/* CSS Design System for Paper Piano Scale Slide-Rule */

@import url('https://fonts.googleapis.com/css2?family=Cinzel:wght@500;700&family=Plus+Jakarta+Sans:wght@400;500;600;700&family=Playfair+Display:ital,wght@0,600;0,700;1,400&family=JetBrains+Mono:wght@500;700&display=swap');

:root {
  /* Color Palette - Authentic Paper & Studio Theme */
  --bg-primary: #121418;
  --bg-surface: #1a1d24;
  --bg-card: #222630;
  --bg-card-border: #323846;
  
  --text-main: #f0f2f5;
  --text-muted: #9ba3b2;
  --text-bright: #ffffff;
  
  --accent-gold: #e5b869;
  --accent-gold-hover: #f0c87d;
  --accent-amber: #d97706;
  --accent-blue: #3b82f6;
  
  /* Paper Slide Rule Colors */
  --paper-bg: #f8f6f0;
  --paper-bg-alt: #f0ede4;
  --paper-border: #2c2925;
  --paper-ink: #1c1a17;
  --paper-shadow: rgba(0, 0, 0, 0.35);
  --paper-dark-bar: #33312e;
  --paper-dark-pattern: repeating-linear-gradient(45deg, #2b2926, #2b2926 2px, #363430 2px, #363430 4px);
  --paper-highlight: #fffae6;
  --paper-accent-red: #c0392b;

  /* Dimensions */
  --cell-width: 44px; /* Width of 1 chromatic semitone cell */
  --rule-border-width: 2px;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  
  --font-serif: 'Playfair Display', 'Georgia', serif;
  --font-sans: 'Plus Jakarta Sans', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --font-header: 'Cinzel', serif;

  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slider: 0.25s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Light / Paper Craft Theme Override */
body.theme-paper-craft {
  --bg-primary: #e8e3d5;
  --bg-surface: #dfd8c6;
  --bg-card: #f4efdf;
  --bg-card-border: #c8bfab;
  --text-main: #2c2720;
  --text-muted: #6b6354;
  --text-bright: #12100d;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  line-height: 1.5;
  background-image: 
    radial-gradient(circle at 50% 0%, rgba(229, 184, 105, 0.08) 0%, transparent 60%),
    radial-gradient(circle at 10% 90%, rgba(59, 130, 246, 0.05) 0%, transparent 50%);
}

/* Header & Title Bar */
header.app-header {
  padding: 1.25rem 2rem;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--bg-card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.brand-section {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.brand-icon {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-amber));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #12100d;
  font-family: var(--font-header);
  font-weight: 700;
  font-size: 1.4rem;
  box-shadow: 0 4px 12px rgba(217, 119, 6, 0.3);
}

.brand-title h1 {
  font-family: var(--font-header);
  font-size: 1.35rem;
  letter-spacing: 0.05em;
  color: var(--text-bright);
  line-height: 1.1;
}

.brand-title p {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
}

/* MIDI Status Badge */
.midi-badge {
  font-size: 0.78rem;
  font-weight: 700;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}

.midi-badge.midi-active {
  border-color: #2e7d32;
  color: #4caf50;
  background: rgba(76, 175, 80, 0.1);
  box-shadow: 0 0 10px rgba(76, 175, 80, 0.2);
}

.btn-group {
  display: inline-flex;
  background: var(--bg-card);
  padding: 3px;
  border-radius: var(--radius-md);
  border: 1px solid var(--bg-card-border);
}

.btn-group button {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.45rem 0.85rem;
  font-size: 0.82rem;
  font-weight: 600;
  font-family: var(--font-sans);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.btn-group button:hover {
  color: var(--text-bright);
}

.btn-group button.active {
  background: var(--accent-gold);
  color: #12100d;
  font-weight: 700;
  box-shadow: 0 2px 8px rgba(229, 184, 105, 0.25);
}

/* Main Container */
main.app-main {
  flex: 1;
  max-width: 1480px;
  width: 100%;
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Controls Panel */
.panel-card {
  background: var(--bg-surface);
  border: 1px solid var(--bg-card-border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
}

.controls-grid {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.control-group label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

select.custom-select {
  background: var(--bg-card);
  color: var(--text-bright);
  border: 1px solid var(--bg-card-border);
  padding: 0.6rem 0.85rem;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  outline: none;
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

select.custom-select:focus {
  border-color: var(--accent-gold);
}

/* Key Quick Selector Chips (Forced Single Horizontal Row Layout) */
.key-chips {
  display: flex;
  flex-wrap: nowrap !important;
  align-items: center;
  justify-content: space-between;
  gap: 0.3rem;
  width: 100%;
  overflow-x: auto;
  scrollbar-width: none;
}

.key-chips::-webkit-scrollbar {
  display: none;
}

.key-chip {
  flex: 1 1 0px;
  min-width: 0;
  padding: 0.45rem 0.2rem;
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-size: 0.82rem;
  font-weight: 700;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
  font-family: var(--font-mono);
  white-space: nowrap;
}

.key-chip:hover {
  border-color: var(--accent-gold);
  color: var(--text-bright);
}

.key-chip.active {
  background: var(--accent-gold);
  color: #12100d;
  border-color: var(--accent-gold);
}

/* Audio Player Section */
.audio-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.action-btn {
  background: linear-gradient(135deg, #2b303c, #1f232c);
  color: var(--text-bright);
  border: 1px solid var(--bg-card-border);
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.action-btn:hover {
  background: linear-gradient(135deg, #353b49, #252a35);
  border-color: var(--accent-gold);
  transform: translateY(-1px);
}

.action-btn.btn-primary {
  background: linear-gradient(135deg, var(--accent-gold), var(--accent-amber));
  color: #12100d;
  border: none;
  box-shadow: 0 4px 15px rgba(217, 119, 6, 0.3);
}

.action-btn.btn-primary:hover {
  background: linear-gradient(135deg, var(--accent-gold-hover), #e68508);
  box-shadow: 0 6px 18px rgba(217, 119, 6, 0.4);
}

.action-btn.danger-btn {
  background: rgba(229, 57, 53, 0.15);
  color: #ef5350;
  border: 1px solid #ef5350;
}

.action-btn.danger-btn:hover {
  background: #e53935;
  color: #ffffff;
  border-color: #e53935;
  box-shadow: 0 0 12px rgba(229, 57, 53, 0.35);
}

.tempo-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
}

.tempo-control input[type="range"] {
  accent-color: var(--accent-gold);
  width: 80px;
  cursor: pointer;
}

/* Slide Rule Workbench Arena */
.workbench-container {
  background: var(--bg-surface);
  border: 1px solid var(--bg-card-border);
  border-radius: var(--radius-lg);
  padding: 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.3), 0 10px 40px rgba(0, 0, 0, 0.25);
}

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

.workbench-title {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-header);
  font-size: 1.1rem;
  letter-spacing: 0.05em;
  color: var(--accent-gold);
}

.instruction-badge {
  font-size: 0.78rem;
  background: var(--bg-card);
  color: var(--text-muted);
  padding: 0.3rem 0.75rem;
  border-radius: 20px;
  border: 1px solid var(--bg-card-border);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* Slide Rule Viewport & Scroll Area */
.slider-viewport {
  position: relative;
  width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
  padding: 1.5rem 0 2.5rem 0;
  scrollbar-width: thin;
  scrollbar-color: var(--bg-card-border) transparent;
  user-select: none;
}

.slider-viewport::-webkit-scrollbar {
  height: 8px;
}

.slider-viewport::-webkit-scrollbar-thumb {
  background: var(--bg-card-border);
  border-radius: 4px;
}

/* The Paper Slide Rule Outer Structure */
.slide-rule-paper-assembly {
  position: relative;
  min-width: max-content;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  margin: 0 auto;
  background: #d8d3c5;
  padding: 12px;
  border-radius: 6px;
  box-shadow: 
    0 15px 35px rgba(0, 0, 0, 0.5),
    0 2px 8px rgba(0, 0, 0, 0.3),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
  border: 1px solid #a8a090;
}

/* 1. TOP CHROMATIC STRIP */
.chromatic-track {
  display: flex;
  background: var(--paper-bg);
  border: var(--rule-border-width) solid var(--paper-border);
  box-shadow: 0 3px 6px var(--paper-shadow);
  position: relative;
  z-index: 2;
}

.chromatic-cell {
  width: var(--cell-width);
  height: 64px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-right: 1px solid var(--paper-border);
  position: relative;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--paper-ink);
  background: var(--paper-bg);
  transition: background-color var(--transition-fast);
}

.chromatic-cell:last-child {
  border-right: none;
}

.chromatic-cell.dark-bar {
  background: var(--paper-dark-pattern);
  color: #e0dad0;
  box-shadow: inset 0 0 4px rgba(0, 0, 0, 0.5);
}

.chromatic-cell.dark-bar .note-label-text {
  color: #f0e6d2;
  font-size: 0.92rem;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.8);
}

.chromatic-cell.octave-divider {
  border-right: 2px solid var(--paper-border);
}

/* Red Circle around Selected Note Names on Chromatic Track */
.note-label-text {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 30px;
  height: 30px;
  border-radius: 50%;
  border: 2px solid transparent;
  transition: all var(--transition-fast);
}

/* Clean Piano Key Labels & In-Scale Highlighting (Bolder Text) */
.piano-key .key-label {
  font-weight: 500;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.piano-key.in-scale.white-key {
  background: linear-gradient(to bottom, #ffffff 0%, #f7f3ea 100%);
  border-bottom: 3px solid var(--accent-gold);
}

.piano-key.in-scale.white-key .key-label {
  font-weight: 900 !important;
  color: #12100d !important;
  font-size: 0.85rem !important;
}

.piano-key.in-scale.black-key {
  background: linear-gradient(to bottom, #3d3528 0%, #1e1913 100%);
  border-bottom: 3px solid var(--accent-gold);
}

.piano-key.in-scale.black-key .key-label {
  font-weight: 900 !important;
  color: #ffffff !important;
  font-size: 0.72rem !important;
}

.piano-key:not(.in-scale) .key-label {
  opacity: 0.45;
  font-weight: 400;
}

.note-label-text.note-selected-circle {
  border: 2.5px solid #d32f2f !important; /* Vivid Red Circle */
  color: #b71c1c !important;
  font-weight: 800;
  box-shadow: 0 0 0 2px rgba(211, 47, 47, 0.15), inset 0 0 4px rgba(211, 47, 47, 0.1);
  background: rgba(255, 255, 255, 0.85);
}

.chromatic-cell.dark-bar .note-label-text.note-selected-circle {
  border: 2.5px solid #ff5252 !important;
  color: #ffffff !important;
  background: rgba(229, 57, 53, 0.85);
  box-shadow: 0 0 8px rgba(255, 82, 82, 0.4);
}

.chromatic-cell.active-playing {
  background: #ffea9f !important;
  color: #8a3b00;
  box-shadow: inset 0 0 10px rgba(217, 119, 6, 0.6);
}

/* 2. MIDDLE SLIDER CHANNEL & SLIDING RIBBON */
.slider-channel {
  position: relative;
  width: 100%;
  height: 58px;
  margin: -2px 0;
  z-index: 5;
  background: #efebe0;
  border-left: var(--rule-border-width) solid var(--paper-border);
  border-right: var(--rule-border-width) solid var(--paper-border);
  box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.25);
  overflow: visible;
}

/* The physical sliding paper piece */
.paper-slider-ribbon {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  display: flex;
  align-items: center;
  background: #ffffff;
  border: var(--rule-border-width) solid var(--paper-border);
  box-shadow: 
    0 6px 16px var(--paper-shadow),
    inset 0 1px 0 #ffffff,
    inset 0 -1px 0 #e0dad0;
  cursor: grab;
  touch-action: none;
  transition: transform var(--transition-slider);
  z-index: 10;
  border-radius: 2px;
}

.paper-slider-ribbon:active,
.paper-slider-ribbon.is-dragging {
  cursor: grabbing;
  transition: none; /* Instant movement while dragging */
  box-shadow: 0 10px 24px var(--paper-shadow);
}

.slider-handle-start {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
  height: 100%;
  border-right: 1px solid var(--paper-border);
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--paper-ink);
  background: #f7f3e9;
  cursor: grab;
}

.degree-cell {
  width: var(--cell-width);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-right: 1px solid var(--paper-border);
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1.4rem;
  color: var(--paper-ink);
  position: relative;
  background: #ffffff;
  transition: background-color var(--transition-fast);
}

.degree-cell.empty-gap {
  background: rgba(240, 237, 228, 0.4);
  color: transparent;
}

.degree-cell.active-degree {
  background: #fffdf5;
  cursor: pointer;
}

.degree-cell.active-degree:hover {
  background: #fff8d6;
  color: var(--accent-amber);
}

.degree-cell.root-degree {
  color: var(--paper-accent-red);
}

.degree-cell.active-playing {
  background: #ffd642 !important;
  color: #12100d !important;
  font-weight: 900;
  transform: scale(1.05);
  box-shadow: 0 0 12px rgba(255, 214, 66, 0.8);
}

.slider-handle-end {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 8px;
  height: 100%;
  border-left: 1px solid var(--paper-border);
  font-size: 1.1rem;
  color: var(--paper-ink);
  background: #f7f3e9;
}

/* Drag indicator handle on slider */
.drag-tab {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gold);
  color: #12100d;
  font-size: 0.65rem;
  font-weight: 800;
  padding: 2px 10px;
  border-radius: 10px 10px 0 0;
  border: 1px solid var(--paper-border);
  border-bottom: none;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  box-shadow: 0 -2px 5px rgba(0, 0, 0, 0.2);
  cursor: grab;
  display: flex;
  align-items: center;
  gap: 4px;
}

/* 3. BOTTOM CUTOUT MASK TRACK */
.bottom-mask-track {
  display: flex;
  background: var(--paper-bg);
  border: var(--rule-border-width) solid var(--paper-border);
  box-shadow: 0 6px 12px var(--paper-shadow);
  position: relative;
  z-index: 2;
}

.mask-cell {
  width: var(--cell-width);
  height: 52px;
  border-right: 1px solid var(--paper-border);
  position: relative;
  background: var(--paper-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
}

.mask-cell:last-child {
  border-right: none;
}

.mask-cell.dark-bar {
  background: var(--paper-dark-pattern);
}

/* Paper Notch Cutouts extending down */
.mask-notch {
  width: 80%;
  height: 20px;
  background: var(--paper-bg);
  border: 1px solid var(--paper-border);
  border-top: none;
  border-radius: 0 0 4px 4px;
  margin-bottom: -16px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-family: var(--font-serif);
  font-weight: 700;
  color: var(--paper-ink);
  z-index: 4;
}

.mask-notch.notch-active {
  background: #fffae6;
  border-color: var(--accent-amber);
  color: var(--accent-amber);
}

/* 4. REALISTIC SYNTH PIANO KEYBOARD */
.piano-keyboard-container {
  width: 100%;
  margin-top: 1.5rem;
  display: flex;
  justify-content: center;
  position: relative;
}

.piano-keyboard {
  display: flex;
  position: relative;
  background: #111;
  padding: 8px;
  border-radius: 8px;
  box-shadow: 
    0 12px 30px rgba(0, 0, 0, 0.6),
    inset 0 2px 4px rgba(255, 255, 255, 0.1);
  border: 1px solid #333;
}

/* Piano Key Styling */
.piano-key {
  position: relative;
  cursor: pointer;
  user-select: none;
  transition: transform 0.05s ease;
}

.piano-key.white-key {
  width: var(--cell-width);
  height: 150px;
  background: linear-gradient(to bottom, #ffffff 0%, #f4f4f4 85%, #e2e2e2 100%);
  border: 1px solid #bbb;
  border-radius: 0 0 5px 5px;
  z-index: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  padding-bottom: 10px;
  color: #444;
  font-size: 0.78rem;
  font-weight: 700;
  box-shadow: 
    inset 0 -5px 10px rgba(0, 0, 0, 0.1),
    0 3px 5px rgba(0, 0, 0, 0.2);
}

.piano-key.white-key:hover {
  background: linear-gradient(to bottom, #ffffff 0%, #ebebeb 100%);
}

.piano-key.black-key {
  width: calc(var(--cell-width) * 0.65);
  height: 95px;
  background: linear-gradient(to bottom, #333 0%, #111 100%);
  border: 1px solid #000;
  border-radius: 0 0 3px 3px;
  z-index: 2;
  margin-left: calc(var(--cell-width) * -0.325);
  margin-right: calc(var(--cell-width) * -0.325);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  padding-bottom: 6px;
  color: #aaa;
  font-size: 0.65rem;
  font-weight: 600;
  box-shadow: 
    inset 0 -3px 4px rgba(255, 255, 255, 0.15),
    0 4px 8px rgba(0, 0, 0, 0.5);
}

.piano-key.black-key:hover {
  background: linear-gradient(to bottom, #444 0%, #222 100%);
}

/* Key Labels & Red Circles for Selected Notes */
.piano-key .key-label {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 26px;
  height: 26px;
  border-radius: 50%;
  border: 2px solid transparent;
  transition: all var(--transition-fast);
  font-size: 0.75rem;
}

.piano-key.black-key .key-label {
  font-size: 0.62rem;
}

/* Clean Piano Key Labels */

/* Circle of Fifths & Diatonic Matrix Dual Layout */
.circle-fifths-card {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.circle-fifths-dual-layout {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 2.5rem;
  width: 100%;
  padding: 0.5rem 0;
}

/* Diatonic Scale Matrix Table */
.diatonic-matrix-container {
  flex: 1;
  min-width: 320px;
  max-width: 480px;
  overflow-x: auto;
}

.diatonic-matrix-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0 6px;
  font-family: var(--font-sans);
}

.diatonic-matrix-table th {
  padding: 0.4rem 0.6rem;
  text-anchor: middle;
  text-align: center;
}

.diatonic-matrix-table th.roman-header {
  color: #e53935;
  font-weight: 800;
  font-size: 1.1rem;
  font-family: var(--font-serif);
  position: relative;
}

.shortcut-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  background: var(--bg-card-border);
  color: var(--text-bright);
  border-radius: 4px;
  font-size: 0.72rem;
  font-family: var(--font-mono);
  margin-right: 4px;
  vertical-align: middle;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.diatonic-matrix-table td.chord-cell.key-pressed-flash {
  background: #ffea78 !important;
  color: #12100d !important;
  font-weight: 900 !important;
  transform: scale(1.15) !important;
  box-shadow: 0 0 12px rgba(255, 234, 120, 0.9) !important;
}

.diatonic-matrix-table tbody tr {
  cursor: pointer;
  background: var(--bg-card);
  transition: all var(--transition-fast);
  border-radius: var(--radius-sm);
}

.diatonic-matrix-table tbody tr:hover {
  background: rgba(229, 184, 105, 0.15);
}

.diatonic-matrix-table td {
  padding: 0.5rem 0.65rem;
  text-align: center;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-main);
  user-select: none;
}

.diatonic-matrix-table td.chord-cell {
  cursor: pointer;
  transition: all var(--transition-fast);
  border-radius: 4px;
}

.diatonic-matrix-table td.chord-cell:hover {
  background: rgba(229, 184, 105, 0.35);
  color: var(--accent-gold) !important;
  font-weight: 800;
  transform: scale(1.08);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.diatonic-matrix-table td.key-badge-cell {
  padding-left: 0;
  text-align: left;
  width: 45px;
}

.key-badge-btn {
  background: #12100d;
  color: #ffffff;
  font-weight: 800;
  font-size: 0.95rem;
  padding: 4px 10px;
  border-radius: 4px;
  display: inline-block;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* Active Row Highlight (Yellow Box with Red Outline) */
.diatonic-matrix-table tbody tr.row-active {
  background: #fff8c6 !important;
  color: #12100d !important;
  font-weight: 800;
  box-shadow: 
    0 0 0 2px #e53935,
    0 4px 12px rgba(229, 57, 53, 0.25);
  border-radius: 6px;
}

.diatonic-matrix-table tbody tr.row-active td {
  color: #12100d !important;
  font-weight: 800;
}

.diatonic-matrix-table tbody tr.row-active .key-badge-btn {
  background: #12100d;
  color: #ffffff;
}

/* Circle of Fifths Container & SVG */
.circle-fifths-container {
  flex: 1;
  min-width: 320px;
  max-width: 440px;
  display: flex;
  justify-content: center;
  align-items: center;
}

.circle-fifths-svg-wrapper {
  width: 100%;
  max-width: 420px;
  aspect-ratio: 1 / 1;
  position: relative;
}

.circle-fifths-svg-wrapper svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 10px 25px rgba(0, 0, 0, 0.35));
}

.circle-sector {
  cursor: pointer;
  transition: all var(--transition-fast);
  stroke: #ffffff;
  stroke-width: 3px;
}

.circle-sector:hover {
  filter: brightness(1.1);
  opacity: 0.95;
}

/* Diatonic 6-Sector Highlight Wedge (Warm Yellow) */
.circle-sector.sector-diatonic-active {
  fill: #ffea78 !important;
  stroke: #e53935 !important;
  stroke-width: 3.5px !important;
}

.circle-sector.inner-sector.sector-diatonic-active {
  fill: #fff5a5 !important;
}

.circle-sector.sector-tonic-active {
  fill: #ffd54f !important;
  stroke: #d32f2f !important;
  stroke-width: 4.5px !important;
}

.circle-text {
  font-weight: 800;
  fill: #12100d;
  user-select: none;
  pointer-events: none;
  text-anchor: middle;
  dominant-baseline: central;
}

.circle-text.outer-text {
  font-size: 22px;
  font-family: var(--font-sans);
}

.circle-text.inner-text {
  font-size: 14px;
  font-family: var(--font-sans);
  font-weight: 700;
}

.circle-center-hub {
  fill: #ffffff;
  stroke: #d0dcd5;
  stroke-width: 3px;
}

.circle-hub-text {
  fill: #2c2720;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: 11px;
  letter-spacing: 0.1em;
  text-anchor: middle;
  dominant-baseline: central;
}
/* 10 Essential Chord Progressions Section */
.chord-progressions-card {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.loop-toggle-btn {
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  color: var(--text-muted);
  font-weight: 700;
  font-size: 0.8rem;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}

.loop-toggle-btn:hover {
  border-color: var(--accent-gold);
  color: var(--text-bright);
}

.loop-toggle-btn.active {
  background: rgba(76, 175, 80, 0.18);
  border-color: #4caf50;
  color: #81c784;
  box-shadow: 0 0 10px rgba(76, 175, 80, 0.25);
}

.progressions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1rem;
  width: 100%;
}

.progression-card {
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  transition: all var(--transition-fast);
  position: relative;
}

.progression-card:hover {
  border-color: rgba(229, 184, 105, 0.4);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

.progression-card.is-playing-progression {
  border-color: #e53935;
  background: rgba(229, 57, 53, 0.08);
  box-shadow: 0 0 12px rgba(229, 57, 53, 0.25);
}

.progression-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.progression-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--text-bright);
}

.progression-num-badge {
  background: #12100d;
  color: #ffd54f;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 0.8rem;
  padding: 2px 7px;
  border-radius: 4px;
  border: 1px solid rgba(255, 213, 79, 0.3);
}

.btn-play-progression {
  background: rgba(229, 184, 105, 0.15);
  color: var(--accent-gold);
  border: 1px solid var(--accent-gold);
  font-weight: 700;
  font-size: 0.8rem;
  padding: 4px 10px;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.btn-play-progression:hover {
  background: var(--accent-gold);
  color: #12100d;
  transform: scale(1.05);
}

.progression-chords-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.4rem;
  background: rgba(0, 0, 0, 0.2);
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
}

.progression-chord-pill {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  flex: 1;
  padding: 4px 2px;
  border-radius: 4px;
  transition: all var(--transition-fast);
  cursor: pointer;
}

.progression-chord-pill:hover {
  background: rgba(229, 184, 105, 0.25);
}

.progression-chord-pill.active-chord-step {
  background: #ffea78 !important;
  box-shadow: 0 0 10px rgba(255, 234, 120, 0.8);
  transform: scale(1.1);
}

.progression-chord-name {
  font-weight: 800;
  font-size: 0.95rem;
  color: var(--text-main);
}

.progression-chord-pill.active-chord-step .progression-chord-name {
  color: #12100d;
}

.progression-roman-num {
  font-size: 0.75rem;
  color: #e53935;
  font-weight: 700;
  font-family: var(--font-serif);
}

.progression-chord-pill.active-chord-step .progression-roman-num {
  color: #12100d;
}.piano-key.active-playing {
  transform: translateY(3px);
}

.piano-key.white-key.is-pressed,
.piano-key.white-key.active-playing {
  background: linear-gradient(to bottom, #ffe485 0%, #fcae1e 100%) !important;
  color: #12100d;
}

.piano-key.black-key.is-pressed,
.piano-key.black-key.active-playing {
  background: linear-gradient(to bottom, #d97706 0%, #92400e 100%) !important;
  color: #ffffff;
}

.key-degree-badge {
  background: rgba(0, 0, 0, 0.15);
  padding: 2px 5px;
  border-radius: 4px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 0.85rem;
}

.black-key .key-degree-badge {
  background: rgba(255, 255, 255, 0.2);
}

/* Theory Information Drawer Card */
.info-drawer {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 0.5rem;
}

.info-card {
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  padding: 1.25rem;
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.info-card h3 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent-gold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.info-card p, .info-card ul {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.info-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.info-card li {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px dashed var(--bg-card-border);
  padding-bottom: 0.25rem;
}

.info-card li span.val {
  font-weight: 700;
  color: var(--text-bright);
  font-family: var(--font-mono);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  :root {
    --cell-width: 36px;
  }
  
  header.app-header {
    padding: 1rem;
    flex-direction: column;
    align-items: flex-start;
  }

  .controls-grid {
    grid-template-columns: 1fr;
  }
  
  .piano-key.white-key {
    height: 120px;
  }

  .piano-key.black-key {
    height: 75px;
  }
}

/* Active Playing Key & Bass Highlights (Layer-Safe: White Keys Stay Below Black Keys) */
.piano-key.white-key.active-playing {
  background: var(--accent-gold) !important;
  color: #12100d !important;
  z-index: 1 !important;
  box-shadow: inset 0 -4px 8px rgba(0, 0, 0, 0.25) !important;
}

.piano-key.white-key.active-bass-playing {
  background: #d32f2f !important;
  color: #ffffff !important;
  z-index: 1 !important;
  box-shadow: inset 0 -4px 8px rgba(0, 0, 0, 0.35) !important;
}

.piano-key.black-key.active-playing {
  background: var(--accent-gold) !important;
  color: #12100d !important;
  z-index: 5 !important;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5), inset 0 -3px 4px rgba(255, 255, 255, 0.3) !important;
}

.piano-key.black-key.active-bass-playing {
  background: #d32f2f !important;
  color: #ffffff !important;
  z-index: 5 !important;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5), inset 0 -3px 4px rgba(255, 255, 255, 0.3) !important;
}

.piano-key.active-bass-playing .key-label {
  color: #ffffff !important;
  font-weight: 700 !important;
}

.chromatic-cell.active-playing {
  background: var(--accent-gold) !important;
  color: #12100d !important;
  box-shadow: 0 2px 8px rgba(229, 184, 105, 0.35) !important;
}

.chromatic-cell.active-bass-playing {
  background: #d32f2f !important;
  color: #ffffff !important;
  box-shadow: 0 2px 8px rgba(211, 47, 47, 0.4) !important;
}