/* Brian+ Insights — Article Design System v2 */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{
  --bg:#0a0a0f;--bg-alt:#0e0e16;--surface:#13131d;--card:#111119;
  --cyan:#00d4ff;--cyan-dim:rgba(0,212,255,.10);--cyan-glow:rgba(0,212,255,.25);
  --purple:#7c3aed;--purple-dim:rgba(124,58,237,.08);
  --amber:#f59e0b;--amber-dim:rgba(245,158,11,.08);
  --green:#10b981;--green-dim:rgba(16,185,129,.08);
  --text:#f0f0f5;--text-secondary:#a0a0b8;--text-dim:#7e7e9a;
  --border:#1a1a28;--border-light:#252538;
  --radius:16px;--radius-sm:10px;--radius-xs:6px;
  --ease:cubic-bezier(.4,0,.2,1);--ease-out:cubic-bezier(.16,1,.3,1);
  --ease-spring:cubic-bezier(.34,1.56,.64,1);
}
html{scroll-behavior:smooth}
body{font-family:'Inter',system-ui,sans-serif;background:var(--bg);color:var(--text);line-height:1.78;-webkit-font-smoothing:antialiased}

/* Subtle grid background */
body::before{content:'';position:fixed;inset:0;z-index:0;pointer-events:none;
  background-image:
    radial-gradient(ellipse 80% 50% at 50% -20%,rgba(0,212,255,.04),transparent),
    linear-gradient(var(--border) 1px,transparent 1px),
    linear-gradient(90deg,var(--border) 1px,transparent 1px);
  background-size:100% 100%,60px 60px,60px 60px;opacity:1}

a{color:var(--cyan);text-decoration:none;transition:color .2s}
a:hover{color:var(--text)}
a:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}

/* === READING PROGRESS === */
.reading-progress{position:fixed;top:0;left:0;width:0;height:3px;
  background:linear-gradient(90deg,var(--cyan),var(--purple),var(--amber));
  z-index:100;transition:width 50ms linear;
  box-shadow:0 0 12px var(--cyan-glow)}

/* === LAYOUT === */
.page{max-width:740px;margin:0 auto;padding:3rem 1.5rem 5rem;position:relative;z-index:1}

/* === NAV === */
nav{padding:1.5rem 0 2.5rem;display:flex;align-items:center;justify-content:space-between}
.logo{font-family:'Bebas Neue',sans-serif;font-size:1.4rem;letter-spacing:.06em;color:var(--text)}
.logo span{color:var(--cyan)}
.back{font-size:.82rem;color:var(--text-dim);transition:color .2s;
  display:inline-flex;align-items:center;gap:.3rem}
.back:hover{color:var(--cyan)}

/* === LANG TOGGLE === */
.lang-toggle{display:flex;border:1px solid var(--border-light);border-radius:100px;overflow:hidden;flex-shrink:0}
.lang-btn{padding:.35rem .65rem;font-size:.72rem;font-weight:600;font-family:'Inter',sans-serif;
  letter-spacing:.04em;background:transparent;color:var(--text-dim);text-decoration:none;
  min-height:36px;min-width:36px;display:inline-flex;align-items:center;justify-content:center;
  transition:.25s var(--ease)}
.lang-btn.active{background:var(--cyan);color:var(--bg);box-shadow:0 0 0 2px rgba(0,212,255,.4)}
.lang-btn:not(.active):hover{color:var(--text)}

/* === BREADCRUMB === */
.breadcrumb{font-size:.72rem;color:var(--text-dim);margin-bottom:2rem;letter-spacing:.01em}
.breadcrumb a{color:var(--text-dim)}.breadcrumb a:hover{color:var(--cyan)}

/* === HERO === */
h1{font-family:'Bebas Neue',sans-serif;font-size:clamp(2.2rem,5.5vw,3.4rem);line-height:1.02;
  letter-spacing:.015em;margin-bottom:1.5rem;
  background:linear-gradient(160deg,var(--text) 30%,var(--cyan) 100%);
  -webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}

.meta-line{font-size:.78rem;color:var(--text-dim);margin-bottom:1rem;
  display:flex;align-items:center;gap:1.2rem;flex-wrap:wrap}
.meta-line .separator{width:3px;height:3px;border-radius:50%;background:var(--text-dim);opacity:.5}
.reading-time{display:inline-flex;align-items:center;gap:.35rem;
  background:var(--cyan-dim);color:var(--cyan);
  padding:.2rem .7rem;border-radius:100px;font-weight:600;font-size:.72rem;
  border:1px solid rgba(0,212,255,.12)}

/* === TAG LINE === */
.tag-line{display:flex;gap:.5rem;flex-wrap:wrap;margin-bottom:2.5rem}
.tag{font-size:.68rem;font-weight:600;letter-spacing:.04em;text-transform:uppercase;
  padding:.25rem .7rem;border-radius:100px;
  background:var(--cyan-dim);color:var(--cyan);border:1px solid rgba(0,212,255,.12);
  transition:.2s var(--ease)}
.tag:hover{background:rgba(0,212,255,.18);border-color:rgba(0,212,255,.25)}

/* === TABLE OF CONTENTS === */
.toc{background:linear-gradient(135deg,var(--card),var(--surface));
  border:1px solid var(--border-light);border-radius:var(--radius);
  padding:1.75rem 2rem;margin-bottom:3rem;
  position:relative;overflow:hidden}
.toc::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--cyan),transparent 70%)}
.toc-title{font-family:'Inter',sans-serif;font-size:.72rem;font-weight:700;
  letter-spacing:.14em;text-transform:uppercase;color:var(--cyan);margin-bottom:1.1rem}
.toc ol{list-style:none;counter-reset:toc}
.toc li{counter-increment:toc;margin-bottom:.7rem}
.toc li::before{content:counter(toc,decimal-leading-zero);
  font-family:'JetBrains Mono',monospace;font-size:.7rem;color:var(--cyan);opacity:.5;
  margin-right:.7rem;font-weight:500}
.toc a{font-size:.88rem;font-weight:400;color:var(--text-secondary);transition:.2s}
.toc a:hover{color:var(--cyan);padding-left:.3rem}

/* === ARTICLE BODY === */
article{margin-bottom:3rem}

article h2{font-family:'Inter',sans-serif;font-size:1.35rem;font-weight:700;
  margin:3.5rem 0 1.2rem;color:var(--text);position:relative;
  padding-left:1.2rem;border-left:3px solid var(--cyan)}

article h3{font-family:'Inter',sans-serif;font-size:1.08rem;font-weight:600;
  margin:2.5rem 0 .7rem;color:var(--text);
  padding-left:1.2rem;border-left:2px solid var(--purple);opacity:.9}

article p{color:var(--text-secondary);font-size:.95rem;line-height:1.9;margin-bottom:1.5rem;font-weight:300}
article p:first-of-type{font-size:1.08rem;line-height:1.85;color:var(--text);font-weight:400}
article strong{color:var(--text);font-weight:600}
article em{color:var(--cyan);font-style:normal;font-weight:500}

article ul,article ol{color:var(--text-secondary);font-size:.95rem;margin:0 0 1.5rem 0;line-height:1.9;
  list-style:none;padding:0}
article li{margin-bottom:.7rem;padding-left:1.6rem;position:relative}
article li::before{content:'';position:absolute;left:0;top:.72rem;
  width:7px;height:7px;border-radius:50%;
  background:linear-gradient(135deg,var(--cyan),var(--purple));opacity:.7}

article blockquote{border-left:3px solid var(--purple);padding:1.25rem 1.75rem;margin:2.5rem 0;
  background:linear-gradient(135deg,var(--purple-dim),transparent);
  border-radius:0 var(--radius-sm) var(--radius-sm) 0;
  position:relative}
article blockquote::before{content:'\201C';position:absolute;top:-.3rem;left:.75rem;
  font-size:2.5rem;color:var(--purple);opacity:.3;font-family:Georgia,serif}
article blockquote p{color:var(--text);font-style:italic;margin:0;font-weight:400}

/* Highlight box for key takeaways */
article .highlight{background:var(--cyan-dim);border:1px solid rgba(0,212,255,.15);
  border-radius:var(--radius-sm);padding:1.25rem 1.5rem;margin:2rem 0;
  position:relative}
article .highlight::before{content:'';position:absolute;top:0;left:0;bottom:0;
  width:3px;background:var(--cyan);border-radius:3px 0 0 3px}

/* Code blocks */
article code{font-family:'JetBrains Mono',monospace;font-size:.82rem;
  background:var(--surface);color:var(--cyan);padding:.15rem .45rem;
  border-radius:var(--radius-xs);border:1px solid var(--border)}
article pre{background:var(--surface);border:1px solid var(--border);
  border-radius:var(--radius-sm);padding:1.25rem 1.5rem;margin:2rem 0;
  overflow-x:auto;line-height:1.6}
article pre code{background:none;border:none;padding:0;color:var(--text-secondary)}

/* === RELATED ARTICLES === */
.related{margin-bottom:3rem}
.related-title{font-family:'Inter',sans-serif;font-size:.72rem;font-weight:700;
  letter-spacing:.14em;text-transform:uppercase;color:var(--cyan);margin-bottom:1.2rem}
.related-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:1rem}
.related-card{background:linear-gradient(135deg,var(--card),var(--surface));
  border:1px solid var(--border);border-radius:var(--radius-sm);
  padding:1.5rem;transition:.35s var(--ease);display:block;color:inherit;
  position:relative;overflow:hidden}
.related-card::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--purple));opacity:0;transition:.35s}
.related-card:hover{border-color:rgba(0,212,255,.2);transform:translateY(-3px);
  box-shadow:0 8px 32px rgba(0,0,0,.3)}
.related-card:hover::before{opacity:1}
.related-card h3{font-family:'Inter',sans-serif;font-size:.88rem;font-weight:600;
  margin:0 0 .5rem;color:var(--text);line-height:1.35;letter-spacing:0;
  border:none;padding:0}
.related-card p{font-size:.75rem;color:var(--text-dim);line-height:1.5;margin:0;font-weight:400}

/* === CTA BOX === */
.cta-box{background:linear-gradient(135deg,var(--card),var(--surface));
  border:1px solid var(--border-light);border-radius:var(--radius);
  padding:3rem 2.5rem;margin:0 0 3rem;text-align:center;position:relative;overflow:hidden}
.cta-box::before{content:'';position:absolute;top:0;left:0;right:0;height:2px;
  background:linear-gradient(90deg,var(--cyan),var(--purple),var(--amber))}
.cta-box::after{content:'';position:absolute;bottom:-50%;right:-20%;
  width:300px;height:300px;border-radius:50%;
  background:radial-gradient(circle,rgba(0,212,255,.06),transparent 70%);pointer-events:none}
.cta-box p{color:var(--text-secondary);margin-bottom:1.4rem;font-size:.98rem}
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.9rem 2.2rem;
  border-radius:100px;font-size:.88rem;font-weight:600;
  background:linear-gradient(135deg,var(--cyan),#0099cc);color:var(--bg);
  text-decoration:none;transition:.3s var(--ease);position:relative;overflow:hidden;
  box-shadow:0 4px 16px rgba(0,212,255,.2)}
.btn:hover{box-shadow:0 6px 32px rgba(0,212,255,.35);transform:translateY(-2px);color:var(--bg)}
.btn::after{content:'';position:absolute;inset:0;
  background:linear-gradient(90deg,transparent,rgba(255,255,255,.18),transparent);
  transform:translateX(-100%);transition:none}
.btn:hover::after{transform:translateX(100%);transition:transform .6s var(--ease)}

/* === NAV ARTICLES (prev/next) === */
.article-nav{display:grid;grid-template-columns:1fr 1fr;gap:1rem;margin-bottom:3rem}
.article-nav a{display:block;background:var(--card);border:1px solid var(--border);
  border-radius:var(--radius-sm);padding:1.25rem;transition:.3s var(--ease);color:inherit}
.article-nav a:hover{border-color:rgba(0,212,255,.2);background:var(--surface)}
.article-nav .dir{font-size:.68rem;font-weight:600;letter-spacing:.08em;
  text-transform:uppercase;color:var(--text-dim);margin-bottom:.4rem}
.article-nav .title{font-size:.85rem;font-weight:500;color:var(--text);line-height:1.35}
.article-nav .next{text-align:right}

/* === FOOTER === */
footer{padding:2rem 0;border-top:1px solid var(--border);text-align:center;
  font-size:.75rem;color:var(--text-dim)}
footer a{color:var(--cyan)}

/* === BACK TO TOP === */
.back-to-top{position:fixed;bottom:2rem;right:2rem;width:42px;height:42px;
  border-radius:50%;background:var(--card);border:1px solid var(--border);
  color:var(--text-dim);font-size:1.1rem;cursor:pointer;z-index:50;
  display:flex;align-items:center;justify-content:center;
  opacity:0;transform:translateY(10px);transition:.3s var(--ease-spring);pointer-events:none;
  backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px)}
.back-to-top.visible{opacity:1;transform:none;pointer-events:auto}
.back-to-top:hover{border-color:var(--cyan);color:var(--cyan);background:var(--cyan-dim);
  box-shadow:0 0 20px rgba(0,212,255,.15)}

/* === SHARE BAR === */
.share-bar{display:flex;align-items:center;gap:.6rem;margin:2.5rem 0;
  padding:1rem 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.share-label{font-size:.72rem;font-weight:600;letter-spacing:.08em;
  text-transform:uppercase;color:var(--text-dim);margin-right:.5rem}
.share-btn{display:inline-flex;align-items:center;justify-content:center;
  width:36px;height:36px;border-radius:50%;background:var(--card);
  border:1px solid var(--border);color:var(--text-dim);font-size:.85rem;
  cursor:pointer;transition:.2s var(--ease);text-decoration:none}
.share-btn:hover{border-color:var(--cyan);color:var(--cyan);background:var(--cyan-dim)}

/* === RESPONSIVE === */
@media(max-width:600px){
  .page{padding:2rem 1rem 3rem}
  h1{font-size:1.9rem}
  .related-grid{grid-template-columns:1fr}
  .article-nav{grid-template-columns:1fr}
  .share-bar{flex-wrap:wrap}
  .toc{padding:1.25rem 1.5rem}
  .cta-box{padding:2rem 1.5rem}
  article h2{font-size:1.2rem}
  article h3{font-size:1rem}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}
  .reading-progress{display:none}
}