:root{
  --bg:#071127; --panel:#0b1220; --accent:#7dd3fc; --muted:#94a3b8; --glass:rgba(255,255,255,0.03);
  --card-radius:12px;
}
*{box-sizing:border-box}
body{margin:0;font-family:Inter,system-ui,Segoe UI,Roboto,Arial;color:#e6eef8;background:linear-gradient(180deg,#041028 0%, #07162b 100%)}
.top{padding:18px 24px}
.top h1{margin:0;font-size:20px}
.top .sub{margin:6px 0 0;color:var(--muted);font-size:13px}

.container{display:grid;grid-template-columns:320px 1fr;gap:18px;padding:12px;max-width:1200px;margin:0 auto}
.panel{background:var(--panel);padding:12px;border-radius:var(--card-radius);box-shadow:0 6px 20px rgba(0,0,0,0.6)}
.controls .freqList{display:flex;flex-direction:column;gap:6px;max-height:260px;overflow:auto;margin-bottom:8px}
.freqBtn{display:flex;justify-content:space-between;align-items:center;padding:8px;border-radius:8px;border:1px solid rgba(255,255,255,0.03);background:linear-gradient(180deg,rgba(255,255,255,0.01),transparent);cursor:pointer}
.row{display:flex;align-items:center;gap:8px;margin:8px 0}
.row label{min-width:140px;color:var(--muted);font-size:13px}
.row input[type=range]{flex:1}
.row input[type=number]{width:120px}
.two-cols .btn{flex:1}
.btn{background:var(--accent);border:none;padding:10px;border-radius:8px;cursor:pointer;color:#06202b;font-weight:600}
.btn.alt{background:#f97316;color:white}

.visuals .visRow{display:flex;gap:12px;margin-bottom:12px}
.visBox{flex:1}
.canvas{width:100%;height:220px;background:linear-gradient(90deg, rgba(255,255,255,0.01), rgba(255,255,255,0.015));border-radius:8px;display:block}
.footer{max-width:1200px;margin:12px auto;color:var(--muted);font-size:13px;padding:0 12px}
.hint{font-size:12px;color:var(--muted)}