:root{
  --paper:#eef1f5;
  --paper-2:#e2e7ee;
  --paper-3:#f7f9fc;
  --ink:#0d1622;
  --ink-2:#1b2636;
  --ink-3:#2a3a52;
  --steel:#3b5877;
  --mute:#7a8ca4;
  --fog:#b5c2d2;
  --line:rgba(13,22,34,.10);
  --line-2:rgba(13,22,34,.22);

  --mincho:"Shippori Mincho","Hiragino Mincho ProN","Yu Mincho",serif;
  --sans:"Noto Sans JP","Hiragino Sans","Yu Gothic",sans-serif;
  --serif-en:"IBM Plex Serif",Georgia,serif;
  --mono:"IBM Plex Mono",ui-monospace,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--paper);color:var(--ink);
  font-family:var(--mincho);font-weight:500;
  line-height:1.9;letter-spacing:.02em;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}

body::before{
  content:"";position:fixed;inset:0;pointer-events:none;z-index:200;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='240'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.05  0 0 0 0 0.08  0 0 0 0 0.13  0 0 0 0.04 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
  opacity:.45;mix-blend-mode:multiply;
}

/* NAV */
nav.top{
  position:sticky;top:0;z-index:50;
  display:flex;justify-content:space-between;align-items:center;
  padding:18px 40px;
  background:rgba(238,241,245,.88);
  backdrop-filter:blur(14px) saturate(1.1);
  border-bottom:1px solid var(--line);
}
nav.top .brand{
  font-family:var(--serif-en);font-size:19px;
  font-weight:700;letter-spacing:.05em;
  color:var(--ink);display:flex;align-items:baseline;gap:8px;
}
nav.top .brand b{font-weight:800;font-size:22px;line-height:1}
nav.top .brand span{color:var(--steel);font-style:italic;font-weight:500}
nav.top .brand .sep{color:var(--fog);font-weight:300}
nav.top .brand i{
  font-family:var(--mincho);font-style:normal;font-weight:700;
  font-size:14px;color:var(--ink-2);letter-spacing:.08em;
}
nav.top .back{
  font-family:var(--mono);font-size:11px;font-weight:500;
  letter-spacing:.24em;color:var(--ink-2);text-transform:uppercase;
  display:inline-flex;align-items:center;gap:8px;
}
nav.top .back:hover{color:var(--steel)}
@media(max-width:640px){
  nav.top{padding:12px 16px}
  nav.top .brand{font-size:16px}
  nav.top .brand b{font-size:19px}
  nav.top .brand i{font-size:12px}
  nav.top .back{font-size:10px;letter-spacing:.18em}
}

/* HEADER */
.page-head{
  background:var(--ink);color:var(--paper);
  padding:100px 40px 80px;
  position:relative;overflow:hidden;
}
.page-head::before{
  content:"";position:absolute;inset:0;
  background:
    radial-gradient(1200px 500px at 20% 30%, rgba(59,88,119,.35), transparent 60%),
    repeating-linear-gradient(180deg, transparent 0, transparent 3px, rgba(0,0,0,.08) 3px, rgba(0,0,0,.08) 4px);
  mix-blend-mode:screen;pointer-events:none;
}
.page-head .inner{
  max-width:1040px;margin:0 auto;position:relative;z-index:2;
}
.page-head .chapter{
  font-family:var(--mono);font-size:11px;letter-spacing:.28em;
  color:var(--fog);text-transform:uppercase;
  display:inline-flex;align-items:center;gap:14px;
  margin-bottom:26px;
}
.page-head .chapter::before{
  content:"";width:36px;height:1px;background:var(--fog);
}
.page-head h1{
  font-family:var(--mincho);font-weight:800;
  font-size:clamp(34px,5.4vw,58px);
  line-height:1.3;letter-spacing:.02em;
  color:var(--paper);margin-bottom:22px;
}
.page-head h1 .en{
  display:block;
  font-family:var(--serif-en);font-style:italic;font-weight:500;
  font-size:.34em;letter-spacing:.05em;
  color:var(--fog);margin-bottom:10px;
}
.page-head .sub{
  font-family:var(--mincho);font-size:15px;
  color:rgba(238,241,245,.75);line-height:1.95;
  max-width:640px;
}
.page-head .meta{
  margin-top:36px;
  display:inline-flex;gap:0;
  border:1px solid rgba(238,241,245,.25);
  font-family:var(--mono);font-size:10px;letter-spacing:.22em;
  color:var(--fog);text-transform:uppercase;
  flex-wrap:wrap;
}
.page-head .meta span{
  padding:9px 16px;border-right:1px solid rgba(238,241,245,.2);
}
.page-head .meta span:last-child{border-right:none}
.page-head .meta em{color:rgba(238,241,245,.55);font-style:normal;margin-right:6px}
@media(max-width:640px){
  .page-head{padding:60px 20px 50px}
  .page-head h1{font-size:30px}
  .page-head .sub{font-size:13.5px}
  .page-head .meta{font-size:9px;letter-spacing:.14em}
  .page-head .meta span{padding:7px 11px}
}

/* CONTENT */
.page-body{
  max-width:1040px;margin:0 auto;padding:80px 40px 40px;
  display:grid;grid-template-columns:220px 1fr;gap:72px;
  align-items:start;
}
@media(max-width:820px){
  .page-body{grid-template-columns:1fr;gap:32px;padding:48px 20px 24px}
}
.toc{
  position:sticky;top:100px;
  font-family:var(--mono);font-size:11px;letter-spacing:.18em;
  color:var(--steel);text-transform:uppercase;
  padding-top:8px;
  border-top:1px solid var(--line-2);
}
.toc .toc-head{
  font-family:var(--mono);font-size:9.5px;letter-spacing:.3em;
  color:var(--mute);padding:10px 0;border-bottom:1px solid var(--line);
  margin-bottom:10px;
}
.toc ol{list-style:none;counter-reset:t}
.toc ol li{
  counter-increment:t;padding:8px 0;border-bottom:1px solid var(--line);
  display:flex;gap:10px;
}
.toc ol li::before{
  content:counter(t,decimal-leading-zero);
  color:var(--mute);font-size:10px;flex-shrink:0;
}
.toc ol li a{
  color:var(--ink-2);font-family:var(--mincho);
  font-size:12.5px;letter-spacing:.04em;line-height:1.5;
  text-transform:none;font-weight:600;
}
.toc ol li a:hover{color:var(--steel)}
@media(max-width:820px){
  .toc{position:static;border-top:1px solid var(--line-2);padding:12px 0}
  .toc ol{display:grid;grid-template-columns:1fr 1fr;gap:0 16px}
}

.content article{
  padding-bottom:56px;border-bottom:1px solid var(--line);
  margin-bottom:56px;
}
.content article:last-child{border-bottom:none;margin-bottom:0}
.content h2{
  font-family:var(--mincho);font-weight:800;
  font-size:22px;letter-spacing:.03em;line-height:1.5;
  color:var(--ink);margin-bottom:18px;
  display:flex;align-items:baseline;gap:14px;
}
.content h2 .num{
  font-family:var(--serif-en);font-style:italic;font-weight:500;
  font-size:14px;color:var(--steel);letter-spacing:.05em;
  padding:3px 10px;border:1px solid var(--line-2);
  flex-shrink:0;
}
.content p{
  font-family:var(--mincho);font-size:14.5px;line-height:2.05;
  color:var(--ink-3);margin-bottom:14px;
}
.content p b{color:var(--ink);font-weight:700}
.content ul,.content ol{
  margin:12px 0 18px 22px;
  font-family:var(--mincho);font-size:14px;line-height:2.0;
  color:var(--ink-3);
}
.content ul li,.content ol li{margin-bottom:6px;padding-left:6px}
.content ul li::marker{color:var(--steel);font-size:.8em}

/* Table (SCTL) */
.sctl-table{
  width:100%;border-collapse:collapse;
  border-top:1px solid var(--ink);
  border-bottom:1px solid var(--ink);
  font-family:var(--mincho);
}
.sctl-table tr{border-bottom:1px solid var(--line)}
.sctl-table tr:last-child{border-bottom:none}
.sctl-table th,.sctl-table td{
  padding:20px 22px;vertical-align:top;text-align:left;
  font-size:14px;line-height:1.95;
}
.sctl-table th{
  width:210px;
  font-weight:700;color:var(--ink);letter-spacing:.05em;
  background:var(--paper-3);
  border-right:1px solid var(--line);
  position:relative;
}
.sctl-table th .en{
  display:block;font-family:var(--mono);font-size:9.5px;
  letter-spacing:.22em;color:var(--steel);font-weight:500;
  text-transform:uppercase;margin-bottom:4px;
}
.sctl-table td{color:var(--ink-3)}
.sctl-table td b{color:var(--ink);font-weight:700}
@media(max-width:640px){
  .sctl-table th,.sctl-table td{display:block;width:100%;padding:14px 16px}
  .sctl-table th{border-right:none;border-bottom:1px solid var(--line)}
}

.note{
  margin-top:32px;padding:24px 24px;
  background:var(--paper-3);border-left:3px solid var(--steel);
  position:relative;
}
.note::before{
  content:"NOTE";position:absolute;top:-1px;left:22px;transform:translateY(-50%);
  font-family:var(--mono);font-size:9.5px;letter-spacing:.3em;
  background:var(--paper);padding:3px 10px;color:var(--steel);
}
.note p{font-size:13.5px;margin-bottom:8px;color:var(--ink-2)}
.note p:last-child{margin-bottom:0}

/* FOOTER */
footer{
  background:var(--ink);color:var(--paper);
  padding:56px 40px 32px;text-align:center;
  margin-top:40px;
}
footer .fbrand{
  font-family:var(--serif-en);font-size:22px;font-weight:700;
  letter-spacing:.05em;margin-bottom:10px;
}
footer .fbrand span{color:var(--fog);font-style:italic;font-weight:500}
footer .ftag{
  font-family:var(--mincho);font-size:13px;
  color:rgba(238,241,245,.65);margin-bottom:28px;
}
footer .flinks{
  display:flex;justify-content:center;gap:24px;flex-wrap:wrap;
  font-family:var(--mono);font-size:10.5px;letter-spacing:.22em;
  color:rgba(238,241,245,.7);text-transform:uppercase;
}
footer .flinks a:hover{color:var(--paper)}
footer .fcopy{
  margin-top:28px;font-family:var(--mono);font-size:9.5px;
  color:rgba(238,241,245,.4);letter-spacing:.2em;
}
@media(max-width:640px){
  footer{padding:40px 20px 28px}
  footer .flinks{gap:14px;font-size:9.5px;letter-spacing:.16em}
}