/* ═══════════════════ GLOBAL STYLES ═══════════════════ */
:root{
  --bg:#f0f4f8;--bg2:#ffffff;--bg3:#e8edf3;--bg4:#dde3eb;
  --border:rgba(0,0,0,0.07);--border2:rgba(0,0,0,0.12);
  --text:#1a2236;--muted:#7a8ba8;--dim:#4a5c7a;
  --accent:#0369a1;--accent2:#6d28d9;
  --c-alkali:#dc2626;--c-alkaline:#ea580c;--c-trans:#ca8a04;
  --c-post:#16a34a;--c-metal:#0d9488;--c-nonmetal:#2563eb;
  --c-halogen:#7c3aed;--c-noble:#be185d;--c-lan:#d97706;--c-act:#059669;--c-unk:#64748b;
  --r:6px;--r2:10px;--r3:14px;
  --shadow:0 1px 3px rgba(0,0,0,0.08),0 1px 2px rgba(0,0,0,0.05);
  --shadow2:0 4px 16px rgba(0,0,0,0.1);
}
*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{background:var(--bg);color:var(--text);font-family:'Poppins',sans-serif;min-height:100vh;}
a{color:var(--accent);text-decoration:none;}
a:hover{text-decoration:underline;}
img{max-width:100%;}

/* ═══════════════════ HEADER / NAV ═══════════════════ */
#site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(240,244,248,0.96);backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border);
  padding:0.6rem 1.5rem;
  display:flex;align-items:center;gap:1rem;flex-wrap:wrap;
}
.site-logo{font-family:'IBM Plex Mono',monospace;font-size:.92rem;font-weight:700;color:var(--accent);white-space:nowrap;flex-shrink:0;display:flex;align-items:center;gap:6px;}
.site-logo em{color:var(--muted);font-style:normal;font-weight:400;}
.logo-mark{font-size:1.1rem;line-height:1;}
@media(max-width:560px){
  .site-logo{font-size:.7rem;}
  .logo-mark{font-size:.92rem;}
}
@media(max-width:400px){
  .site-logo{font-size:.62rem;}
}
.site-nav{display:flex;gap:.3rem;flex-wrap:wrap;margin-left:auto;}
.nav-link{font-size:.8rem;font-weight:500;color:var(--dim);padding:.4rem .75rem;border-radius:var(--r);transition:all .15s;white-space:nowrap;border:1px solid transparent;}
.nav-link:hover,.nav-link.active{background:var(--accent);color:#fff;text-decoration:none;border-color:var(--accent);}

/* ═══════════════════ FOOTER ═══════════════════ */
#site-footer{
  border-top:1px solid var(--border);
  padding:2rem 1.5rem;text-align:center;
  font-size:.78rem;color:var(--muted);
  margin-top:3rem;
}
#site-footer a{color:var(--accent);}
.footer-logo{font-family:'IBM Plex Mono',monospace;font-size:1.05rem;font-weight:700;color:var(--accent);margin-bottom:.75rem;display:flex;align-items:center;justify-content:center;gap:6px;}
.footer-logo em{color:var(--muted);font-style:normal;font-weight:400;}

/* Print-only logo (hidden on screen, shown on printed/PDF output) */
.print-logo{display:none;}
@media print{
  .print-logo{
    display:flex!important;align-items:center;gap:8px;
    font-family:'IBM Plex Mono',monospace;font-size:1.1rem;font-weight:700;
    color:#000!important;padding:.5rem 0 1rem;border-bottom:2px solid #000;margin-bottom:.5rem;
  }
  .print-logo em{font-style:normal;font-weight:400;color:#444!important;}
  .print-footer{
    display:block!important;text-align:center;font-size:.7rem;color:#444!important;
    margin-top:1rem;padding-top:.5rem;border-top:1px solid #999;
  }
}
.print-footer{display:none;}
.print-howto{font-size:.75rem;color:#444!important;text-align:center;padding:0 0 .5rem;}
.footer-links{display:flex;gap:1.5rem;justify-content:center;flex-wrap:wrap;margin-bottom:.75rem;}

/* ═══════════════════ CONTAINERS ═══════════════════ */
.container{max-width:1100px;margin:0 auto;padding:0 1.5rem;}
.container-narrow{max-width:760px;margin:0 auto;padding:0 1.5rem;}

/* ═══════════════════ BUTTONS ═══════════════════ */
.btn{display:inline-flex;align-items:center;gap:6px;background:var(--accent);border:none;color:#fff;font-family:'Poppins',sans-serif;font-size:.85rem;font-weight:500;padding:.55rem 1.1rem;border-radius:var(--r);cursor:pointer;transition:all .15s;text-decoration:none;}
.btn:hover{background:#025d8f;color:#fff;text-decoration:none;}
.btn-outline{background:transparent;color:var(--accent);border:1px solid var(--accent);}
.btn-outline:hover{background:var(--accent);color:#fff;}
.btn-sm{font-size:.78rem;padding:.4rem .8rem;}

/* ═══════════════════ CARDS ═══════════════════ */
.card{background:var(--bg2);border:0.5px solid var(--border2);border-radius:var(--r2);padding:1.25rem;box-shadow:var(--shadow);}

/* ═══════════════════ BREADCRUMB ═══════════════════ */
.breadcrumb{font-size:.78rem;color:var(--muted);padding:1rem 0 .5rem;display:flex;gap:.4rem;align-items:center;flex-wrap:wrap;}
.breadcrumb a{color:var(--muted);}
.breadcrumb a:hover{color:var(--accent);}
.breadcrumb span{color:var(--border2);}

/* ═══════════════════ BLOG LIST PAGE ═══════════════════ */
.blog-hero{padding:2.5rem 0 1.5rem;}
.blog-hero h1{font-size:2rem;font-weight:600;margin-bottom:.5rem;}
.blog-hero p{color:var(--muted);font-size:1rem;}
.blog-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:1.25rem;margin:1.5rem 0;}
.blog-card{background:var(--bg2);border:0.5px solid var(--border2);border-radius:var(--r2);padding:1.25rem 1.4rem;box-shadow:var(--shadow);transition:box-shadow .15s,transform .15s;display:flex;flex-direction:column;}
.blog-card:hover{box-shadow:var(--shadow2);transform:translateY(-2px);}
.blog-card-cat{font-size:.7rem;font-weight:600;text-transform:uppercase;letter-spacing:.07em;color:var(--accent);margin-bottom:.5rem;}
.blog-card h2{font-size:1rem;font-weight:600;margin-bottom:.6rem;line-height:1.4;color:var(--text);}
.blog-card h2 a{color:inherit;text-decoration:none;}
.blog-card h2 a:hover{color:var(--accent);}
.blog-card-intro{font-size:.84rem;color:var(--muted);line-height:1.6;flex:1;margin-bottom:1rem;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden;}
.blog-card-meta{font-size:.75rem;color:var(--muted);display:flex;gap:.75rem;align-items:center;}
.blog-cats{display:flex;gap:.5rem;flex-wrap:wrap;margin:1rem 0;}
.cat-btn{font-size:.75rem;padding:.3rem .75rem;border-radius:20px;border:1px solid var(--border2);background:var(--bg2);color:var(--dim);cursor:pointer;transition:all .15s;}
.cat-btn:hover,.cat-btn.on{background:var(--accent);color:#fff;border-color:var(--accent);}

/* ═══════════════════ BLOG POST PAGE ═══════════════════ */
.post-header{padding:2rem 0 1.5rem;}
.post-cat{font-size:.72rem;font-weight:600;text-transform:uppercase;letter-spacing:.07em;color:var(--accent);margin-bottom:.6rem;}
.post-header h1{font-size:1.9rem;font-weight:700;line-height:1.25;margin-bottom:.75rem;}
.post-meta{font-size:.78rem;color:var(--muted);display:flex;gap:1rem;flex-wrap:wrap;margin-bottom:1.5rem;}
.post-intro{font-size:1.05rem;color:var(--dim);line-height:1.7;padding:1rem 1.25rem;background:var(--bg3);border-left:3px solid var(--accent);border-radius:0 var(--r) var(--r) 0;margin-bottom:2rem;}
.post-content h2{font-size:1.2rem;font-weight:600;margin:1.8rem 0 .7rem;color:var(--text);}
.post-content p{font-size:.95rem;color:var(--dim);line-height:1.75;margin-bottom:1rem;}
.post-content ul,.post-content ol{padding-left:1.4rem;margin-bottom:1rem;}
.post-content li{font-size:.95rem;color:var(--dim);line-height:1.7;margin-bottom:.4rem;}
.post-content strong{color:var(--text);font-weight:600;}
.post-content em{font-style:italic;}
.post-nav{display:flex;gap:1rem;margin-top:2rem;padding-top:1.5rem;border-top:1px solid var(--border);flex-wrap:wrap;}
.related-posts{margin-top:2.5rem;}
.related-posts h3{font-size:1rem;font-weight:600;margin-bottom:1rem;}
.related-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:1rem;}
.related-card{background:var(--bg2);border:0.5px solid var(--border2);border-radius:var(--r);padding:1rem;font-size:.84rem;}
.related-card a{color:var(--text);font-weight:500;text-decoration:none;}
.related-card a:hover{color:var(--accent);}
.related-card .rc-cat{font-size:.68rem;color:var(--accent);font-weight:600;text-transform:uppercase;letter-spacing:.05em;margin-bottom:.3rem;}

/* ═══════════════════ SIDEBAR ═══════════════════ */
.post-layout{display:grid;grid-template-columns:1fr 280px;gap:2rem;align-items:start;}
.sidebar{position:sticky;top:80px;}
.sidebar-card{background:var(--bg2);border:0.5px solid var(--border2);border-radius:var(--r2);padding:1.1rem;margin-bottom:1rem;box-shadow:var(--shadow);}
.sidebar-card h4{font-size:.82rem;font-weight:600;color:var(--text);margin-bottom:.75rem;text-transform:uppercase;letter-spacing:.05em;}
.sidebar-toc a{display:block;font-size:.8rem;color:var(--muted);padding:.25rem 0;border-bottom:0.5px solid var(--border);transition:color .15s;}
.sidebar-toc a:hover{color:var(--accent);text-decoration:none;}
.sidebar-toc a:last-child{border-bottom:none;}
.adsense-placeholder{background:var(--bg3);border:1px dashed var(--border2);border-radius:var(--r);padding:1rem;text-align:center;font-size:.75rem;color:var(--muted);min-height:250px;display:flex;align-items:center;justify-content:center;}

/* ═══════════════════ ADS AREAS ═══════════════════ */
.ad-banner{background:var(--bg3);border:1px dashed var(--border2);border-radius:var(--r);padding:.75rem;text-align:center;font-size:.72rem;color:var(--muted);margin:1rem 0;}
.ad-label{font-size:.65rem;color:var(--muted);text-align:center;margin-bottom:3px;letter-spacing:.05em;}

/* ═══════════════════ RESPONSIVE ═══════════════════ */
@media(max-width:768px){
  .post-layout{grid-template-columns:1fr;}
  .sidebar{position:static;}
  .blog-hero h1{font-size:1.5rem;}
  .post-header h1{font-size:1.4rem;}
  #site-header{padding:.6rem 1rem;}
}

/* ═══════════════════ ELEMENT DETAIL PAGE ═══════════════════ */
.el-hero{display:flex;gap:1.75rem;align-items:center;padding:2rem 0 1.5rem;flex-wrap:wrap;}
.el-hero-box{
  width:130px;height:130px;border-radius:var(--r3);flex-shrink:0;
  display:flex;flex-direction:column;align-items:center;justify-content:center;
  position:relative;overflow:hidden;border:1.5px solid;
}
.el-hero-box::after{content:'';position:absolute;inset:0;opacity:.16;}
.el-hero-inner{position:relative;z-index:1;display:flex;flex-direction:column;align-items:center;}
.el-hero-n{font-size:.85rem;color:rgba(0,0,0,.45);font-family:'IBM Plex Mono',monospace;}
.el-hero-s{font-size:3.2rem;font-weight:700;font-family:'IBM Plex Mono',monospace;line-height:1;}
.el-hero-m{font-size:.7rem;color:rgba(0,0,0,.45);margin-top:2px;}
.el-hero-info{flex:1;min-width:200px;}
.el-hero-cat{display:inline-block;font-size:.72rem;font-weight:600;padding:3px 11px;border-radius:20px;margin-bottom:.5rem;}
.el-hero-info h1{font-size:1.9rem;font-weight:700;line-height:1.15;margin-bottom:.35rem;}
.el-hero-sub{font-size:.92rem;color:var(--muted);}
.el-quickfacts{display:grid;grid-template-columns:repeat(auto-fit,minmax(110px,1fr));gap:.6rem;margin:1.5rem 0 2rem;}
.eqf{background:var(--bg3);border:1px solid var(--border);border-radius:var(--r);padding:.65rem .8rem;}
.eqf-l{font-size:.66rem;color:var(--muted);margin-bottom:2px;text-transform:uppercase;letter-spacing:.05em;}
.eqf-v{font-size:.95rem;font-weight:600;color:var(--text);font-family:'IBM Plex Mono',monospace;}
.el-toc{background:var(--bg3);border:1px solid var(--border);border-radius:var(--r2);padding:1rem 1.2rem;margin-bottom:2rem;}
.el-toc-title{font-size:.78rem;font-weight:600;color:var(--text);margin-bottom:.6rem;}
.el-toc-list{display:flex;flex-direction:column;gap:.3rem;}
.el-toc-list a{font-size:.82rem;color:var(--accent);text-decoration:none;}
.el-toc-list a:hover{text-decoration:underline;}
.el-neighbors{display:flex;justify-content:space-between;gap:1rem;margin:2.5rem 0;padding-top:1.5rem;border-top:1px solid var(--border);flex-wrap:wrap;}
.el-neighbor{flex:1;min-width:140px;}
.el-neighbor a{display:flex;align-items:center;gap:.6rem;text-decoration:none;color:var(--text);padding:.7rem .9rem;background:var(--bg3);border-radius:var(--r);transition:all .15s;}
.el-neighbor a:hover{background:var(--bg4);}
.el-neighbor.next a{justify-content:flex-end;text-align:right;}
.el-neighbor-sym{font-family:'IBM Plex Mono',monospace;font-weight:700;font-size:1.1rem;}
.el-neighbor-lbl{font-size:.68rem;color:var(--muted);text-transform:uppercase;letter-spacing:.04em;}
.el-related-table{margin:2rem 0;}
.el-mini-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(70px,1fr));gap:6px;margin-top:.75rem;}
.el-mini{
  background:var(--bg3);border:1px solid var(--border);border-radius:var(--r);
  padding:.5rem .3rem;text-align:center;text-decoration:none;color:var(--text);
  transition:all .15s;
}
.el-mini:hover{background:var(--bg4);border-color:var(--accent);}
.el-mini-n{font-size:.6rem;color:var(--muted);font-family:'IBM Plex Mono',monospace;}
.el-mini-s{font-size:1rem;font-weight:700;font-family:'IBM Plex Mono',monospace;}
.el-cta{
  background:linear-gradient(135deg,rgba(3,105,161,.08),rgba(109,40,217,.05));
  border:1px solid rgba(3,105,161,.2);border-radius:var(--r2);
  padding:1.25rem 1.4rem;margin:2rem 0;text-align:center;
}
.el-cta p{font-size:.88rem;color:var(--dim);margin-bottom:.75rem;}

@media(max-width:768px){
  .el-hero{flex-direction:column;text-align:center;}
  .el-hero-info h1{font-size:1.5rem;}
  .el-neighbors{flex-direction:column;}
  .el-neighbor.next a{justify-content:flex-start;text-align:left;}
}