* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: #0a0a0a;
  color: #e0e0e0;
  font-family: system-ui, -apple-system, sans-serif;
  line-height: 1.5;
  position: relative;
}
.chain-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(90deg, transparent 0 40px, rgba(60,60,60,0.15) 40px 44px),
    repeating-linear-gradient(0deg, transparent 0 40px, rgba(60,60,60,0.08) 40px 44px);
  z-index: 0;
}
.top, main, footer { position: relative; z-index: 1; }
.top {
  text-align: center;
  padding: 3rem 1rem 2rem;
  border-bottom: 1px solid #222;
}
.top h1 {
  font-size: clamp(3.5rem, 12vw, 7rem);
  letter-spacing: 0.15em;
  font-weight: 700;
  color: #fff;
}
.version {
  display: inline-block;
  background: #222;
  color: #aaa;
  padding: 0.2rem 0.8rem;
  border-radius: 99px;
  font-size: 0.85rem;
  margin: 0.5rem 0;
}
.byline { color: #888; margin-bottom: 1.5rem; }
.features {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 1rem;
}
.features li {
  background: #1a1a1a;
  border: 1px solid #333;
  padding: 0.4rem 0.9rem;
  border-radius: 6px;
  font-size: 0.9rem;
}
.panel-section {
  padding: 3rem 1rem;
  text-align: center;
}
#fm1-panel {
  background: linear-gradient(180deg, #1c1c1c, #111);
  border: 3px solid #2a2a2a;
  border-radius: 18px;
  padding: 1.75rem;
  max-width: 680px;
  margin: 0 auto 1.5rem;
  box-shadow: 0 20px 50px rgba(0,0,0,0.6), inset 0 1px 0 rgba(255,255,255,0.05);
}
.screen {
  background: #050505;
  color: #0f0;
  font-family: ui-monospace, monospace;
  font-size: 1.4rem;
  letter-spacing: 0.4em;
  text-align: center;
  padding: 1.2rem;
  border-radius: 8px;
  margin-bottom: 1.25rem;
  border: 1px solid #222;
}
.knobs {
  display: flex;
  justify-content: space-around;
  margin-bottom: 1.5rem;
}
.knob {
  width: 44px;
  height: 44px;
  background: radial-gradient(circle at 40% 35%, #555, #222);
  border-radius: 50%;
  border: 2px solid #444;
  position: relative;
  cursor: ns-resize;
  box-shadow: 0 2px 4px rgba(0,0,0,0.5);
}
.knob::after {
  content: attr(data-label);
  position: absolute;
  bottom: -20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  color: #777;
}
#keys {
  display: flex;
  height: 130px;
  background: #0d0d0d;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid #2a2a2a;
}
.key {
  flex: 1;
  background: #222;
  border-right: 1px solid #111;
  cursor: pointer;
  transition: background 0.04s;
}
.key:last-child { border-right: none; }
.key.white { background: #d0d0d0; }
.key.active, .key:active {
  background: #0f0 !important;
  filter: brightness(1.4);
}
.history, .matrix-section, .install {
  max-width: 860px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}
.history h2, .matrix-section h2, .install h2 {
  font-size: 1.6rem;
  margin-bottom: 1rem;
  color: #fff;
}
.synthi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin: 1.25rem 0;
}
.synthi-grid img {
  width: 100%;
  border-radius: 8px;
  border: 1px solid #333;
}
#matrix {
  display: grid;
  grid-template-columns: repeat(16, 1fr);
  gap: 3px;
  background: #111;
  padding: 10px;
  max-width: 560px;
  margin: 1rem auto;
  border: 2px solid #2a2a2a;
  border-radius: 8px;
}
.cell {
  aspect-ratio: 1;
  background: #1e1e1e;
  border-radius: 2px;
  cursor: pointer;
}
.cell.white { background: #ddd; }
.cell.red { background: #c33; }
.cell.green { background: #3c3; }
.install ul { margin: 0.75rem 0 0 1.2rem; }
footer {
  text-align: center;
  padding: 3rem 1rem;
  color: #666;
  border-top: 1px solid #222;
  font-size: 0.9rem;
}
a { color: #8cf; }
.hint { font-size: 0.9rem; color: #888; margin-top: 0.75rem; }