:root{
  --bg:#07060d;
  --panel:rgba(20,18,34,.72);
  --line:rgba(255,255,255,.14);
  --text:#e8e6f5;
  --dim:#9a95b8;
  --accent:#8ad7ff;
}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{
  background:var(--bg);
  color:var(--text);
  font:13px/1.5 "Hiragino Sans","Yu Gothic UI","Meiryo",system-ui,sans-serif;
  overflow:hidden;
  -webkit-user-select:none;user-select:none;
}
#stage{position:fixed;inset:0;touch-action:none;cursor:crosshair;display:block}

/* ── コントロールパネル ── */
#panel{
  position:fixed;top:14px;left:14px;width:224px;padding:14px 14px 12px;
  background:var(--panel);border:1px solid var(--line);border-radius:14px;
  backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  box-shadow:0 10px 40px rgba(0,0,0,.5);
  transition:opacity .25s, transform .25s;
  z-index:10;
}
#panel.hidden{opacity:0;transform:translateX(-16px);pointer-events:none}
#panel h1{margin:0 0 10px;font-size:13px;letter-spacing:.14em;font-weight:600}
#panel h1 small{display:block;font-size:10px;letter-spacing:.06em;color:var(--dim);font-weight:400;margin-top:3px}
.row{margin:9px 0}
.row label{display:flex;justify-content:space-between;font-size:11px;color:var(--dim);margin-bottom:4px}
.row label b{color:var(--text);font-weight:500;font-variant-numeric:tabular-nums}
input[type=range]{width:100%;height:18px;margin:0;background:transparent;-webkit-appearance:none;appearance:none}
input[type=range]::-webkit-slider-runnable-track{height:3px;border-radius:3px;background:rgba(255,255,255,.22)}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:13px;height:13px;margin-top:-5px;border-radius:50%;background:var(--accent);border:0;cursor:pointer}
input[type=range]::-moz-range-track{height:3px;border-radius:3px;background:rgba(255,255,255,.22)}
input[type=range]::-moz-range-thumb{width:13px;height:13px;border:0;border-radius:50%;background:var(--accent);cursor:pointer}
select{
  width:100%;padding:5px 7px;border-radius:8px;border:1px solid var(--line);
  background:rgba(0,0,0,.35);color:var(--text);font:inherit;font-size:12px;cursor:pointer;
}
.btns{display:grid;grid-template-columns:1fr 1fr;gap:6px;margin-top:12px}
button{
  padding:7px 4px;border-radius:9px;border:1px solid var(--line);
  background:rgba(255,255,255,.05);color:var(--text);font:inherit;font-size:11.5px;cursor:pointer;
  transition:background .15s,border-color .15s;
}
button:hover{background:rgba(255,255,255,.12)}
button.on{background:rgba(138,215,255,.2);border-color:rgba(138,215,255,.55);color:#d5f2ff}
button.wide{grid-column:1/-1}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.hint{margin-top:11px;padding-top:9px;border-top:1px solid var(--line);font-size:10.5px;color:var(--dim);line-height:1.7}
kbd{
  display:inline-block;min-width:15px;text-align:center;padding:0 4px;border-radius:4px;
  background:rgba(255,255,255,.1);border:1px solid var(--line);font:inherit;font-size:10px;
}

/* ── 最初のオーバーレイ（音声解禁のため要クリック） ── */
#splash{
  position:fixed;inset:0;z-index:20;display:grid;place-content:center;justify-items:center;gap:14px;
  background:radial-gradient(circle at 50% 45%,rgba(30,26,60,.65),rgba(7,6,13,.94));
  text-align:center;cursor:pointer;transition:opacity .5s;
}
#splash.gone{opacity:0;pointer-events:none}
#splash .t{font-size:24px;letter-spacing:.3em;font-weight:600;text-indent:.3em}
#splash .s{font-size:12px;color:var(--dim);letter-spacing:.1em;line-height:2}
#splash .p{
  margin-top:6px;font-size:11px;color:var(--accent);letter-spacing:.16em;
  animation:blink 1.9s ease-in-out infinite;
}
@keyframes blink{0%,100%{opacity:.35}50%{opacity:1}}

@media (prefers-reduced-motion: reduce){
  #splash .p{animation:none;opacity:.9}
}
@media (max-width:520px){
  #panel{width:190px;top:10px;left:10px;padding:11px}
  #panel .hint{display:none}
}