/*
Theme Name: 建築を読む — 子テーマ
Theme URI: https://example.com
Description: 「建築を読む」ブログシリーズ用の子テーマ。Kadence テーマをベースに作成。
Author: あなたの名前
Template: kadence
Version: 1.0.0
*/

/* ============================================================
   1. GOOGLE FONTS（functions.php で読み込み済み）
   ============================================================ */

/* ============================================================
   2. CSS カスタムプロパティ（デザイントークン）
   ============================================================ */
:root {
  /* カラー */
  --yk-ink:         #16181a;
  --yk-ink-mid:     #353a3f;
  --yk-ink-light:   #6e7680;
  --yk-paper:       #f4f1ec;
  --yk-paper-warm:  #eae5dc;
  --yk-accent:      #1a4a6b;
  --yk-accent-2:    #2e7d9e;
  --yk-rule:        #ccc8bf;

  /* フォント */
  --yk-serif-jp:    'Noto Serif JP', serif;
  --yk-display-jp:  'Shippori Mincho', serif;
  --yk-display-en:  'DM Serif Display', serif;
}

/* ============================================================
   3. ベーススタイル上書き
   ============================================================ */
body {
  background-color: var(--yk-paper) !important;
  color: var(--yk-ink) !important;
  font-family: var(--yk-serif-jp) !important;
  font-size: 17px !important;
  line-height: 1.95 !important;
  -webkit-font-smoothing: antialiased;
}

/* Kadence のデフォルトリンク色を上書き */
a { color: var(--yk-accent); }
a:hover { color: var(--yk-accent-2); }

/* ============================================================
   4. マストヘッド（サイトヘッダー）
   ============================================================ */
.yk-masthead {
  border-bottom: 1px solid var(--yk-rule);
  padding: 1.1rem 2.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--yk-paper);
}
.yk-masthead-series {
  font-family: var(--yk-display-jp);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.13em;
  color: var(--yk-ink-light);
}
.yk-masthead-num {
  font-family: var(--yk-display-en);
  font-size: 13px;
  color: var(--yk-accent);
  font-style: italic;
}

/* ============================================================
   5. 記事ヒーロー
   ============================================================ */
.yk-hero {
  max-width: 900px;
  margin: 0 auto;
  padding: 5rem 2.5rem 3.5rem;
}
.yk-hero-kicker {
  font-family: var(--yk-display-jp);
  font-size: 10.5px;
  letter-spacing: 0.28em;
  color: var(--yk-accent-2);
  font-weight: 600;
  margin-bottom: 1.4rem;
  display: flex;
  align-items: center;
  gap: 10px;
}
.yk-hero-kicker::before {
  content: '';
  display: inline-block;
  width: 28px;
  height: 1px;
  background: var(--yk-accent-2);
}
.yk-hero-title {
  font-family: var(--yk-display-jp);
  font-size: clamp(2.3rem, 5vw, 3.8rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--yk-ink);
  margin-bottom: 0.9rem;
}
.yk-hero-subtitle {
  font-family: var(--yk-display-en);
  font-size: clamp(1rem, 2.4vw, 1.35rem);
  font-style: italic;
  color: var(--yk-ink-light);
  margin-bottom: 2.5rem;
}
.yk-hero-meta {
  display: flex;
  align-items: center;
  gap: 1.4rem;
  font-size: 11.5px;
  color: var(--yk-ink-light);
  letter-spacing: 0.06em;
  font-family: var(--yk-display-jp);
}
.yk-hero-meta-sep { color: var(--yk-rule); }

/* ============================================================
   6. 本文レイアウト（2カラム）
   ============================================================ */
.yk-article-body {
  max-width: 900px;
  margin: 3.5rem auto 0;
  padding: 0 2.5rem;
  display: grid;
  grid-template-columns: 1fr 210px;
  gap: 4rem;
  align-items: start;
}

/* ============================================================
   7. 本文プロズ
   ============================================================ */
.yk-prose p {
  margin-bottom: 1.65rem;
  font-size: 17px;
  line-height: 2;
  color: var(--yk-ink-mid);
}
.yk-prose p:first-of-type::first-letter {
  font-family: var(--yk-display-en);
  font-size: 4.2em;
  font-style: italic;
  float: left;
  line-height: 0.8;
  margin: 0.1em 0.12em 0 0;
  color: var(--yk-accent);
}

/* ============================================================
   8. セクション見出し
   ============================================================ */
.yk-style-section {
  margin: 3.5rem 0 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1.2rem;
}
.yk-style-era-badge {
  flex-shrink: 0;
  width: 56px;
  text-align: center;
  padding-top: 4px;
}
.yk-style-era-year {
  font-family: var(--yk-display-en);
  font-size: 11px;
  font-style: italic;
  color: var(--yk-accent-2);
  line-height: 1.3;
  display: block;
  border-bottom: 1px solid var(--yk-rule);
  padding-bottom: 4px;
  margin-bottom: 4px;
}
.yk-style-era-label {
  font-family: var(--yk-display-jp);
  font-size: 9.5px;
  color: var(--yk-ink-light);
  letter-spacing: 0.08em;
  display: block;
}
.yk-section-rule {
  width: 36px;
  height: 2px;
  background: var(--yk-accent);
  margin: 1rem 0 1.3rem;
}
.yk-style-num {
  font-family: var(--yk-display-jp);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--yk-ink-light);
  font-weight: 600;
  margin-bottom: 0.35rem;
}
.yk-style-name {
  font-family: var(--yk-display-jp);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--yk-ink);
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-bottom: 0.25rem;
}
.yk-style-name-en {
  font-family: var(--yk-display-en);
  font-size: 1rem;
  font-style: italic;
  color: var(--yk-ink-light);
  display: block;
}

/* ============================================================
   9. 特集ボックス（キーコンセプト）
   ============================================================ */
.yk-feature-box {
  background: var(--yk-paper-warm);
  border: 1px solid var(--yk-rule);
  border-left: 3px solid var(--yk-accent);
  padding: 1.3rem 1.5rem;
  margin: 2.2rem 0;
}
.yk-feature-box-label {
  font-family: var(--yk-display-jp);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--yk-accent);
  font-weight: 600;
  margin-bottom: 0.45rem;
}
.yk-feature-box-title {
  font-family: var(--yk-display-jp);
  font-size: 1rem;
  font-weight: 600;
  color: var(--yk-ink);
  margin-bottom: 0.45rem;
}
.yk-feature-box p {
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--yk-ink-mid);
  margin: 0;
}

/* ============================================================
   10. プルクオート
   ============================================================ */
.yk-pullquote {
  margin: 2.5rem 0;
  padding: 1.2rem 1.5rem;
  border-top: 1.5px solid var(--yk-ink);
  border-bottom: 1px solid var(--yk-rule);
}
.yk-pullquote-text {
  font-family: var(--yk-display-jp);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.75;
  color: var(--yk-ink);
  margin-bottom: 0.5rem;
}
.yk-pullquote-attr {
  font-size: 12px;
  color: var(--yk-ink-light);
  letter-spacing: 0.05em;
  font-family: var(--yk-display-jp);
}

/* ============================================================
   11. 要素リスト（グリッド）
   ============================================================ */
.yk-elements-list {
  margin: 1.5rem 0 2rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}
.yk-el-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 13.5px;
  color: var(--yk-ink-mid);
  line-height: 1.55;
}
.yk-el-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--yk-accent-2);
  flex-shrink: 0;
  margin-top: 7px;
}

/* ============================================================
   12. 様式フロー図
   ============================================================ */
.yk-transition-diagram {
  margin: 2.5rem 0;
  display: flex;
  align-items: center;
  overflow-x: auto;
  padding-bottom: 4px;
}
.yk-td-block {
  flex: 1;
  min-width: 80px;
  text-align: center;
  padding: 10px 6px;
  background: var(--yk-paper-warm);
  border: 1px solid var(--yk-rule);
  font-family: var(--yk-display-jp);
}
.yk-td-block:first-child { border-radius: 4px 0 0 4px; }
.yk-td-era { font-size: 9.5px; color: var(--yk-ink-light); letter-spacing: 0.08em; margin-bottom: 3px; }
.yk-td-name { font-size: 12px; font-weight: 600; color: var(--yk-ink); }
.yk-td-arrow { font-size: 16px; color: var(--yk-accent-2); padding: 0 4px; flex-shrink: 0; }
.yk-td-block.yk-highlight { background: var(--yk-accent); border-color: var(--yk-accent); }
.yk-td-block.yk-highlight .yk-td-era  { color: rgba(255,255,255,0.65); }
.yk-td-block.yk-highlight .yk-td-name { color: #fff; }

/* ============================================================
   13. サイドバー
   ============================================================ */
.yk-sidebar { position: sticky; top: 2rem; }
.yk-sidebar-section { margin-bottom: 2.4rem; }
.yk-sidebar-label {
  font-family: var(--yk-display-jp);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--yk-ink-light);
  font-weight: 600;
  border-bottom: 1px solid var(--yk-rule);
  padding-bottom: 0.55rem;
  margin-bottom: 0.9rem;
}
.yk-sidebar-toc-item {
  font-family: var(--yk-serif-jp);
  font-size: 12.5px;
  color: var(--yk-ink-mid);
  padding: 0.35rem 0;
  border-bottom: 1px dotted var(--yk-rule);
  display: flex;
  gap: 8px;
  align-items: baseline;
}
.yk-sidebar-toc-num {
  font-family: var(--yk-display-en);
  font-style: italic;
  color: var(--yk-accent);
  font-size: 11.5px;
  min-width: 16px;
}
.yk-sidebar-word {
  background: var(--yk-paper-warm);
  border: 1px solid var(--yk-rule);
  padding: 0.75rem 0.9rem;
  margin-bottom: 0.7rem;
}
.yk-sidebar-word-term {
  font-family: var(--yk-display-jp);
  font-size: 12.5px;
  font-weight: 600;
  color: var(--yk-ink);
  margin-bottom: 0.25rem;
}
.yk-sidebar-word-def {
  font-size: 11.5px;
  color: var(--yk-ink-light);
  line-height: 1.6;
}

/* ============================================================
   14. 次の記事フッター
   ============================================================ */
.yk-article-closing {
  max-width: 900px;
  margin: 4rem auto 0;
  padding: 2.5rem;
  border-top: 1px solid var(--yk-rule);
  display: flex;
  justify-content: flex-end;
}
.yk-next-label {
  font-family: var(--yk-display-jp);
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--yk-ink-light);
  font-weight: 600;
  margin-bottom: 0.3rem;
}
.yk-next-title {
  font-family: var(--yk-display-jp);
  font-size: 1rem;
  font-weight: 600;
  color: var(--yk-ink);
  line-height: 1.5;
}
.yk-next-arrow {
  font-family: var(--yk-display-en);
  font-size: 2rem;
  color: var(--yk-accent);
  font-style: italic;
  display: block;
  margin-top: 0.3rem;
}

/* ============================================================
   15. タイムラインストリップ
   ============================================================ */
.yk-timeline-strip {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2.5rem 3rem;
}
.yk-timeline-label {
  font-family: var(--yk-display-jp);
  font-size: 10px;
  letter-spacing: 0.22em;
  color: var(--yk-ink-light);
  font-weight: 600;
  margin-bottom: 0.9rem;
}
.yk-timeline-track {
  position: relative;
  height: 52px;
  display: flex;
  align-items: center;
}
.yk-timeline-line {
  position: absolute;
  left: 0; right: 0;
  top: 50%;
  height: 1px;
  background: var(--yk-rule);
}
.yk-timeline-items {
  display: flex;
  justify-content: space-between;
  width: 100%;
  position: relative;
  z-index: 1;
}
.yk-t-item { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.yk-t-dot {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--yk-accent);
  border: 2px solid var(--yk-paper);
  box-shadow: 0 0 0 1px var(--yk-accent);
}
.yk-t-dot.dim { background: var(--yk-ink-light); box-shadow: 0 0 0 1px var(--yk-ink-light); }
.yk-t-era { font-family: var(--yk-display-jp); font-size: 10px; color: var(--yk-ink-light); white-space: nowrap; }
.yk-t-era.accent { color: var(--yk-accent); font-weight: 600; }

/* ============================================================
   16. レスポンシブ
   ============================================================ */
@media (max-width: 768px) {
  .yk-article-body {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 0 1.2rem;
  }
  .yk-sidebar { position: static; }
  .yk-hero { padding: 3rem 1.2rem 2rem; }
  .yk-hero-title { font-size: 2rem; }
  .yk-elements-list { grid-template-columns: 1fr; }
  .yk-style-section { flex-direction: column; gap: 0.5rem; }
  .yk-masthead { padding: 1rem 1.2rem; }
}