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

.feature-series{border:1px solid #d7cfc1;border-left:7px solid #2f6b4f;background:#fbfaf6;border-radius:26px;padding:30px;margin:0 0 32px}.feature-series .tag{color:#2f6b4f}.feature-series h2{font-size:clamp(28px,4vw,44px);line-height:1.25}.feature-series .lead-small{font-size:1.08rem;color:#514c44}.feature-series .phrase{margin:18px 0 0;padding:15px 18px;background:#f1e8d8;border-radius:16px;color:#242424}
@media(max-width:720px){.feature-series{padding:22px}}

/* GitHub Desktop test */

/* academic journal style: shared lower pages */
:root{
  --bg:#faf7f0;
  --paper:#fffdf8;
  --text:#242424;
  --muted:#66625a;
  --line:rgba(151,139,119,.36);
  --accent:#245c63;
  --accent-soft:#f1e8d8;
  --link:#245c63;
  --shadow:none;
}
.site-header{background:rgba(250,247,240,.94);border-bottom:1px solid var(--line)}
.site-header .brand .emoji{display:none}
.site-header .brand .mark{font-family:Georgia,"Times New Roman",serif;font-size:14px;letter-spacing:.14em;font-weight:700;color:var(--text)}
.site-header .brand .name{font-size:0;letter-spacing:.22em;font-weight:400;color:var(--muted)}
.site-header .brand .name::before{content:"生成AI論";font-size:12px;letter-spacing:.24em}
.site-header .nav{font-size:14px;color:var(--muted)}
.hero,.article-head,.card,.notice,.prose{
  border-radius:0;
  background:rgba(255,253,248,.62);
  box-shadow:none;
}
.article-head{border-left:0;border-right:0;background:transparent;padding-left:0;padding-right:0}
.article-head h1{letter-spacing:-.02em;font-weight:600}
.card{padding:26px 0;border-left:0;border-right:0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);background:transparent}
.articles{display:block;margin:24px 0}
.articles .card{margin:0 0 18px}
.tag{border:0;border-radius:0;padding:0;color:var(--muted);font-size:.78rem;letter-spacing:.14em;text-transform:uppercase}
.button{border-radius:0;background:transparent!important;color:var(--accent)!important;border-color:var(--accent);padding:.55em .9em}.button:hover{background:rgba(36,92,99,.08)!important;text-decoration:none}
.prose{border-radius:0;background:rgba(255,253,248,.70)}
.prose blockquote{border-left:3px solid var(--accent);background:transparent;border-radius:0}
.chapter-nav a{border-radius:0;background:transparent}.chapter-nav a.current{background:var(--accent)}
.site-footer{border-top:1px solid var(--line);padding-top:22px;font-size:.78rem;letter-spacing:.08em;text-transform:uppercase}
@media(max-width:720px){
  body{font-size:19px;line-height:1.9}
  .site-header .brand .mark{font-size:18px}
  .site-header .brand .name{font-size:0}
  .site-header .brand .name::before{font-size:14px}
  .site-header .nav{font-size:17px;line-height:1.55}
  .site-main{padding:18px 18px 64px}
  .article-head h1{font-size:2.25rem}
  .subtitle,.hero .lead{font-size:1.28rem;line-height:1.72}
  .card h2{font-size:1.62rem}
  .card p,.prose p,.prose li{font-size:1.18rem;line-height:1.9}
  .meta,.muted{font-size:1.08rem}
  .tag{font-size:1rem}
  .button{font-size:1.08rem}
  .prose.full-text h2{font-size:1.62rem}
  .prose.full-text h3{font-size:1.34rem}
}