/* VIZ — palette purple/cyan sur fond deep space */
:root{
  --bg-deep:#02040a; --bg-elev:#08111e; --bg-card:rgba(10,18,36,0.6);
  --border:rgba(120,180,255,0.14); --border-strong:rgba(120,180,255,0.32);
  --text:#e8edf5; --text-muted:#a3b0c5; --text-soft:#7d8aa1;
  --accent:#c084fc; --accent-deep:#7c3aed; --accent-soft:rgba(192,132,252,0.10);
  --accent-glow:rgba(192,132,252,0.32);
  --secondary:#5dd4f7;
  --radius:14px; --radius-sm:8px;
  --tween:200ms cubic-bezier(.2,.8,.2,1);
}
*,*::before,*::after{box-sizing:border-box}
html{background:var(--bg-deep)}
body{
  margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  font-size:16px;line-height:1.55;color:var(--text);background:transparent;
  min-height:100dvh;
  -webkit-font-smoothing:antialiased;
}
/* HAL background layer */
.neural-bg{position:fixed;inset:0;width:100vw;height:100dvh;z-index:-2;pointer-events:none;display:block}
.neural-overlay{position:fixed;inset:0;z-index:-1;pointer-events:none;
  background:repeating-linear-gradient(0deg,rgba(0,0,0,0.10) 0 1px,transparent 1px 3px),
             radial-gradient(ellipse at center,transparent 25%,rgba(0,0,0,0.55) 90%);
  mix-blend-mode:multiply}
.back-to-menu{
  position:fixed;top:12px;left:12px;z-index:10;
  padding:.55rem .85rem;border-radius:999px;background:var(--bg-card);
  border:1px solid var(--border);color:var(--text-muted);text-decoration:none;
  font-weight:600;font-size:.85rem;backdrop-filter:blur(10px);
  transition:background var(--tween),color var(--tween),border-color var(--tween);
}
.back-to-menu:hover{color:var(--accent);border-color:var(--accent);background:var(--accent-soft)}
.topbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:.85rem;padding:1.5rem 1rem .8rem;text-align:center}
.topbar .brand{
  font-size:2rem;font-weight:900;letter-spacing:.15em;
  background:linear-gradient(135deg,var(--accent),var(--secondary));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.topbar .tag{
  font-size:.7rem;font-family:ui-monospace,SFMono-Regular,monospace;color:var(--text-soft);
  letter-spacing:.14em;text-transform:uppercase;padding:.35rem .8rem;
  border:1px solid var(--border);border-radius:999px;background:var(--bg-card);
}
.layout{max-width:1200px;margin:0 auto;padding:1rem 1.25rem 4rem;display:grid;gap:1rem}
.grid-2{display:grid;grid-template-columns:1fr;gap:1rem}
@media (min-width:900px){.grid-2{grid-template-columns:420px 1fr}}
.panel{
  background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);
  padding:1.4rem 1.6rem;backdrop-filter:blur(10px);
}
.p-title{font-size:1.15rem;margin:0 0 .75rem;display:flex;align-items:center;gap:.7rem;line-height:1.3}
.p-num{
  display:inline-grid;place-items:center;width:1.8rem;height:1.8rem;
  background:var(--accent-soft);color:var(--accent);
  border:1px solid var(--border-strong);border-radius:8px;
  font-family:ui-monospace,SFMono-Regular,monospace;font-weight:800;font-size:.9rem;
}
.p-hint{margin:.4rem 0;color:var(--text-muted);font-size:.9rem;line-height:1.55}
.p-hint em{color:var(--text);font-style:normal;font-weight:600}
.p-hint strong{color:var(--accent);font-weight:700}
.btn-row{display:flex;flex-wrap:wrap;gap:.4rem}
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.55rem 1rem;border-radius:var(--radius-sm);border:1px solid var(--border);
  background:var(--bg-elev);color:var(--text-muted);font-weight:600;font-size:.85rem;
  cursor:pointer;font-family:inherit;
  transition:background var(--tween),border-color var(--tween),color var(--tween);
}
.btn:hover{color:var(--accent);border-color:var(--border-strong);background:var(--accent-soft)}
.btn.tab[aria-pressed="true"]{background:var(--accent-soft);border-color:var(--accent);color:var(--accent)}
.btn-primary{background:linear-gradient(135deg,var(--accent),var(--accent-deep));border-color:transparent;color:#0e0620;box-shadow:0 6px 20px -6px var(--accent-glow)}
.btn-primary:hover{color:#0e0620;filter:brightness(1.1);border-color:transparent}
.btn-ghost{background:transparent}
.params{display:flex;flex-direction:column;gap:.9rem;margin-top:.35rem}
.param{display:flex;flex-direction:column;gap:.35rem}
.param label{font-size:.82rem;font-weight:600;color:var(--text);display:flex;justify-content:space-between;gap:.5rem}
.param label output{font-family:ui-monospace,SFMono-Regular,monospace;color:var(--accent);font-weight:800;padding:.1rem .5rem;background:var(--accent-soft);border-radius:999px;font-size:.78rem}
.param input[type="range"]{width:100%;accent-color:var(--accent);height:6px}
.param .p-desc{color:var(--text-soft);font-size:.75rem;line-height:1.5}
.actions{display:flex;flex-wrap:wrap;gap:.5rem;margin:1rem 0 .5rem}
.metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem;margin-top:.9rem}
.metric{padding:.6rem;background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius-sm);display:flex;flex-direction:column;gap:.2rem;text-align:center}
.mlbl{font-size:.65rem;color:var(--text-soft);text-transform:uppercase;letter-spacing:.05em;font-weight:700}
.mval{font-family:ui-monospace,SFMono-Regular,monospace;font-size:.95rem;font-weight:700;color:var(--accent)}
.canvas-wrap{background:#010204;border:1px solid var(--border-strong);border-radius:var(--radius-sm);padding:.5rem;display:flex;justify-content:center}
#viz-canvas{max-width:100%;height:auto;display:block;image-rendering:crisp-edges}
.viz-legend{margin:.75rem 0 .25rem;text-align:center;font-size:.82rem}
.explainer{margin-top:.75rem;background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius-sm);padding:.7rem 1rem;transition:border-color var(--tween)}
.explainer[open]{border-color:var(--border-strong)}
.explainer summary{cursor:pointer;font-weight:700;color:var(--accent);padding:.15rem 0;font-size:.9rem;list-style:none;display:flex;align-items:center;gap:.5rem}
.explainer summary::before{content:"▸";color:var(--text-soft);transition:transform var(--tween)}
.explainer[open] summary::before{transform:rotate(90deg)}
.explainer p{margin:.5rem 0}
.explainer p:last-child{margin-bottom:0}
@media (max-width:600px){
  .topbar .brand{font-size:1.5rem}
  .panel{padding:1rem 1.15rem}
  .metrics{grid-template-columns:repeat(3,1fr);font-size:.75rem}
}