/* 本文だけの頁
   html に .tate が付くと縦組、無ければ横組。どちらも明朝の一段組で、本文以外の要素は置かない。 */

:root {
  --paper: #fcfbf8;
  --ink: #26241f;
  --ink-soft: #77736a;
  --rule: #dcd8cf;
  --veil: rgb(252 251 248 / 0.94);
  --mincho: "Shippori Mincho", "Hiragino Mincho ProN", "Yu Mincho", "YuMincho", "Noto Serif JP", serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #1a1916;
    --ink: #dcd8cf;
    --ink-soft: #8f8a80;
    --rule: #3a3833;
    --veil: rgb(26 25 22 / 0.94);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mincho);
}
::selection { background: var(--ink); color: var(--paper); }
a:focus-visible, button:focus-visible, main:focus-visible { outline: 1px solid var(--ink-soft); outline-offset: 4px; }

/* ---------- 本文 ---------- */
article, nav.toc {
  font-size: 1.0625rem;
  line-height: 2;
  letter-spacing: 0.04em;
  line-break: strict;
  hanging-punctuation: allow-end;
  text-spacing-trim: trim-start;
}
h1 { font-size: 1.35rem; font-weight: 600; letter-spacing: 0.12em; line-height: 1.6; }
p { margin: 0; text-indent: 1em; }
.break { color: var(--ink-soft); text-indent: 0; text-align: center; }
.colophon { color: var(--ink-soft); font-size: 0.85rem; text-indent: 0; }
.back { font-size: 0.85rem; text-indent: 0; }
.back a { color: var(--ink-soft); text-underline-offset: 0.3em; text-decoration-thickness: 1px; }

/* 見出し：本文と同じ大きさの太字で三字下げ、前に二行・後ろに一行の空き（後ろの本文に付いて見えるように）。番号の後ろに一字空ける */
h2 { margin: 0; margin-block: 2em 1em; padding-inline-start: 3em; font-size: 1em; font-weight: 600; line-height: inherit; letter-spacing: 0.08em; }
h2 .no { margin-inline-end: 1em; letter-spacing: 0; }
html:not(.tate) h2 .no { color: var(--ink-soft); }

/* ルビ・縦中横 */
rt { font-size: 0.5em; letter-spacing: 0; }
.tcy { text-combine-upright: all; }

/* 強調は傍点（ゴマ点）。縦組では右、横組では上 */
em {
  font-style: normal;
  -webkit-text-emphasis: filled sesame;
  text-emphasis: filled sesame;
  -webkit-text-emphasis-position: over right;
  text-emphasis-position: over right;
}

/* 和欧間の空き（四分） */
.ws { margin-inline-start: 0.25em; }
.we { margin-inline-end: 0.25em; }
/* 全角英数字は横組で半角に戻るので、そのときだけ空きを付ける */
html:not(.tate) .zen.zws { margin-inline-start: 0.25em; }
html:not(.tate) .zen.zwe { margin-inline-end: 0.25em; }

/* 注番号・図番号は縦組で漢数字、横組で算用数字 */
html.tate .na, html:not(.tate) .nk { display: none; }

/* 引用：二字下げ、一回り小さく、前後に一行ずつの空き。出典は行の終わりに寄せる */
blockquote { margin: 0; margin-block: 2em; padding-inline-start: 2em; font-size: 0.92em; }
blockquote .src { text-indent: 0; text-align: end; color: var(--ink-soft); font-size: 0.92em; margin-block-start: 0.5em; }

/* 箇条書き：前後に一行ずつの空き、記号は段落の字下げと同じ一字目に置き、二行目以降は本文の頭に揃える。
   記号の幅（--lm-k / --lm-a）は lib/markdown.js が一覧ごとに付ける */
.items { list-style: none; margin: 0; margin-block: 1em; padding: 0; padding-inline-start: 1em; --lm: var(--lm-a); }
html.tate .items { --lm: var(--lm-k); }
.items .items { margin-block: 0; padding-inline-start: 0; }
.items li { padding-inline-start: var(--lm); }
.items li p { text-indent: 0; }
.lm { display: inline-block; min-inline-size: var(--lm); margin-inline-start: calc(-1 * var(--lm)); text-indent: 0; letter-spacing: 0; }
ul.items > li > .lm, ul.items > li > p:first-child > .lm { color: var(--ink-soft); }

/* 注番号と末尾の注 */
.fnref { font-size: 0.6em; vertical-align: super; line-height: 0; margin-inline-start: 0.1em; color: var(--ink-soft); text-decoration: none; letter-spacing: 0; }
html.tate .fnref { vertical-align: top; }
.fnref:hover { color: var(--ink); }
.fns { margin-block-start: 3em; font-size: 0.75em; color: var(--ink-soft); }
.fns::before { content: ""; display: block; inline-size: 5em; border-block-start: 1px solid var(--rule); margin-block-end: 1.25em; }
.fns ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 0.25em; }
.fns li { display: flex; gap: 1em; min-width: 0; min-height: 0; }
.fns a { color: inherit; }
.fnback { flex: none; text-decoration: none; min-inline-size: 1.5em; }
.fnbody { min-width: 0; min-height: 0; overflow-wrap: anywhere; }
.fnbody a { text-underline-offset: 0.3em; text-decoration-thickness: 1px; }
html.tate .fnbody a { text-underline-position: right; }

/* 図の参照。本文の中では薄い色の（図一）だけを見せる */
.figref { font-size: 0.85em; letter-spacing: 0; color: var(--ink-soft); text-decoration: none; cursor: pointer; }
.figref:hover { color: var(--ink); }
/* 図そのもの。スクリプトが動く環境では窓で開くので隠し、動かない環境では末尾に並べる */
html.js .figs { display: none; }
.figs { margin-block-start: 3em; display: flex; flex-direction: column; gap: 2em; }
.figs figure { margin: 0; }
.figs img { display: block; max-width: 100%; max-height: 70vh; }
.figs figcaption { font-size: 0.8em; color: var(--ink-soft); text-indent: 0; }
.figs figcaption b, .lb-fig figcaption b { font-weight: 600; color: var(--ink); margin-inline-end: 1em; }

/* 図を開いた窓。頁を薄く沈め、画像は画面いっぱい近くまで */
.lightbox {
  position: fixed; inset: 0; z-index: 20;
  display: grid; place-items: center;
  background: var(--veil);
  writing-mode: horizontal-tb;
  padding-block: calc(3.5rem + env(safe-area-inset-top, 0px)) calc(2rem + env(safe-area-inset-bottom, 0px));
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}
.lb-fig { margin: 0; display: flex; flex-direction: column; align-items: center; gap: 1rem; max-width: 100%; }
.lb-fig img { display: block; max-width: min(100%, 1100px); max-height: calc(100vh - 9rem); object-fit: contain; box-shadow: 0 10px 40px rgb(0 0 0 / 0.12); background: var(--paper); }
.lb-fig figcaption { max-width: 34em; font-size: 0.85rem; line-height: 1.8; letter-spacing: 0.06em; color: var(--ink-soft); text-align: center; text-wrap: balance; }
.lb-close {
  position: absolute;
  top: calc(0.5rem + env(safe-area-inset-top, 0px));
  right: max(12px, env(safe-area-inset-right, 0px));
}

/* ---------- 目次へ・組方の切り替え（線だけのアイコン） ---------- */
.tools { display: flex; }
.toc-ico, .kumi-ico, .lb-close {
  display: grid; place-items: center;
  width: 2.25rem; height: 2.25rem;
  padding: 0; border: 0; border-radius: 50%;
  background: none; color: var(--ink-soft); cursor: pointer;
  transition: color 0.2s ease;
}
.toc-ico:hover, .kumi-ico:hover, .lb-close:hover { color: var(--ink); }
.toc-ico svg, .kumi-ico svg, .lb-close svg { width: 1.1rem; height: 1.1rem; display: block; }
.kumi-ico .to-yoko { display: none; }
html.tate .kumi-ico .to-tate { display: none; }
html.tate .kumi-ico .to-yoko { display: block; }
/* 目次へのアイコンは、いまの組方での目次の並びを描く */
.toc-ico .in-tate { display: none; }
html.tate .toc-ico .in-yoko { display: none; }
html.tate .toc-ico .in-tate { display: block; }
html:not(.js) .tools { display: none; }
/* 押すと何が起きるかを添える札。title の既定の札は出るまで遅いので、自前で出す。
   横組では下に、縦組では（下に並ぶアイコンに重ならないよう）左に出す */
.toc-ico, .kumi-ico { position: relative; }
.toc-ico::after, .kumi-ico::after {
  content: attr(data-tip);
  position: absolute; z-index: 10;
  writing-mode: horizontal-tb;
  white-space: nowrap;
  padding: 0.3em 0.7em;
  border: 1px solid var(--rule); border-radius: 3px;
  background: var(--paper); color: var(--ink-soft);
  font-size: 0.75rem; line-height: 1.6; letter-spacing: 0.06em;
  opacity: 0; pointer-events: none;
  transition: opacity 0.15s ease;
}
html:not(.tate) .toc-ico::after, html:not(.tate) .kumi-ico::after { top: calc(100% + 0.25rem); right: 0; }
html.tate .toc-ico::after, html.tate .kumi-ico::after { right: calc(100% + 0.25rem); top: 50%; transform: translateY(-50%); }
@media (hover: hover) {
  .toc-ico:hover::after, .kumi-ico:hover::after { opacity: 1; transition-delay: 0.3s; }
}
.toc-ico:focus-visible::after, .kumi-ico:focus-visible::after { opacity: 1; }
@media (prefers-reduced-motion: reduce) { .toc-ico, .kumi-ico, .lb-close, .toc-ico::after, .kumi-ico::after { transition: none; } }

/* ---------- 目次 ---------- */
nav.toc h1 { letter-spacing: 0.5em; }
nav.toc ol { list-style: none; margin: 0; padding: 0; padding-inline-start: 3em; display: flex; flex-direction: column; gap: 1.8em; }
nav.toc li { display: flex; align-items: center; }
nav.toc li::before { content: "・"; display: inline-block; inline-size: 1.5em; margin-inline-start: -1.5em; color: var(--ink-soft); }
nav.toc li a { color: inherit; text-decoration: none; }
nav.toc .t { text-decoration: underline; text-underline-offset: 0.35em; text-decoration-thickness: 1px; text-decoration-color: var(--ink-soft); }
html.tate nav.toc .t { text-underline-position: right; }
nav.toc li a:hover .t, nav.toc li a:focus-visible .t { text-decoration-color: var(--ink); }

/* ---------- 横組 ---------- */
html:not(.tate) body {
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  padding-block: calc(12vh + env(safe-area-inset-top, 0px)) calc(16vh + env(safe-area-inset-bottom, 0px));
}
html:not(.tate) article { max-width: 36em; margin: 0 auto; }
html:not(.tate) nav.toc { max-width: 32em; margin: 0 auto; }
html:not(.tate) h1 { margin: 0 0 3.5em; text-wrap: balance; }
html:not(.tate) nav.toc h1 { margin: 0 0 3em; }
html:not(.tate) .break { margin: 2em 0; letter-spacing: 1em; text-indent: 1em; }
html:not(.tate) .colophon { margin-top: 4em; text-align: right; }
html:not(.tate) .back { margin-top: 1em; text-align: right; }
html:not(.tate) .tools { justify-content: flex-end; margin: 0 -0.5rem 1.5em 0; }

/* ---------- 縦組 ---------- */
html.tate, html.tate body { height: 100%; overflow: hidden; }
html.tate body { padding-top: env(safe-area-inset-top, 0px); padding-bottom: env(safe-area-inset-bottom, 0px); }
html.tate main {
  /* 縦組のブロックは幅が内容なりに広がるので、画面幅に固定して中だけを横にスクロールさせる */
  width: 100%;
  height: 100%;
  writing-mode: vertical-rl;
  overflow-x: auto;
  overflow-y: hidden;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  scrollbar-width: thin;
}
html.tate article, html.tate nav.toc {
  margin-inline: auto;
  padding-block: 10vw;
  padding-inline: 8vh 6vh;
  letter-spacing: 0.06em;
  text-orientation: mixed;
}
html.tate article { inline-size: min(38em, 100%); }
html.tate nav.toc { inline-size: min(28em, 100%); }
html.tate h1 { letter-spacing: 0.15em; margin: 0 0 0 3em; padding-inline-start: 2em; }
html.tate nav.toc h1 { letter-spacing: 0.5em; }
html.tate .break { margin: 0 1.5em; }
html.tate .colophon { margin-block-start: 3em; text-align: end; }
html.tate .back { margin-block-start: 1em; text-align: end; }
html.tate .tools { justify-content: flex-start; margin: -0.5rem 0 0 1.25em; }