/* Modern dark theme — zero deps, accessible, responsive */
:root{
  --bg:#0b0d10; --surface:#0f1318; --panel:#11161b; --text:#e9eef3; --muted:#9fb0c1;
  --accent:#6aa9ff; --accent-2:#a7ffcf; --border:#1f2630;
  --radius:16px; --shadow:0 10px 40px rgba(0,0,0,.35);
  --w:1040px; --g:16px; --pad:22px;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font:16px/1.6 system-ui,-apple-system,Segoe UI,Inter,Roboto,Arial;
  color:var(--text); background:var(--bg);
  -webkit-font-smoothing:antialiased; text-rendering:optimizeLegibility;
}
.container{max-width:var(--w); margin:auto; padding:0 var(--pad)}
.section{padding:56px 0}
h1,h2,h3{line-height:1.2; margin:.2em 0 .4em}
h1{font-size:clamp(28px,4.2vw,46px)}
h2{font-size:clamp(22px,2.6vw,30px)}
h3{font-size:clamp(18px,2vw,22px)}
p{margin:.6rem 0}
a{color:var(--accent); text-decoration:none; text-underline-offset:3px}
a:hover{opacity:.9}

/* Background glow layers */
.bg{position:fixed; inset:0; pointer-events:none; z-index:-1}
.fx-1{
  background:
    radial-gradient(600px 300px at 10% -10%, rgba(106,169,255,.18), transparent),
    radial-gradient(700px 350px at 110% 0%, rgba(167,255,207,.12), transparent);
}
.fx-2{
  background:
    radial-gradient(700px 420px at 50% 120%, rgba(106,169,255,.10), transparent);
}

/* Header & nav (no shrinking) */
.site-header{position:sticky; top:0; z-index:10; backdrop-filter: blur(8px)}
.nav{
  height:64px; display:flex; align-items:center; justify-content:space-between; gap:10px;
  border-bottom:1px solid rgba(255,255,255,.04);
  background:linear-gradient(180deg, rgba(12,16,21,.75), rgba(12,16,21,.42));
}
.brand{font-weight:700; color:var(--text)}
.nav-links{display:flex; gap:14px; align-items:center}
.nav-links a{color:var(--muted)}
.nav-links a:hover{color:var(--text)}
.nav-toggle{
  display:none; width:40px; height:40px; border:1px solid var(--border); background:transparent;
  border-radius:10px; color:var(--text)
}
.nav-toggle .bar{display:block; width:20px; height:2px; background:var(--text); margin:4px auto}

/* Mobile nav */
@media (max-width:760px){
  .nav-toggle{display:inline-block}
  .nav-links{
    position:absolute; right:var(--pad); top:70px; background:var(--panel);
    border:1px solid var(--border); border-radius:14px; padding:10px;
    display:none; flex-direction:column; gap:10px
  }
  .nav-links.open{display:flex}
}

/* Intro block tweaks */
.intro .sub { color: var(--muted); max-width: 720px; }


/* Cards & grid */
.grid{display:grid; gap:var(--g); grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.card{
  position:relative; padding:16px; border-radius:var(--radius);
  background:linear-gradient(180deg,rgba(255,255,255,.02),rgba(255,255,255,.01));
  border:1px solid var(--border); box-shadow:var(--shadow);
}
.card h3{margin-top:.2rem}
.links{margin-top:10px}
.tags{list-style:none; padding:0; margin:10px 0 0; display:flex; flex-wrap:wrap; gap:8px}
.tags li{
  padding:6px 10px; border-radius:999px; border:1px solid var(--border);
  color:var(--muted); background:#0e1318;
}

/* Misc sections */
.callout{
  margin-top:10px; padding:12px 14px; border-radius:12px;
  border:1px dashed var(--border); color:var(--muted); background:#0e1318;
}
.cols{display:grid; gap:var(--g)}
@media (min-width:760px){ .cols{grid-template-columns:1fr 1fr} }

/* Footer */
.site-footer{padding:24px 0 60px; color:var(--muted); border-top:1px solid var(--border)}

/* Focus & a11y */
:focus-visible{outline:2px solid var(--accent); outline-offset:3px}
@media (prefers-reduced-motion:reduce){ *{animation:none !important; transition:none !important} }

/* Light theme for users who prefer it */
@media (prefers-color-scheme: light){
  :root{
    --bg:#f7f9fc; --surface:#fff; --panel:#fff; --text:#111; --muted:#556270; --border:#e6eaf0;
  }
  .nav{background:linear-gradient(180deg, rgba(255,255,255,.8), rgba(255,255,255,.55))}
  .btn.primary{color:#041018}
}