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

/* Ensure [hidden] always wins regardless of display rules on other selectors */
[hidden] { display: none !important; }

/* ── Themes ──────────────────────────────────────────────────────────────── */

:root {
  --bg:              #f0f2f5;
  --surface:         #ffffff;
  --surface-alt:     #f8f9fb;
  --border:          #dde1e7;
  --text:            #1a1d23;
  --text-muted:      #6b7280;
  --primary:         #5c4dff;
  --primary-hover:   #4a3de0;
  --secondary:       #e8e6ff;
  --secondary-hover: #d5d1ff;
  --code-bg:         #1e1e2e;
  --code-text:       #cdd6f4;
  --shadow:          0 2px 12px rgba(0,0,0,0.08);
  --radius:          12px;
}

[data-theme="dark"] {
  --bg:              #0f1117;
  --surface:         #1a1d27;
  --surface-alt:     #141720;
  --border:          #2d3142;
  --text:            #e2e8f0;
  --text-muted:      #94a3b8;
  --primary:         #7c6dff;
  --primary-hover:   #6a5de0;
  --secondary:       #2d2a4a;
  --secondary-hover: #3d3a5a;
  --code-bg:         #0d0e1a;
  --code-text:       #cdd6f4;
  --shadow:          0 2px 16px rgba(0,0,0,0.3);
}

/* ── Base ────────────────────────────────────────────────────────────────── */

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding: 2rem 1rem 3rem;
  transition: background 0.2s, color 0.2s;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

h2 {
  font-weight: 600;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

/* ── Header ─────────────────────────────────────────────────────────────── */

.header-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.25rem;
}

h1 {
  font-size: 1.85rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.subtitle {
  color: var(--text-muted);
  margin-top: 0.3rem;
  font-size: 0.95rem;
}

/* Theme toggle */
.theme-toggle {
  flex-shrink: 0;
  width: 2.25rem;
  height: 2.25rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
  margin-top: 0.2rem;
}

.theme-toggle:hover {
  background: var(--secondary);
  color: var(--primary);
  border-color: var(--primary);
}

[data-theme="light"] .icon-sun  { display: none; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="dark"]  .icon-moon { display: none; }
[data-theme="dark"]  .icon-sun  { display: block; }

/* ── Cards ───────────────────────────────────────────────────────────────── */

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  transition: background 0.2s, border-color 0.2s;
}

/* ── Top row: upload + preview ───────────────────────────────────────────── */

.top-row {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 1.25rem;
  align-items: start;
}

/* Upload card — square */
.upload-card {
  padding: 0.6rem;
  aspect-ratio: 1 / 1;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.upload-card.drag-over {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(92, 77, 255, 0.18);
}

.upload-label {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  height: 100%;
  border: 2px dashed var(--border);
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-muted);
  text-align: center;
  padding: 1rem;
  transition: border-color 0.15s, background 0.15s, color 0.15s;
}

.upload-label:hover,
.upload-card.drag-over .upload-label {
  border-color: var(--primary);
  background: var(--secondary);
  color: var(--primary);
}

.upload-label input[type="file"] { display: none; }

.upload-text {
  font-size: 0.9rem;
  font-weight: 600;
}

.upload-hint {
  font-size: 0.75rem;
}

/* Preview card */
.preview-card {
  display: flex;
  flex-direction: column;
  min-height: 200px;
}

.preview-empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  color: var(--text-muted);
  background: var(--surface-alt);
  border-radius: 8px;
  border: 1px dashed var(--border);
  font-size: 0.875rem;
}

.preview-content {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.preview-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
}

.canvas-wrapper {
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: auto;
  display: inline-block;
  max-width: 100%;
  max-height: 380px;
  background:
    linear-gradient(45deg, var(--surface-alt) 25%, transparent 25%),
    linear-gradient(-45deg, var(--surface-alt) 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, var(--surface-alt) 75%),
    linear-gradient(-45deg, transparent 75%, var(--surface-alt) 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0px;
  background-color: var(--surface);
}

#preview-canvas {
  display: block;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
}

/* ── Controls ────────────────────────────────────────────────────────────── */

.controls-row {
  display: flex;
  align-items: flex-end;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.control-group > label {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
}

/* Type toggle */
.type-toggle {
  display: flex;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.type-btn {
  flex: 1;
  height: 2.5rem;
  padding: 0 1rem;
  border: none;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}

.type-btn + .type-btn {
  border-left: 1px solid var(--border);
}

.type-btn.active {
  background: var(--primary);
  color: #fff;
}

.type-btn:not(.active):hover {
  background: var(--secondary);
  color: var(--primary);
}

/* Select + number inputs */
select,
input[type="number"] {
  height: 2.5rem;
  padding: 0 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.875rem;
  color: var(--text);
  background: var(--surface);
  outline: none;
  transition: border-color 0.15s, background 0.15s;
}

select:focus,
input[type="number"]:focus {
  border-color: var(--primary);
}

select {
  min-width: 140px;
  cursor: pointer;
}

.custom-size-inputs {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.custom-size-inputs input[type="number"] {
  width: 70px;
  text-align: center;
}

.times {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Greyscale checkbox */
.control-group-check {
  justify-content: flex-end;
  padding-bottom: 0.4rem;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 0.875rem;
  color: var(--text);
  user-select: none;
}

.checkbox-label input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Buttons */
.btn {
  height: 2.5rem;
  padding: 0 1.25rem;
  border: none;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  white-space: nowrap;
}

.btn:active { transform: scale(0.97); }

.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); }

.btn-secondary { background: var(--secondary); color: var(--primary); }
.btn-secondary:hover { background: var(--secondary-hover); }

/* ── Used colors palette ─────────────────────────────────────────────────── */

.palette-section {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}

.palette-heading {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
}

.palette-swatches {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.swatch {
  width: 36px;
  height: 36px;
  border-radius: 6px;
  border: 1px solid rgba(0,0,0,0.15);
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  padding: 2px 3px;
  cursor: default;
}

.swatch span {
  font-size: 0.6rem;
  font-weight: 700;
  font-family: monospace;
  line-height: 1;
  mix-blend-mode: difference;
  color: #fff;
  user-select: none;
}

.swatch-transparent {
  background-image:
    linear-gradient(45deg, #ccc 25%, transparent 25%),
    linear-gradient(-45deg, #ccc 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ccc 75%),
    linear-gradient(-45deg, transparent 75%, #ccc 75%);
  background-size: 10px 10px;
  background-position: 0 0, 0 5px, 5px -5px, -5px 0px;
  background-color: #fff;
}

.swatch-transparent span {
  mix-blend-mode: normal;
  color: #555;
}

/* ── Output (full width) ─────────────────────────────────────────────────── */

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.output-header h2 { margin-bottom: 0; }

.code-block {
  background: var(--code-bg);
  border-radius: 8px;
  padding: 1rem;
  overflow: auto;
  max-height: 480px;
}

.code-block code {
  font-family: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
  font-size: 0.8rem;
  color: var(--code-text);
  white-space: pre;
  display: block;
}

/* ── Credits ─────────────────────────────────────────────────────────────── */

.credits {
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 0.5rem 0 0.25rem;
}

.credits strong {
  color: var(--text);
}

/* ── Toast ───────────────────────────────────────────────────────────────── */

.toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%) translateY(0.75rem);
  background: #1a1d23;
  color: #fff;
  padding: 0.65rem 1.25rem;
  border-radius: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s, transform 0.2s;
  white-space: nowrap;
  z-index: 999;
}

.toast.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateX(-50%) translateY(0);
}

.toast.toast-error { background: #b91c1c; }

/* ── Site nav ────────────────────────────────────────────────────────────── */

.site-nav {
  display: flex;
  gap: 0.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.nav-link {
  padding: 0.4rem 0.9rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  transition: background 0.15s, color 0.15s;
}

.nav-link:hover {
  background: var(--secondary);
  color: var(--primary);
}

.nav-link.active {
  background: var(--secondary);
  color: var(--primary);
  font-weight: 600;
}

/* ── BPM control ─────────────────────────────────────────────────────────── */

.bpm-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.bpm-control input[type="range"] {
  width: 110px;
  height: 4px;
  accent-color: var(--primary);
  cursor: pointer;
  padding: 0;
  border: none;
  background: transparent;
}

.bpm-control input[type="number"] {
  width: 58px;
  text-align: center;
  padding: 0 0.4rem;
}

/* ── Play / Stop button ──────────────────────────────────────────────────── */

.btn-stop { background: #b91c1c; color: #fff; }
.btn-stop:hover { background: #991b1b; }

/* ── Step sequencer ──────────────────────────────────────────────────────── */

.track-card {
  padding: 1.25rem;
}

.track-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.track-identity {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  min-width: 0;
}

.track-color-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  flex-shrink: 0;
}

.track-name {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  outline: none;
  border-radius: 4px;
  padding: 2px 5px;
  cursor: text;
  white-space: nowrap;
  overflow: hidden;
  max-width: 160px;
}

.track-name:focus {
  background: var(--secondary);
  color: var(--primary);
  text-transform: none;
  cursor: text;
}

/* ── Collapse toggle ──────────────────────────────────────────────────────── */

.btn-track-collapse {
  width: 1.5rem;
  height: 1.5rem;
  border: none;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  flex-shrink: 0;
  border-radius: 4px;
  transition: color 0.12s, background 0.12s;
}

.btn-track-collapse:hover {
  color: var(--text);
  background: var(--surface-alt);
}

.btn-track-collapse svg {
  transition: transform 0.18s ease;
}

.track-card[data-collapsed="true"] .btn-track-collapse svg {
  transform: rotate(-90deg);
}

/* ── Mini preview (shown when collapsed) ─────────────────────────────────── */

.track-mini {
  display: none;
  height: 14px;
  margin-top: 0.6rem;
  gap: 2px;
}

.track-card[data-collapsed="true"] .track-mini {
  display: flex;
}

.track-card[data-collapsed="true"] .sequencer-scroll {
  display: none;
}

.track-mini-beat {
  flex: 1;
  height: 100%;
  border-radius: 2px;
  background: var(--border);
  min-width: 0;
  transition: background 0.1s;
}

.track-mini-beat.active {
  background: var(--track-color, var(--primary));
}

.track-mini-beat.bar-start {
  margin-left: 2px;
}

.track-every {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  white-space: nowrap;
}

.track-every-label {
  font-size: 0.68rem;
  font-weight: 500;
  color: var(--text-muted);
  user-select: none;
}

.track-every-input {
  width: 62px;
  height: 1.75rem;
  text-align: center;
  padding: 0 0.4rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text-muted);
  font-size: 0.78rem;
  font-weight: 600;
  transition: border-color 0.12s, color 0.12s;
}

.track-every-input:focus {
  border-color: var(--primary);
  color: var(--text);
  outline: none;
}

.track-instrument {
  height: 1.75rem;
  padding: 0 0.45rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: var(--surface);
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 500;
  cursor: pointer;
  min-width: 78px;
  transition: border-color 0.12s, color 0.12s;
}

.track-instrument:hover,
.track-instrument:focus {
  border-color: var(--primary);
  color: var(--text);
  outline: none;
}

.track-controls {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-shrink: 0;
}

.btn-track-mute {
  height: 1.75rem;
  padding: 0 0.65rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: transparent;
  color: var(--text-muted);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}

.btn-track-mute:hover {
  background: var(--secondary);
  color: var(--primary);
  border-color: var(--primary);
}

.btn-track-mute.active {
  background: var(--secondary);
  color: var(--primary);
  border-color: var(--primary);
}

.btn-track-remove {
  width: 1.75rem;
  height: 1.75rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: transparent;
  color: var(--text-muted);
  font-size: 1.1rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}

.btn-track-remove:hover {
  background: #fee2e2;
  color: #b91c1c;
  border-color: #f87171;
}

[data-theme="dark"] .btn-track-remove:hover {
  background: #450a0a;
  color: #fca5a5;
  border-color: #7f1d1d;
}

.track-card.muted .sequencer-scroll {
  opacity: 0.25;
  pointer-events: none;
}

.sequencer-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 4px; /* room for scrollbar on some OSes */
}

.sequencer-grid {
  display: grid;
  grid-template-columns: 44px repeat(var(--beats, 16), minmax(28px, 1fr));
  gap: 2px;
  width: 100%;
}

.seq-corner {
  height: 22px;
}

.beat-num {
  height: 22px;
  font-size: 0.62rem;
  font-weight: 500;
  color: var(--text-muted);
  text-align: center;
  line-height: 22px;
  user-select: none;
}

.beat-num.bar-start {
  font-weight: 700;
  color: var(--text);
}

.note-label {
  height: 26px;
  font-size: 0.68rem;
  font-family: 'Cascadia Code', 'Fira Code', monospace;
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 8px;
  user-select: none;
  white-space: nowrap;
}

.note-label.black-key {
  color: var(--text-muted);
  font-size: 0.63rem;
}

.seq-cell {
  height: 26px;
  border: 1px solid var(--border);
  border-radius: 3px;
  background: var(--surface-alt);
  cursor: pointer;
  padding: 0;
  transition: background 0.08s, border-color 0.08s;
}

.seq-cell.bar-start {
  border-left: 2px solid var(--border);
}

.seq-cell:hover {
  border-color: var(--primary);
  background: var(--secondary);
}

.seq-cell:active {
  transform: scale(0.88);
}

.seq-cell.active {
  background: var(--track-color, #4ecdc4);
  border-color: transparent;
}

.seq-cell.active.bar-start {
  border-left-color: transparent;
}

.seq-cell.active:hover {
  filter: brightness(1.12);
}

/* ── Music hint ──────────────────────────────────────────────────────────── */

.music-hint {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  padding: 0.25rem 0 0.5rem;
}

/* ── Beat cursor (playback position) ────────────────────────────────────── */

.beat-num.cursor {
  color: var(--primary);
  font-weight: 800;
}

.seq-cell.cursor:not(.active) {
  background: var(--secondary);
  border-color: var(--primary);
}

.seq-cell.cursor.active {
  filter: brightness(1.2);
}

/* ── Responsive ──────────────────────────────────────────────────────────── */

@media (max-width: 660px) {
  h1 { font-size: 1.4rem; }

  .top-row {
    grid-template-columns: 1fr;
  }

  .upload-card {
    aspect-ratio: auto;
    min-height: 160px;
  }

  .preview-card {
    min-height: 200px;
  }

  .controls-row {
    flex-direction: column;
    align-items: stretch;
  }

  .type-toggle { width: 100%; }

  select { width: 100%; }

  .btn { width: 100%; }

  .custom-size-inputs input[type="number"] { flex: 1; }

  /* Music page mobile */
  .bpm-control input[type="range"] { flex: 1; }
  .track-name { max-width: 100px; }
}