*{box-sizing:border-box}
:root{
  --bg:#0b0b0f; --panel:#151519; --line:#222228;
  --ink:#e8e4dc; --muted:#9a9590; --accent:#b56bff;
}
body{
  margin:0; min-height:100vh;
  background:radial-gradient(900px 500px at 30% 0%,rgba(181,107,255,.07),transparent 60%),linear-gradient(180deg,#100f13,var(--bg));
  color:var(--ink); font-family:ui-sans-system,system-ui,-apple-system,sans-serif;
  display:flex; flex-direction:column;
}
.back{margin:18px 24px 0;color:var(--muted);text-decoration:none;font-size:14px}
.back:hover{color:var(--ink)}
.head{max-width:1000px;width:100%;margin:0 auto;padding:8px 24px 0}
.eyebrow{letter-spacing:.14em;text-transform:uppercase;font-size:12px;color:var(--accent);margin:0 0 6px}
h1{margin:0;font-size:42px;letter-spacing:-.02em;line-height:1}
.lede{color:var(--muted);max-width:60ch;line-height:1.5;margin:10px 0 0}
.layout{max-width:1000px;width:100%;margin:0 auto;padding:20px 24px 28px;flex:1;display:grid;gap:16px}
.controls{
  background:var(--panel);border:1px solid var(--line);border-radius:14px;
  padding:12px;display:flex;gap:10px;align-items:center;flex-wrap:wrap;
  box-shadow:0 10px 30px rgba(0,0,0,.35);
}
button{
  border:1px solid var(--line);background:#1c1c20;color:var(--ink);
  padding:9px 14px;border-radius:10px;font:600 13px/1 system-ui;cursor:pointer;
}
button:hover{border-color:#3a3a42}
button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
button.primary{background:var(--accent);color:#fff;border-color:transparent}
button.ghost{background:transparent}
select{
  background:var(--bg);color:var(--ink);border:1px solid var(--line);
  border-radius:8px;padding:6px 8px;font-size:12px;
}
label{display:flex;gap:6px;align-items:center;font-size:13px;color:var(--muted)}
label span{min-width:36px}
input[type="range"]{accent-color:var(--accent);width:100px}
.hint{width:100%;margin:4px 0 0;font-size:12px;color:var(--muted)}
.hint kbd{border:1px solid var(--line);border-bottom-width:2px;background:var(--bg);padding:1px 6px;border-radius:6px;font-size:11px;color:var(--ink)}
.canvas-wrap{position:relative;display:flex;gap:8px;align-items:stretch}
canvas{
  flex:1;height:320px;display:block;background:#08080c;
  border:1px solid var(--line);border-radius:14px;cursor:crosshair;touch-action:none;
}
.freq-labels{
  display:flex;flex-direction:column;justify-content:space-between;
  padding:8px 0;font:11px ui-monospace,monospace;color:var(--muted);width:54px;text-align:right;
}
.presets{display:flex;flex-direction:column;gap:8px}
.section-label{font-size:12px;color:var(--muted);letter-spacing:.1em;text-transform:uppercase;margin:0}
.preset-grid{display:flex;gap:8px;flex-wrap:wrap}
.preset-btn{
  padding:8px 14px;border:1px solid var(--line);background:var(--panel);color:var(--ink);
  border-radius:10px;font:500 13px/1 system-ui;cursor:pointer;
}
.preset-btn:hover{border-color:var(--accent)}
.preset-btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.foot{
  display:flex;justify-content:space-between;gap:12px;
  padding:14px 24px 20px;color:var(--muted);font-size:13px;
  border-top:1px solid var(--line);max-width:1000px;width:100%;margin:0 auto;
}
.foot a{color:var(--muted);text-decoration:none}
.foot a:hover{color:var(--ink)}
@media(max-width:700px){
  h1{font-size:32px}
  canvas{height:240px}
  .freq-labels{display:none}
}
@media(prefers-reduced-motion:reduce){
  canvas{animation:none!important}
}