@charset "UTF-8";
/* ==========================================================================
   OPEN LOGOS — Design System
   概念：青写真（Mechanics）の上に、活版（Text）を刷る。
   一枚の製図と一枚の写本が、同じ紙の上で重なっている状態を基準にする。
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Zen+Old+Mincho:wght@400;500;600;700;900&family=Zen+Kaku+Gothic+New:wght@400;500;700&family=Spectral:ital,wght@0,300;0,400;0,500;0,600;1,300;1,400&display=swap');

/* --------------------------------------------------------------------------
   1. トークン
   -------------------------------------------------------------------------- */
:root {
  --paper:      #E7E8E2;   /* 製図用リネン紙 */
  --paper-2:    #DFE1DA;
  --paper-3:    #EEEFE9;
  --ink:        #15202B;   /* 青みの黒 */
  --ink-soft:   #43525F;
  --ink-faint:  #7C8892;
  --blue:       #1C4E6E;   /* Mechanics — 青写真 */
  --blue-deep:  #143A52;
  --brass:      #8A6620;   /* Text — 活字の真鍮 */
  --brass-deep: #6B4E17;
  --rule:       #B8BDB5;
  --rule-faint: rgba(21, 32, 43, .13);
  --grid:       rgba(28, 78, 110, .075);
  --focus:      #1C4E6E;

  --font-ja:    "Zen Old Mincho", "Hiragino Mincho ProN", "Yu Mincho", YuMincho, "Noto Serif JP", serif;
  --font-en:    Spectral, "Iowan Old Style", Georgia, "Times New Roman", serif;
  --font-ui:    "Zen Kaku Gothic New", -apple-system, "Hiragino Sans", "Noto Sans JP", sans-serif;
  --font-data:  Spectral, Georgia, serif;

  --measure:    34rem;
  --wrap:       1120px;

  color-scheme: light;
}

html[data-theme="dark"] {
  --paper:      #0E1822;
  --paper-2:    #121F2A;
  --paper-3:    #16242F;
  --ink:        #DCDFD8;
  --ink-soft:   #A3AEB5;
  --ink-faint:  #74838D;
  --blue:       #77AECC;
  --blue-deep:  #9CC6DD;
  --brass:      #CBA658;
  --brass-deep: #DCBE7C;
  --rule:       #2A3A47;
  --rule-faint: rgba(220, 223, 216, .15);
  --grid:       rgba(119, 174, 204, .07);
  --focus:      #77AECC;
  color-scheme: dark;
}

/* --------------------------------------------------------------------------
   2. 基礎
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-ja);
  font-size: 17px;
  line-height: 2.05;
  letter-spacing: .035em;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

[lang="en"], .en-face {
  font-family: var(--font-en);
  line-height: 1.72;
  letter-spacing: .005em;
}

img, svg { max-width: 100%; }
svg { display: block; }
a { color: inherit; text-decoration: none; }
p { margin: 0 0 1.5rem; }
p:last-child { margin-bottom: 0; }
em { font-style: normal; font-weight: 600; }
[lang="en"] em { font-style: italic; font-weight: 500; }
::selection { background: var(--blue); color: var(--paper); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 1px; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 28px; }
.wrap-narrow { max-width: 38rem; margin: 0 auto; padding: 0 28px; }
.link {
  color: var(--blue);
  border-bottom: 1px solid var(--rule);
  border-bottom-color: color-mix(in srgb, var(--blue) 40%, transparent);
}
.link:hover { border-bottom-color: currentColor; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap;
}

/* --------------------------------------------------------------------------
   3. 言語切替（JA / EN / 併記）
   -------------------------------------------------------------------------- */
html[data-lang="ja"] [data-l="en"] { display: none !important; }
html[data-lang="en"] [data-l="ja"] { display: none !important; }

/* 併記モードでは、英文を細い罫で束ねて日本語と見分けられるようにする。
   色罫を持つ要素（見出し・引き句・柱）には適用しない。 */
html[data-lang="both"] p[data-l="en"]:not(.strike):not(.motto):not(.role):not(.call):not(.cover-lede),
html[data-lang="both"] dl[data-l="en"],
html[data-lang="both"] ol[data-l="en"],
html[data-lang="both"] ul[data-l="en"],
html[data-lang="both"] div[data-l="en"] {
  border-left: 2px solid var(--rule-faint);
  padding-left: 1rem;
  color: var(--ink-soft);
}
html[data-lang="both"] h1[data-l="en"],
html[data-lang="both"] h2[data-l="en"],
html[data-lang="both"] h3[data-l="en"],
html[data-lang="both"] .aside[data-l="en"] { color: var(--ink-soft); }
html[data-lang="both"] ol.tenets[data-l="en"] { padding-left: 1rem; }
html[data-lang="both"] ol.tenets[data-l="en"] li { padding-left: 2.6rem; }

/* --------------------------------------------------------------------------
   4. ヘッダー
   -------------------------------------------------------------------------- */
.site-header {
  position: sticky; top: 0; z-index: 60;
  background: var(--paper);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--rule);
}
.site-header .wrap { display: flex; align-items: center; gap: 30px; height: 72px; }

.brand { display: flex; align-items: center; gap: 12px; margin-right: auto; }
.brand .mark { width: 30px; height: 30px; flex: 0 0 30px; }
.brand .mark .arc-t { stroke: var(--brass); }
.brand .mark .arc-m { stroke: var(--blue); }
.brand .mark .datum { stroke: var(--ink); opacity: .8; }
.brand .name {
  font-family: var(--font-en);
  font-weight: 400; font-size: 17px; letter-spacing: .26em;
  line-height: 1; padding-top: 1px;
}

.main-nav { display: flex; gap: 26px; font-family: var(--font-ui); font-size: 13.5px; letter-spacing: .04em; }
.main-nav a { padding: 5px 0; color: var(--ink-soft); border-bottom: 1px solid transparent; }
.main-nav a:hover { color: var(--ink); border-bottom-color: var(--blue); }
.main-nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--blue); }

.header-tools { display: flex; align-items: center; gap: 10px; }

.lang-switch { display: flex; border: 1px solid var(--rule); border-radius: 2px; overflow: hidden; }
.lang-switch button {
  font-family: var(--font-ui); font-size: 11.5px; letter-spacing: .08em;
  padding: 6px 9px; border: 0; background: transparent; color: var(--ink-faint); cursor: pointer;
}
.lang-switch button + button { border-left: 1px solid var(--rule); }
.lang-switch button:hover { color: var(--ink); }
.lang-switch button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }

.icon-btn {
  width: 34px; height: 34px; border: 1px solid var(--rule); border-radius: 2px;
  background: transparent; color: var(--ink-soft); cursor: pointer;
  display: grid; place-items: center;
}
.icon-btn:hover { color: var(--ink); border-color: var(--ink-faint); }
.icon-btn svg { width: 16px; height: 16px; }
.icon-moon { display: none; }
html[data-theme="dark"] .icon-sun { display: none; }
html[data-theme="dark"] .icon-moon { display: block; }

.nav-toggle { display: none; }
.nav-toggle span, .nav-toggle::before, .nav-toggle::after {
  content: ""; display: block; width: 15px; height: 1px; background: currentColor; margin: 3.5px auto;
}

/* --------------------------------------------------------------------------
   5. 表紙／ヒーロー
   -------------------------------------------------------------------------- */
.cover { position: relative; overflow: hidden; border-bottom: 1px solid var(--rule); }
.cover::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    repeating-linear-gradient(to right,  var(--grid) 0 1px, transparent 1px 44px),
    repeating-linear-gradient(to bottom, var(--grid) 0 1px, transparent 1px 44px);
  -webkit-mask-image: radial-gradient(118% 80% at 50% 36%, #000 0%, transparent 76%);
  mask-image: radial-gradient(118% 80% at 50% 36%, #000 0%, transparent 76%);
}
.cover > .wrap, .cover > .wrap-narrow { position: relative; }

.cover-full { min-height: 94svh; display: flex; flex-direction: column; justify-content: center; padding: 5rem 0 4rem; }

.cover-mark {
  font-family: var(--font-en); font-weight: 300;
  font-size: clamp(1.5rem, 6vw, 2.25rem); letter-spacing: .3em;
  line-height: 1.2; margin: 0 0 .2rem; text-indent: .3em;
}
.cover-sub {
  font-family: var(--font-en); font-style: italic; font-weight: 300;
  font-size: .85rem; letter-spacing: .08em; color: var(--ink-faint); margin: 0 0 3rem;
}

.dyad { margin: 0 0 2.6rem; }
.dyad p {
  margin: 0; font-size: clamp(1.6rem, 7.2vw, 2.4rem);
  font-weight: 600; line-height: 1.5; letter-spacing: .06em;
}
.dyad p[lang="en"] { letter-spacing: .01em; font-weight: 500; }
.dyad .t { color: var(--brass); }
.dyad .m { color: var(--blue); }
.dyad .braid { display: block; height: 2.3rem; margin: .15rem 0 .15rem .5em; }
.dyad .braid svg { height: 100%; width: 34px; overflow: visible; }

.cover-lede { font-size: 1.02rem; color: var(--ink-soft); max-width: 31rem; margin: 0 0 2.4rem; }
.cover-lede strong { font-weight: 600; color: var(--ink); }
.cover-meta {
  font-family: var(--font-data); font-size: .74rem; letter-spacing: .12em;
  color: var(--ink-faint); border-top: 1px solid var(--rule); padding-top: .9rem;
}

/* トップページのヒーロー（二段組） */
.hero { padding: 76px 0 84px; }
.hero .wrap { display: grid; grid-template-columns: 1.08fr .92fr; gap: 64px; align-items: center; }
.hero .dyad p { font-size: clamp(1.5rem, 5vw, 2.15rem); }
.hero-lede { font-size: 1rem; color: var(--ink-soft); max-width: 29rem; margin: 0 0 2rem; }

/* --------------------------------------------------------------------------
   6. ボタン
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-ui); font-size: 14px; font-weight: 500; letter-spacing: .06em;
  padding: 12px 24px; border: 1px solid var(--ink); border-radius: 2px;
  background: var(--ink); color: var(--paper); cursor: pointer;
  transition: background .18s ease, color .18s ease;
}
.btn:hover { background: transparent; color: var(--ink); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--rule); }
.btn-ghost:hover { background: transparent; border-color: var(--ink); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

/* --------------------------------------------------------------------------
   7. 表題欄（製図のタイトルブロック）
   -------------------------------------------------------------------------- */
.title-block {
  border: 1px solid var(--ink); background: var(--paper-3);
  font-family: var(--font-ui); max-width: 400px; justify-self: end; width: 100%;
}
.title-block-head {
  display: flex; justify-content: space-between; align-items: baseline; gap: 12px;
  padding: 11px 16px; border-bottom: 1px solid var(--ink);
  font-family: var(--font-data); font-size: 11px; letter-spacing: .14em; color: var(--ink-soft);
}
.title-block-body { padding: 20px 16px 18px; }
.title-block-body h2 { font-family: var(--font-ja); font-size: 1.22rem; font-weight: 700; margin: 0 0 4px; line-height: 1.6; }
.title-block-body h2 a { border-bottom: 1px solid transparent; }
.title-block-body h2 a:hover { color: var(--blue); border-bottom-color: var(--blue); }
.title-block-body .orig { font-family: var(--font-en); font-style: italic; font-size: .85rem; color: var(--ink-soft); margin: 0; }
.title-block dl { display: grid; grid-template-columns: repeat(2, 1fr); margin: 0; border-top: 1px solid var(--rule); }
.title-block dl > div { padding: 10px 16px; border-bottom: 1px solid var(--rule); }
.title-block dl > div:nth-child(odd) { border-right: 1px solid var(--rule); }
.title-block dl > div:nth-last-child(-n+2) { border-bottom: 0; }
.title-block dt { font-size: 10px; letter-spacing: .12em; color: var(--ink-faint); margin-bottom: 2px; }
.title-block dd { margin: 0; font-size: 13px; color: var(--ink); }

/* --------------------------------------------------------------------------
   8. セクション共通
   -------------------------------------------------------------------------- */
.section { padding: 72px 0; border-top: 1px solid var(--rule-faint); }
.section-tint { background: var(--paper-2); }
.inner-narrow { max-width: 38rem; }

.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 20px; margin-bottom: 30px; }
.section-head h2 { font-size: 1.4rem; font-weight: 700; letter-spacing: .08em; margin: 0; }
.section-head h2[lang="en"] { letter-spacing: .02em; }
.section-head .note { font-family: var(--font-ui); font-size: 13px; color: var(--ink-faint); margin: 0; }

/* --------------------------------------------------------------------------
   9. 宣言文（本文組み）
   -------------------------------------------------------------------------- */
.doc { max-width: 38rem; margin: 0 auto; padding: 0 28px; }
.doc section { padding: 4.4rem 0; }
.doc section + section { border-top: 1px solid var(--rule-faint); }

.ch-no { display: block; font-size: .88rem; letter-spacing: .5em; color: var(--ink-faint); margin: 0 0 .5rem; }
.doc h2 {
  font-size: 1.32rem; font-weight: 700; letter-spacing: .09em; line-height: 1.7;
  margin: 0 0 .5rem; padding: 0;
}
.doc h2[data-l="ja"] { margin-bottom: .3rem; }
.doc h2[lang="en"] {
  font-size: 1.06rem; font-weight: 500; letter-spacing: .02em;
  color: var(--ink-soft); margin: 0 0 2rem; padding-bottom: 1.1rem;
  border-bottom: 1px solid var(--rule);
}
html[data-lang="ja"] .doc h2[data-l="ja"] {
  margin-bottom: 2rem; padding-bottom: 1.1rem; border-bottom: 1px solid var(--rule);
}
.doc h3 { font-size: 1.02rem; font-weight: 700; letter-spacing: .09em; margin: 2.6rem 0 .9rem; }
.doc h3[lang="en"] { font-size: .98rem; font-weight: 600; }

.strike {
  margin: 2.2rem 0; padding-left: 1.1rem; border-left: 3px solid var(--ink);
  font-size: 1.16rem; font-weight: 600; line-height: 1.95; letter-spacing: .07em;
}
.strike[lang="en"] { font-size: 1.1rem; line-height: 1.6; letter-spacing: 0; }
.strike.m { border-color: var(--blue); color: var(--blue); }
.strike.t { border-color: var(--brass); color: var(--brass); }

.aside {
  font-size: .9rem; line-height: 1.95; color: var(--ink-faint);
  border-top: 1px solid var(--rule-faint); padding-top: 1.1rem; margin-top: 2.3rem;
}
.aside[lang="en"] { line-height: 1.7; }

/* 二つの柱 */
.pillar { position: relative; margin: 0 0 2.6rem; padding: 1.5rem 0 1.6rem 1.5rem; border-left: 1px solid var(--rule); }
.pillar::before { content: ""; position: absolute; left: -1px; top: 0; width: 3px; height: 3.4rem; }
.pillar.t::before { background: var(--brass); }
.pillar.m::before { background: var(--blue); }
.pillar h3 { margin: 0 0 .1rem; font-size: 1.16rem; letter-spacing: .1em; }
.pillar.t h3 { color: var(--brass); }
.pillar.m h3 { color: var(--blue); }
.pillar .role {
  font-family: var(--font-en); font-style: italic; font-size: .82rem;
  letter-spacing: .05em; color: var(--ink-faint); margin: 0 0 1.3rem;
}
.pillar dl { margin: 1.3rem 0 0; font-size: .92rem; line-height: 1.95; }
.pillar dl[lang="en"] { line-height: 1.7; }
.pillar dt { font-family: var(--font-ui); font-size: .74rem; letter-spacing: .14em; color: var(--ink-faint); margin-top: .9rem; }
.pillar dd { margin: .1rem 0 0; }
.pillar .motto { margin: 1.5rem 0 0; font-weight: 600; font-size: 1.02rem; letter-spacing: .06em; }
.pillar.t .motto { color: var(--brass); }
.pillar.m .motto { color: var(--blue); }

/* 存在のニーズ */
ul.needs { list-style: none; margin: 0 0 1.9rem; padding: 0; }
ul.needs li {
  padding: .68rem 0; border-bottom: 1px solid var(--rule-faint);
  font-size: .98rem; line-height: 1.85;
}
ul.needs li:first-child { border-top: 1px solid var(--rule-faint); }
ul.needs b { font-weight: 700; letter-spacing: .08em; }
ul.needs b::after { content: "──"; margin: 0 .55em; color: var(--ink-faint); font-weight: 400; letter-spacing: 0; }
ul.needs span { color: var(--ink-soft); font-size: .93rem; }
ul.needs[lang="en"] li { line-height: 1.65; }
ul.needs .n { font-family: var(--font-data); font-size: .72rem; color: var(--ink-faint); letter-spacing: .1em; margin-right: .8rem; }

/* 原則 */
ol.tenets { list-style: none; margin: 0; padding: 0; counter-reset: t; }
ol.tenets li {
  counter-increment: t; position: relative;
  padding: 1.2rem 0 1.25rem 2.6rem; border-bottom: 1px solid var(--rule-faint);
  font-size: .95rem; line-height: 1.95;
}
ol.tenets li[lang="en"] { line-height: 1.7; }
ol.tenets li:first-child { border-top: 1px solid var(--rule-faint); }
ol.tenets li::before {
  content: counter(t, decimal-leading-zero); position: absolute; left: 0; top: 1.4rem;
  font-family: var(--font-data); font-size: .78rem; color: var(--blue); letter-spacing: .06em;
}
ol.tenets b { display: block; font-weight: 700; letter-spacing: .09em; font-size: 1.02rem; margin-bottom: .1rem; }

/* 行程 */
.phase { position: relative; padding: 1.25rem 0 1.3rem 1.4rem; border-left: 1px solid var(--rule); }
.phase::before {
  content: ""; position: absolute; left: -4px; top: 1.95rem; width: 7px; height: 7px;
  background: var(--paper); border: 1px solid var(--blue); border-radius: 50%;
}
.phase h3 { margin: 0 0 .3rem; font-size: 1rem; }
.phase .tag {
  display: block; font-family: var(--font-data); font-size: .74rem;
  letter-spacing: .14em; color: var(--ink-faint); margin-bottom: .1rem;
}
.phase p { font-size: .92rem; line-height: 1.95; margin: 0; }
.phase p[lang="en"] { line-height: 1.7; }

/* 結び */
.close { background: var(--paper-2); }
.close .call { font-size: clamp(1.28rem, 5.4vw, 1.72rem); font-weight: 700; line-height: 1.85; letter-spacing: .07em; margin: 2.4rem 0 0; }
.close .call[lang="en"] { line-height: 1.5; letter-spacing: .01em; }
.close .call .t { color: var(--brass); }
.close .call .m { color: var(--blue); }

blockquote { margin: 2.8rem 0 0; padding: 1.7rem 0 0; border-top: 1px solid var(--rule); }
blockquote p { font-size: 1.08rem; font-weight: 600; line-height: 1.95; letter-spacing: .06em; margin: 0 0 .7rem; }
blockquote p[lang="en"] { line-height: 1.6; }
blockquote cite { font-family: var(--font-en); font-style: italic; font-size: .8rem; color: var(--ink-faint); letter-spacing: .04em; }

/* 宣言文ページの目次 */
.doc-toc { border: 1px solid var(--rule); background: var(--paper-3); padding: 20px 22px; margin: 2.6rem 0 0; }
.doc-toc h2 { font-family: var(--font-ui); font-size: 11px; letter-spacing: .16em; color: var(--ink-faint); margin: 0 0 12px; border: 0; padding: 0; font-weight: 500; }
.doc-toc ol { list-style: none; margin: 0; padding: 0; columns: 2; column-gap: 28px; font-size: 13.5px; line-height: 1.95; }
.doc-toc a { color: var(--ink-soft); display: block; }
.doc-toc a:hover { color: var(--blue); }
.doc-toc .n { font-family: var(--font-data); font-size: 11px; color: var(--ink-faint); margin-right: 8px; }

/* --------------------------------------------------------------------------
   10. 蔵書カタログ
   -------------------------------------------------------------------------- */
.catalog { border-top: 1px solid var(--rule); }
.catalog-row {
  display: grid; grid-template-columns: 1fr repeat(4, auto);
  align-items: baseline; gap: 18px; padding: 20px 0; border-bottom: 1px solid var(--rule);
}
.catalog-row .titles a { font-size: 17.5px; font-weight: 500; border-bottom: 1px solid transparent; }
.catalog-row .titles a:hover { color: var(--blue); border-bottom-color: var(--blue); }
.catalog-row .titles .original {
  display: block; font-family: var(--font-en); font-style: italic;
  font-size: 13px; color: var(--ink-faint); margin-top: 2px;
}
.catalog-row time { font-family: var(--font-data); font-size: 13px; color: var(--ink-faint); white-space: nowrap; }

.tag-pill {
  font-family: var(--font-ui); font-size: 11.5px; letter-spacing: .06em;
  border: 1px solid var(--rule); border-radius: 2px; padding: 4px 9px;
  color: var(--ink-soft); white-space: nowrap;
}
.tag-pill.t { color: var(--brass); border-color: var(--rule); border-color: color-mix(in srgb, var(--brass) 45%, transparent); }
.tag-pill.m { color: var(--blue);  border-color: var(--rule); border-color: color-mix(in srgb, var(--blue) 45%, transparent); }

.strand {
  font-family: var(--font-data); font-size: 11px; letter-spacing: .14em;
  color: var(--ink-faint); white-space: nowrap;
}

/* カテゴリ索引 */
.category-index { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); border: 1px solid var(--rule); }
.category-index a { padding: 18px 20px 20px; border-right: 1px solid var(--rule); font-family: var(--font-ui); }
.category-index a:last-child { border-right: 0; }
.category-index a:hover { background: var(--paper-3); }
.category-index .name { display: block; font-family: var(--font-ja); font-size: 15.5px; font-weight: 600; margin-bottom: 5px; }
.category-index .count { font-family: var(--font-data); font-size: 12px; color: var(--ink-faint); }

/* 二つの柱・要約カード（トップページ） */
.pillar-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0; border: 1px solid var(--rule); }
.pillar-grid > div { padding: 30px 30px 32px; }
.pillar-grid > div:first-child { border-right: 1px solid var(--rule); }
.pillar-grid h3 { margin: 0 0 2px; font-size: 1.14rem; letter-spacing: .1em; }
.pillar-grid .t h3 { color: var(--brass); }
.pillar-grid .m h3 { color: var(--blue); }
.pillar-grid .role { font-family: var(--font-en); font-style: italic; font-size: .82rem; color: var(--ink-faint); margin: 0 0 1.1rem; }
.pillar-grid p { font-size: .94rem; color: var(--ink-soft); }
.pillar-grid p[lang="en"] { line-height: 1.7; }
.pillar-grid .motto { font-weight: 600; font-size: .98rem; margin-top: 1.1rem; }
.pillar-grid .t .motto { color: var(--brass); }
.pillar-grid .m .motto { color: var(--blue); }

/* 検索 */
.search-field {
  font-family: var(--font-ui); font-size: 13.5px; padding: 8px 12px;
  border: 1px solid var(--rule); border-radius: 2px;
  background: var(--paper-3); color: var(--ink); width: 230px;
}
.search-field::placeholder { color: var(--ink-faint); }

/* --------------------------------------------------------------------------
   11. 書籍ページ
   -------------------------------------------------------------------------- */
.breadcrumb { font-family: var(--font-ui); font-size: 12.5px; color: var(--ink-faint); padding: 20px 0; margin: 0; }
.breadcrumb a { color: var(--ink-soft); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb .sep { margin: 0 8px; }

.book-head { padding: 8px 0 52px; border-bottom: 1px solid var(--rule); }
.book-head .kicker { font-family: var(--font-ui); font-size: 12.5px; letter-spacing: .1em; color: var(--brass); margin: 0 0 12px; }
.book-head h1 { font-size: clamp(27px, 3.4vw, 38px); font-weight: 700; margin: 0 0 8px; line-height: 1.5; }
.book-head .original-title { font-family: var(--font-en); font-style: italic; font-size: 15.5px; color: var(--ink-soft); margin: 0 0 26px; }

.bib-card { display: grid; grid-template-columns: repeat(2, 1fr); border: 1px solid var(--rule); background: var(--paper-3); margin: 0; }
.bib-field { padding: 15px 20px; border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
.bib-field:nth-child(2n) { border-right: 0; }
.bib-field:nth-last-child(-n+2) { border-bottom: 0; }
.bib-field dt { font-family: var(--font-ui); font-size: 11px; letter-spacing: .1em; color: var(--ink-faint); margin-bottom: 4px; }
.bib-field dd { margin: 0; font-size: 14px; }

.book-body { display: grid; grid-template-columns: 236px 1fr; gap: 60px; padding: 52px 0 88px; align-items: start; }

.toc { position: sticky; top: 92px; font-family: var(--font-ui); font-size: 13px; }
.toc h3 { font-size: 11px; letter-spacing: .14em; color: var(--ink-faint); margin: 0 0 12px; font-weight: 500; }
.toc ol, .toc ul { list-style: none; margin: 0 0 20px; padding: 0; }
.toc a {
  display: flex; gap: 8px; padding: 5px 0 5px 10px; margin-left: -12px;
  color: var(--ink-soft); border-left: 2px solid transparent;
}
.toc a .n { color: var(--ink-faint); flex-shrink: 0; font-family: var(--font-data); }
.toc a:hover, .toc a.current { color: var(--ink); border-left-color: var(--blue); background: var(--paper-3); }
.toc-more { font-size: 12px; color: var(--ink-faint); padding-left: 10px; }

.reader { max-width: var(--measure); }
.reader-tools { display: flex; align-items: center; gap: 9px; margin-bottom: 36px; font-family: var(--font-ui); font-size: 12.5px; color: var(--ink-faint); }
.reader-tools .size-btn { width: 29px; height: 29px; border: 1px solid var(--rule); border-radius: 2px; background: transparent; cursor: pointer; color: var(--ink-soft); }
.reader-tools .size-btn:hover { color: var(--ink); border-color: var(--ink-faint); }
.reader .story-eyebrow { font-family: var(--font-ui); font-size: 12.5px; letter-spacing: .1em; color: var(--ink-faint); margin: 0 0 5px; }
.reader h2 { font-size: 25px; font-weight: 700; margin: 0 0 34px; line-height: 1.55; letter-spacing: .05em; }
.reader p { margin: 0 0 1.5em; }
.reader.text-lg { font-size: 19px; line-height: 2.15; }
.reader .fn-ref { font-size: .7em; vertical-align: super; color: var(--blue); }
.reader .footnotes { margin-top: 38px; padding-top: 18px; border-top: 1px solid var(--rule); font-family: var(--font-ui); font-size: 12.5px; color: var(--ink-soft); }

.reader-figure { margin: 38px 0; padding: 26px; background: var(--paper-3); border: 1px solid var(--rule); text-align: center; }
.reader-figure svg { width: 100%; max-width: 260px; margin: 0 auto; }
.reader-figure figcaption { margin-top: 12px; font-family: var(--font-ui); font-size: 12px; color: var(--ink-faint); }

.story-nav { display: flex; justify-content: space-between; gap: 24px; margin-top: 52px; padding-top: 26px; border-top: 1px solid var(--rule); font-family: var(--font-ui); font-size: 13.5px; }
.story-nav a { color: var(--ink-soft); max-width: 45%; }
.story-nav a:hover { color: var(--blue); }
.story-nav .dir { display: block; font-size: 11px; color: var(--ink-faint); margin-bottom: 3px; }
.story-nav .next { text-align: right; margin-left: auto; }

/* --------------------------------------------------------------------------
   12. フッター
   -------------------------------------------------------------------------- */
.site-footer { border-top: 1px solid var(--rule); padding: 44px 0 56px; }
.site-footer .wrap { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 22px; font-family: var(--font-ui); font-size: 12.5px; color: var(--ink-faint); }
.site-footer .sig { font-family: var(--font-en); letter-spacing: .26em; font-size: 13px; color: var(--ink-soft); }
.site-footer a { color: var(--ink-soft); }
.site-footer a:hover { color: var(--blue); }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }

/* --------------------------------------------------------------------------
   13. 登場（表紙のみ・一度だけ）
   -------------------------------------------------------------------------- */
@keyframes rise { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: none; } }
.cover-full .wrap-narrow > * { animation: rise .9s cubic-bezier(.2,.7,.25,1) both; }
.cover-full .wrap-narrow > *:nth-child(1) { animation-delay: .04s; }
.cover-full .wrap-narrow > *:nth-child(2) { animation-delay: .12s; }
.cover-full .wrap-narrow > *:nth-child(3) { animation-delay: .24s; }
.cover-full .wrap-narrow > *:nth-child(4) { animation-delay: .46s; }
.cover-full .wrap-narrow > *:nth-child(5) { animation-delay: .56s; }
.cover-full .wrap-narrow > *:nth-child(6) { animation-delay: .64s; }

/* --------------------------------------------------------------------------
   14. レスポンシブ
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
  .hero .wrap { grid-template-columns: 1fr; gap: 44px; }
  .title-block { justify-self: start; }
  .book-body { grid-template-columns: 1fr; gap: 32px; }
  .toc { position: static; border-bottom: 1px solid var(--rule); padding-bottom: 20px; }
  .pillar-grid { grid-template-columns: 1fr; }
  .pillar-grid > div:first-child { border-right: 0; border-bottom: 1px solid var(--rule); }
}

@media (max-width: 760px) {
  .wrap, .wrap-narrow, .doc { padding: 0 20px; }
  .main-nav {
    display: none; position: absolute; top: 72px; left: 0; right: 0;
    flex-direction: column; gap: 0; background: var(--paper);
    border-bottom: 1px solid var(--rule); padding: 8px 20px 16px;
  }
  .main-nav.is-open { display: flex; }
  .main-nav a { padding: 11px 0; border-bottom: 1px solid var(--rule-faint); }
  .nav-toggle { display: grid; }
  .hero { padding: 52px 0 60px; }
  .section { padding: 54px 0; }
  .doc section { padding: 3.5rem 0; }
  .catalog-row { grid-template-columns: 1fr; gap: 6px; }
  .catalog-row .meta-line { display: flex; gap: 12px; align-items: center; }
  .bib-card { grid-template-columns: 1fr; }
  .bib-field { border-right: 0 !important; border-bottom: 1px solid var(--rule) !important; }
  .bib-field:last-child { border-bottom: 0 !important; }
  .doc-toc ol { columns: 1; }
  .site-footer .wrap { flex-direction: column; align-items: flex-start; }
  body { font-size: 16.5px; line-height: 2; }
}

@media (max-width: 420px) {
  .lang-switch button { padding: 6px 7px; font-size: 11px; }
}

/* --------------------------------------------------------------------------
   15. 印刷
   -------------------------------------------------------------------------- */
@media print {
  .site-header, .site-footer, .doc-toc, .btn-row, .reader-tools, .story-nav { display: none !important; }
  body { background: #fff; color: #000; font-size: 11pt; }
  .cover::before { display: none; }
  .cover-full { min-height: auto; padding: 0 0 2rem; }
  .doc section { padding: 1.6rem 0; break-inside: avoid; }
  a { color: #000; }
}

/* ==========================================================================
   16. 検証の段階（Mechanics）
   ========================================================================== */
.verify {
  font-family: var(--font-ui); font-size: 11px; letter-spacing: .1em;
  padding: 3px 9px; border-radius: 2px; white-space: nowrap;
  border: 1px solid var(--rule); color: var(--ink-faint);
}
.verify.v0 { color: var(--ink-faint); }
.verify.v1 { color: var(--ink-soft); border-color: var(--ink-faint); }
.verify.v2 { color: var(--blue); border-color: var(--blue); }
.verify.v3 { color: var(--blue); border-color: var(--blue); background: color-mix(in srgb, var(--blue) 10%, transparent); }
.verify.v4 { color: var(--paper); background: var(--blue); border-color: var(--blue); }

.verify-bar { border: 1px solid var(--rule); background: var(--paper-3); padding: 16px 20px 18px; margin: 0 0 26px; }
.verify-bar-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 14px; }
.verify-en { font-family: var(--font-en); font-style: italic; font-size: 12px; color: var(--ink-faint); }

.verify-ladder { display: flex; flex-wrap: wrap; gap: 0; list-style: none; margin: 0 0 12px; padding: 0; counter-reset: vl -1; }
.verify-ladder li {
  counter-increment: vl; position: relative; flex: 1 1 auto; min-width: 88px;
  font-family: var(--font-ui); font-size: 11.5px; color: var(--ink-faint);
  padding: 16px 6px 0; text-align: center; border-top: 2px solid var(--rule);
}
.verify-ladder li::before {
  content: ""; position: absolute; top: -5px; left: 50%; margin-left: -4px;
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--paper-3); border: 2px solid var(--rule);
}
.verify-ladder li.done { color: var(--blue); border-top-color: var(--blue); }
.verify-ladder li.done::before { background: var(--blue); border-color: var(--blue); }
.verify-desc { font-size: 13px; color: var(--ink-soft); margin: 0; line-height: 1.85; }

/* 宣言文の段階リスト（0から数える） */
ol.ladder { list-style: none; margin: 1.6rem 0 1.8rem; padding: 0; counter-reset: lad -1; }
ol.ladder li {
  counter-increment: lad; position: relative;
  padding: .8rem 0 .85rem 2.6rem; border-bottom: 1px solid var(--rule-faint);
  font-size: .96rem; line-height: 1.85;
}
ol.ladder li:first-child { border-top: 1px solid var(--rule-faint); }
ol.ladder li::before {
  content: counter(lad); position: absolute; left: 0; top: 1.05rem;
  font-family: var(--font-data); font-size: .82rem; color: var(--blue);
}
ol.ladder b { font-weight: 700; letter-spacing: .08em; }
ol.ladder b::after { content: "──"; margin: 0 .55em; color: var(--ink-faint); font-weight: 400; }
ol.ladder span { color: var(--ink-soft); font-size: .92rem; }
ol.ladder[lang="en"] li { line-height: 1.65; }

/* ==========================================================================
   17. Markdown 本文
   ========================================================================== */
.reader.md h2 { font-size: 1.5rem; margin: 3rem 0 1.4rem; line-height: 1.6; letter-spacing: .06em; }
.reader.md h2:first-of-type { margin-top: 0; }
.reader.md h3 { font-size: 1.12rem; font-weight: 700; margin: 2.4rem 0 .9rem; letter-spacing: .07em; }
.reader.md h4 { font-size: 1rem; font-weight: 700; margin: 1.8rem 0 .7rem; color: var(--ink-soft); }
.reader.md ul, .reader.md ol { margin: 0 0 1.6em; padding-left: 1.6em; }
.reader.md li { margin-bottom: .45em; }
.reader.md blockquote {
  margin: 1.8rem 0; padding: .2rem 0 .2rem 1.2rem;
  border-top: 0; border-left: 3px solid var(--rule); color: var(--ink-soft);
}
.reader.md blockquote p { font-size: 1rem; font-weight: 400; letter-spacing: .03em; }
.reader.md hr { border: 0; border-top: 1px solid var(--rule); margin: 2.6rem 0; }
.md-summary {
  font-size: 1.04rem; color: var(--ink-soft);
  border-left: 3px solid var(--brass); padding-left: 1.1rem; margin-bottom: 2.4rem;
}
.md-code {
  background: var(--paper-3); border: 1px solid var(--rule); padding: 16px 18px;
  overflow-x: auto; font-size: 13px; line-height: 1.75; margin: 1.8rem 0;
}
.reader.md code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: .88em; background: var(--paper-3); padding: 1px 5px; border-radius: 2px;
}
.md-code code { background: none; padding: 0; }
.md-table-scroll { overflow-x: auto; margin: 1.8rem 0; }
.md-table { border-collapse: collapse; width: 100%; font-family: var(--font-ui); font-size: 13.5px; }
.md-table th, .md-table td { border: 1px solid var(--rule); padding: 9px 13px; text-align: left; vertical-align: top; }
.md-table th { background: var(--paper-3); font-weight: 700; white-space: nowrap; }
.md-figure { margin: 2.2rem 0; padding: 0; text-align: center; }
.md-figure img { margin: 0 auto; border: 1px solid var(--rule); background: var(--paper-3); }
.md-figure figcaption { margin-top: 10px; font-family: var(--font-ui); font-size: 12px; color: var(--ink-faint); }
.reader.md ruby rt { font-size: .5em; color: var(--ink-faint); letter-spacing: 0; }

/* コンテナ :::note / :::warn / :::spec / :::steps */
.md-note, .md-warn, .md-spec, .md-steps {
  border: 1px solid var(--rule); padding: 18px 22px; margin: 2rem 0; background: var(--paper-3);
}
.md-note  { border-left: 3px solid var(--brass); }
.md-warn  { border-left: 3px solid var(--blue); }
.md-spec  { border-left: 3px solid var(--blue); }
.md-steps { border-left: 3px solid var(--ink-faint); }
.md-note > :last-child, .md-warn > :last-child,
.md-spec > :last-child, .md-steps > :last-child { margin-bottom: 0; }
.md-note > p:first-child, .md-warn > p:first-child { margin-top: 0; }
.md-steps ol { counter-reset: st; list-style: none; padding-left: 0; }
.md-steps ol li { counter-increment: st; position: relative; padding-left: 2.4rem; margin-bottom: 1em; }
.md-steps ol li::before {
  content: counter(st, decimal-leading-zero); position: absolute; left: 0; top: .1em;
  font-family: var(--font-data); font-size: .8rem; color: var(--blue);
}

.footnotes h3 { font-size: 11px; letter-spacing: .14em; color: var(--ink-faint); margin: 0 0 10px; font-weight: 500; }
.footnotes ol { padding-left: 1.4em; margin: 0; }
.footnotes li { margin-bottom: .5em; }
.fn-back { color: var(--blue); margin-left: .4em; }

/* 目次の階層 */
.toc li.lv2 a { padding-left: 20px; }
.toc li.lv3 a { padding-left: 32px; font-size: 12.5px; }

/* ==========================================================================
   18. フォーム
   ========================================================================== */
.ol-form { margin-top: 1.8rem; }
.ol-form .field { margin: 0 0 1.5rem; }
.ol-form label { display: block; font-family: var(--font-ui); font-size: 13px; margin-bottom: 7px; }
.ol-form .opt { color: var(--ink-faint); font-size: 11.5px; margin-left: .5em; }
.ol-form input[type="text"], .ol-form input[type="email"],
.ol-form select, .ol-form textarea {
  width: 100%; font-family: var(--font-ui); font-size: 14.5px; line-height: 1.8;
  padding: 10px 13px; border: 1px solid var(--rule); border-radius: 2px;
  background: var(--paper-3); color: var(--ink);
}
.ol-form textarea { font-family: var(--font-ja); resize: vertical; }
.ol-form input:focus, .ol-form select:focus, .ol-form textarea:focus { border-color: var(--blue); }
.field-trap { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form-errors {
  border: 1px solid var(--blue); border-left-width: 3px;
  background: var(--paper-3); padding: 14px 18px; margin: 0 0 1.6rem;
  font-family: var(--font-ui); font-size: 13.5px;
}
.form-errors p { margin: 0 0 .4em; }
.form-errors p:last-child { margin-bottom: 0; }
mark { background: color-mix(in srgb, var(--brass) 22%, transparent); color: inherit; padding: 0 .3em; }

@media (max-width: 760px) {
  .catalog-row { grid-template-columns: 1fr; gap: 6px; }
  .verify-ladder li { min-width: 64px; font-size: 10.5px; }
  .reader.md h2 { font-size: 1.32rem; }
}