*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
@media (prefers-reduced-motion: reduce){*{transition:none!important;scroll-behavior:auto!important}}
:root{
  --ink:#2e3136;--sub:#5f636a;--accent:#c8462c;--accent-dk:#a33820;
  --bg:#ffffff;--pale:#f3f3f2;--line:#d9d9d6;
  --ff:'Zen Kaku Gothic New',sans-serif;--ff-num:'DM Mono',monospace;
  --w:960px;--wtext:720px;
}
body{font-family:var(--ff);color:var(--ink);background:var(--bg);font-size:16px;line-height:1.95;letter-spacing:.02em}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.wrap{max-width:var(--w);margin:0 auto;padding:0 24px}

/* header */
.hd{position:sticky;top:0;z-index:50;background:#fff;border-bottom:1px solid var(--line)}
.hd .wrap{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:64px}
.logo{font-weight:900;font-size:18px;letter-spacing:.04em;white-space:nowrap}
.hd-nav ul{display:flex;gap:4px 22px;flex-wrap:wrap;justify-content:flex-end}
.hd-nav a{display:block;font-size:14px;font-weight:500;color:var(--sub);padding:20px 0 18px;border-bottom:2px solid transparent;transition:color .2s,border-color .2s}
.hd-nav a:hover{color:var(--ink)}
.hd-nav a.is-active{color:var(--ink);border-bottom-color:var(--accent)}
.burger{display:none;width:44px;height:44px;background:none;border:none;cursor:pointer;flex-direction:column;justify-content:center;gap:6px;padding:10px;color:var(--ink)}
.burger span{display:block;height:2px;background:currentColor;transition:transform .25s,opacity .25s}
.burger[aria-expanded="true"] span:nth-child(1){transform:translateY(8px) rotate(45deg)}
.burger[aria-expanded="true"] span:nth-child(2){opacity:0}
.burger[aria-expanded="true"] span:nth-child(3){transform:translateY(-8px) rotate(-45deg)}
.drawer{display:none}
@media(max-width:900px){
  .hd-nav{display:none}
  .burger{display:flex}
  .drawer{display:block;max-height:0;overflow:hidden;transition:max-height .3s ease;background:#fff;border-top:1px solid transparent}
  .drawer.open{max-height:600px;border-top-color:var(--line)}
  .drawer ul{padding:6px 24px 14px}
  .drawer li+li{border-top:1px solid var(--line)}
  .drawer a{display:block;padding:13px 0;font-size:15px}
  .drawer a.is-active{color:var(--accent-dk);font-weight:700}
}

/* top */
.top-head{padding:72px 0 40px;border-bottom:1px solid var(--line)}
.top-head h1{font-size:clamp(24px,4vw,36px);font-weight:900;line-height:1.5;letter-spacing:.03em;max-width:24em}
.top-head .sub{display:block;font-size:clamp(16px,2.2vw,20px);font-weight:500;color:var(--sub);margin-top:10px}
.top-head .lead{margin-top:22px;max-width:40em;color:var(--sub)}
.index-list{margin:8px 0 0}
.index-list li{border-bottom:1px solid var(--line)}
.index-list a{display:grid;grid-template-columns:56px 1fr 24px;gap:20px;align-items:center;padding:26px 4px;transition:background .2s}
.index-list a:hover{background:var(--pale)}
.index-list .no{font-family:var(--ff-num);font-size:15px;color:var(--accent)}
.index-list .t{display:block;font-weight:700;font-size:19px;margin-bottom:4px}
.index-list .d{display:block;font-size:14.5px;color:var(--sub);line-height:1.8}
.index-list .chev{width:10px;height:10px;border-top:2px solid var(--ink);border-right:2px solid var(--ink);transform:rotate(45deg);justify-self:center}
@media(max-width:600px){.index-list a{grid-template-columns:40px 1fr 16px;gap:12px;padding:20px 0}}

/* lower page band */
.band{background:var(--ink);color:#fff}
.band .wrap{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;padding-top:56px;padding-bottom:40px}
.band h1{font-size:clamp(26px,4.4vw,40px);font-weight:900;line-height:1.35;letter-spacing:.04em}
.band .lead{margin-top:10px;font-size:14.5px;color:#c9cbce;max-width:36em}
.band .pno{font-family:var(--ff-num);font-size:clamp(28px,5vw,44px);line-height:1;white-space:nowrap;color:#fff}
.band .pno small{font-size:.45em;color:#9a9ea4;margin-left:4px}
.band .pno b{font-weight:400;color:var(--accent)}
.band.plain .wrap{padding-bottom:44px}

/* article */
.article{max-width:var(--wtext);margin:0 auto;padding:56px 24px 24px}
.article p{margin-bottom:1.5em}
.article h2{font-size:21px;font-weight:700;line-height:1.5;margin:2.4em 0 .9em;padding-left:14px;border-left:4px solid var(--accent)}
.article h2:first-child{margin-top:0}

/* pager */
.pager{max-width:var(--w);margin:32px auto 0;padding:0 24px;display:grid;grid-template-columns:1fr 1fr;gap:16px}
.pager a,.pager .empty{display:block;border:1px solid var(--line);padding:20px 24px;min-height:96px;transition:border-color .2s,background .2s}
.pager a:hover{border-color:var(--ink);background:var(--pale)}
.pager .dir{display:block;font-size:13px;color:var(--sub);margin-bottom:4px}
.pager .ttl{display:block;font-weight:700;font-size:17px}
.pager .next{text-align:right}
.pager .empty{border-style:dashed;background:transparent}
@media(max-width:600px){.pager{grid-template-columns:1fr}.pager .empty{display:none}}

/* sitemap / links */
.plain-body{max-width:var(--wtext);margin:0 auto;padding:48px 24px 16px}
.sitemap-list{border-top:1px solid var(--line)}
.sitemap-list li{border-bottom:1px solid var(--line);padding:20px 0}
.sitemap-list li.child{padding-left:24px}
.sitemap-list a{font-weight:700;font-size:17px;border-bottom:1px solid transparent;transition:border-color .2s,color .2s}
.sitemap-list a:hover{color:var(--accent-dk);border-bottom-color:currentColor}
.sitemap-list p{font-size:14.5px;color:var(--sub);margin-top:4px;line-height:1.8}
.pending{border:1px solid var(--line);background:var(--pale);padding:28px 24px;color:var(--sub)}

/* footer */
.ft{margin-top:88px;border-top:1px solid var(--line);background:var(--pale)}
.ft .wrap{display:flex;justify-content:space-between;gap:32px;flex-wrap:wrap;padding-top:44px;padding-bottom:32px}
.ft-name{font-weight:900;font-size:17px}
.ft-nav ul{display:grid;grid-template-columns:repeat(3,auto);gap:8px 32px;font-size:14px}
.ft-nav a{color:var(--sub)}
.ft-nav a:hover{color:var(--ink);text-decoration:underline;text-underline-offset:3px}
.ft-copy{border-top:1px solid var(--line);font-size:12px;color:var(--sub);text-align:center;padding:14px 24px}
@media(max-width:600px){.ft-nav ul{grid-template-columns:repeat(2,auto)}}

.to-top{position:fixed;right:18px;bottom:18px;width:44px;height:44px;background:var(--ink);color:#fff;display:flex;align-items:center;justify-content:center;opacity:0;pointer-events:none;transition:opacity .3s;z-index:60}
.to-top::before{content:"";width:10px;height:10px;border-top:2px solid #fff;border-left:2px solid #fff;transform:translateY(3px) rotate(45deg)}
.to-top.show{opacity:1;pointer-events:auto}
@media(max-width:600px){.band .wrap{flex-direction:column-reverse;align-items:flex-start;gap:14px;padding-top:40px;padding-bottom:32px}.band .pno{font-size:24px}}