site .addr{font-size:13.5px;line-height:1.9;color:#9DB3C2}

/* ---------- code ---------- */
pre.code{
  background:var(--navy);color:#DCE9F2;border-radius:4px;padding:22px 24px;overflow-x:auto;
  font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;line-height:1.75;
  margin:26px 0;letter-spacing:0;
}
pre.code .c{color:#7E97A8}
pre.code .k{color:#7FC6EE}
pre.code .s{color:#A8D6A0}
code.inl{background:var(--panel);border:1px solid var(--line);border-radius:2px;padding:1px 6px;
  font-family:ui-monospace,Menlo,monospace;font-size:.88em}
.codecap{font-size:12.5px;color:var(--ink3);margin:-16px 0 26px}

/* ---------- filter chips ---------- */
.filter{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 34px}
.filter button{
  font:inherit;font-size:13px;font-weight:700;letter-spacing:.03em;padding:8px 15px;border-radius:2px;
  background:#fff;border:1px solid var(--line);color:var(--ink2);cursor:pointer;
}
.filter button:hover{border-color:#A9C9DC;color:var(--brand-d)}
.filter button.on{background:var(--brand);border-color:var(--brand);color:#fff}

/* ---------- article body ---------- */
.article h2{font-size:22px;margin:56px 0 18px;padding-top:0}
.article h3{font-size:17px;margin:38px 0 12px}
.article ul,.article ol{margin-bottom:1.5em}
.article .figure{margin:32px 0}
.article table.t{margin:28px 0}

/* ---------- diagram helpers ---------- */
.figure{margin:0}
.figure figcaption{font-size:12.5px;color:var(--ink3);margin-top:14px;line-height:1.8}
.thumb{aspect-ratio:16/9;border-radius:3px 3px 0 0;display:block;width:100%}
a.card.hasthumb{padding:0;overflow:hidden}
a.card.hasthumb .cbody{padding:26px 26px 28px;display:flex;flex-direction:column;flex:1}

/* ---------- review notes ---------- */
.rev{position:fixed;right:16px;bottom:16px;z-index:80}
.rev button{background:var(--navy);color:#fff;border:0;border-radius:20px;padding:11px 18px;
  font:inherit;font-size:13px;font-weight:700;cursor:pointer;box-shadow:0 4px 18px rgba(15,42,63,.3)}
.revpanel{position:fixed;right:16px;bottom:66px;width:min(430px,calc(100vw - 32px));max-height:70vh;overflow:auto;
  background:#fff;border:1px solid var(--line);border-radius:6px;box-shadow:0 12px 40px rgba(20,33,46,.2);
  padding:22px 24px;z-index:80;display:none;font-size:13.5px;line-height:1.85}
.revpanel.open{display:block}
.revpanel h4{margin:0 0 12px;font-size:14px}
.revpanel ul{padding-left:18px;margin:0 0 14px}
.revpanel li{margin:7px 0;color:var(--ink2)}
.revpanel b{color:var(--ink)}

/* ---------- responsive ---------- */
@media(max-width:900px){
  :root{--sp:64px}
  .g3,.g4{grid-template-columns:repeat(2,1fr)}
  .split,.split.n{grid-template-columns:1fr;gap:36px}
  .hold{grid-template-columns:1fr;gap:24px}
  footer.site .fg{grid-template-columns:1fr 1fr;gap:32px}
  nav.main{display:none}
  nav.main.open{display:flex;position:absolute;top:74px;left:0;right:0;background:#fff;
    flex-direction:column;align-items:stretch;padding:12px;border-bottom:1px solid var(--line);gap:0}
  nav.main.open a{padding:13px 14px}
  .burger{display:block}
  dl.kv{grid-template-columns:1fr}
  dl.kv dt{border-bottom:0;padding-bottom:0}
  dl.kv dd{border-top:0;padding-top:6px}
}
@media(max-width:560px){
  .g2,.g3,.g4{grid-template-columns:1fr}
  .wrap{padding:0 20px}
  .stats{grid-template-columns:1fr 1fr}
}