:root {
  --bg: #0b0d12;
  --fg: #e7e7ea;
  --muted: #a6a7ad;
  --panel: #111522;
  --line: rgba(231,231,234,0.12);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: radial-gradient(1000px 600px at 50% 10%, #141a2a 0%, var(--bg) 55%);
  color: var(--fg);
}

.wrap {
  max-width: 900px;
  margin: 0 auto;
  padding: 28px 18px 40px;
}

header h1 {
  margin: 0 0 6px;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.sub { margin: 0 0 18px; color: var(--muted); }

.panel {
  border: 1px solid var(--line);
  background: rgba(17,21,34,0.7);
  border-radius: 16px;
  padding: 16px;
  box-shadow: 0 14px 40px rgba(0,0,0,0.35);
}

.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 14px;
}

label {
  display: grid;
  gap: 8px;
  font-size: 14px;
  color: var(--muted);
}

input[type="range"] { width: 100%; }

#signal {
  width: 140px;
  height: 140px;
  border-radius: 999px;
  background: rgba(231,231,234,0.22);

  /* NEW: give it a visible “stain” */
  box-shadow: 0 0 120px 30px rgba(231,231,234,0.06);

  filter: blur(10px);
  opacity: 0.18;
  transform: scale(0.9);

  transition: opacity 1.2s ease, transform 1.2s ease, filter 1.2s ease, border-radius 1.2s ease;
}


/* The “blur thickening” signal */
#signal {
  width: 120px;
  height: 120px;
  border-radius: 999px;
  background: rgba(231,231,234,0.22);
  filter: blur(14px);
  opacity: 0.25;
  transform: scale(1);
  transition: opacity 0.6s ease, transform 0.6s ease, filter 0.6s ease;
}

.readout {
  display: flex;
  gap: 18px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.hint {
  margin-top: 14px;
  color: var(--muted);
  font-size: 13px;
}