/* 文芸結社 共通スタイル
   方針: 解説はゴシック、作品（作例）は明朝。紺と生成りはファビコンの色から。
   ボタンは塗り・枠・下端の影で押せる形にする。目次は初期展開。 */

:root {
  --kon: #0a2342;          /* 紺：ブランド・主要ボタン */
  --kon-deep: #061833;
  --kon-link: #17406f;     /* 本文リンク */
  --kon-hover: #1f5290;
  --kon-tint: #e8edf5;
  --kinari: #f0e4d1;       /* 生成り：ファビコンの文字色 */
  --washi: #f8f3ea;        /* 作例の紙面 */
  --washi-line: #e3d7c2;   /* 作例の罫線 */
  --ink: #1d2127;          /* 本文 */
  --ink-sub: #4a525b;      /* 補足（白地で 7.9:1） */
  --line: #d3d8de;
  --line-strong: #9aa3ad;
  --shu: #a3362a;          /* 朱：修正前・削除・エラーだけに使う */
  --shu-tint: #fbece9;
  --matsu: #23613f;        /* 松葉：修正後・追加 */
  --matsu-tint: #e7f2ea;
  --ochre: #7a5410;        /* 注意 */
  --ochre-tint: #fbf3e2;
  --focus: #b86e00;
  --bg: #ffffff;
  --radius: 8px;
  --measure: 40em;
  --sans: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "BIZ UDPGothic", "Yu Gothic", YuGothic, Meiryo, "Noto Sans JP", "Noto Sans CJK JP", sans-serif;
  --serif: "Hiragino Mincho ProN", "BIZ UDPMincho", "Yu Mincho", YuMincho, "Noto Serif JP", "Noto Serif CJK JP", serif;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.85;
  letter-spacing: 0.02em;
  overflow-wrap: anywhere;
  line-break: strict;
}
@media (min-width: 768px) { body { font-size: 1.125rem; } }

img { max-width: 100%; height: auto; }

a { color: var(--kon-link); text-decoration-thickness: 1px; text-underline-offset: 0.22em; }
a:visited { color: #4a3a78; }
a:hover { color: var(--kon-hover); text-decoration-thickness: 2px; }

:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; border-radius: 3px; }

.bk-skip {
  position: absolute; left: 0.5rem; top: -4rem; z-index: 100;
  background: #fff; color: var(--kon); padding: 0.6rem 1rem; border: 2px solid var(--kon); border-radius: var(--radius);
  font-weight: 700;
}
.bk-skip:focus { top: 0.5rem; }

.bk-wrap { max-width: 72rem; margin: 0 auto; padding: 0 1rem; }
@media (min-width: 768px) { .bk-wrap { padding: 0 1.5rem; } }

/* ---------------------------------------------------------------- ヘッダー */

.bk-header { background: var(--kon); color: var(--kinari); }
.bk-header-in { display: flex; align-items: center; gap: 0.75rem; min-height: 4rem; padding-top: 0.5rem; padding-bottom: 0.5rem; }
.bk-logo { display: flex; align-items: center; gap: 0.6rem; color: var(--kinari); text-decoration: none; margin-right: auto; min-width: 0; }
.bk-logo:visited, .bk-logo:hover { color: var(--kinari); }
.bk-logo img { width: 40px; height: 40px; flex: none; border-radius: 9px; box-shadow: 0 0 0 1px rgba(240, 228, 209, 0.35); }
.bk-logo-name { font-family: var(--serif); font-size: 1.35rem; font-weight: 700; letter-spacing: 0.12em; line-height: 1.2; display: block; }
.bk-logo-sub { font-size: 0.75rem; letter-spacing: 0.04em; opacity: 0.88; display: block; line-height: 1.4; }
@media (max-width: 420px) { .bk-logo-sub { display: none; } }

.bk-hbtn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.35rem;
  min-height: 44px; padding: 0.35rem 0.9rem;
  background: transparent; color: var(--kinari);
  border: 2px solid rgba(240, 228, 209, 0.7); border-radius: var(--radius);
  font: inherit; font-size: 0.95rem; font-weight: 700; letter-spacing: 0.04em;
  text-decoration: none; cursor: pointer; white-space: nowrap;
}
.bk-hbtn:visited { color: var(--kinari); }
.bk-hbtn:hover { background: rgba(240, 228, 209, 0.14); color: #fff; border-color: var(--kinari); }
.bk-hbtn[aria-expanded="true"] { background: var(--kinari); color: var(--kon); border-color: var(--kinari); }
.bk-hbtn svg { width: 1.1em; height: 1.1em; flex: none; }
.bk-hnav { display: flex; gap: 0.5rem; align-items: center; }
.bk-hnav .bk-only-wide { display: none; }
@media (min-width: 860px) { .bk-hnav .bk-only-wide { display: inline-flex; } }

.bk-menu { background: var(--kon-deep); color: var(--kinari); border-top: 1px solid rgba(240, 228, 209, 0.2); }
.bk-menu[hidden] { display: none; }
.bk-menu-in { padding-top: 1.25rem; padding-bottom: 1.5rem; display: grid; gap: 1.25rem; }
@media (min-width: 768px) { .bk-menu-in { grid-template-columns: 1fr 1fr 1fr; } }
.bk-menu h2 { font-size: 0.95rem; margin: 0 0 0.5rem; letter-spacing: 0.06em; color: #fff; }
.bk-menu ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.35rem; }
.bk-menu a { display: flex; flex-direction: column; color: var(--kinari); text-decoration: none; padding: 0.45rem 0.7rem; border-radius: 6px; border: 1px solid rgba(240, 228, 209, 0.22); line-height: 1.45; }
.bk-menu a:hover { background: rgba(240, 228, 209, 0.1); border-color: rgba(240, 228, 209, 0.6); }
.bk-menu a small { font-size: 0.8rem; opacity: 0.85; }
.bk-menu-close { justify-self: start; }

/* ---------------------------------------------------------------- パンくず */

.bk-crumbs { font-size: 0.875rem; color: var(--ink-sub); margin: 1rem 0 0; }
.bk-crumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 0.15rem 0.4rem; }
.bk-crumbs li { display: inline-flex; align-items: center; gap: 0.4rem; }
.bk-crumbs li + li::before { content: "›"; color: var(--line-strong); }
.bk-crumbs a { color: var(--ink-sub); }
.bk-crumbs [aria-current] { color: var(--ink); }

/* ---------------------------------------------------------------- 記事レイアウト */

.bk-main { padding-bottom: 3rem; }

.bk-article { display: grid; grid-template-columns: minmax(0, 1fr); grid-template-areas: "head" "lead" "toc" "body" "foot"; column-gap: 3rem; }
@media (min-width: 1100px) {
  .bk-article.has-toc { grid-template-columns: minmax(0, 44rem) 17.5rem; grid-template-areas: "head ." "lead toc" "body toc" "foot toc"; justify-content: center; }
  .bk-article.has-toc .bk-toc { position: sticky; top: 1rem; align-self: start; max-height: calc(100vh - 2rem); overflow: auto; margin-top: 0; }
}
.bk-article:not(.has-toc) { max-width: 44rem; margin: 0 auto; }
.bk-ahead { grid-area: head; }
.bk-lead { grid-area: lead; }
.bk-toc { grid-area: toc; }
.bk-body { grid-area: body; min-width: 0; }
.bk-afoot { grid-area: foot; min-width: 0; }

.bk-cat { display: inline-block; margin: 1.25rem 0 0; font-size: 0.875rem; font-weight: 700; color: var(--kon); text-decoration: none; border: 1px solid var(--kon); border-radius: 999px; padding: 0.1rem 0.8rem; }
.bk-cat:visited { color: var(--kon); }
.bk-cat:hover { background: var(--kon-tint); }

h1, .bk-h1 {
  font-family: var(--serif); font-weight: 700; font-feature-settings: "palt";
  font-size: 1.6rem; line-height: 1.45; letter-spacing: 0.04em;
  margin: 0.6rem 0 0.5rem;
}
@media (min-width: 768px) { h1, .bk-h1 { font-size: 2.05rem; } }

.bk-meta { font-size: 0.875rem; color: var(--ink-sub); margin: 0.25rem 0 0; display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; align-items: center; }

.bk-pr-note { display: inline-flex; align-items: center; gap: 0.45rem; font-size: 0.875rem; color: var(--ink-sub); margin: 0.75rem 0 0; }
.bk-pr {
  display: inline-block; font-size: 0.8125rem; line-height: 1.2; font-weight: 700; letter-spacing: 0.06em;
  color: #3b424a; background: #fff; border: 1px solid #6b737c; border-radius: 4px; padding: 0.12rem 0.38rem;
  font-family: var(--sans); flex-shrink: 0; white-space: nowrap;
}

/* この記事の答え */
.bk-answer { position: relative; margin: 1.5rem 0 0; padding: 1.4rem 1.2rem 1rem; border: 2px solid var(--kon); border-radius: var(--radius); background: #fff; }
.bk-answer-label { position: absolute; top: -0.85rem; left: 0.9rem; margin: 0; background: var(--kon); color: #fff; font-size: 0.85rem; font-weight: 700; letter-spacing: 0.06em; padding: 0.1rem 0.75rem; border-radius: 4px; line-height: 1.6; }
.bk-answer > :last-child { margin-bottom: 0; }
.bk-answer p { margin: 0 0 0.6rem; }
.bk-answer ul, .bk-answer ol { margin: 0 0 0.6rem; padding-left: 1.3em; }

/* 目次 */
.bk-toc { margin: 1.75rem 0 0; border: 1px solid var(--line); border-radius: var(--radius); background: #fbfbfa; font-size: 0.95rem; }
.bk-toc summary { list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 0.6rem 0.75rem 0.6rem 1rem; cursor: pointer; font-weight: 700; min-height: 48px; border-radius: var(--radius); }
.bk-toc summary::-webkit-details-marker { display: none; }
.bk-toc-state { display: inline-flex; align-items: center; gap: 0.3rem; font-size: 0.85rem; font-weight: 700; color: var(--kon); border: 2px solid var(--kon); background: #fff; border-radius: 6px; padding: 0.2rem 0.7rem; min-height: 36px; box-shadow: 0 2px 0 var(--line-strong); }
.bk-toc summary:hover .bk-toc-state { background: var(--kon-tint); }
.bk-toc-state::after { content: "閉じる"; }
.bk-toc:not([open]) .bk-toc-state::after { content: "開く"; }
.bk-toc-state::before { content: ""; width: 0.5em; height: 0.5em; border-right: 2px solid currentColor; border-bottom: 2px solid currentColor; transform: rotate(-135deg) translate(-0.1em, -0.1em); }
.bk-toc:not([open]) .bk-toc-state::before { transform: rotate(45deg) translate(-0.1em, -0.1em); }
.bk-toc ol { list-style: none; margin: 0; padding: 0 1rem 0.9rem; counter-reset: toc; }
.bk-toc li { margin: 0; }
.bk-toc a { display: block; padding: 0.38rem 0.4rem; color: var(--ink); text-decoration: none; border-radius: 4px; line-height: 1.55; }
.bk-toc a:hover { background: var(--kon-tint); color: var(--kon); }
.bk-toc a.is-current { background: var(--kon-tint); color: var(--kon); font-weight: 700; }
.bk-toc .lv2 > a { counter-increment: toc; display: grid; grid-template-columns: 1.8em 1fr; }
.bk-toc .lv2 > a::before { content: counter(toc) "."; color: var(--ink-sub); }
.bk-toc .lv3 > a { padding-left: 2.2em; font-size: 0.9em; color: var(--ink-sub); }

/* ---------------------------------------------------------------- 本文 */

.bk-body { margin-top: 0.5rem; }
.bk-body > * { max-width: var(--measure); }
.bk-body > .bk-table, .bk-body > .bk-compare, .bk-body > .bk-poem, .bk-body > .bk-cards { max-width: none; }
.bk-body p { margin: 0 0 1.1em; }
.bk-body h2 {
  font-family: var(--serif); font-feature-settings: "palt"; font-weight: 700;
  font-size: 1.4rem; line-height: 1.5; letter-spacing: 0.04em;
  margin: 3rem 0 1.1rem; padding-top: 1.1rem; border-top: 3px solid var(--kon);
  scroll-margin-top: 1rem;
}
@media (min-width: 768px) { .bk-body h2 { font-size: 1.55rem; } }
.bk-body h3 { font-size: 1.12rem; line-height: 1.6; margin: 2.2rem 0 0.8rem; padding-left: 0.7rem; border-left: 4px solid var(--kinari); scroll-margin-top: 1rem; }
.bk-body h4 { font-size: 1rem; margin: 1.6rem 0 0.6rem; }
.bk-body ul, .bk-body ol { padding-left: 1.4em; margin: 0 0 1.2em; }
.bk-body li { margin: 0.3em 0; }
.bk-body li > p { margin: 0 0 0.4em; }
.bk-body strong { font-weight: 700; background: linear-gradient(transparent 62%, #f3e6c4 62%); }
.bk-body blockquote { margin: 0 0 1.2em; padding: 0.6rem 1rem; border-left: 4px solid var(--line-strong); color: var(--ink-sub); background: #fafafa; }
.bk-body hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }
.bk-body ruby rt { font-size: 0.55em; letter-spacing: 0; }
.bk-body del { color: var(--shu); text-decoration-color: var(--shu); text-decoration-thickness: 2px; background: var(--shu-tint); }
.bk-body ins { color: var(--matsu); text-decoration: none; border-bottom: 2px solid var(--matsu); background: var(--matsu-tint); }
.bk-body code { font-family: inherit; background: #f2f3f5; padding: 0.05em 0.3em; border-radius: 3px; }
.bk-pre { white-space: pre-wrap; background: #f6f7f8; border: 1px solid var(--line); border-radius: 6px; padding: 0.8rem 1rem; font-family: var(--sans); font-size: 0.95em; line-height: 1.75; margin: 0 0 1.2em; overflow-x: auto; }

/* 表 */
.bk-table { overflow-x: auto; margin: 0 0 1.5em; border: 1px solid var(--line); border-radius: 6px; -webkit-overflow-scrolling: touch; }
.bk-table table { border-collapse: collapse; width: 100%; font-size: 0.95em; line-height: 1.65; }
.bk-table th, .bk-table td { border-bottom: 1px solid var(--line); padding: 0.6rem 0.8rem; text-align: left; vertical-align: top; min-width: 7em; }
.bk-table tr > :first-child { min-width: 6em; }
.bk-table thead th { background: var(--washi); font-weight: 700; border-bottom: 2px solid var(--washi-line); white-space: nowrap; }
.bk-table tbody tr:last-child > * { border-bottom: 0; }
.bk-table tbody th { background: #fbfaf7; font-weight: 700; }
.bk-table td + td, .bk-table th + th, .bk-table th + td { border-left: 1px solid var(--line); }

/* 囲み（要点・注意・練習・手順・確認表） */
.bk-box { margin: 1.6em 0; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; }
.bk-box-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0.2rem 0.7rem; margin: 0 !important; padding: 0.65rem 1rem 0; }
.bk-box-label { display: inline-block; font-size: 0.8125rem; font-weight: 700; letter-spacing: 0.06em; color: #fff; background: var(--ink-sub); border-radius: 4px; padding: 0.05rem 0.55rem; line-height: 1.7; }
.bk-box-title { font-weight: 700; font-size: 1rem; }
.bk-box-body { padding: 0.6rem 1rem 0.4rem; }
.bk-box-body > :last-child { margin-bottom: 0.6rem; }
.bk-point { border-color: #b8c6da; background: #f6f8fc; }
.bk-point .bk-box-label { background: var(--kon); }
.bk-note { border-color: #e2cfa6; background: var(--ochre-tint); }
.bk-note .bk-box-label { background: var(--ochre); }
.bk-exercise { border: 2px dashed #9fbfaa; background: #fbfdfb; }
.bk-exercise .bk-box-label { background: var(--matsu); }
.bk-steps .bk-box-label { background: var(--kon); }
.bk-checklist .bk-box-label { background: var(--kon); }

ol.bk-steps-list { list-style: none; counter-reset: st; padding-left: 0; }
ol.bk-steps-list > li { counter-increment: st; position: relative; padding-left: 2.6rem; margin: 0 0 0.9em; }
ol.bk-steps-list > li::before { content: counter(st); position: absolute; left: 0; top: 0.1em; width: 1.9rem; height: 1.9rem; border-radius: 50%; background: var(--kon); color: #fff; font-weight: 700; font-size: 0.95rem; display: flex; align-items: center; justify-content: center; line-height: 1; }

ul.bk-checks { list-style: none; padding-left: 0; }
ul.bk-checks > li { display: grid; grid-template-columns: 1.6rem 1fr; gap: 0.6rem; align-items: start; margin: 0 0 0.55em; }
.bk-ck { width: 1.35rem; height: 1.35rem; margin: 0.25em 0 0; accent-color: var(--kon); cursor: pointer; }
ul.bk-checks > li > p, .bk-ck-text > p { margin: 0; }

/* 作例（散文）：生成りの紙と罫線、明朝 */
.bk-example { background: var(--washi); border-color: var(--washi-line); }
.bk-example .bk-box-label, .bk-poem .bk-box-label, .bk-verse .bk-box-label { background: #6d5a3a; }
.bk-example .bk-box-body {
  font-family: var(--serif); font-size: 1.02em; letter-spacing: 0.04em;
  line-height: 2em; padding: 0.9rem 1.2rem 1rem;
  background-image: linear-gradient(to bottom, transparent calc(2em - 1px), var(--washi-line) calc(2em - 1px));
  background-size: 100% 2em; background-position: 0 0.9rem; background-origin: padding-box; background-repeat: repeat-y;
}
.bk-example .bk-box-body p { margin: 0; text-indent: 1em; }
.bk-example .bk-box-body p.dlg { text-indent: 0; }
.bk-example .bk-box-body p + p { margin-top: 0; }
.bk-example .bk-box-body ul, .bk-example .bk-box-body ol { margin: 0; font-family: var(--sans); }
.bk-example .bk-box-body > :last-child { margin-bottom: 0; }
.bk-example .bk-box-body strong { background: none; }

/* 短詩：縦書きの短冊＋音数表 */
.bk-poem { margin: 1.6em 0; border: 1px solid var(--washi-line); border-radius: var(--radius); background: #fff; }
.bk-poem .bk-box-head { padding-bottom: 0.2rem; }
.bk-poem-grid { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: 1rem 1.4rem; padding: 0.7rem 1rem 0.9rem; align-items: start; }
.bk-poem-v {
  writing-mode: vertical-rl; text-orientation: mixed;
  font-family: var(--serif); font-size: 1.3rem; line-height: 1.75; letter-spacing: 0.14em;
  background: var(--washi); border: 1px solid var(--washi-line); border-radius: 4px;
  padding: 1rem 0.7rem; justify-self: start;
  box-shadow: inset 0 0 0 4px #fff, inset 0 0 0 5px var(--washi-line);
}
.bk-poem-ku { display: block; }
.bk-poem-table table { border-collapse: collapse; width: 100%; font-size: 0.92em; line-height: 1.55; }
.bk-poem-table th { text-align: left; font-size: 0.8rem; color: var(--ink-sub); font-weight: 700; padding: 0.2rem 0.5rem; border-bottom: 2px solid var(--washi-line); }
.bk-poem-table td { padding: 0.35rem 0.5rem; border-bottom: 1px solid #eee5d6; vertical-align: top; }
.bk-poem-t { font-family: var(--serif); }
.bk-poem-r { color: var(--ink-sub); }
@media (min-width: 561px) { .bk-poem-t { min-width: 5.5em; } .bk-poem-r { min-width: 6em; } }
.bk-poem-grid > *, .bk-compare-grid > * { min-width: 0; }
.bk-poem-table { overflow-x: auto; }
.bk-poem-n { white-space: nowrap; font-weight: 700; }
.bk-poem-inner { display: block; font-weight: 400; font-size: 0.82em; color: var(--ink-sub); }
.bk-poem-diff { display: block; font-weight: 700; font-size: 0.8em; color: var(--shu); }
.bk-poem-sum { margin: 0.55rem 0 0 !important; font-size: 0.85rem; color: var(--ink-sub); }
.bk-poem-cap { margin: 0 !important; padding: 0 1rem 0.8rem; font-size: 0.9rem; color: var(--ink-sub); }
@media (max-width: 560px) {
  .bk-poem-grid { grid-template-columns: 1fr; }
  .bk-poem-v { justify-self: center; min-height: 0; }
  .bk-poem-t { white-space: normal; }
}

/* 詩の作例 */
.bk-verse { margin: 1.6em 0; border: 1px solid var(--washi-line); border-radius: var(--radius); background: var(--washi); }
.bk-verse-body { padding: 0.6rem 1.4rem 0.9rem; font-family: var(--serif); line-height: 2; letter-spacing: 0.05em; }
.bk-verse-body p { margin: 0 0 1.2em; }
.bk-verse-body p:last-child { margin-bottom: 0.2rem; }

/* 修正前後 */
.bk-compare { margin: 1.8em 0; border: 1px solid var(--line); border-radius: var(--radius); background: #fcfcfb; padding: 0.8rem; }
.bk-compare > .bk-box-title { display: block; margin: 0.1rem 0.2rem 0.7rem !important; font-weight: 700; }
.bk-compare-grid { display: grid; grid-template-columns: 1fr; gap: 0.8rem; }
@media (min-width: 720px) { .bk-compare-grid { grid-template-columns: 1fr 1fr; } .bk-compare-grid > .bk-why { grid-column: 1 / -1; } }
.bk-before, .bk-after, .bk-why { margin: 0; border-radius: 6px; background: #fff; }
.bk-before { border: 1px solid #e6c1bb; }
.bk-after { border: 1px solid #a9cbb5; }
.bk-before > .bk-box-label, .bk-after > .bk-box-label, .bk-why > .bk-box-label { display: inline-block; margin: 0.7rem 0.9rem 0 !important; }
.bk-before > .bk-box-label { background: var(--shu); }
.bk-after > .bk-box-label { background: var(--matsu); }
.bk-before .bk-box-body, .bk-after .bk-box-body { padding: 0.5rem 0.9rem 0.3rem; font-family: var(--serif); line-height: 1.95; }
.bk-before .bk-box-body p, .bk-after .bk-box-body p { margin: 0 0 0.6em; }
.bk-before .bk-poem, .bk-after .bk-poem, .bk-before .bk-verse, .bk-after .bk-verse { margin: 0.4em 0 0.6em; font-family: var(--sans); }
.bk-before .bk-poem-grid, .bk-after .bk-poem-grid { grid-template-columns: 1fr; }
.bk-before .bk-poem-v, .bk-after .bk-poem-v { justify-self: center; min-height: 0; }
.bk-why { border: 1px dashed var(--line-strong); padding: 0 0.9rem 0.5rem; }
.bk-why > .bk-box-label { background: var(--ink-sub); margin-left: 0 !important; }
.bk-why p, .bk-why ul { margin: 0.5rem 0; }

/* ひな形（コピーできる文面） */
.bk-template { margin: 1.6em 0; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; padding-bottom: 0.9rem; }
.bk-template-text { white-space: pre-wrap; font-family: var(--sans); font-size: 0.95em; line-height: 1.8; margin: 0.6rem 1rem 0.8rem; padding: 0.8rem 1rem; background: #f7f8f9; border-radius: 6px; border: 1px solid #e5e8eb; overflow-x: auto; }
.bk-template .bk-copy { margin-left: 1rem; }

/* 次にすること */
.bk-next { margin: 2em 0; border: 2px solid var(--kon); border-radius: var(--radius); background: #f5f8fc; padding: 1rem 1.1rem 1.1rem; }
.bk-next-label { margin: 0 0 0.3rem !important; font-size: 0.85rem; font-weight: 700; color: var(--kon); letter-spacing: 0.05em; }
.bk-next-body p { margin: 0 0 0.75rem; }
.bk-next .bk-btn { margin-top: 0.2rem; }

/* 紹介枠 */
.bk-offer { margin: 2em 0; border: 1px solid var(--line-strong); border-radius: var(--radius); background: #fff; padding: 0.9rem 1.1rem 1.1rem; }
.bk-offer-top { display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem 0.7rem; margin: 0 0 0.4rem !important; }
.bk-offer-name { font-weight: 700; font-size: 1.02rem; }
.bk-offer-kind { font-size: 0.8rem; color: var(--ink-sub); }
.bk-offer-desc p { margin: 0 0 0.7rem; }
.bk-offer-foot { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center; margin-top: 0.4rem; }
.bk-offer.is-plain { background: #fbfbfa; border-color: var(--line); }
.bk-offer-fine { font-size: 0.85rem; color: var(--ink-sub); margin: 0.5rem 0 0 !important; }

/* 問いと答え */
.bk-qa { margin: 1.2em 0; border-top: 1px solid var(--line); padding-top: 0.8em; }
.bk-qa-q { font-weight: 700; margin: 0 0 0.4em !important; }
.bk-qa-q::before { content: "問"; display: inline-flex; align-items: center; justify-content: center; width: 1.6em; height: 1.6em; margin-right: 0.5em; border-radius: 4px; background: var(--kon); color: #fff; font-size: 0.85em; }
.bk-aside { background: #fafafa; padding: 0.8rem 1rem; }

/* カード一覧（案内ページ） */
.bk-cards { margin: 1.2em 0 2em; }
.bk-cards-title { font-weight: 700; margin: 0 0 0.6rem !important; }
.bk-cards ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.6rem; }
@media (min-width: 720px) { .bk-cards ul { grid-template-columns: 1fr 1fr; } }
.bk-card { border: 1px solid var(--line); border-radius: var(--radius); background: #fff; padding: 0.75rem 0.95rem 0.8rem; display: flex; flex-direction: column; gap: 0.2rem; margin: 0 !important; position: relative; }
.bk-card:hover { border-color: var(--kon); box-shadow: 0 0 0 1px var(--kon); }
.bk-card-link { font-weight: 700; line-height: 1.55; text-decoration: none; color: var(--kon-link); }
.bk-card-link::after { content: ""; position: absolute; inset: 0; border-radius: var(--radius); }
.bk-card-link:hover { text-decoration: underline; }
.bk-card-desc { font-size: 0.9rem; color: var(--ink-sub); line-height: 1.65; }

/* ---------------------------------------------------------------- ボタン */

.bk-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.45rem;
  min-height: 48px; padding: 0.55rem 1.3rem;
  background: var(--kon); color: #fff !important;
  border: 2px solid var(--kon); border-radius: var(--radius);
  box-shadow: 0 3px 0 var(--kon-deep);
  font: inherit; font-weight: 700; font-size: 1rem; line-height: 1.45; letter-spacing: 0.03em;
  text-decoration: none !important; text-align: center; cursor: pointer;
  transition: background-color 0.12s ease;
}
.bk-btn:hover { background: var(--kon-hover); border-color: var(--kon-hover); }
.bk-btn:active { transform: translateY(2px); box-shadow: 0 1px 0 var(--kon-deep); }
.bk-btn-sub { background: #fff; color: var(--kon) !important; box-shadow: 0 3px 0 var(--line-strong); }
.bk-btn-sub:hover { background: var(--kon-tint); border-color: var(--kon); }
.bk-btn-sub:active { box-shadow: 0 1px 0 var(--line-strong); }
.bk-btn[disabled], .bk-btn[aria-disabled="true"] { background: #e9ebee; border-color: #c4c9cf; color: #59616a !important; box-shadow: none; cursor: not-allowed; transform: none; }
.bk-btn.is-done { background: var(--matsu); border-color: var(--matsu); box-shadow: 0 3px 0 #164029; }
.bk-btn-sub.is-done { background: var(--matsu-tint); color: var(--matsu) !important; border-color: var(--matsu); }
.bk-btn-block { display: flex; width: 100%; }
.bk-btns { display: flex; flex-wrap: wrap; gap: 0.7rem; align-items: center; margin: 1rem 0; }

/* ---------------------------------------------------------------- 記事の末尾 */

.bk-sources { margin-top: 3rem; padding-top: 0.5rem; border-top: 1px solid var(--line); font-size: 0.92rem; }
.bk-sources summary { list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 0.4rem 0; cursor: pointer; min-height: 48px; }
.bk-sources summary::-webkit-details-marker { display: none; }
.bk-sources summary:hover .bk-toc-state { background: var(--kon-tint); }
.bk-sources h2 { font-size: 1.05rem; margin: 0; font-family: var(--sans); border: 0; padding: 0; }
.bk-src-n { font-size: 0.85rem; font-weight: 400; color: var(--ink-sub); }
.bk-sources .bk-toc-state::after { content: "閉じる"; }
.bk-sources:not([open]) .bk-toc-state::after { content: "開く"; }
.bk-sources:not([open]) .bk-toc-state::before { transform: rotate(45deg) translate(-0.1em, -0.1em); }
.bk-sources ol { padding-left: 1.4em; margin: 0.4rem 0 0; }
.bk-sources li { margin: 0 0 0.45em; line-height: 1.6; }
.bk-sources .pub { color: var(--ink-sub); }

.bk-back { margin-top: 2.5rem; display: flex; flex-wrap: wrap; gap: 0.7rem; }

/* ---------------------------------------------------------------- フッター */

.bk-footer { background: var(--kon); color: var(--kinari); margin-top: 3rem; font-size: 0.92rem; }
.bk-footer-in { padding-top: 2rem; padding-bottom: 2rem; display: grid; gap: 1.5rem; }
@media (min-width: 768px) { .bk-footer-in { grid-template-columns: 1.3fr 1fr 1fr; } }
.bk-footer a { color: var(--kinari); }
.bk-footer a:visited { color: var(--kinari); }
.bk-footer a:hover { color: #fff; }
.bk-footer h2 { font-size: 0.95rem; margin: 0 0 0.5rem; color: #fff; }
.bk-footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.3rem; }
.bk-footer-name { font-family: var(--serif); font-size: 1.2rem; letter-spacing: 0.12em; margin: 0 0 0.3rem; color: #fff; }
.bk-footer-copy { grid-column: 1 / -1; border-top: 1px solid rgba(240, 228, 209, 0.25); padding-top: 1rem; font-size: 0.82rem; opacity: 0.9; margin: 0; }

/* ---------------------------------------------------------------- 案内ページ・トップ */

.bk-hub-head { max-width: 44rem; margin: 0 auto; }
.bk-hub-lead { font-size: 1.05em; }
.bk-plain { max-width: 44rem; margin: 0 auto; }
.bk-plain .bk-body > * { max-width: none; }

/* トップ：短冊の分野入口 */
.bk-hero { background: linear-gradient(var(--kon) 0, var(--kon) 100%); color: var(--kinari); padding: 2.2rem 0 2.6rem; }
.bk-hero h1 { color: #fff; font-size: 1.55rem; margin: 0 0 0.5rem; letter-spacing: 0.08em; }
@media (min-width: 768px) { .bk-hero h1 { font-size: 2.1rem; } }
.bk-hero p { margin: 0 0 1.2rem; max-width: 38em; }
.bk-strips { list-style: none; margin: 1.4rem 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0.6rem; }
@media (min-width: 640px) { .bk-strips { grid-template-columns: repeat(7, minmax(0, 1fr)); gap: 0.8rem; } }
.bk-strip a {
  display: flex; flex-direction: column; align-items: center; gap: 0.6rem;
  height: 100%; min-height: 11.5rem; padding: 1rem 0.3rem 0.8rem;
  background: var(--kinari); color: var(--kon); text-decoration: none;
  border-radius: 4px; border: 2px solid var(--kinari);
  box-shadow: 0 4px 0 rgba(0, 0, 0, 0.35);
}
.bk-strip a:visited { color: var(--kon); }
.bk-strip a:hover { background: #fff; border-color: #fff; }
.bk-strip a:active { transform: translateY(2px); box-shadow: 0 2px 0 rgba(0, 0, 0, 0.35); }
.bk-strip-name { writing-mode: vertical-rl; font-family: var(--serif); font-weight: 700; font-size: 1.45rem; letter-spacing: 0.2em; line-height: 1; flex: 1; white-space: nowrap; }
.bk-strip-desc { font-size: 0.75rem; line-height: 1.4; text-align: center; color: #3c4652; letter-spacing: 0; }
@media (min-width: 768px) { .bk-strip-name { font-size: 1.7rem; } .bk-strip-desc { font-size: 0.8rem; } }

.bk-section { padding: 2.4rem 0 0.5rem; }
.bk-section > h2 { font-family: var(--serif); font-size: 1.4rem; margin: 0 0 0.4rem; letter-spacing: 0.05em; }
.bk-section > p { margin: 0 0 1rem; color: var(--ink-sub); }
.bk-purpose { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.7rem; }
@media (min-width: 720px) { .bk-purpose { grid-template-columns: repeat(3, 1fr); } }
.bk-purpose a { display: flex; flex-direction: column; gap: 0.2rem; height: 100%; padding: 0.9rem 1rem; border: 2px solid var(--kon); border-radius: var(--radius); text-decoration: none; color: var(--ink); background: #fff; box-shadow: 0 3px 0 var(--line-strong); }
.bk-purpose a:hover { background: var(--kon-tint); }
.bk-purpose strong { color: var(--kon); font-size: 1.05rem; }
.bk-purpose span { font-size: 0.9rem; color: var(--ink-sub); line-height: 1.6; }

/* ---------------------------------------------------------------- ツール */

.bk-tool { margin: 1.5rem 0 2rem; border: 2px solid var(--kon); border-radius: var(--radius); background: #fff; padding: 1rem 1rem 1.2rem; }
.bk-tool label, .bk-form label { font-weight: 700; display: block; margin: 0 0 0.35rem; }
.bk-field { margin: 0 0 1rem; }
.bk-hint { font-size: 0.88rem; color: var(--ink-sub); margin: 0.25rem 0 0; }
.bk-input, .bk-tool textarea, .bk-tool input[type="text"], .bk-tool input[type="number"], .bk-tool input[type="date"], .bk-tool select,
.bk-form input[type="text"], .bk-form input[type="email"], .bk-form textarea, .bk-form select {
  width: 100%; font: inherit; font-size: 1rem; line-height: 1.6; color: var(--ink);
  padding: 0.6rem 0.75rem; min-height: 48px;
  border: 2px solid var(--line-strong); border-radius: 6px; background: #fff;
}
.bk-tool textarea, .bk-form textarea { min-height: 10rem; resize: vertical; }
.bk-tool input:focus, .bk-tool textarea:focus, .bk-tool select:focus, .bk-form input:focus, .bk-form textarea:focus, .bk-form select:focus { border-color: var(--kon); outline: 3px solid var(--focus); outline-offset: 1px; }
.bk-result { margin: 1rem 0 0; border-radius: 6px; background: var(--kon-tint); padding: 0.9rem 1rem; }
.bk-result[hidden] { display: none; }
.bk-result-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr)); gap: 0.6rem; margin: 0; }
.bk-result-grid div { background: #fff; border-radius: 6px; padding: 0.55rem 0.75rem; border: 1px solid #c9d4e5; }
.bk-result-grid dt { font-size: 0.82rem; color: var(--ink-sub); }
.bk-result-grid dd { margin: 0; font-size: 1.35rem; font-weight: 700; color: var(--kon); line-height: 1.3; }
.bk-error { color: var(--shu); font-weight: 700; }
.bk-msg { margin: 0.8rem 0 0; padding: 0.6rem 0.9rem; border-radius: 6px; font-size: 0.95rem; }
.bk-msg-ok { background: var(--matsu-tint); color: #17452c; border: 1px solid #a9cbb5; }
.bk-msg-ng { background: var(--shu-tint); color: #7a2219; border: 1px solid #e6c1bb; }
.bk-msg-info { background: #f3f5f8; color: var(--ink); border: 1px solid var(--line); }
.bk-checkrow, .bk-tool label.bk-checkrow, .bk-form label.bk-checkrow { display: flex; gap: 0.6rem; align-items: flex-start; font-weight: 400; }
.bk-checkrow input { width: 1.3rem; height: 1.3rem; margin-top: 0.3em; accent-color: var(--kon); flex: none; }
.bk-fieldset { border: 1px solid var(--line); border-radius: 6px; padding: 0.6rem 0.9rem 0.4rem; margin: 0 0 1rem; }
.bk-fieldset legend { font-weight: 700; padding: 0 0.3rem; }
.bk-inline-fields { display: grid; gap: 0.8rem; grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr)); }

/* デモ・ローカル確認の帯 */
.bk-demo-band { background: #fff5d6; color: #4d3a00; border-bottom: 2px solid #e4c66a; font-size: 0.9rem; }
.bk-demo-band p { margin: 0; padding: 0.5rem 0; }

/* 検索 */
.bk-search-form { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.bk-search-form input { flex: 1 1 14rem; }
.bk-search-results { list-style: none; padding: 0; margin: 1.2rem 0 0; display: grid; gap: 0.7rem; }
.bk-search-results li { border: 1px solid var(--line); border-radius: var(--radius); padding: 0.7rem 0.9rem; }
.bk-search-results a { font-weight: 700; }
.bk-search-results p { margin: 0.2rem 0 0; font-size: 0.9rem; color: var(--ink-sub); }

.bk-visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.bk-hp { position: absolute !important; left: -10000px; width: 1px; height: 1px; overflow: hidden; }

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

@media print {
  .bk-header, .bk-menu, .bk-footer, .bk-toc, .bk-skip, .bk-crumbs, .bk-back, .bk-offer, .bk-copy, .bk-demo-band, .bk-noprint { display: none !important; }
  body { font-size: 11pt; }
  .bk-article { display: block; }
  a { color: inherit; }
  .bk-box, .bk-poem, .bk-compare { break-inside: avoid; }
}

/* 3列以上の表：狭い画面では行ごとに縦並び */
@media (max-width: 600px) {
  .bk-table-stack { border: 0; overflow: visible; }
  .bk-table-stack table, .bk-table-stack tbody, .bk-table-stack tr, .bk-table-stack td { display: block; width: 100%; }
  .bk-table-stack thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .bk-table-stack tr { border: 1px solid var(--line); border-radius: 6px; margin: 0 0 0.7rem; background: #fff; overflow: hidden; }
  .bk-table-stack td { border: 0 !important; border-bottom: 1px solid #eceef0 !important; padding: 0.45rem 0.8rem; min-width: 0; }
  .bk-table-stack td:last-child { border-bottom: 0 !important; }
  .bk-table-stack td::before { content: attr(data-label); display: block; font-size: 0.8rem; font-weight: 700; color: var(--ink-sub); line-height: 1.5; }
  .bk-table-stack td:first-child { background: var(--washi); font-weight: 700; }
  .bk-table-stack td:first-child::before { font-weight: 700; }
}
.bk-logo-name { white-space: nowrap; }
@media (max-width: 480px) {
  .bk-logo-name { font-size: 1.2rem; letter-spacing: 0.06em; }
  .bk-logo img { width: 34px; height: 34px; }
  .bk-hbtn { padding: 0.3rem 0.6rem; font-size: 0.9rem; }
  .bk-header-in { gap: 0.5rem; }
  .bk-hnav { gap: 0.35rem; }
}

@media (max-width: 360px) {
  .bk-logo-name { font-size: 1.05rem; letter-spacing: 0.02em; }
  .bk-logo img { width: 30px; height: 30px; }
  .bk-hbtn { padding: 0.25rem 0.45rem; font-size: 0.85rem; gap: 0.2rem; min-height: 44px; }
  .bk-hbtn svg { width: 1em; height: 1em; }
  .bk-wrap.bk-header-in { padding-left: 0.6rem; padding-right: 0.6rem; }
}

/* 記事の終わりの「人に見てもらう」枠（分野ごとのおすすめ） */
.bk-promo { margin: 2.4em 0 2em; background: var(--washi); border: 1px solid var(--washi-line); border-radius: var(--radius); padding: 1.1rem 1.2rem 1.15rem; }
.bk-promo-head { display: flex; align-items: center; gap: 0.5rem; margin: 0 0 0.5rem !important; }
.bk-promo-title { font-family: var(--serif); font-weight: 700; font-size: 1.15rem; color: var(--kon); line-height: 1.5; }
.bk-promo-lead { margin: 0 0 0.9rem !important; }
.bk-promo-cta { margin: 0 0 0.6rem !important; }
.bk-promo-guide { font-size: 0.9rem; color: var(--ink-sub); margin: 0 !important; }
.bk-promo-subs { border-top: 1px solid var(--washi-line); margin-top: 0.9rem; padding-top: 0.7rem; }
.bk-promo-subhead { font-size: 0.85rem; font-weight: 700; color: var(--ink-sub); margin: 0 0 0.35rem !important; }
.bk-promo-subs ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.4rem; }
.bk-promo-subs li { margin: 0 !important; font-size: 0.92rem; line-height: 1.7; }
.bk-promo-name { margin-right: 0.5em; }
.bk-promo-link { color: var(--kon-link); }
.bk-promo-links span[aria-hidden] { margin: 0 0.35em; color: var(--line-strong); }

/* 比較記事の冒頭の「この記事で紹介する」一覧 */
.bk-olist { margin: 1.2em 0 1.6em; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; padding: 0.8rem 1rem 0.5rem; }
.bk-olist-head { display: flex; align-items: center; gap: 0.5rem; font-weight: 700; margin: 0 0 0.5rem !important; }
.bk-olist ol { margin: 0; padding: 0 0 0 1.4em; }
.bk-olist li { margin: 0 0 0.6rem !important; }
.bk-olist-name { font-weight: 700; margin-right: 0.6em; }
.bk-olist-links { display: inline-flex; flex-wrap: wrap; gap: 0.4rem; vertical-align: middle; }
.bk-olist-btn { display: inline-block; font-size: 0.85rem; line-height: 1.4; padding: 0.3rem 0.75rem; border: 1px solid var(--kon); border-radius: 999px; color: var(--kon) !important; text-decoration: none; background: #fff; }
.bk-olist-btn:hover { background: var(--kon-tint); }