@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  /* Harmonious Dark Mode HSL Color Palette */
  --bg-main: hsl(230, 25%, 7%);
  --bg-sidebar: hsl(230, 25%, 9%);
  --bg-card: hsla(230, 25%, 12%, 0.6);
  --bg-card-hover: hsla(230, 25%, 18%, 0.8);
  --border-glass: hsla(230, 25%, 25%, 0.3);
  --border-glass-focus: hsla(200, 100%, 50%, 0.5);
  
  --color-text-main: hsl(220, 20%, 90%);
  --color-text-muted: hsl(220, 15%, 60%);
  
  /* Accent Colors */
  --accent-cyan: hsl(185, 100%, 50%);
  --accent-blue: hsl(210, 100%, 50%);
  --accent-indigo: hsl(245, 100%, 65%);
  --accent-emerald: hsl(150, 100%, 40%);
  --accent-ruby: hsl(345, 100%, 55%);
  
  --gradient-accent: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  --gradient-neon: linear-gradient(135deg, var(--accent-cyan), var(--accent-indigo));
  
  /* Fonts */
  --font-main: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  
  /* Layout constraints */
  --sidebar-width: 320px;
  --header-height: 70px;
  --transition-speed: 0.2s;
  
  color-scheme: dark;
}

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

body {
  font-family: var(--font-main);
  background-color: var(--bg-main);
  color: var(--color-text-main);
  min-height: 100vh;
  display: flex;
  overflow: hidden;
  line-height: 1.5;
  background-image: 
    radial-gradient(at 0% 0%, hsla(245, 100%, 65%, 0.08) 0px, transparent 50%),
    radial-gradient(at 100% 0%, hsla(185, 100%, 50%, 0.05) 0px, transparent 50%),
    radial-gradient(at 50% 100%, hsla(210, 100%, 50%, 0.05) 0px, transparent 50%);
}

/* Scrollbar customization */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-sidebar);
}

::-webkit-scrollbar-thumb {
  background: hsla(230, 25%, 25%, 0.5);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: hsla(230, 25%, 35%, 0.8);
}

/* Typography elements */
h1, h2, h3, h4 {
  font-weight: 600;
  letter-spacing: -0.02em;
}

/* App Layout Grid */
.app-container {
  display: flex;
  width: 100vw;
  height: 100vh;
  position: relative;
}

/* Sidebar Styling (Glassmorphic) */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-glass);
  display: flex;
  flex-direction: column;
  height: 100%;
  flex-shrink: 0;
  z-index: 10;
}

.sidebar-header {
  padding: 24px;
  border-bottom: 1px solid var(--border-glass);
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-accent);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.3);
}

.logo-text {
  font-weight: 700;
  font-size: 1.25rem;
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.sidebar-content {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Main Workspace Area */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
  position: relative;
}

/* Top Navigation Bar */
.top-nav {
  height: var(--header-height);
  border-bottom: 1px solid var(--border-glass);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  background-color: hsla(230, 25%, 7%, 0.5);
  backdrop-filter: blur(12px);
  z-index: 5;
}

.song-info {
  display: flex;
  align-items: center;
  gap: 16px;
}

.song-title-input {
  background: transparent;
  border: 1px solid transparent;
  color: var(--color-text-main);
  font-family: var(--font-main);
  font-size: 1.3rem;
  font-weight: 700;
  padding: 4px 8px;
  border-radius: 6px;
  transition: all var(--transition-speed);
  width: 240px;
}

.song-title-input:hover {
  background: var(--bg-card);
}

.song-title-input:focus {
  outline: none;
  background: var(--bg-card);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 8px rgba(0, 242, 254, 0.2);
}

.song-meta-input {
  background: transparent;
  border: 1px solid transparent;
  color: var(--color-text-muted);
  font-family: var(--font-main);
  font-size: 0.9rem;
  padding: 4px 8px;
  border-radius: 6px;
  width: 150px;
}

.song-meta-input:hover {
  background: var(--bg-card);
}

.song-meta-input:focus {
  outline: none;
  background: var(--bg-card);
  border-color: var(--accent-cyan);
}

/* Workspace Canvas */
.workspace-canvas {
  flex: 1;
  overflow-y: auto;
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Floating Actions Bar / Control Panel */
.control-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  backdrop-filter: blur(16px);
  border-radius: 16px;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.control-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.divider {
  width: 1px;
  height: 24px;
  background-color: var(--border-glass);
}

/* Premium Buttons & Controls */
.btn {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  color: var(--color-text-main);
  font-family: var(--font-main);
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-speed);
  font-size: 0.9rem;
  user-select: none;
}

.btn:hover {
  background: var(--bg-card-hover);
  border-color: var(--color-text-muted);
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--gradient-accent);
  border: none;
  color: hsl(230, 25%, 5%);
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(0, 242, 254, 0.2);
}

.btn-primary:hover {
  background: linear-gradient(135deg, hsl(185, 100%, 55%), hsl(210, 100%, 55%));
  box-shadow: 0 6px 20px rgba(0, 242, 254, 0.35);
  border: none;
  color: hsl(230, 25%, 5%);
}

.btn-icon {
  padding: 8px;
  border-radius: 8px;
}

.btn-danger {
  background: rgba(255, 30, 80, 0.15);
  border-color: rgba(255, 30, 80, 0.3);
  color: var(--accent-ruby);
}

.btn-danger:hover {
  background: rgba(255, 30, 80, 0.25);
  border-color: var(--accent-ruby);
}

.btn-active {
  background: rgba(0, 242, 254, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(0, 242, 254, 0.1);
}

/* Playback tempo input & slider */
.tempo-control {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

.tempo-slider {
  -webkit-appearance: none;
  width: 100px;
  height: 4px;
  border-radius: 2px;
  background: var(--border-glass);
  outline: none;
}

.tempo-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-cyan);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-cyan);
  transition: transform 0.1s;
}

.tempo-slider::-webkit-slider-thumb:hover {
  transform: scale(1.3);
}

.tempo-val {
  font-family: var(--font-mono);
  color: var(--color-text-main);
  min-width: 32px;
  text-align: right;
}

/* Guitar Tab Sheet Block Container */
.tab-sheet-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  backdrop-filter: blur(12px);
  border-radius: 16px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.tab-sheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tab-sheet-title {
  font-size: 1.1rem;
  color: var(--color-text-main);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Horizontal Scroll Tab Editor View */
.tab-editor-scroll-container {
  width: 100%;
  padding-bottom: 12px;
  position: relative;
  border-radius: 8px;
  background: rgba(0,0,0,0.15);
  border: 1px solid rgba(255,255,255,0.03);
}

/* Guitar Tab Layout: Flex wrap measure blocks */
.tab-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 24px 16px;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 14px;
  min-height: auto;
}

/* self-contained measure blocks that wrap */
.measure-block {
  display: grid;
  grid-template-rows: 24px 24px 20px 20px 20px 20px 20px 20px; /* chords, lyrics, e, B, G, D, A, E */
  grid-template-columns: 24px repeat(8, 36px) 10px; /* header, 8 beats, barline */
  position: relative;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--border-glass);
  border-radius: 8px;
  padding: 12px 8px;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.3);
}

/* Horizontal string lines within each measure block */
.measure-block::before {
  content: '';
  position: absolute;
  left: 32px;
  right: 18px;
  top: 70px; /* padding 12px + 24px + 24px + 10px half string height */
  height: 100px; /* 5 intervals of 20px */
  background: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 9px,
    hsla(220, 15%, 60%, 0.18) 9px,
    hsla(220, 15%, 60%, 0.18) 11px,
    transparent 11px,
    transparent 20px
  );
  pointer-events: none;
  z-index: 1;
}

.measure-header-cell {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  font-weight: bold;
  color: var(--accent-cyan);
  font-size: 12px;
  font-family: var(--font-mono);
  user-select: none;
}

.measure-header-cell.string-header {
  height: 20px;
}

.measure-barline {
  border-right: 2px solid rgba(255, 255, 255, 0.35);
  margin-left: 4px;
  height: 100%;
}

/* Individual Grid Cells */
.tab-cell {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  z-index: 2;
  transition: background-color var(--transition-speed);
  cursor: pointer;
}

.tab-cell.note-cell {
  height: 20px;
  color: var(--color-text-main);
  font-weight: 500;
}

.tab-cell.note-cell::before {
  content: '';
  position: absolute;
  width: 14px;
  height: 14px;
  background: var(--bg-main);
  border-radius: 3px;
  z-index: -1;
  display: none;
}

.tab-cell.note-cell.has-note::before {
  display: block;
}

.tab-cell.chord-cell {
  height: 24px;
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 11px;
  text-transform: uppercase;
}

.tab-cell.lyric-cell {
  height: 24px;
  color: var(--color-text-muted);
  font-size: 10px;
  white-space: nowrap;
}

/* Cell Focus / Playback States */
.tab-cell.focused {
  outline: 2px solid var(--accent-cyan);
  border-radius: 4px;
  background-color: rgba(0, 242, 254, 0.1);
  z-index: 4;
}

.tab-cell.note-cell.focused::before {
  background: transparent;
}

.tab-cell.drag-over {
  background-color: rgba(0, 242, 254, 0.2);
  outline: 2px dashed var(--accent-cyan);
  border-radius: 4px;
}

.tab-column-highlight {
  grid-row: 1 / -1;
  background-color: transparent;
  border-left: 1px dashed transparent;
  border-right: 1px dashed transparent;
  pointer-events: none;
  z-index: 1;
}

.tab-column-highlight.playing {
  background-color: hsla(150, 100%, 40%, 0.08);
  border-left: 1px solid var(--accent-emerald);
  border-right: 1px solid var(--accent-emerald);
  box-shadow: 0 0 10px rgba(0, 255, 120, 0.1);
}

/* Chord Library Elements */
.chord-library-section {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.section-title {
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  font-weight: 600;
  border-bottom: 1px solid var(--border-glass);
  padding-bottom: 8px;
}

.chord-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(75px, 1fr));
  gap: 10px;
}

.chord-card {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: 8px;
  padding: 8px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-speed);
  position: relative;
}

.chord-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
  transform: translateY(-2px);
}

.chord-card.active-tab-chord {
  border-color: var(--accent-indigo);
  background: rgba(100, 100, 255, 0.05);
}

.chord-card-name {
  font-size: 0.85rem;
  font-weight: 600;
  text-align: center;
}

.chord-card-diagram {
  width: 55px;
  height: 65px;
}

/* Predefined list of chords used in song (placed on main canvas) */
.song-chords-panel {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  padding: 16px;
  border-radius: 12px;
}

/* Modals & Dialog overlays */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(6, 7, 14, 0.8);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-card {
  background: var(--bg-sidebar);
  border: 1px solid var(--border-glass);
  border-radius: 20px;
  width: 90%;
  max-width: 550px;
  box-shadow: 0 20px 50px rgba(0,0,0,0.5);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.9);
  transition: transform 0.3s;
}

.modal-overlay.active .modal-card {
  transform: scale(1);
}

.modal-header {
  padding: 24px;
  border-bottom: 1px solid var(--border-glass);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
  max-height: 70vh;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-glass);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

.form-group {
  margin-bottom: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-muted);
}

.form-input {
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  color: var(--color-text-main);
  padding: 10px 14px;
  border-radius: 8px;
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: border-color var(--transition-speed);
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-cyan);
  box-shadow: 0 0 8px rgba(0,242,254,0.15);
}

/* Custom Chord Builder Grid Layout */
.builder-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.builder-fretboard-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

.builder-fretboard {
  display: grid;
  grid-template-columns: repeat(6, 28px); /* 6 frets: open, 1, 2, 3, 4, 5 */
  grid-template-rows: repeat(6, 24px); /* 6 strings */
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  padding: 10px;
  border-radius: 8px;
}

.builder-fretboard::before {
  content: '';
  position: absolute;
  left: 24px;
  top: 10px;
  bottom: 10px;
  width: 140px; /* 5 frets * 28px */
  background: repeating-linear-gradient(
    to right,
    transparent 0px,
    transparent 27px,
    hsla(220, 15%, 60%, 0.3) 27px,
    hsla(220, 15%, 60%, 0.3) 28px
  );
  pointer-events: none;
}

/* Vertical string lines for builder board */
.builder-fretboard::after {
  content: '';
  position: absolute;
  left: 10px;
  right: 10px;
  top: 22px;
  height: 120px; /* 5 gaps * 24px */
  background: repeating-linear-gradient(
    to bottom,
    transparent 0px,
    transparent 11px,
    hsla(220, 15%, 60%, 0.2) 11px,
    hsla(220, 15%, 60%, 0.2) 13px,
    transparent 13px,
    transparent 24px
  );
  pointer-events: none;
}

.builder-cell {
  width: 28px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 2;
  position: relative;
}

.builder-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 8px var(--accent-cyan);
  display: none;
}

.builder-cell.active .builder-dot {
  display: block;
}

/* Show open/mute status markers at top of builder */
.builder-status-row {
  display: flex;
  justify-content: space-around;
  width: 100%;
  padding: 0 10px;
}

.builder-status-indicator {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: bold;
  border-radius: 4px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
}

.builder-status-indicator.muted {
  color: var(--accent-ruby);
  border-color: rgba(255, 30, 80, 0.3);
}

.builder-status-indicator.open {
  color: var(--accent-emerald);
  border-color: rgba(0, 255, 120, 0.3);
}

/* Chord preview in builder modal */
.builder-preview-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: 12px;
  padding: 20px;
}

.builder-preview-svg {
  width: 120px;
  height: 150px;
}

/* File / Song Management Sidebar Listing */
.song-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: 250px;
  overflow-y: auto;
}

.song-list-item {
  padding: 10px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: all var(--transition-speed);
}

.song-list-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent-cyan);
}

.song-list-item.active {
  border-color: var(--accent-cyan);
  background: rgba(0, 242, 254, 0.05);
}

.song-item-info {
  display: flex;
  flex-direction: column;
}

.song-item-title {
  font-size: 0.9rem;
  font-weight: 600;
}

.song-item-artist {
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.song-item-actions {
  opacity: 0;
  transition: opacity var(--transition-speed);
}

.song-list-item:hover .song-item-actions {
  opacity: 1;
}

/* ASCII export textarea panel */
.ascii-textarea {
  width: 100%;
  height: 300px;
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--border-glass);
  color: var(--color-text-main);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 16px;
  border-radius: 8px;
  resize: none;
  outline: none;
}

.ascii-textarea:focus {
  border-color: var(--accent-cyan);
}

/* Chord Grid inside Header for PDF output */
.print-chords-container {
  display: none;
  flex-wrap: wrap;
  gap: 20px;
  margin-bottom: 24px;
}

/* Printing styles */
@media print {
  body {
    background: #fff;
    color: #000;
    overflow: visible;
    background-image: none;
  }
  
  .app-container {
    height: auto;
    width: auto;
    display: block;
  }
  
  .sidebar, .top-nav, .control-panel, .tab-sheet-header, .logo-icon, .btn, .divider, .track-switcher-bar {
    display: none !important;
  }
  
  .main-content {
    display: block;
    height: auto;
    overflow: visible;
  }
  
  .workspace-canvas {
    padding: 0;
    display: block;
  }
  
  .tab-sheet-card {
    background: transparent !important;
    border: none !important;
    box-shadow: none !important;
    padding: 0 !important;
  }
  
  .tab-editor-scroll-container {
    background: transparent;
    border: none;
  }
  
  .tab-grid {
    padding: 0;
    gap: 20px 8px;
  }
  
  .measure-block {
    background: transparent !important;
    border: 1px solid #ccc !important;
    box-shadow: none !important;
    page-break-inside: avoid;
  }
  
  .measure-header-cell {
    color: #000 !important;
  }
  
  .measure-barline {
    border-right: 2px solid #000 !important;
  }
  
  .tab-cell {
    color: #000 !important;
  }
  
  .tab-cell.note-cell::before {
    background: #fff !important;
  }
  
  .tab-cell.chord-cell {
    color: #000 !important;
  }
  
  .tab-cell.focused {
    outline: none !important;
    background: transparent !important;
  }
  
  /* Show chord diagram prints at the top of the page */
  .print-chords-container {
    display: flex !important;
  }
  
  /* SVG colors for print */
  svg text {
    fill: #000 !important;
  }
  svg line, svg circle {
    stroke: #000 !important;
  }
  svg circle.pressed-dot {
    fill: #000 !important;
  }
}

/* Chord Cards Enhancements: draggable and delete actions */
.chord-card {
  position: relative;
  user-select: none;
}

.chord-card .chord-card-delete {
  position: absolute;
  top: -6px;
  right: -6px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent-ruby);
  color: #fff;
  border: 1px solid var(--border-glass);
  font-size: 11px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition-speed), transform var(--transition-speed);
  z-index: 5;
}

.chord-card:hover .chord-card-delete {
  opacity: 1;
}

.chord-card .chord-card-delete:hover {
  transform: scale(1.15);
  background: hsl(345, 100%, 65%);
}

/* Track Switcher & Tabs styling */
.track-tab-btn {
  background: var(--bg-sidebar);
  border: 1px solid var(--border-glass);
  color: var(--color-text-muted);
  padding: 6px 12px;
  border-radius: 6px;
  font-family: var(--font-main);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-speed);
}

.track-tab-btn:hover {
  background: var(--bg-card-hover);
  color: var(--color-text-main);
  border-color: var(--color-text-muted);
}

.track-tab-btn.active {
  background: rgba(0, 242, 254, 0.15);
  border-color: var(--accent-cyan);
  color: var(--accent-cyan);
  font-weight: 600;
  box-shadow: 0 0 10px rgba(0, 242, 254, 0.15);
}

.track-tab-delete-btn {
  background: transparent;
  border: none;
  color: var(--accent-ruby);
  font-weight: bold;
  cursor: pointer;
  padding: 0 2px;
  font-size: 0.95rem;
  line-height: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.6;
  transition: opacity var(--transition-speed), transform var(--transition-speed);
}

.track-tab-delete-btn:hover {
  opacity: 1;
  transform: scale(1.2);
}

/* Bass Track Layout Overrides */
.measure-block.bass-track {
  grid-template-rows: 24px 24px 20px 20px 20px 20px; /* chords, lyrics, and 4 bass string rows */
}

.measure-block.bass-track::before {
  top: 70px;
  height: 60px; /* 3 intervals of 20px for 4 strings */
}

/* YouTube Backing Player CSS */
.youtube-player-container {
  width: 100%;
  height: 160px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border-glass);
  background: #000;
  position: relative;
  margin-top: 8px;
}

.youtube-player-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}