/* BrainTreat blog styles. Self-contained: no external fonts or requests. */
:root{--bl-primary:#E97462;--bl-accent:#6366f1;--bl-ink:#1f2937;--bl-muted:#5b6472;--bl-bg:#fffaf7;--bl-card:#fff;--bl-line:#eadfd8;--bl-font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;--bl-serif:Georgia,"Times New Roman",serif}
[data-theme=halloween]{--bl-primary:#8e44ad;--bl-accent:#f39c12}
[data-theme=winter]{--bl-primary:#3498db;--bl-accent:#2ecc71}
*{box-sizing:border-box}
body{margin:0;background:var(--bl-bg);color:var(--bl-ink);font:17px/1.7 var(--bl-serif)}
a{color:var(--bl-accent)}
a:focus-visible,summary:focus-visible,button:focus-visible{outline:3px solid var(--bl-accent);outline-offset:2px}
.bl-header{background:var(--bl-primary);color:#fff;padding:12px 20px;display:flex;justify-content:space-between;align-items:center;gap:12px;font-family:var(--bl-font)}
.bl-header a{color:#fff;text-decoration:none;font-weight:800}
.bl-header nav{display:flex;gap:18px;font-size:.95rem}
.bl-wrap{max-width:720px;margin:0 auto;padding:28px 20px 56px}
.bl-wrap.wide{max-width:960px}
h1,h2,h3{font-family:var(--bl-font);line-height:1.25}
h1{font-size:2rem;margin:.3em 0}
h2{font-size:1.45rem;margin:1.8em 0 .5em}
.bl-crumbs,.bl-meta{font:.88rem/1.5 var(--bl-font);color:var(--bl-muted)}
.bl-crumbs a{color:var(--bl-muted)}
.bl-toc,.bl-cta,.bl-author,.bl-card{background:var(--bl-card);border:1px solid var(--bl-line);border-radius:12px;padding:16px 20px;margin:24px 0}
.bl-toc ol{margin:.4em 0 0;padding-left:1.2em;font-family:var(--bl-font);font-size:.95rem}
.bl-cta{border-left:6px solid var(--bl-primary);font-family:var(--bl-font)}
.bl-cta a.bl-btn{display:inline-block;margin-top:6px;padding:10px 18px;min-height:44px;background:var(--bl-primary);color:#fff;border-radius:22px;font-weight:800;text-decoration:none}
.bl-note{background:#fff4e5;border-radius:10px;padding:12px 16px;font-family:var(--bl-font);font-size:.95rem}
details{border-bottom:1px solid var(--bl-line);padding:10px 0}
summary{cursor:pointer;font:700 1rem var(--bl-font)}
.bl-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:16px}
.bl-card h3{margin:.2em 0}.bl-card a{text-decoration:none;color:inherit}
.bl-card p{margin:.4em 0;font-size:.95rem}
figure{margin:24px 0}figcaption{font:.85rem var(--bl-font);color:var(--bl-muted)}
img,svg{max-width:100%;height:auto}
.bt-ad{margin:32px 0;min-height:100px;text-align:center}
.bt-ad::before{content:"Advertisement";display:block;font:.72rem var(--bl-font);color:var(--bl-muted);margin-bottom:6px}
.bl-print-sheet{background:#fff;border:1px solid var(--bl-line);padding:24px}
.bl-lines{display:flex;gap:24px;font-family:var(--bl-font)}.bl-lines span{flex:1;border-bottom:1px solid #000;min-height:1.6em}
.bl-problems{display:grid;grid-template-columns:repeat(2,1fr);gap:22px 32px;font:1.2rem var(--bl-font);margin-top:24px}
@media print{.bl-header,#global-footer,.bt-ad,.bl-noprint{display:none!important}body{background:#fff;font-size:12pt}.bl-wrap{max-width:none;padding:0}}
@media (prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}