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

:root {
  --bg: #0d0d0d;
  --surface: #181818;
  --surface-alt: #1f1f1f;
  --border: #2a2a2a;
  --border-bright: #3a3a3a;
  --text: #ddd;
  --text-muted: #555;
  --text-dim: #888;
  --active: #f06030;
  --active-bright: #ff7840;
  --active-glow: rgba(240, 96, 48, 0.35);
  --playhead-bg: rgba(255, 255, 255, 0.06);
  --play-green: #4caf50;
  --stop-red: #e0443a;
  --grid-cols: 96px repeat(4, 1fr) 8px repeat(4, 1fr) 8px repeat(4, 1fr) 8px repeat(4, 1fr);
}

html, body {
  min-height: 100%;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 14px;
  line-height: 1.4;
  display: flex;
  flex-direction: column;
}

/* ── Header ── */

header {
  padding: 28px 28px 0;
  display: flex;
  align-items: baseline;
  gap: 14px;
}

header h1 {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--text);
}

.greeting {
  font-size: 12px;
  color: var(--text-muted);
}

/* ── Main ── */

main {
  flex: 1;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 28px;
  max-width: 980px;
  width: 100%;
  margin: 0 auto;
}

/* ── Transport ── */

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

.play-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 20px;
  background: var(--surface);
  border: 1px solid var(--border-bright);
  border-radius: 5px;
  color: var(--text);
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
  letter-spacing: 0.03em;
}

.play-btn:hover {
  background: var(--surface-alt);
  border-color: #4a4a4a;
}

.play-btn:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 2px;
}

.play-btn.playing {
  color: var(--stop-red);
  border-color: var(--stop-red);
}

.play-btn.playing:hover {
  background: rgba(224, 68, 58, 0.08);
}

.bpm-wrap,
.swing-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

#bpmVal {
  font-size: 28px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  color: var(--text);
  min-width: 3ch;
  text-align: right;
}

.bpm-right,
.swing-right {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.bpm-label {
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  cursor: default;
}

#bpmSlider {
  -webkit-appearance: none;
  appearance: none;
  width: 130px;
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

#bpmSlider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  background: var(--active);
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.1s;
}

#bpmSlider:hover::-webkit-slider-thumb,
#bpmSlider:focus-visible::-webkit-slider-thumb {
  transform: scale(1.25);
  box-shadow: 0 0 6px var(--active-glow);
}

#bpmSlider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  background: var(--active);
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

#bpmSlider:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 4px;
  border-radius: 2px;
}

/* ── Swing ── */

#swingVal {
  font-size: 20px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  color: var(--text);
  min-width: 4ch;
  text-align: right;
}

#swingSlider {
  -webkit-appearance: none;
  appearance: none;
  width: 110px;
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

#swingSlider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  background: var(--active);
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.1s, box-shadow 0.1s;
}

#swingSlider:hover::-webkit-slider-thumb,
#swingSlider:focus-visible::-webkit-slider-thumb {
  transform: scale(1.25);
  box-shadow: 0 0 6px var(--active-glow);
}

#swingSlider::-moz-range-thumb {
  width: 14px;
  height: 14px;
  background: var(--active);
  border-radius: 50%;
  border: none;
  cursor: pointer;
}

#swingSlider:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 4px;
  border-radius: 2px;
}

.share-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
}

.share-btn {
  padding: 9px 16px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 5px;
  color: var(--text-muted);
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
  transition: color 0.1s, border-color 0.1s;
}

.share-btn:hover {
  color: var(--text);
  border-color: var(--border-bright);
}

.share-btn:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 2px;
}

#shareConfirm {
  font-size: 12px;
  color: var(--active);
  opacity: 0;
  transition: opacity 0.25s;
  pointer-events: none;
  white-space: nowrap;
}

#shareConfirm.visible {
  opacity: 1;
}

/* ── Sequencer ── */

.sequencer {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.seq-inner {
  min-width: 620px;
}

.step-header,
.track-row {
  display: grid;
  grid-template-columns: var(--grid-cols);
  column-gap: 3px;
  align-items: center;
  margin-bottom: 3px;
}

.step-header {
  margin-bottom: 6px;
}

.header-spacer,
.track-label {
  /* first column */
}

.step-header-cell {
  text-align: center;
  font-size: 10px;
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  user-select: none;
}

.step-header-cell.beat {
  color: var(--text-dim);
  font-weight: 600;
}

.group-spacer {
  /* occupies the 8px spacer column — no content needed */
}

.track-label {
  font-size: 10px;
  font-family: 'Courier New', 'Lucida Console', monospace;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding-right: 6px;
  user-select: none;
  display: flex;
  align-items: center;
  gap: 5px;
}

/* ── Mute button ── */

.mute-btn {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 2px;
  color: var(--text-muted);
  font-size: 9px;
  font-family: 'Courier New', monospace;
  font-weight: 700;
  letter-spacing: 0;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.1s, border-color 0.1s, color 0.1s;
}

.mute-btn:hover {
  border-color: var(--border-bright);
  color: var(--text);
}

.mute-btn.muted {
  background: var(--active);
  border-color: var(--active);
  color: #fff;
}

.mute-btn:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 1px;
}

.track-row.row-muted .step-btn {
  opacity: 0.3;
}

.track-row.row-muted .track-name {
  opacity: 0.4;
}

.step-btn {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  min-height: 34px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 3px;
  cursor: pointer;
  transition: background 0.06s, border-color 0.06s, box-shadow 0.06s;
  position: relative;
  outline: none;
}

.step-btn:hover {
  background: var(--surface-alt);
  border-color: var(--border-bright);
}

.step-btn:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 1px;
}

.step-btn.active {
  background: var(--active);
  border-color: var(--active);
  box-shadow: 0 0 7px var(--active-glow);
}

.step-btn.active:hover {
  background: var(--active-bright);
  border-color: var(--active-bright);
}

/* playhead: highlights the current column */
.step-btn.playhead {
  background: var(--playhead-bg);
  border-color: #333;
}

.step-btn.active.playhead {
  background: var(--active-bright);
  box-shadow: 0 0 14px var(--active-glow), 0 0 0 1px rgba(255, 255, 255, 0.15);
}

/* ── Presets ── */

.presets {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.presets-label {
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.preset-row {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.preset-btn {
  padding: 6px 13px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-muted);
  font-size: 12px;
  font-family: inherit;
  cursor: pointer;
  transition: color 0.1s, border-color 0.1s, background 0.1s;
}

.preset-btn:hover {
  color: var(--text);
  border-color: var(--border-bright);
  background: var(--surface);
}

.preset-btn:focus-visible {
  outline: 2px solid var(--active);
  outline-offset: 2px;
}

.preset-clear:hover {
  color: var(--stop-red);
  border-color: var(--stop-red);
  background: transparent;
}

/* ── Footer ── */

footer {
  padding: 20px 28px;
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  gap: 6px;
  max-width: 980px;
  width: 100%;
  margin: 0 auto;
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.1s;
}

footer a:hover {
  color: var(--text-dim);
}

footer a:focus-visible {
  outline: 2px solid var(--active);
  border-radius: 2px;
  outline-offset: 2px;
}

/* ── Mobile ── */

@media (max-width: 580px) {
  main {
    padding: 18px;
    gap: 20px;
  }

  header {
    padding: 20px 18px 0;
  }

  footer {
    padding: 16px 18px;
  }

  .transport {
    gap: 14px;
  }

  #bpmSlider {
    width: 100px;
  }

  .step-btn {
    min-height: 28px;
  }

  .seq-inner {
    min-width: 560px;
  }
}