:root{
  --bg:#0a0a0a;
  --surface:#141414;
  --surface-2:#1c1c1c;
  --border:#2a2a2a;
  --fg:#f3f4f6;
  --muted:#9aa0a6;
  --primary:#e31937;
  --primary-glow:#ff3a55;
  --radius:14px;
  --font-sans:"Manrope",ui-sans-serif,system-ui,sans-serif;
  --font-display:"Sora",ui-sans-serif,system-ui,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--fg);font-family:var(--font-sans);-webkit-font-smoothing:antialiased;line-height:1.65}
a{color:var(--fg);text-decoration:none}
code{background:#222;padding:.12em .4em;border-radius:6px;font-size:.9em;color:#ffb3c0;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}

/* Sidebar */
#sidebar{position:fixed;top:0;left:0;bottom:0;width:280px;background:var(--surface);border-right:1px solid var(--border);padding:28px 22px;overflow-y:auto;z-index:20}
.brand{display:flex;gap:12px;align-items:center;margin-bottom:28px}
.brand img{width:42px;height:42px;object-fit:cover;border-radius:50%;border:1px solid rgba(255,255,255,.08);box-shadow:0 0 18px rgba(227,25,55,.55)}
.brand-title{font-family:var(--font-display);font-weight:700;font-size:1rem}
#toc{display:flex;flex-direction:column;gap:2px}
#toc a{display:block;padding:7px 10px;border-radius:8px;font-size:.88rem;color:#cfd1d4;border-left:2px solid transparent;transition:.15s}
#toc a:hover{background:var(--surface-2);color:#fff}
#toc a.active{color:#fff;border-left-color:var(--primary);background:linear-gradient(90deg,rgba(227,25,55,.12),transparent)}
.side-foot{margin-top:30px;padding-top:18px;border-top:1px solid var(--border);font-size:.72rem;color:var(--muted);line-height:1.5}

#menuBtn{display:none;position:fixed;top:14px;right:14px;z-index:30;background:var(--surface);color:#fff;border:1px solid var(--border);border-radius:10px;width:42px;height:42px;font-size:18px;cursor:pointer}

/* Main */
#content{margin-left:280px;padding:64px max(40px,6vw) 80px;max-width:980px}
section{padding:48px 0;border-top:1px solid var(--border)}
section:first-of-type{border-top:0}

h1{font-family:var(--font-display);font-weight:800;font-size:clamp(2.2rem,4.5vw,3.6rem);line-height:1.05;letter-spacing:-.02em;margin:.4em 0 .3em}
h2{font-family:var(--font-display);font-weight:700;font-size:clamp(1.6rem,2.6vw,2.1rem);letter-spacing:-.01em;margin:0 0 .8em;position:relative;padding-left:18px}
h2::before{content:"";position:absolute;left:0;top:.3em;bottom:.3em;width:4px;background:var(--primary);border-radius:4px;box-shadow:0 0 18px rgba(227,25,55,.6)}
h3{font-family:var(--font-display);font-weight:600;font-size:1.2rem;margin:1.8em 0 .5em;color:#fff}
h4{font-family:var(--font-display);font-weight:600;font-size:1rem;margin:1.4em 0 .4em;color:#fff}
h5{font-family:var(--font-display);font-weight:600;font-size:.92rem;margin:0 0 .5em;color:#fff}
p{color:#d5d7da}
.lede{font-size:1.12rem;color:#cfd1d4;max-width:62ch}
.grad{background:linear-gradient(135deg,var(--primary),var(--primary-glow));-webkit-background-clip:text;background-clip:text;color:transparent}

/* Hero */
.hero{position:relative;padding-top:24px}
.hero-glow{position:absolute;inset:-80px -80px auto auto;width:520px;height:520px;background:radial-gradient(closest-side,rgba(227,25,55,.35),transparent 70%);filter:blur(20px);pointer-events:none;z-index:-1}
.eyebrow{display:inline-block;font-family:var(--font-display);font-size:.72rem;letter-spacing:.22em;text-transform:uppercase;color:var(--primary);background:rgba(227,25,55,.1);border:1px solid rgba(227,25,55,.35);padding:6px 12px;border-radius:999px}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:22px}
.chip{font-size:.78rem;padding:6px 12px;border-radius:999px;background:var(--surface);border:1px solid var(--border);color:#cfd1d4}

blockquote{margin:18px 0;padding:18px 22px;background:linear-gradient(180deg,rgba(227,25,55,.07),transparent);border-left:3px solid var(--primary);border-radius:0 12px 12px 0;color:#e8eaed;font-style:italic}
blockquote.final{font-size:1.05rem;line-height:1.8}

.math{margin:14px 0;padding:18px 22px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow-x:auto}
.katex{font-size:1.05em !important}
.katex-display{margin:0 !important}

/* Cards */
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin:16px 0}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px;position:relative;transition:.2s}
.card:hover{border-color:rgba(227,25,55,.5);transform:translateY(-2px)}
.card .num{font-family:var(--font-display);font-weight:800;font-size:.75rem;color:var(--primary);letter-spacing:.15em;margin-bottom:6px}
.card h4{margin:.2em 0 .4em}
.card p{font-size:.9rem;color:#b8babd;margin:0}

.formula-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px;margin-top:14px}

.modes{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:14px}
.mode{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px}
.mode h4{margin-top:0}

.stat-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:14px;margin-top:18px}
.stat{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:22px;text-align:center}
.stat-v{font-family:var(--font-display);font-weight:800;font-size:1.6rem;background:linear-gradient(135deg,var(--primary),var(--primary-glow));-webkit-background-clip:text;background-clip:text;color:transparent}
.stat-l{font-size:.78rem;color:var(--muted);margin-top:4px;text-transform:uppercase;letter-spacing:.12em}

.flow{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:18px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;color:#ffb3c0;overflow-x:auto}
.two-col{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin-top:14px}
.two-col>div{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:20px}
ul,ol{padding-left:20px;color:#d5d7da}
li{margin:.3em 0}

.roadmap{counter-reset:phase;list-style:none;padding:0}
.roadmap li{background:var(--surface);border:1px solid var(--border);border-left:3px solid var(--primary);border-radius:var(--radius);padding:16px 20px;margin:12px 0}

footer{margin-top:60px;padding:30px 0;border-top:1px solid var(--border);display:flex;justify-content:space-between;color:var(--muted);font-size:.82rem;flex-wrap:wrap;gap:10px}

@media (max-width:900px){
  #menuBtn{display:block}
  #sidebar{transform:translateX(-100%);transition:.25s}
  #sidebar.open{transform:translateX(0)}
  #content{margin-left:0;padding:64px 20px}
}
.hero-logo{width:84px;height:84px;border-radius:50%;object-fit:cover;display:block;margin:0 0 22px;box-shadow:0 0 0 1px rgba(255,255,255,.08),0 20px 60px -10px rgba(227,25,55,.55)}