/* reference/prototype.html の見た目を引き継ぐ。一列の読書欄。段落を開くと原文/英訳の二列パネル */
:root {
  --paper: #f2f3f0;
  --ink: #1d2230;
  --ink-soft: #5b6273;
  --rule: #d5d8d6;
  --panel: #e8eae6;
  --beni: #a3213a;
  --beni-wash: rgba(163, 33, 58, 0.16);
  --kin: #9a7a2c;
  --f-tr: "Shippori Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --f-orig: "Zen Old Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
  --f-en: "EB Garamond", Georgia, "Times New Roman", serif;
  --f-ui: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #121621; --ink: #e4e2da; --ink-soft: #9aa0ae; --rule: #2a3040;
    --panel: #1a1f2c; --beni: #e2677e; --beni-wash: rgba(226, 103, 126, 0.22); --kin: #d2b062;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #121621; --ink: #e4e2da; --ink-soft: #9aa0ae; --rule: #2a3040;
  --panel: #1a1f2c; --beni: #e2677e; --beni-wash: rgba(226, 103, 126, 0.22); --kin: #d2b062;
  color-scheme: dark;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--f-tr);
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}
a { color: inherit; text-decoration-color: var(--kin); text-underline-offset: 0.2em; }
a:hover { color: var(--beni); }
.wrap { max-width: 42rem; margin: 0 auto; padding-block: 1.5rem 4rem; display: grid; gap: 2.5rem; }

/* サイト共通 */
.site-nav { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; flex-wrap: wrap;
  font-family: var(--f-ui); font-size: 0.78rem; letter-spacing: 0.08em; color: var(--ink-soft); }
.site-nav a { text-decoration: none; }
.site-nav .site-name { color: var(--ink); font-weight: 500; }
.site-foot { font-family: var(--f-ui); font-size: 0.78rem; line-height: 1.8; color: var(--ink-soft);
  border-top: 1px solid var(--rule); padding-top: 1.2rem; }
.site-foot p { margin: 0; }

.page-head { display: grid; gap: 0.9rem; }
.source { font-family: var(--f-ui); font-size: 0.78rem; letter-spacing: 0.14em; color: var(--ink-soft); }
.source a { text-decoration: none; }
h1 { font-weight: 600; font-size: clamp(2rem, 6vw, 2.8rem); line-height: 1.2; margin: 0; letter-spacing: 0.06em; text-wrap: balance; }
h1 .en { display: block; font-family: var(--f-en); font-style: italic; font-weight: 400; font-size: 0.42em; letter-spacing: 0.02em; color: var(--kin); margin-top: 0.35rem; }
.lead { line-height: 2; margin: 0; }
.how { font-family: var(--f-ui); font-size: 0.86rem; line-height: 1.8; color: var(--ink-soft); margin: 0; max-width: 34em; }
.tools { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.tools button {
  font-family: var(--f-ui); font-size: 0.8rem; color: var(--ink); background: transparent;
  border: 1px solid var(--rule); border-radius: 999px; padding: 0.35rem 0.9rem; cursor: pointer;
}
.tools button:hover { border-color: var(--kin); }
.tools button:focus-visible, .ja:focus-visible, .ph:focus-visible, a:focus-visible { outline: 2px solid var(--kin); outline-offset: 3px; }

/* 目次 */
.toc { list-style: none; margin: 0; padding: 0; }
.toc li { border-top: 1px solid var(--rule); }
.toc li:last-child { border-bottom: 1px solid var(--rule); }
.toc a { display: grid; gap: 0.2rem; padding-block: 1.1rem; text-decoration: none; }
.toc-book { font-family: var(--f-ui); font-size: 0.72rem; color: var(--kin); letter-spacing: 0.12em; }
.toc-title { font-size: 1.3rem; letter-spacing: 0.06em; }
.toc-en { font-family: var(--f-en); font-style: italic; color: var(--ink-soft); }
.toc-note { margin: 0 0 1.1rem; font-size: 0.92rem; line-height: 1.9; color: var(--ink-soft); }
.base-text { font-family: var(--f-ui); font-size: 0.8rem; color: var(--ink-soft); margin-top: 1.5rem; }

/* 章段本文 */
main { display: grid; gap: 0.4rem; }
.para { border-top: 1px solid var(--rule); }
.para:last-child { border-bottom: 1px solid var(--rule); }

.ja {
  font-size: 1.12rem; line-height: 2.25; padding-block: 1.3rem; cursor: pointer;
  display: grid; grid-template-columns: 2.2rem 1fr; gap: 0.6rem; align-items: start;
}
.num { font-family: var(--f-ui); font-size: 0.72rem; color: var(--kin); letter-spacing: 0.1em; padding-top: 0.85rem; }
.ja-text { min-width: 0; }
.ja:hover .ja-text { color: color-mix(in srgb, var(--ink) 82%, var(--kin)); }
ruby { ruby-align: center; }
/* 和訳のあとに添える原文の歌(ウェイリー版源氏の日本語訳にならう) */
.waka { display: block; padding-left: 3em; margin-block: 2.25em; margin-block: 1lh; font-family: var(--f-orig); color: var(--ink-soft); }
ruby rt { font-family: var(--f-ui); font-size: 0.5em; color: var(--kin); letter-spacing: 0.04em; }

.ph { border-radius: 2px; transition: background-color .18s ease, color .18s ease; }
.para.open .ja .ph { background-image: linear-gradient(var(--kin), var(--kin)); background-size: 100% 1px; background-position: 0 92%; background-repeat: no-repeat; cursor: pointer; }
.para.open .ja .ph:hover { background-color: var(--beni-wash); }
.ph.on { background-color: var(--beni-wash) !important; color: var(--beni); box-shadow: 0 0 0 2px var(--beni-wash); }

.panel {
  margin: 0 0 1.4rem 2.8rem; background: var(--panel); border-radius: 4px;
  padding: 1.2rem 1.3rem; display: grid; grid-template-columns: 1fr 1fr; gap: 1.4rem;
}
.panel[hidden] { display: none; }
.col { min-width: 0; display: grid; gap: 0.5rem; align-content: start; }
.lab { font-family: var(--f-ui); font-size: 0.7rem; letter-spacing: 0.16em; color: var(--ink-soft); }
.orig p { font-family: var(--f-orig); font-size: 1rem; line-height: 2.05; margin: 0; }
.en p { font-family: var(--f-en); font-size: 1.08rem; line-height: 1.65; margin: 0; }
.orig .ph, .en .ph { cursor: pointer; }

/* 解説・前後 */
.note, .prose { line-height: 2; }
.note h2, .prose h2 { font-size: 1.05rem; letter-spacing: 0.1em; margin: 2rem 0 0.6rem; font-weight: 600; }
.note p, .prose p { margin: 0 0 1em; }
.note { font-size: 0.95rem; }
.prose { display: block; }
.pager { display: flex; justify-content: space-between; gap: 1rem; font-family: var(--f-ui); font-size: 0.85rem; }
.pager a { text-decoration: none; }

@media (max-width: 560px) {
  .wrap { padding-block: 1.2rem 3rem; }
  .ja { grid-template-columns: 1fr; gap: 0; font-size: 1.05rem; }
  .num { padding-top: 0; }
  .panel { grid-template-columns: 1fr; margin-left: 0; }
}
@media (prefers-reduced-motion: reduce) { .ph { transition: none; } }