/* ==========================================================================
   Spectral — Sine Wave Explorer
   Main Stylesheet
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
  /* Background & Surface Colors */
  --color-bg: #1a1a2e;
  --color-bg-surface: #16213e;
  --color-bg-card: #1f2b47;
  --color-bg-card-hover: #253352;
  --color-bg-input: #0f1729;
  --color-border: #2a3a5c;
  --color-border-light: #3a4a6c;

  /* Text Colors */
  --color-text: #e0e0e0;
  --color-text-muted: #8892a4;
  --color-text-bright: #ffffff;

  /* Accent / Primary */
  --color-primary: #56b4e9;
  --color-primary-hover: #7cc8f0;
  --color-primary-active: #3a9cd6;

  /* Semantic Colors */
  --color-danger: #d55e00;
  --color-danger-hover: #e87830;
  --color-success: #009e73;

  /* Wave Colors — Wong colorblind-friendly palette */
  --wave-color-1: #E69F00;
  --wave-color-2: #56B4E9;
  --wave-color-3: #009E73;
  --wave-color-4: #F0E442;
  --wave-color-5: #0072B2;
  --wave-color-6: #D55E00;
  --wave-color-7: #CC79A7;
  --wave-color-8: #999999;

  /* Combined wave color */
  --color-combined-wave: #ffffff;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
    Ubuntu, Cantarell, 'Helvetica Neue', Arial, sans-serif;
  --font-size-sm: 14px;
  --font-size-base: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-round: 50%;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;

  /* Layout */
  --controls-width: 320px;
  --header-height: 48px;
  --footer-height: 48px;
  --slider-thumb-size: 20px;
  --slider-track-height: 6px;
}

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

html, body {
  height: 100vh;
  overflow: hidden;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--font-size-base);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--color-text);
  background-color: var(--color-bg);
  display: grid;
  grid-template-rows: auto 1fr auto;
}

img, canvas {
  display: block;
  max-width: 100%;
}

button, input, select {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

/* Screen reader only utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.hidden {
  display: none !important;
}

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.app-header {
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--color-bg-surface) 0%, var(--color-bg) 100%);
  border-bottom: 1px solid var(--color-border);
  padding: 0 var(--space-md);
}

.app-title {
  text-align: center;
}

.app-title h1 {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.05em;
  line-height: 1.1;
}

.app-title .subtitle {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

/* --------------------------------------------------------------------------
   Main Layout — CSS Grid
   -------------------------------------------------------------------------- */
.app-main {
  display: grid;
  grid-template-columns: var(--controls-width) 1fr;
  gap: 0;
  min-height: 0; /* allow grid children to shrink */
  overflow: hidden;
}

/* --------------------------------------------------------------------------
   Controls Panel (left sidebar)
   -------------------------------------------------------------------------- */
.controls-panel {
  background-color: var(--color-bg-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  min-height: 0;
}

/* Scrollbar styling for controls panel */
.controls-panel::-webkit-scrollbar {
  width: 6px;
}

.controls-panel::-webkit-scrollbar-track {
  background: transparent;
}

.controls-panel::-webkit-scrollbar-thumb {
  background-color: var(--color-border-light);
  border-radius: 3px;
}

.controls-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-md);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.controls-header h2 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-bright);
}

.wave-controls-list {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-md);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* Scrollbar styling for wave controls */
.wave-controls-list::-webkit-scrollbar {
  width: 6px;
}

.wave-controls-list::-webkit-scrollbar-track {
  background: transparent;
}

.wave-controls-list::-webkit-scrollbar-thumb {
  background-color: var(--color-border-light);
  border-radius: 3px;
}

/* --------------------------------------------------------------------------
   Wave Card
   -------------------------------------------------------------------------- */
.wave-card {
  background-color: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  transition: background-color var(--transition-fast),
              border-color var(--transition-fast);
  position: relative;
}

.wave-card:hover {
  background-color: var(--color-bg-card-hover);
  border-color: var(--color-border-light);
}

/* Wave toggle button */
.btn-toggle-wave {
  width: 24px;
  height: 24px;
  padding: 0;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--color-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: all var(--transition-fast);
  flex-shrink: 0;
  margin-top: 4px;
}

.btn-toggle-wave:hover {
  border-color: var(--color-primary);
}

/* When wave is enabled, show checkmark with color */
.btn-toggle-wave.enabled {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-toggle-wave.enabled .toggle-icon {
  color: var(--color-bg);
}

.btn-toggle-wave:not(.enabled) .toggle-icon {
  visibility: hidden;
}

/* Disabled wave card */
.wave-card.disabled {
  opacity: 0.5;
}

.wave-card.disabled .note-selector,
.wave-card.disabled .frequency-input,
.wave-card.disabled .slider-amplitude {
  opacity: 0.6;
}

/* Fade-out animation when a wave card is being removed */
.wave-card.removing {
  opacity: 0;
  transform: translateX(-10px);
  transition: opacity 200ms ease, transform 200ms ease;
}

.wave-color-indicator {
  width: 12px;
  height: 12px;
  border-radius: var(--radius-round);
  flex-shrink: 0;
  margin-top: 6px;
}

.wave-card-controls {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.wave-note-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.wave-amplitude-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.wave-label {
  flex: 1;
  min-width: 0;
}

.frequency-display {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
  min-width: 72px;
  text-align: right;
}

.amplitude-value {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  min-width: 36px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------------------
   Note Selector (dropdown)
   -------------------------------------------------------------------------- */
.note-selector {
  width: 100%;
  padding: var(--space-xs) var(--space-sm);
  background-color: var(--color-bg-input);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: border-color var(--transition-fast);
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%238892a4' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  padding-right: 28px;
}

.note-selector:hover,
.note-selector:focus {
  border-color: var(--color-primary);
  outline: none;
}

.note-selector:focus-visible {
  box-shadow: 0 0 0 2px var(--color-primary);
}

/* --------------------------------------------------------------------------
   Buttons
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-weight: 500;
  cursor: pointer;
  transition: background-color var(--transition-fast),
              border-color var(--transition-fast),
              color var(--transition-fast),
              box-shadow var(--transition-fast);
  background: none;
  color: var(--color-text);
  line-height: 1.4;
  white-space: nowrap;
  min-height: 36px;
}

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

/* Add Wave button */
.btn-add {
  background-color: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
}

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

.btn-add:active {
  background-color: var(--color-primary-active);
}

.btn-add:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-add .btn-icon {
  font-size: var(--font-size-lg);
  font-weight: 700;
  line-height: 1;
}

/* Remove Wave button */
.btn-remove {
  width: 28px;
  height: 28px;
  min-height: 28px;
  padding: 0;
  border-radius: var(--radius-sm);
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  flex-shrink: 0;
  align-self: flex-start;
  margin-top: 2px;
}

.btn-remove:hover {
  background-color: var(--color-danger);
  color: var(--color-text-bright);
}

/* Play/Stop button */
.btn-play {
  width: 48px;
  height: 48px;
  min-height: 48px;
  padding: 0;
  border-radius: var(--radius-round);
  background-color: var(--color-primary);
  color: var(--color-bg);
  font-size: var(--font-size-xl);
  transition: background-color var(--transition-fast),
              transform var(--transition-fast);
}

.btn-play:hover {
  background-color: var(--color-primary-hover);
  transform: scale(1.05);
}

.btn-play:active {
  background-color: var(--color-primary-active);
  transform: scale(0.95);
}

.btn-play.playing {
  background-color: var(--color-danger);
}

.btn-play.playing:hover {
  background-color: var(--color-danger-hover);
}

/* View Mode Toggle buttons */
.view-mode-toggle {
  display: flex;
  justify-content: center;
  gap: 0;
  padding: var(--space-xs) var(--space-md);
  flex-shrink: 0;
}

.btn-view {
  padding: var(--space-xs) var(--space-md);
  background-color: var(--color-bg-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  min-height: 36px;
}

.btn-view:first-child {
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}

.btn-view:last-child {
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.btn-view:not(:first-child) {
  border-left: none;
}

.btn-view:hover {
  background-color: var(--color-bg-card-hover);
  color: var(--color-text);
}

.btn-view.active {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-bg);
  font-weight: 600;
}

/* Animate toggle button */
.btn-animate {
  padding: 4px 12px;
  font-size: var(--font-size-sm);
  background: var(--color-bg-surface);
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-animate:hover {
  border-color: var(--color-primary);
}

.btn-animate.animating {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

/* Share button */
.btn-share {
  padding: 6px 12px;
  font-size: var(--font-size-sm);
  background: var(--color-bg-surface);
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-share:hover {
  border-color: var(--color-primary);
  background: rgba(86, 180, 233, 0.1);
}

.btn-share.copied {
  background: var(--color-success);
  border-color: var(--color-success);
  color: white;
}

/* Animation controls container (animate button + speed slider) */
.animation-controls {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}

.speed-label {
  font-size: var(--font-size-xs, 12px);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.slider-speed {
  width: 80px;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

.slider-speed::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
}

.slider-speed::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-primary);
  cursor: pointer;
  border: none;
}

.speed-value {
  font-size: var(--font-size-xs, 12px);
  color: var(--color-text-muted);
  min-width: 32px;
  text-align: right;
}

/* --------------------------------------------------------------------------
   Visualization Area
   -------------------------------------------------------------------------- */
.visualization-area {
  display: flex;
  flex-direction: column;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
  background-color: var(--color-bg);
}

.canvas-container {
  flex: 1;
  position: relative;
  min-height: 0;
  padding: var(--space-sm);
}

#waveform-canvas {
  width: 100%;
  height: 100%;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-bg-input);
}

/* --------------------------------------------------------------------------
   Global Controls Bar (footer)
   -------------------------------------------------------------------------- */
.global-controls {
  height: var(--footer-height);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  padding: 0 var(--space-md);
  background-color: var(--color-bg-surface);
  border-top: 1px solid var(--color-border);
}

.footer-links {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-left: auto;
}

.footer-link {
  font-size: 12px;
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
  white-space: nowrap;
}

.footer-link:hover {
  color: var(--color-primary);
}

.transport-controls {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* ── Pluck Button ── */

.btn-pluck {
  width: 48px;
  height: 48px;
  min-height: 48px;
  padding: 0;
  border-radius: var(--radius-round);
  background-color: #2E7D32;
  border: none;
  color: #fff;
  font-size: 20px;
  cursor: pointer;
  transition: background-color var(--transition-fast),
              transform var(--transition-fast),
              box-shadow var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-pluck:hover {
  background-color: #388E3C;
  transform: scale(1.05);
}

.btn-pluck:active {
  background-color: #1B5E20;
  transform: scale(0.95);
}

.btn-pluck.plucking {
  background-color: #4CAF50;
  box-shadow: 0 0 12px rgba(76, 175, 80, 0.5);
  animation: pluck-glow 2s ease-out forwards;
}

@keyframes pluck-glow {
  0% {
    background-color: #4CAF50;
    box-shadow: 0 0 12px rgba(76, 175, 80, 0.5);
  }
  100% {
    background-color: #2E7D32;
    box-shadow: 0 0 0px rgba(76, 175, 80, 0);
  }
}

.volume-control {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.volume-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  white-space: nowrap;
}

.volume-value {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  min-width: 36px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* --------------------------------------------------------------------------
   Sliders (Range Inputs) — Cross-browser styling
   -------------------------------------------------------------------------- */
.slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: var(--slider-track-height);
  background: var(--color-border);
  border-radius: calc(var(--slider-track-height) / 2);
  outline: none;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.slider:hover {
  background: var(--color-border-light);
}

.slider:focus-visible {
  box-shadow: 0 0 0 2px var(--color-primary);
}

/* Webkit (Chrome, Safari, Edge) thumb */
.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: var(--slider-thumb-size);
  height: var(--slider-thumb-size);
  border-radius: var(--radius-round);
  background: var(--color-primary);
  border: 2px solid var(--color-bg);
  cursor: pointer;
  transition: background-color var(--transition-fast),
              transform var(--transition-fast);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.slider::-webkit-slider-thumb:hover {
  background: var(--color-primary-hover);
  transform: scale(1.15);
}

.slider::-webkit-slider-thumb:active {
  background: var(--color-primary-active);
  transform: scale(0.95);
}

/* Firefox thumb */
.slider::-moz-range-thumb {
  width: var(--slider-thumb-size);
  height: var(--slider-thumb-size);
  border-radius: var(--radius-round);
  background: var(--color-primary);
  border: 2px solid var(--color-bg);
  cursor: pointer;
  transition: background-color var(--transition-fast),
              transform var(--transition-fast);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.slider::-moz-range-thumb:hover {
  background: var(--color-primary-hover);
}

/* Firefox track */
.slider::-moz-range-track {
  height: var(--slider-track-height);
  background: var(--color-border);
  border-radius: calc(var(--slider-track-height) / 2);
  border: none;
}

/* Volume slider specific width */
.slider-volume {
  width: 120px;
}

/* Amplitude slider fills available space */
.slider-amplitude {
  width: 100%;
}

/* --------------------------------------------------------------------------
   Presets Section
   -------------------------------------------------------------------------- */
.presets-section {
  padding: var(--space-sm);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.presets-section .section-header {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  user-select: none;
  -webkit-user-select: none;
}

.presets-section .presets-content {
  max-height: 500px;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 var(--space-sm) var(--space-sm);
}

.presets-section.collapsed .presets-content {
  max-height: 0;
  overflow: hidden;
  padding-top: 0;
  padding-bottom: 0;
}

.section-header {
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  user-select: none;
  -webkit-user-select: none;
}

.collapse-icon {
  font-size: 0.7em;
  line-height: 1;
  flex-shrink: 0;
}

.preset-base-note {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-sm);
}

.preset-base-note label {
  color: var(--color-text-muted);
  white-space: nowrap;
}

.preset-base-note select {
  flex: 1;
  /* reuse existing note-selector styles */
}

.preset-group {
  margin-bottom: var(--space-sm);
}

.preset-group:last-child {
  margin-bottom: 0;
}

.preset-group-title {
  font-size: var(--font-size-xs, 12px);
  color: var(--color-text-muted);
  margin-bottom: var(--space-xs);
  font-weight: normal;
}

.preset-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.btn-preset {
  padding: 4px 8px;
  font-size: var(--font-size-xs, 12px);
  background: var(--color-bg-card);
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.btn-preset.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

/* Random preset button — visually distinct generative action */
.btn-random {
  background: linear-gradient(135deg, #2a1f47 0%, #1f2b47 100%);
  border-color: rgba(204, 121, 167, 0.4);
  color: var(--color-text-bright);
}

.btn-random:hover {
  background: linear-gradient(135deg, #3a2a5c 0%, #253352 100%);
  border-color: #CC79A7;
  color: var(--color-text-bright);
}

.btn-random.active {
  background: linear-gradient(135deg, #4a3570 0%, #2a3d60 100%);
  border-color: #CC79A7;
  box-shadow: 0 0 8px rgba(204, 121, 167, 0.3);
}

/* --------------------------------------------------------------------------
   Tone Analyzer Section
   -------------------------------------------------------------------------- */
.analyzer-section {
  padding: var(--space-sm);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.analyzer-section .analyzer-content {
  max-height: 500px;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 var(--space-sm) var(--space-sm);
}

.analyzer-section.collapsed .analyzer-content {
  max-height: 0;
  padding-top: 0;
  padding-bottom: 0;
}

.analyzer-canvas-container {
  margin-bottom: var(--space-sm);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.analyzer-canvas-container canvas {
  width: 100%;
  height: 120px;
  display: block;
  background: #1a1a2e;
  border-radius: var(--radius-sm);
}

.analyzer-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
  font-size: 0.85rem;
  min-height: 3em;
}

.analyzer-pitch,
.analyzer-harmonics {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.pitch-label,
.harmonics-label {
  color: var(--color-text-muted);
}

.pitch-value {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--color-primary);
}

.harmonics-value {
  color: var(--color-text);
  font-size: 0.8rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 100px;
}

.analyzer-controls {
  display: flex;
  gap: var(--space-sm);
  margin-bottom: var(--space-xs);
}

.analyzer-btn {
  flex: 1;
}

.analyzer-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.analyzer-btn.listening {
  background: var(--color-danger);
  color: white;
  animation: pulse-recording 1.5s ease-in-out infinite;
}

@keyframes pulse-recording {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

.analyzer-apply-btn:not(:disabled) {
  background: var(--color-success);
  color: white;
}

.analyzer-status {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  min-height: 1.2em;
  text-align: center;
}

.analyzer-status.error {
  color: var(--color-danger);
}

/* --------------------------------------------------------------------------
   Frequency Input
   -------------------------------------------------------------------------- */
.frequency-input {
  width: 80px;
  padding: 2px 4px;
  font-size: var(--font-size-sm);
  background: var(--color-bg-input);
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  text-align: right;
}

/* Remove spinner arrows for cleaner look */
.frequency-input::-webkit-inner-spin-button,
.frequency-input::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.frequency-input[type=number] {
  -moz-appearance: textfield;
}

.frequency-input:hover,
.frequency-input:focus {
  border-color: var(--color-primary);
  outline: none;
}

.frequency-unit {
  font-size: var(--font-size-xs, 12px);
  color: var(--color-text-muted);
}

/* --------------------------------------------------------------------------
   Responsive Design
   -------------------------------------------------------------------------- */

/* Tablet and below: stack layout vertically */
@media (max-width: 768px) {
  body {
    grid-template-rows: auto 1fr auto; /* header, main, footer */
    height: 100vh;
    height: 100dvh; /* dynamic viewport height for mobile browsers */
  }

  .app-main {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
    overflow: hidden;
  }

  .controls-panel {
    border-right: none;
    border-top: 1px solid var(--color-border);
    order: 2;
    max-height: none;
    overflow-y: auto;
    width: 100%;
    -webkit-overflow-scrolling: touch;
  }

  .visualization-area {
    order: 1;
    min-height: 0;
  }

  .canvas-container {
    min-height: 100px;
    max-height: 120px;
    flex: 0 0 auto;
  }

  /* Compact header on mobile */
  .app-header {
    height: auto;
    padding: var(--space-sm) var(--space-md);
  }

  .app-title h1 {
    font-size: var(--font-size-lg);
  }

  .app-title .subtitle {
    font-size: 11px;
  }

  /* Compact wave cards on mobile */
  .wave-card {
    padding: var(--space-xs) var(--space-sm);
    gap: var(--space-xs);
  }

  .wave-card .wave-card-controls {
    gap: var(--space-xs);
  }

  .wave-card .wave-amplitude-row {
    display: flex;
    flex-direction: row;
    align-items: center;
    gap: var(--space-xs);
    flex-wrap: nowrap;
  }

  .wave-card .wave-label {
    flex-direction: row;
    align-items: center;
    gap: var(--space-xs);
    min-width: 0;
  }

  .wave-card .wave-label .sr-only {
    display: none;
  }

  .wave-card .slider-amplitude {
    min-width: 60px;
    flex: 1;
  }

  .wave-controls-list {
    padding: var(--space-sm);
    gap: var(--space-sm);
  }

  /* Wrap footer controls */
  .global-controls {
    height: auto;
    padding: var(--space-sm) var(--space-md);
    gap: var(--space-sm);
    flex-wrap: wrap;
    justify-content: center;
  }

  /* Compact view mode buttons on mobile */
  .view-mode-toggle {
    gap: var(--space-xs);
  }

  .view-mode-toggle .btn-view {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--font-size-xs);
    min-height: 28px;
  }

  /* Wrap view mode + animation controls */
  .view-mode-toggle {
    flex-wrap: wrap;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
  }

  .animation-controls {
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--space-xs);
    margin-left: 0;
    width: 100%;
  }

  /* Preset buttons wrap properly */
  .preset-buttons {
    flex-wrap: wrap;
    gap: 4px;
  }

  /* Collapsible presets on mobile */
  .presets-section {
    padding: 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
  }

  .presets-section .section-header {
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    margin: 0;
    user-select: none;
    -webkit-user-select: none;
  }

  .presets-section .presets-content {
    max-height: 500px;
    overflow-y: auto;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 var(--space-sm) var(--space-sm);
  }

  .presets-section.collapsed .presets-content {
    max-height: 0;
    overflow: hidden;
    padding-top: 0;
    padding-bottom: 0;
  }

  .preset-group {
    margin-bottom: var(--space-xs);
  }

  /* Collapsible analyzer on mobile */
  .analyzer-section {
    padding: 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
  }

  .analyzer-section .section-header {
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-sm);
    margin: 0;
    user-select: none;
    -webkit-user-select: none;
  }

  .analyzer-section .analyzer-content {
    max-height: 500px;
    overflow-y: auto;
    transition: max-height 0.3s ease, padding 0.3s ease;
    padding: 0 var(--space-sm) var(--space-sm);
  }

  .analyzer-section.collapsed .analyzer-content {
    max-height: 0;
    overflow: hidden;
    padding-top: 0;
    padding-bottom: 0;
  }

  .analyzer-canvas-container canvas {
    height: 100px;
  }

  /* Frequency input slightly narrower on mobile */
  .frequency-input {
    width: 65px;
  }

  :root {
    --controls-width: 1fr;
  }
}

/* Hide animation controls on very small screens */
@media (max-width: 480px) {
  .animation-controls {
    display: none;
  }
}

/* Small phones */
@media (max-width: 400px) {
  .app-title h1 {
    font-size: var(--font-size-base);
  }

  .app-title .subtitle {
    display: none;
  }

  .global-controls {
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-sm);
  }

  .volume-control {
    gap: var(--space-xs);
  }

  .slider-volume {
    width: 80px;
  }

  .btn-view {
    padding: var(--space-xs) var(--space-sm);
    font-size: 12px;
  }
}

/* Larger desktops */
@media (min-width: 1440px) {
  :root {
    --controls-width: 360px;
  }
}

/* Touch-friendly: ensure minimum touch target size */
@media (pointer: coarse) {
  .btn {
    min-height: 44px;
    min-width: 44px;
  }

  .btn-remove {
    width: 44px;
    height: 44px;
    min-height: 44px;
    font-size: var(--font-size-xl);
  }

  .btn-toggle-wave {
    width: 44px;
    height: 44px;
    min-width: 44px;
    min-height: 44px;
  }

  .btn-preset {
    min-height: 36px;
    padding: var(--space-sm) var(--space-md);
  }

  .slider::-webkit-slider-thumb {
    width: 28px;
    height: 28px;
  }

  .slider::-moz-range-thumb {
    width: 28px;
    height: 28px;
  }

  .slider-speed::-webkit-slider-thumb {
    width: 22px;
    height: 22px;
  }

  .slider-speed::-moz-range-thumb {
    width: 22px;
    height: 22px;
  }

  .note-selector {
    padding: var(--space-sm);
    min-height: 44px;
  }

  .frequency-input {
    min-height: 44px;
    padding: var(--space-sm);
  }
}

/* --------------------------------------------------------------------------
   Smooth Transitions on Interactive Elements
   -------------------------------------------------------------------------- */
.wave-card,
.btn,
.slider,
.note-selector {
  transition-property: background-color, border-color, color, box-shadow, transform;
  transition-duration: 150ms;
  transition-timing-function: ease;
}

/* --------------------------------------------------------------------------
   Focus Styles for Keyboard Navigation
   -------------------------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Remove default focus outline when not using keyboard */
:focus:not(:focus-visible) {
  outline: none;
}