:root {
  --bg: #0d1117;
  --panel: #161b22;
  --panel-2: #1c232c;
  --accent: #39c0ff;
  --accent-2: #7fd1ff;
  --text: #e6edf3;
  --muted: #8b949e;
  --border: #30363d;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

/* start overlay */
.overlay {
  position: fixed; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: radial-gradient(circle at 50% 35%, #15212e 0%, var(--bg) 70%);
}
.card {
  text-align: center;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 36px 44px;
  max-width: 460px;
  box-shadow: 0 10px 40px rgba(0,0,0,.5);
}
.card h1 { margin: 0 0 8px; font-size: 28px; }
.card p { color: var(--muted); line-height: 1.5; }
.hint { font-size: 12px; opacity: .8; margin-top: 14px; }
button {
  background: var(--accent); color: #04121b; border: none;
  font-weight: 600; padding: 10px 22px; border-radius: 8px; cursor: pointer;
  font-size: 15px;
}
button:hover { filter: brightness(1.08); }
button:disabled { opacity: .6; cursor: default; }

/* studio */
.studio { max-width: 960px; margin: 0 auto; padding: 24px 20px 60px; }
header { display: flex; align-items: baseline; gap: 14px; margin-bottom: 18px; }
header h1 { font-size: 26px; margin: 0; }
header .sub { color: var(--accent); font-size: 14px; font-weight: 400; }
.meta { color: var(--muted); font-size: 13px; }

.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px 18px;
  margin-bottom: 16px;
}
.panel h2 { font-size: 14px; margin: 0 0 14px; font-weight: 600; letter-spacing: .3px; }
.muted { color: var(--muted); font-weight: 400; }

select {
  background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 8px 10px; font-size: 14px; min-width: 240px;
}

.sliders { display: grid; grid-template-columns: 1fr 1fr; gap: 10px 28px; }
.sliders label { display: grid; grid-template-columns: 64px 1fr 44px; align-items: center; gap: 8px; font-size: 13px; color: var(--muted); }
.sliders .v { text-align: right; font-variant-numeric: tabular-nums; color: var(--accent-2); }

input[type="range"] { width: 100%; accent-color: var(--accent); }

canvas#scope { width: 100%; height: 120px; border-radius: 8px; background: #0a0e14; border: 1px solid var(--border); }
canvas#piano { display: block; border-radius: 8px; margin-top: 4px; }

.row { display: flex; align-items: center; gap: 14px; margin-top: 12px; }
.status { color: var(--muted); font-size: 12px; }