:root {
  --bg: #0a0a0b;
  --fg: #f2f2f2;
  --muted: #5a5a60;
  --line: #1c1c1f;
  --cell: #161618;
  --cell-hover: #232327;
  --playhead: #2a2a30;
  --accent-k: #ff5a5f;
  --accent-s: #ffd166;
  --accent-h: #4ad991;
  --accent-p: #6ab7ff;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: ui-monospace, SFMono-Regular, "JetBrains Mono", Menlo, monospace;
  font-size: 14px;
  height: 100%;
  -webkit-font-smoothing: antialiased;
}

#app {
  max-width: 980px;
  margin: 0 auto;
  padding: 32px 24px 40px;
  display: flex;
  flex-direction: column;
  gap: 28px;
  min-height: 100vh;
}

.topbar {
  display: flex;
  align-items: center;
  gap: 24px;
  justify-content: space-between;
  border-bottom: 1px solid var(--line);
  padding-bottom: 16px;
}

.brand {
  font-weight: 700;
  letter-spacing: 0.02em;
  font-size: 18px;
}

.room {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--muted);
}

.room-id {
  color: var(--fg);
  background: var(--line);
  padding: 4px 8px;
  border-radius: 4px;
  letter-spacing: 0.04em;
}

.presence {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--muted);
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--muted);
  transition: background 0.2s;
}
.dot[data-state="solo"] { background: var(--muted); }
.dot[data-state="connected"] { background: var(--accent-h); box-shadow: 0 0 8px var(--accent-h); }

.transport {
  display: flex;
  align-items: center;
  gap: 20px;
}

.play {
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 12px 22px;
  background: var(--fg);
  color: var(--bg);
  border: 0;
  border-radius: 6px;
  cursor: pointer;
  min-width: 90px;
  transition: opacity 0.15s;
}
.play[aria-pressed="true"] {
  background: var(--accent-h);
}
.play:hover { opacity: 0.9; }

.ghost {
  font-family: inherit;
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--line);
  padding: 6px 10px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 12px;
  transition: color 0.15s, border-color 0.15s;
}
.ghost:hover { color: var(--fg); border-color: var(--muted); }

.bpm {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  color: var(--muted);
  font-size: 12px;
}
.bpm input[type="range"] {
  flex: 1;
  max-width: 320px;
  accent-color: var(--fg);
}
.bpm output {
  color: var(--fg);
  min-width: 32px;
  text-align: right;
}

.grid {
  display: grid;
  grid-template-columns: 48px repeat(16, 1fr);
  gap: 4px;
  user-select: none;
}

.track-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.cell {
  aspect-ratio: 1 / 1;
  background: var(--cell);
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.08s, transform 0.05s;
  position: relative;
}
.cell:hover { background: var(--cell-hover); }
.cell:active { transform: scale(0.96); }

.cell[data-on="1"][data-track="kick"]  { background: var(--accent-k); }
.cell[data-on="1"][data-track="snare"] { background: var(--accent-s); }
.cell[data-on="1"][data-track="hat"]   { background: var(--accent-h); }
.cell[data-on="1"][data-track="perc"]  { background: var(--accent-p); }

.cell[data-beat="1"]:not([data-on="1"]) {
  background: var(--cell-hover);
}

.cell[data-step="0"],
.cell[data-step="4"],
.cell[data-step="8"],
.cell[data-step="12"] {
  border-left: 1px solid var(--line);
}

.grid.is-playing .cell[data-playhead="1"]:not([data-on="1"]) {
  background: var(--playhead);
}
.grid.is-playing .cell[data-playhead="1"][data-on="1"]::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 4px;
  box-shadow: inset 0 0 0 2px var(--fg);
}

.hint {
  color: var(--muted);
  font-size: 11px;
  margin-top: auto;
  border-top: 1px solid var(--line);
  padding-top: 16px;
}

@media (max-width: 720px) {
  #app { padding: 16px 12px 28px; gap: 18px; }
  .grid { grid-template-columns: 36px repeat(16, 1fr); gap: 3px; }
  .topbar { flex-wrap: wrap; gap: 12px; }
  .transport { flex-wrap: wrap; }
}