:root{
  --bg:#fbfaf7; --paper:#fffefb; --text:#181714; --muted:#777166;
  --line:#e7e0d5; --accent:#7a5a3a; --accent-soft:#eee2d3;
  --link:#5b3f24; --shadow:0 24px 60px rgba(58,48,36,.08);
}
body{margin:0;background:var(--bg);color:var(--text);font-family:"Yu Mincho",YuMincho,"Hiragino Mincho ProN","Hiragino Mincho Pro","Noto Serif JP","Times New Roman",serif;line-height:1.9;letter-spacing:.018em;}
body.theme-article-02{--bg:#f5f1ea;--paper:#fffaf2;--line:#ded4c6;--accent:#7a5635;--accent-soft:#eadcc9;}
a{color:var(--link);text-decoration:none} a:hover{text-decoration:underline}
.site-header{max-width:1120px;margin:0 auto;padding:28px 22px;display:flex;justify-content:space-between;gap:20px;align-items:center}
.brand{display:inline-flex;flex-direction:column;gap:1px;color:var(--text);line-height:1;text-decoration:none}.brand-en{font-size:.78rem;letter-spacing:.38em;color:var(--muted);font-weight:500}.brand-ja{font-size:1.28rem;letter-spacing:.1em;color:var(--text);font-weight:500}.brand-ja .logo-emoji{font-size:.9em;vertical-align:.08em}
.site-nav{display:flex;gap:18px;font-size:.92rem;color:var(--muted)}
.site-main{max-width:980px;margin:0 auto;padding:20px 22px 80px}
.hero,.article-head,.card,.notice{background:var(--paper);border:1px solid var(--line);border-radius:22px;padding:32px 36px;box-shadow:var(--shadow)}
.hero h1{font-size:clamp(1.35rem,2.2vw,2.25rem);line-height:1.18;margin:.35em 0 .34em}.hero .lead{font-size:1.05rem;max-width:760px}
.articles{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px;margin:32px 0}
.card h2,.card h3{margin-top:0;line-height:1.35}.meta,.muted{color:var(--muted);font-size:.9rem}.tag{display:inline-block;border:1px solid var(--line);border-radius:999px;padding:.15em .75em;color:var(--muted);font-size:.82rem;margin-bottom:1em}
.button-row{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px}.button{display:inline-block;padding:.7em 1.05em;border-radius:999px;border:1px solid var(--accent);background:var(--accent);color:#fff}.button.secondary{background:transparent;color:var(--accent)}
.article-head{margin-bottom:28px}.article-head h1{font-size:clamp(1.8rem,3.5vw,3rem);line-height:1.25;margin:.15em 0}.subtitle{font-size:1.08rem;color:var(--muted)}
.toc{columns:2;column-gap:34px}.toc li{break-inside:avoid;margin:.35em 0}
.chapter-nav{display:flex;flex-wrap:wrap;gap:8px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:14px 0;margin:24px 0}.chapter-nav a{border:1px solid var(--line);border-radius:999px;padding:.25em .7em;background:rgba(255,255,255,.35)}.chapter-nav a.current{background:var(--accent);color:#fff;border-color:var(--accent)}
.prose{background:var(--paper);border:1px solid var(--line);border-radius:22px;padding:34px;box-shadow:var(--shadow)}
.prose h1{font-size:1.9rem;line-height:1.35}.prose h2{margin-top:2.2em;border-top:1px solid var(--line);padding-top:1.2em}
.prose p{margin:1.05em 0}.prose blockquote{border-left:4px solid var(--accent);background:var(--accent-soft);padding:1em 1.2em;margin:1.5em 0;border-radius:0 14px 14px 0}.prose blockquote p{margin:.4em 0}
.key-lines{list-style:none;padding:0;margin:1.4em 0}.key-lines li{background:var(--accent-soft);border-left:4px solid var(--accent);padding:.75em 1em;margin:.75em 0;border-radius:0 12px 12px 0;font-weight:600}
.table-wrap{overflow:auto} table{border-collapse:collapse;width:100%;margin:1.5em 0;background:var(--paper)}th,td{border:1px solid var(--line);padding:.65em .8em;text-align:left}th{background:var(--accent-soft)}
.prev-next{display:flex;justify-content:space-between;gap:16px;margin-top:26px}.prev-next a{max-width:48%}
.notice{margin:28px 0;border-style:dashed}.source-list code{font-size:.9rem}
@media(max-width:720px){.site-header{display:block}.site-nav{margin-top:12px}.toc{columns:1}.hero,.article-head,.card,.prose,.notice{padding:22px}.prev-next{display:block}.prev-next a{display:block;max-width:100%;margin:.8em 0}}

button,input,textarea,select{font-family:inherit}

.hero p{max-width:none;letter-spacing:.012em;line-break:strict;overflow-wrap:normal;word-break:normal}
.hero .lead{max-width:none}

.hero{box-sizing:border-box}


/* v1.7: top-page hero title sizing */
body .hero h1{
  font-size:clamp(1.35rem,2.2vw,2.25rem) !important;
  line-height:1.18 !important;
  margin:.35em 0 .34em !important;
  letter-spacing:.08em;
}


.site-footer{max-width:980px;margin:0 auto;padding:0 22px 48px;color:var(--muted);font-size:.9rem;box-sizing:border-box}

.site-footer p{margin:.25em 0}


/* v1.9: split hero title sizing */
body .hero h1.hero-title{
  line-height:1.16 !important;
  margin:.35em 0 .42em !important;
}
body .hero h1.hero-title .hero-en{
  display:inline-block;
  font-size:clamp(1.15rem,1.9vw,1.75rem) !important;
  letter-spacing:.16em;
  font-weight:500;
}
body .hero h1.hero-title .hero-ja{
  display:inline-block;
  font-size:clamp(2rem,4vw,4rem) !important;
  letter-spacing:.04em;
  font-weight:500;
}

/* v2 public full text */
.prose.full-text h1{margin-bottom:1.6em;}
.prose.full-text h2{font-size:1.35rem;line-height:1.55;}
.prose.full-text h3{font-size:1.08rem;line-height:1.6;margin-top:1.8em;}
.prose.full-text p{line-height:2.05;}
.prose.full-text li{margin:.35em 0;line-height:1.85;}


/* v2.1: left side table of contents for long articles */
.site-main.with-side-toc{
  max-width:1180px;
  display:grid;
  grid-template-columns:220px minmax(0, 1fr);
  gap:28px;
  align-items:start;
}

.side-toc{
  position:sticky;
  top:20px;
  align-self:start;
  max-height:calc(100vh - 40px);
  overflow:auto;
  padding:4px 0 24px;
}

.side-toc-inner{
  border:1px solid var(--line);
  background:rgba(255,255,255,.45);
  border-radius:18px;
  padding:16px 14px;
}

.side-toc-label{
  margin:0 0 10px;
  color:var(--muted);
  font-size:.82rem;
  letter-spacing:.08em;
}

.side-toc-nav{
  display:flex;
  flex-direction:column;
  gap:4px;
}

.side-toc-link{
  display:grid;
  grid-template-columns:2.8em minmax(0, 1fr);
  gap:6px;
  align-items:baseline;
  padding:.42em .5em;
  border-radius:10px;
  color:var(--muted);
  font-size:.86rem;
  line-height:1.45;
  text-decoration:none;
}

.side-toc-link:hover{
  background:var(--accent-soft);
  text-decoration:none;
  color:var(--text);
}

.side-toc-link.current{
  background:var(--accent);
  color:#fff;
}

.side-toc-num{
  font-size:.78rem;
  opacity:.82;
  letter-spacing:.04em;
}

.mobile-toc{
  display:none;
}



@media(max-width:980px){
  .site-main.with-side-toc{
    display:block;
    max-width:980px;
  }
  .side-toc{
    display:none;
  }
  .mobile-toc{
    display:block;
    background:var(--paper);
    border:1px solid var(--line);
    border-radius:16px;
    padding:12px 16px;
    margin:0 0 18px;
    box-shadow:var(--shadow);
  }
  .mobile-toc summary{
    cursor:pointer;
    color:var(--muted);
  }
  .mobile-toc nav{
    display:flex;
    flex-direction:column;
    gap:4px;
    margin-top:10px;
  }
  .mobile-toc .side-toc-link{
    grid-template-columns:2.8em minmax(0, 1fr);
  }
}


/* v2.2: fix sidebar grid vertical gap */
.site-main.with-side-toc{
  max-width:1180px;
  display:grid;
  grid-template-columns:220px minmax(0, 1fr);
  column-gap:28px;
  row-gap:0;
  align-items:start;
}

.site-main.with-side-toc > .side-toc{
  grid-column:1;
  grid-row:1;
}

.site-main.with-side-toc > .mobile-toc{
  grid-column:1 / -1;
}

.site-main.with-side-toc > .article-content{
  grid-column:2;
  grid-row:1;
  min-width:0;
}

.article-content > .chapter-nav:first-child{
  margin-top:0;
}

@media(max-width:980px){
  .site-main.with-side-toc{
    display:block;
    max-width:980px;
  }
  .site-main.with-side-toc > .article-content{
    display:block;
  }
}


/* v4: reader width and matching top buttons */
:root{--reader-width:760px;}
.articles .button{background:var(--accent);color:#fff;border-color:var(--accent);}
.articles .button.secondary{background:transparent;color:var(--accent);border-color:var(--accent);}
.site-main.with-side-toc{
  max-width:1040px;
  grid-template-columns:220px minmax(0,var(--reader-width));
  justify-content:center;
}
.site-main.with-side-toc > .article-content{
  max-width:var(--reader-width);
  width:100%;
}
.site-main.with-side-toc .prose.full-text,
.site-main.with-side-toc .prose{
  max-width:var(--reader-width);
}
@media(max-width:980px){
  .site-main.with-side-toc{max-width:980px;display:block;}
  .site-main.with-side-toc > .article-content{max-width:none;}
}


/* v5: article-specific color tone based on genai-ron.jp Notion design memo */
body.article-understanding-defense-action{
  --bg:#f6f3ee;
  --paper:#fffaf8;
  --line:#e1d8ca;
  --accent:#7a6a50;
  --accent-soft:#f0ebe3;
  --link:#5f4d35;
}
body.article-understanding-defense-action .article-head,
body.article-understanding-defense-action .prose,
body.article-understanding-defense-action .card,
body.article-understanding-defense-action .notice{
  background:#fffaf8;
}
body.article-understanding-defense-action blockquote,
body.article-understanding-defense-action .strong,
body.article-understanding-defense-action .key-lines li{
  border-left-color:#9a8664;
  background:#f0ebe3;
}
.article-card-defense,
.card.article-card-defense{
  background:#f6f3ee;
  border-color:#e1d8ca;
}
.article-card-defense .tag,
.article-card-defense .article-number,
.article-card-defense .article-card-label{
  color:#7a6a50;
}


/* v5.5: production-compatible header */
.site-header{
  position:sticky;
  top:0;
  z-index:10;
  max-width:none;
  margin:0;
  padding:0;
  display:block;
  background:rgba(251,250,247,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(10px);
}
.header-inner{
  max-width:1120px;
  margin:0 auto;
  padding:16px 22px;
  display:flex;
  justify-content:space-between;
  align-items:flex-end;
  gap:20px;
  box-sizing:border-box;
}
.brand{
  display:block;
  text-decoration:none;
  color:var(--text);
  line-height:1.15;
}
.brand .mark{
  display:block;
  font-family:-apple-system,BlinkMacSystemFont,"Noto Sans JP",sans-serif;
  font-size:13px;
  letter-spacing:.16em;
  color:var(--muted);
  margin-bottom:2px;
}
.brand .name{
  display:flex;
  align-items:center;
  gap:5px;
  font-size:20px;
  letter-spacing:.04em;
}
.brand .emoji{
  font-size:.9em;
}
.nav,
.site-nav{
  display:flex;
  gap:18px;
  font-size:.92rem;
  color:var(--muted);
  align-items:center;
}
.nav a,
.site-nav a{
  color:inherit;
  text-decoration:none;
}
.nav a:hover,
.site-nav a:hover{
  text-decoration:underline;
}
@media(max-width:720px){
  .header-inner{
    display:block;
    padding:14px 18px;
  }
  .nav,
  .site-nav{
    margin-top:10px;
  }
}


/* v5.6: hard header fix and cache-bust */
body > .site-header{
  position:sticky !important;
  top:0 !important;
  z-index:100 !important;
  display:block !important;
  width:100% !important;
  max-width:none !important;
  margin:0 !important;
  padding:0 !important;
  background:rgba(247,244,238,.94) !important;
  border-bottom:1px solid var(--line, #d7cfc1) !important;
  backdrop-filter:blur(10px);
}
body > .site-header > .header-inner{
  max-width:980px !important;
  margin:0 auto !important;
  padding:16px 22px !important;
  display:flex !important;
  justify-content:space-between !important;
  align-items:flex-end !important;
  gap:20px !important;
  box-sizing:border-box !important;
}
body > .site-header .brand{
  display:block !important;
  text-decoration:none !important;
  color:inherit !important;
  line-height:1.15 !important;
}
body > .site-header .brand .mark{
  display:block !important;
  font-family:-apple-system,BlinkMacSystemFont,"Noto Sans JP",sans-serif !important;
  font-size:13px !important;
  letter-spacing:.16em !important;
  color:var(--muted, #6f6a61) !important;
  margin:0 0 2px 0 !important;
}
body > .site-header .brand .name{
  display:flex !important;
  align-items:center !important;
  gap:5px !important;
  font-size:20px !important;
  letter-spacing:.04em !important;
  color:inherit !important;
}
body > .site-header .brand .emoji{
  font-size:.9em !important;
  line-height:1 !important;
}
body > .site-header .nav{
  display:flex !important;
  gap:18px !important;
  font-size:.92rem !important;
  color:var(--muted, #6f6a61) !important;
  align-items:center !important;
  margin:0 !important;
}
body > .site-header .nav a{
  color:inherit !important;
  text-decoration:none !important;
}
body > .site-header .nav a:hover{
  text-decoration:underline !important;
}
@media(max-width:720px){
  body > .site-header > .header-inner{
    display:block !important;
    padding:14px 18px !important;
  }
  body > .site-header .nav{
    margin-top:10px !important;
  }
}


/* v5.7: inline header fallback */
body > .site-header,
body > .site-header *{
  box-sizing:border-box;
}
body > .site-header .nav a:hover{
  text-decoration:underline !important;
}