:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #14141f;
  --bg-tertiary: #1e1e2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent: #00d4ff;
  --accent-secondary: #00ff88;
  --danger: #ff4466;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 255, 0.4);
  --radius-md: 12px;

  --kick: #00d4ff;
  --snare: #00ff88;
  --hat: #ffb020;
  --cell-idle: #1e1e2e;
  --cell-border: #2c2c3e;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  width: 600px; height: 600px; overflow: hidden;
  background: #000;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  -webkit-font-smoothing: antialiased;
}

#app { width: 100%; height: 100%; position: relative; }

.screen {
  width: 100%; height: 100%; position: absolute; top: 0; left: 0;
  display: flex; flex-direction: column;
  padding: 18px; gap: 12px;
}
.screen.hidden { display: none; }

.focusable {
  transition: box-shadow 0.12s ease, border-color 0.12s ease, transform 0.08s ease;
  border: 2px solid transparent;
  cursor: pointer; outline: none;
  font-family: inherit;
}
.focusable:focus {
  border-color: var(--focus-ring);
  box-shadow: 0 0 20px var(--focus-glow);
  outline: 2px solid var(--focus-ring);
  outline-offset: 1px;
}
.hidden { display: none !important; }

/* ---------- HOME ---------- */
.app-header { padding: 22px 6px 8px; }
.app-title {
  font-size: 58px; font-weight: 800; letter-spacing: 2px; line-height: 1;
}
.app-title .accent { color: var(--accent); }
.app-sub { color: var(--text-secondary); font-size: 20px; margin-top: 10px; letter-spacing: 1px; }

.menu { display: flex; flex-direction: column; gap: 14px; flex: 1; justify-content: center; }
.menu-item {
  display: flex; align-items: center; gap: 18px;
  min-height: 88px; padding: 0 26px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 26px; font-weight: 600; text-align: left;
}
.menu-item .mi-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; flex: 0 0 48px;
  background: var(--bg-tertiary); color: var(--accent);
  border-radius: 10px; font-size: 24px;
}
.hint { color: var(--text-muted); font-size: 16px; text-align: center; padding-bottom: 4px; }

/* ---------- SEQUENCER / shared header ---------- */
.seq-header {
  display: flex; align-items: center; gap: 14px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 14px 20px; min-height: 56px;
}
.seq-title { font-size: 24px; font-weight: 700; letter-spacing: 2px; flex: 1; }
.seq-stat { font-size: 18px; color: var(--text-secondary); }
.seq-stat strong { color: var(--text-primary); font-size: 22px; }
.playflag {
  padding: 4px 12px; border-radius: 999px; background: var(--bg-tertiary);
  color: var(--text-muted); font-weight: 700; font-size: 15px; letter-spacing: 1px;
}
.playflag.on { color: var(--accent-secondary); background: rgba(0,255,136,0.12); }

/* ---------- beat markers ---------- */
.beat-markers {
  display: grid; grid-template-columns: 64px repeat(16, 1fr);
  gap: 4px; padding: 0 2px;
}
.bm {
  text-align: center; font-size: 13px; color: var(--text-muted); font-weight: 600;
}
.bm.bm-beat { color: var(--text-secondary); }

/* ---------- grid ---------- */
.grid { display: flex; flex-direction: column; gap: 8px; flex: 1; justify-content: center; }
.track-row {
  display: grid; grid-template-columns: 64px repeat(16, 1fr);
  gap: 4px; align-items: stretch;
}
.track-label {
  display: flex; align-items: center;
  font-size: 14px; font-weight: 800; letter-spacing: 1px;
}
.t-kick { color: var(--kick); }
.t-snare { color: var(--snare); }
.t-hat { color: var(--hat); }

.cell {
  min-height: 64px;
  background: var(--cell-idle);
  border: 2px solid var(--cell-border);
  border-radius: 7px;
}
.cell.beat-start { border-left-width: 4px; border-left-color: #3a3a52; }

.cell.active.t-kick  { background: var(--kick);  border-color: var(--kick); }
.cell.active.t-snare { background: var(--snare); border-color: var(--snare); }
.cell.active.t-hat   { background: var(--hat);   border-color: var(--hat); }

.cell.playhead { background: #2e2e44; }
.cell.beat-start.playhead { background: #34344e; }
.cell.active.playhead { filter: brightness(1.45) saturate(1.1); }

/* ---------- transport ---------- */
.transport { display: flex; gap: 10px; }
.tbtn {
  flex: 1; min-height: 64px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  font-size: 17px; font-weight: 700; letter-spacing: 0.5px;
  display: flex; align-items: center; justify-content: center;
}
.tbtn-play { background: rgba(0,212,255,0.14); color: var(--accent); }
.tbtn-play.playing { background: rgba(255,68,102,0.16); color: var(--danger); }

/* ---------- presets ---------- */
.preset-list { display: flex; flex-direction: column; gap: 12px; flex: 1; justify-content: center; }
.preset-item {
  min-height: 76px; padding: 0 24px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  font-size: 22px; font-weight: 600; text-align: left;
  display: flex; align-items: center;
}
.preset-item::before {
  content: "♫"; color: var(--accent); margin-right: 16px; font-size: 22px;
}

/* ---------- help ---------- */
.help-body {
  flex: 1; background: var(--bg-secondary); border-radius: var(--radius-md);
  padding: 22px 24px; display: flex; flex-direction: column; gap: 14px;
  font-size: 18px; line-height: 1.45; color: var(--text-secondary);
  overflow: hidden;
}
.help-body strong { font-weight: 700; }
.help-body .accent { color: var(--accent); }
.help-body .t-kick { font-weight: 700; }
.help-body .t-snare { font-weight: 700; }
.help-body .t-hat { font-weight: 700; }