:root{
  --font-system-sans:-apple-system,BlinkMacSystemFont,"Segoe UI","Hiragino Kaku Gothic ProN","Hiragino Sans","Noto Sans JP","Yu Gothic",Meiryo,sans-serif;
  --header-height:56px;
  --color-primary:#0017c1; --color-primary-strong:#000071; --color-primary-soft:#e8f1fe;
  --color-accent:#b78f00; --color-text:#1a1a1a; --color-muted:#666;
  --color-bg:#f7f8fb; --color-surface:#fff; --color-border:#ccc; --color-border-strong:#999;
  --color-pbox-bg:#fff7d6;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;font-size:16px;scroll-padding-top:calc(var(--header-height) + 12px);}
body{font-family:var(--font-system-sans);color:var(--color-text);background:var(--color-bg);line-height:1.85;text-rendering:optimizeLegibility;}
a{color:var(--color-primary);text-underline-offset:.18em;}
a:hover{color:var(--color-primary-strong);}
:where(a,button):focus-visible{outline:4px solid var(--color-accent);outline-offset:2px;}

/* skip-link */
.skip-link{position:fixed;top:.5rem;left:.5rem;z-index:200;transform:translateY(-160%);
  padding:.55rem .8rem;background:var(--color-surface);color:var(--color-primary-strong);
  border:2px solid var(--color-accent);border-radius:4px;font-weight:700;text-decoration:none;}
.skip-link:focus{transform:translateY(0);}

/* ヘッダー */
.site-header{position:fixed;top:0;left:0;right:0;height:var(--header-height);
  background:var(--color-primary-strong);color:#fff;z-index:100;display:flex;align-items:center;
  border-bottom:4px solid var(--color-accent);}
.site-header-inner{padding:0 1.25rem;display:flex;align-items:center;gap:1.25rem;width:100%;}
.site-title{color:#fff;text-decoration:none;font-size:1rem;font-weight:700;line-height:1.4;}
.site-header a{color:#fff;}
.site-header a:hover{text-decoration:underline;text-decoration-thickness:2px;text-underline-offset:.22em;}
.variant-tag{margin-left:auto;font-size:.8rem;font-weight:700;background:var(--color-accent);
  color:#1a1a1a;padding:.15rem .6rem;border-radius:999px;}

/* セクションナビ（サイドバーの代わりに上部横並び） */
.topnav{position:sticky;top:var(--header-height);z-index:90;background:#f3f5f9;
  border-bottom:1px solid var(--color-border);padding:.4rem 1.25rem;}
.topnav ul{list-style:none;display:flex;flex-wrap:wrap;gap:.3rem 1rem;margin:0;padding:0;font-size:.9rem;}
.topnav a{color:var(--color-primary);text-decoration:none;font-weight:600;}
.topnav a.cur{color:var(--color-primary-strong);text-decoration:underline;text-underline-offset:.2em;}
.topnav a:hover{text-decoration:underline;}

/* レイアウト（サイドバー無し＝全幅） */
.content{margin-top:calc(var(--header-height));padding:1.75rem clamp(0.75rem,2vw,1.5rem) 6rem;min-width:0;}
.sheet{max-width:1440px;margin-inline:auto;background:var(--color-surface);
  padding:2.25rem clamp(1rem,2vw,1.75rem) 3rem;border:1px solid var(--color-border);border-radius:2px;}
.sheet > header h1{font-size:1.6rem;font-weight:700;line-height:1.5;color:var(--color-primary-strong);
  border-bottom:3px solid var(--color-primary);padding-bottom:.6rem;margin-bottom:1.4rem;}

/* パンくず */
.breadcrumb{margin:0 0 .7rem;font-size:.88rem;line-height:1.6;color:var(--color-muted);}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:.2rem .1rem;list-style:none;}
.breadcrumb li{display:inline-flex;align-items:center;}
.breadcrumb li + li::before{content:"›";margin:0 .5rem;color:var(--color-border-strong);}
.breadcrumb a{color:var(--color-primary);text-decoration:none;}
.breadcrumb a:hover{text-decoration:underline;}
.breadcrumb [aria-current="page"]{color:var(--color-text);font-weight:600;}

/* 見出し */
.sheet h2{font-size:1.2rem;font-weight:700;line-height:1.5;color:var(--color-primary-strong);
  margin:2rem 0 .6rem;border-left:5px solid var(--color-primary);padding-left:.6rem;}
.sheet h3{font-size:1rem;font-weight:700;margin:1.2rem 0 .4rem;color:var(--color-text);}
.src-page{font-size:.8rem;font-weight:400;color:var(--color-muted);margin-left:.6rem;}

/* 本文・ポイントボックス */
.sheet section p{margin:.5rem 0;}
.p-box{background:var(--color-pbox-bg);border-left:4px solid var(--color-accent);
  padding:.8rem 1rem;margin:1rem 0;border-radius:0 4px 4px 0;font-size:.95rem;}
.cont{font-size:.85rem;color:var(--color-primary);margin:.4rem 0;}

/* 表（A4横・全体幅統一／列幅%はcolgroup） */
figure.tbl{margin:1rem 0;overflow-x:auto;}
table.std{border-collapse:collapse;font-size:.78rem;margin:.4rem 0 1.2rem;table-layout:fixed;
  width:100%;max-width:100%;background:var(--color-surface);}
table.std th,table.std td{border:1px solid var(--color-border-strong);padding:.3rem .45rem;
  vertical-align:middle;text-align:center;word-break:break-word;overflow-wrap:anywhere;line-height:1.5;}
table.std th{background:var(--color-primary-soft);font-weight:700;color:var(--color-primary-strong);}
/* 列ヘッダは縦横中央(スペースは除去、均等割りはしない) */
table.std th.hd{vertical-align:middle;text-align:center;}
table.std th.v.hd{text-align:center;}
/* サブヘッダ(平均値/個々/鋼桁等)は高さを詰めて主ヘッダ行と揃える */
table.std th.subh{height:0;line-height:1.25;}
/* 枝番ヘッダは余白を詰めて幅を変えず折返さない */
table.std th.tight{padding-left:0;padding-right:0;white-space:nowrap;}
table.std td.v,table.std th.v{writing-mode:vertical-rl;text-orientation:upright;white-space:nowrap;letter-spacing:1px;}
table.std td.top,table.std th.top{vertical-align:top;}
table.std td.v.top,table.std th.v.top{text-align:start;}
table.std td.tl,table.std th.tl{vertical-align:top;text-align:left;}
table.std td.fig img{height:auto;display:block;margin:0 auto;max-width:min(100%,230px);}
table.std .formula{display:block;margin:.15rem 0 .35rem;}
table.std .formula img{display:inline-block;margin:0;}
.figure-caption{display:block;font-size:.85em;line-height:1.5;margin-top:.3rem;}
.toc-sec{background:#dde6f3;text-align:left !important;font-weight:700;}

/* 前後ナビ */
.page-nav{max-width:1440px;margin:1.25rem auto 0;display:flex;justify-content:space-between;gap:1rem;}
.page-nav a{display:inline-block;padding:.6rem 1rem;background:var(--color-surface);
  border:1px solid var(--color-border);border-radius:4px;color:var(--color-primary);
  text-decoration:none;font-weight:600;font-size:.9rem;}
.page-nav a:hover{background:var(--color-primary-soft);}
.page-nav-placeholder{flex:1;}

/* スクロールトップ */
.scroll-top-btn{position:fixed;right:1.1rem;bottom:1.1rem;width:3rem;height:3rem;border-radius:50%;
  border:none;background:var(--color-primary-strong);color:#fff;font-size:1.3rem;cursor:pointer;
  box-shadow:0 2px 8px rgba(0,0,0,.3);opacity:0;pointer-events:none;transition:opacity .2s;z-index:120;}
.scroll-top-btn.is-visible{opacity:1;pointer-events:auto;}
.scroll-top-btn:hover{background:var(--color-primary);}

/* 索引ページ */
.index-grid{display:grid;gap:1.4rem;}
.index-grid section{border-bottom:1px solid var(--color-border);padding-bottom:1rem;}
.index-grid ul{list-style:none;display:flex;flex-wrap:wrap;gap:.4rem .8rem;margin:.5rem 0 0;}
.index-grid li a{display:inline-block;padding:.35rem .7rem;border:1px solid var(--color-border);
  border-radius:4px;text-decoration:none;background:var(--color-surface);font-size:.9rem;}
.index-grid li a:hover{background:var(--color-primary-soft);}
.lead{color:var(--color-muted);font-size:.95rem;margin:.3rem 0 1.2rem;}

/* ===== ドキュメントレイアウト（サイドバー＋本文）: 公開版 ===== */
.layout{display:block;}
body.has-sidebar{padding-top:var(--header-height);}
body.has-sidebar .layout{display:grid;grid-template-columns:clamp(216px,17vw,264px) minmax(0,1fr);
  max-width:1900px;margin-inline:auto;align-items:start;}
body.has-sidebar .content{margin-top:0;}
.menu-toggle{display:none;}
.sidebar-backdrop{display:none;}  /* デスクトップでは常に非表示(グリッドを占有させない)。モバイルのみ使用 */

/* サイドバー */
.sidebar{position:sticky;top:var(--header-height);align-self:start;
  height:calc(100vh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;
  background:var(--color-surface);border-right:1px solid var(--color-border);
  padding:1rem .75rem 3rem;}
.sidebar h2{font-size:.72rem;letter-spacing:.08em;text-transform:none;color:var(--color-muted);
  margin:1.1rem .25rem .35rem;font-weight:700;}
.doc-tree{font-size:.9rem;line-height:1.5;}
.doc-tree ul{list-style:none;margin:0;padding:0;}
.doc-tree > ul > li{margin-bottom:.15rem;}
.doc-tree details{margin:0;}
.doc-tree summary{cursor:pointer;padding:.35rem .5rem;border-radius:5px;font-weight:700;
  color:var(--color-primary-strong);list-style:none;}
.doc-tree summary::-webkit-details-marker{display:none;}
.doc-tree summary::before{content:"▸";display:inline-block;width:1em;color:var(--color-border-strong);
  transition:transform .15s;}
.doc-tree details[open] > summary::before{transform:rotate(90deg);}
.doc-tree summary:hover{background:var(--color-primary-soft);}
.doc-tree a{display:block;padding:.32rem .5rem .32rem 1.6rem;border-radius:5px;
  text-decoration:none;color:var(--color-text);}
.doc-tree a:hover{background:var(--color-primary-soft);}
.doc-tree a.top{padding-left:.5rem;font-weight:700;color:var(--color-primary-strong);}
.doc-tree a[aria-current="page"]{background:var(--color-primary);color:#fff;font-weight:700;}
.doc-tree a[aria-current="page"]:hover{background:var(--color-primary-strong);}

/* サイト内検索 */
.doc-search{position:relative;margin:.25rem .25rem .5rem;}
.doc-search input{width:100%;padding:.5rem .7rem;font-size:.9rem;border:1px solid var(--color-border-strong);
  border-radius:6px;background:var(--color-surface);color:var(--color-text);}
.doc-search input:focus-visible{outline:3px solid var(--color-accent);outline-offset:1px;}
.search-results{list-style:none;margin:.3rem 0 0;padding:0;max-height:48vh;overflow-y:auto;
  border:1px solid var(--color-border);border-radius:6px;background:var(--color-surface);display:none;}
.search-results.is-open{display:block;}
.search-results li{border-bottom:1px solid var(--color-border);}
.search-results li:last-child{border-bottom:none;}
.search-results a{display:block;padding:.45rem .6rem;text-decoration:none;color:var(--color-text);font-size:.85rem;line-height:1.4;}
.search-results a:hover,.search-results a.active{background:var(--color-primary-soft);}
.search-results .sr-title{font-weight:700;color:var(--color-primary-strong);}
.search-results .sr-path{display:block;font-size:.76rem;color:var(--color-muted);margin-top:.1rem;}
.search-results .sr-empty{padding:.5rem .6rem;color:var(--color-muted);font-size:.84rem;}

/* 広い表は横スクロール（モバイルで崩さない） */
.table-scroll{overflow-x:auto;margin:.4rem 0 1.2rem;-webkit-overflow-scrolling:touch;}
.table-scroll table.std{margin:0;min-width:760px;}
/* 1440x900 ノートでも読みやすく: 本文幅をほぼ全幅に、規格値表の文字をやや大きく(中身は不変) */
body.has-sidebar .sheet{max-width:none;}
body.has-sidebar table.std{font-size:.82rem;}
body.has-sidebar table.std th,body.has-sidebar table.std td{padding:.32rem .5rem;}
/* 狭い列(編章節条枝番)が列幅からはみ出さないよう、縦書き・狭ヘッダのパディング/字間を詰める */
body.has-sidebar table.std td.v,body.has-sidebar table.std th.v{padding-left:1px;padding-right:1px;letter-spacing:0;}
body.has-sidebar table.std th.hd{padding-left:1px;padding-right:1px;}
body.has-sidebar table.std th.tight{padding-left:0;padding-right:0;font-size:.74rem;}

/* 目次(準用索引) toc_doc: 編›章›節 の階層見出し行＋本文体裁 */
table.toc-grid{min-width:0;}
table.toc-grid .toc-group{background:var(--color-primary-soft);color:var(--color-primary-strong);
  text-align:left !important;font-weight:700;padding:.45rem .7rem;font-size:.92rem;letter-spacing:.01em;}
table.toc-grid td.tl{text-align:left;}
table.toc-grid td{vertical-align:middle;}
table.toc-grid a{font-weight:600;text-decoration:none;}
table.toc-grid a:hover{text-decoration:underline;}

/* 一般文書・目的/目次・参考: 項番の見出し化とインデント(土木共通仕様書に倣う) */
.doc-prose .doc-sec{font-size:1.1rem;font-weight:700;color:var(--color-primary-strong);
  margin:1.6rem 0 .5rem;border-left:4px solid var(--color-primary);padding-left:.55rem;line-height:1.6;text-indent:0;}
/* （１）括弧項目・（ア）片仮名項目: 土木共通仕様書に倣いぶら下げインデント。本文(折返し/続き)は項目本文位置に揃える */
.doc-prose .lv1{margin-left:2em;padding-left:2.95em;text-indent:-2.95em;}
.doc-prose .lv1-body{margin-left:2em;padding-left:2.95em;text-indent:1em;}
.doc-prose .lv2{margin-left:4em;padding-left:2.95em;text-indent:-2.95em;}
.doc-prose .lv2-body{margin-left:4em;padding-left:2.95em;text-indent:1em;}
.doc-prose .doc-tocline{text-indent:0;padding-left:1em;border-bottom:1px dotted var(--color-border);
  padding-bottom:.15rem;margin:.1rem 0;}
/* 品質などの目次リスト（頁ラベル→該当ページへリンク） */
.doc-prose .toc-plist{list-style:none;margin:.3rem 0 1rem;padding:0;}
.doc-prose .toc-plist li{border-bottom:1px dotted var(--color-border);padding:.3rem .2rem;line-height:1.6;}
.doc-prose .toc-plist li.toc-cont{border-bottom:none;padding:0 .2rem .3rem 1.6em;font-size:.88rem;color:var(--color-muted);}
.doc-prose .toc-plist a{text-decoration:none;display:block;}
.doc-prose .toc-plist a:hover{text-decoration:underline;}

/* データ（AI利用）パネル */
.data-panel{margin:1.6rem 0 0;padding:1rem 1.1rem;background:var(--color-primary-soft);
  border:1px solid #cdd8f0;border-radius:8px;font-size:.9rem;}
.data-panel h2{border:none;padding:0;margin:0 0 .4rem;font-size:1rem;color:var(--color-primary-strong);}
.data-panel ul{list-style:none;margin:.3rem 0 0;padding:0;display:flex;flex-wrap:wrap;gap:.4rem .9rem;}
.data-panel a{font-weight:600;}
/* 共通仕様書の項番(編章節条枝番)バッジ */
.koban{display:inline-block;font-size:.76rem;font-weight:700;color:var(--color-primary-strong);
  background:#eef2fb;border:1px solid #cdd8f0;border-radius:4px;padding:.05rem .4rem;margin-left:.3rem;}

@media (max-width:900px){
  body.has-sidebar .layout{display:block;}
  .menu-toggle{display:inline-flex;align-items:center;gap:.3rem;margin-right:.4rem;
    background:transparent;border:1px solid rgba(255,255,255,.6);color:#fff;border-radius:5px;
    padding:.3rem .55rem;font-size:.85rem;cursor:pointer;}
  .sidebar{position:fixed;top:var(--header-height);left:0;bottom:0;width:min(84vw,320px);z-index:95;
    transform:translateX(-100%);transition:transform .2s;box-shadow:2px 0 12px rgba(0,0,0,.18);}
  body.nav-open .sidebar{transform:none;}
  .sidebar-backdrop{display:none;position:fixed;inset:var(--header-height) 0 0;background:rgba(0,0,0,.35);z-index:94;}
  body.nav-open .sidebar-backdrop{display:block;}
}

@media (max-width:640px){
  .sheet{padding:1.25rem 1rem 2rem;}
  .content{padding:1.25rem 1rem 4rem;}
}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto !important;transition-duration:.01ms !important;}}

/* 印刷（A4横・表が主役） */
@page{size:A4 landscape;margin:12mm 10mm;}
/* 表紙(p1): 文書タイトル・年月・発行者を中央寄せ */
.cover{min-height:68vh;display:flex;flex-direction:column;justify-content:center;
  align-items:center;text-align:center;gap:2.2em;padding:2em 1em;}
.cover-title{font-size:28px;font-weight:700;letter-spacing:.12em;line-height:1.5;margin:0;}
.cover-sub{font-size:17px;letter-spacing:.3em;margin:0;}
/* 中扉(p4/p212): 節タイトルのみ大きく中央 */
.nakatobira{min-height:46vh;display:flex;justify-content:center;align-items:center;
  text-align:center;padding:2em 1em;}
.nakatobira-title{font-size:24px;font-weight:700;letter-spacing:.12em;margin:0;}
/* 一般文書・目的/目次・参考資料の本文(prose)。フォント・インデントは土木共通仕様書に合わせる(16px基準・本文2em+1字下げ) */
.doc-prose{font-size:1rem;line-height:1.85;}
.doc-prose p{margin:.55rem 0;text-indent:1em;}
.doc-prose img{display:block;margin:1em auto;}
@media print{
  html{font-size:9pt;}
  body{background:#fff;color:#000;}
  .site-header,.topnav,.page-nav,.skip-link,.scroll-top-btn,.qa-pdf,.qa-banner,.qa-legend{display:none !important;}
  .content{margin:0;padding:0;}
  .sheet{max-width:100%;border:0;padding:0;}
  table.std{width:100%;font-size:8pt;}
  table.std th{background:#eef2fb !important;-webkit-print-color-adjust:exact;print-color-adjust:exact;}
  .cover,.nakatobira{min-height:92vh;page-break-after:always;}
}