/* ========== RESET & BASE ========== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-display);
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  min-height: 100dvh;
  display: flex;
  justify-content: center;
  transition: background var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

/* Vanta.js animated background */
.vanta-bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  display: none;
}

[data-theme="vanta1"] .vanta-bg,
[data-theme="vanta2"] .vanta-bg,
[data-theme="vanta3"] .vanta-bg,
[data-theme="vanta4"] .vanta-bg,
[data-theme="vanta5"] .vanta-bg {
  display: block;
}

[data-theme="vanta1"] #app,
[data-theme="vanta2"] #app,
[data-theme="vanta3"] #app,
[data-theme="vanta4"] #app,
[data-theme="vanta5"] #app {
  position: relative;
  z-index: 1;
}

/* Glass theme gradient background with animation */
[data-theme="glass"] body {
  background: var(--body-bg-extra);
  background-size: 200% 200%;
  animation: glass-bg-shift 12s ease-in-out infinite;
}

@keyframes glass-bg-shift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* Neon ambient glow */
[data-theme="dark-neon"] body::after {
  content: '';
  position: fixed;
  top: 30%;
  left: 50%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(0, 255, 170, 0.04) 0%, transparent 70%);
  transform: translateX(-50%);
  pointer-events: none;
  z-index: -1;
}

/* Minimal dot grid */
[data-theme="minimal"] body::after {
  content: '';
  position: fixed;
  inset: 0;
  background: radial-gradient(circle, rgba(0,0,0,0.04) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
  z-index: -1;
}

/* Retro texture overlay */
[data-theme="retro"] body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(0,0,0,0.03) 2px,
      rgba(0,0,0,0.03) 4px
    );
  pointer-events: none;
  z-index: 9999;
}

/* ========== APP CONTAINER ========== */
#app {
  width: 100%;
  max-width: 480px;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-height: 100dvh;
}

/* ========== HEADER ========== */
.tuner-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 0;
}

.app-title {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 5vw, 1.5rem);
  font-weight: 700;
  color: var(--color-text-primary);
  letter-spacing: -0.02em;
}

/* ========== THEME SELECT DROPDOWN ========== */
.theme-select {
  padding: 0 30px 0 14px;
  border-radius: var(--radius-full);
  border: var(--card-border-style);
  background-color: var(--color-bg-card);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238a8070' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  background-size: 12px;
  color: var(--color-text-accent);
  cursor: pointer;
  transition: all var(--transition-fast);
  height: 36px;
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  appearance: none;
  -webkit-appearance: none;
  outline: none;
}

.theme-select:hover {
  background-color: var(--color-bg-card-hover);
  box-shadow: var(--glow-accent);
}

.theme-select:focus {
  box-shadow: var(--glow-accent);
}

.theme-select option {
  background: #1a1a1a;
  color: #e8d5b5;
  text-transform: uppercase;
  font-size: 0.75rem;
}

/* ========== CONTROLS BAR ========== */
.controls-bar {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 8px;
  align-items: center;
}

.controls-select {
  appearance: none;
  -webkit-appearance: none;
  padding: 8px 28px 8px 10px;
  border: 1px solid var(--color-select-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-primary);
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: border-color var(--transition-fast);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23888' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  min-width: 0;
}

.controls-select:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.controls-select option {
  background: var(--color-bg-secondary);
  color: var(--color-text-primary);
}

.controls-btn {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 10px;
  border: 1px solid var(--color-select-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-secondary);
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.controls-btn:hover {
  color: var(--color-text-primary);
  border-color: var(--color-text-secondary);
}

.controls-btn[aria-expanded="true"] {
  border-color: var(--color-accent);
  color: var(--color-text-accent);
}

.controls-btn[aria-expanded="true"] .advanced-toggle-arrow {
  transform: rotate(180deg);
}

.controls-btn .advanced-toggle-arrow {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-fast);
}

/* ========== GAUGE SECTION ========== */
.gauge-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  background:
    radial-gradient(ellipse at 50% 40%, rgba(var(--color-accent-rgb), 0.04) 0%, transparent 70%),
    var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: 20px 16px 16px;
  border: var(--card-border-style);
  box-shadow: var(--shadow-card), 0 0 50px rgba(var(--color-accent-rgb), 0.13);
  backdrop-filter: var(--card-backdrop);
  -webkit-backdrop-filter: var(--card-backdrop);
  position: relative;
  overflow: hidden;
  transition: box-shadow 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Retro: inner bevel effect + screws */
[data-theme="retro"] .gauge-section {
  background: linear-gradient(180deg, #3e3e3e 0%, #2e2e2e 100%);
}

[data-theme="retro"] .gauge-section::before,
[data-theme="retro"] .gauge-section::after {
  content: '';
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #666 0%, #444 40%, #333 100%);
  box-shadow: inset 0 1px 2px rgba(255,255,255,0.15), inset 0 -1px 1px rgba(0,0,0,0.3);
  top: 10px;
  z-index: 2;
}

[data-theme="retro"] .gauge-section::before {
  left: 12px;
}

[data-theme="retro"] .gauge-section::after {
  right: 12px;
}

/* ========== NOTE DISPLAY ========== */
.note-display {
  text-align: center;
  margin-bottom: 0;
  position: relative;
}

.note-name {
  font-family: var(--font-primary);
  font-size: clamp(3.5rem, 14vw, 5rem);
  font-weight: 600;
  line-height: 1;
  transition: color var(--transition-fast), transform 0.15s ease;
  will-change: color, transform;
  color: var(--color-text-primary);
  position: relative;
  display: inline-block;
}

/* Glow halo behind note name */
.note-name::before {
  content: attr(data-note);
  position: absolute;
  inset: 0;
  color: transparent;
  filter: blur(20px);
  opacity: 0;
  transition: opacity var(--transition-fast);
  z-index: -1;
}

.note-name.in-tune {
  color: var(--color-success);
  text-shadow: 0 0 30px rgba(var(--color-accent-rgb), 0.4);
  transform: scale(1.05);
}

.note-name.in-tune::before {
  background: var(--color-success);
  opacity: 0.15;
}

.note-name.flat {
  color: var(--color-danger);
  text-shadow: 0 0 20px rgba(255, 68, 102, 0.15);
}

.note-name.sharp {
  color: var(--color-warning);
  text-shadow: 0 0 20px rgba(255, 170, 0, 0.15);
}

/* Emboss effect for minimal theme */
[data-theme="minimal"] .note-name {
  text-shadow: 0 1px 0 rgba(255,255,255,0.8), 0 -1px 0 rgba(0,0,0,0.05);
}
[data-theme="minimal"] .note-name.in-tune,
[data-theme="minimal"] .note-name.flat,
[data-theme="minimal"] .note-name.sharp {
  text-shadow: none;
}

.note-octave {
  font-family: var(--font-primary);
  font-size: clamp(1.2rem, 4vw, 1.8rem);
  color: var(--color-text-secondary);
  vertical-align: sub;
}

/* ========== GAUGE CONTAINER ========== */
.gauge-container {
  width: 100%;
  max-width: 300px;
  aspect-ratio: 5 / 3;
  margin-top: -4px;
}

.gauge-container svg {
  width: 100%;
  height: 100%;
  display: block;
}

.gauge-needle {
  will-change: transform;
}

.ghost-needle {
  pointer-events: none;
  will-change: transform, opacity;
}

.gauge-center-glow {
  transition: r 0.2s ease, opacity 0.2s ease;
}

@keyframes gauge-glow-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.55; }
}

.gauge-glow-pulse {
  animation: gauge-glow-pulse 1.2s ease-in-out infinite;
}

/* ========== CENTS BAR ========== */
.cents-bar-container {
  width: 100%;
  max-width: 260px;
  padding: 4px 0 8px;
}

.cents-bar-track {
  position: relative;
  height: 6px;
  background: var(--color-gauge-track);
  border-radius: 3px;
  overflow: hidden;
}

.cents-bar-fill {
  position: absolute;
  top: 0;
  height: 100%;
  border-radius: 3px;
  transition: left 100ms ease-out, width 100ms ease-out, background 100ms ease;
  will-change: left, width, background-color;
  left: 50%;
  width: 0;
  background: var(--color-gauge-in-tune);
}

.cents-bar-fill.flat {
  background: var(--color-gauge-flat);
}

.cents-bar-fill.sharp {
  background: var(--color-gauge-sharp);
}

.cents-bar-fill.in-tune {
  background: var(--color-gauge-in-tune);
  box-shadow: 0 0 8px rgba(var(--color-accent-rgb), 0.4);
}

.cents-bar-center {
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 8px;
  background: var(--color-text-secondary);
  border-radius: 1px;
  opacity: 0.5;
}

/* ========== FREQUENCY DISPLAY ========== */
.frequency-display {
  display: flex;
  gap: 16px;
  justify-content: center;
  font-family: var(--font-primary);
  font-size: clamp(0.8rem, 3vw, 0.95rem);
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
}

.cents-display {
  font-weight: 600;
}

.cents-display.in-tune {
  color: var(--color-success);
}

.cents-display.flat {
  color: var(--color-danger);
}

.cents-display.sharp {
  color: var(--color-warning);
}

/* ========== STRINGS SECTION ========== */
.strings-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.strings-container {
  display: flex;
  gap: 6px;
  justify-content: center;
  flex-wrap: nowrap;
}

.string-btn {
  width: clamp(44px, 13vw, 60px);
  height: clamp(44px, 13vw, 60px);
  border-radius: var(--radius-full);
  border: 2px solid var(--color-string-inactive);
  background: var(--color-string-bg);
  color: var(--color-text-secondary);
  font-family: var(--font-primary);
  font-size: clamp(0.7rem, 2.5vw, 0.85rem);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.15);
}

.string-btn:hover {
  border-color: var(--color-string-active);
  color: var(--color-string-active);
  background: var(--color-string-bg);
  transform: translateY(-1px);
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.15), 0 4px 8px rgba(0,0,0,0.15);
}

.string-btn:active {
  transform: scale(0.88);
  transition: transform 60ms ease-out;
}

.string-btn.ringing {
  border-color: var(--color-string-active);
  color: var(--color-string-active);
  box-shadow: var(--glow-accent), inset 0 1px 3px rgba(0,0,0,0.1);
  animation: pulse-ring 1.2s ease-in-out 0.15s infinite;
}

.string-btn.in-tune {
  border-color: var(--color-success);
  color: var(--color-success);
  box-shadow: 0 0 20px rgba(var(--color-accent-rgb), 0.3), 0 0 0 3px rgba(var(--color-accent-rgb), 0.12);
}

.string-btn.playing {
  background: var(--color-btn-active-bg);
  color: var(--color-btn-active-text);
  border-color: var(--color-btn-active-bg);
  animation: ripple-out 0.6s ease-out;
}

.string-btn-label {
  position: relative;
  z-index: 1;
}

.string-vibration-svg {
  position: absolute;
  inset: -4px;
  width: calc(100% + 8px);
  height: calc(100% + 8px);
  pointer-events: none;
  z-index: 0;
}

.vibration-path {
  transition: stroke-opacity 200ms ease;
}

@media (prefers-reduced-motion: reduce) {
  .string-vibration-svg {
    display: none;
  }
}

/* ========== MIC BUTTON ========== */
.mic-button {
  width: 100%;
  padding: 16px 24px;
  border: none;
  border-radius: var(--radius-md);
  margin-top: -8px;
  background: var(--color-accent);
  color: var(--color-bg-primary);
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
}

.mic-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

.mic-button:hover {
  opacity: 0.9;
  box-shadow: var(--glow-strong);
}

.mic-button:active {
  transform: scale(0.98);
}

.mic-button.listening {
  background: var(--color-bg-card);
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
  animation: pulse-border 2s ease-in-out infinite;
}

.mic-button.listening .mic-icon {
  animation: mic-pulse 2s ease-in-out infinite;
}

[data-theme="minimal"] .mic-button {
  color: #ffffff;
}

[data-theme="retro"] .mic-button {
  color: #2a2a2a;
  background: linear-gradient(180deg, #ffcc66 0%, #ffbb44 50%, #ee9922 100%);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.3), 0 2px 4px rgba(0,0,0,0.4);
}

[data-theme="retro"] .mic-button:active {
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
}

/* ========== STUDIO (RETRO 2) OVERRIDES ========== */
[data-theme="retro2"] body {
  background: radial-gradient(ellipse at 50% 30%, #1a1816 0%, #0c0c0e 70%);
}

[data-theme="retro2"] .gauge-section {
  background: linear-gradient(180deg, #1e1e20 0%, #141416 100%);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.05),
    inset 0 -1px 0 rgba(0,0,0,0.5),
    0 4px 16px rgba(0,0,0,0.6),
    0 12px 40px rgba(0,0,0,0.4),
    0 0 50px rgba(var(--color-accent-rgb), 0.13);
  border: 1px solid rgba(255,255,255,0.06);
  border-top-color: rgba(255,255,255,0.1);
}

[data-theme="retro2"] .gauge-section::before,
[data-theme="retro2"] .gauge-section::after {
  content: '';
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #444 0%, #222 60%, #111 100%);
  box-shadow: inset 0 1px 1px rgba(255,255,255,0.1), inset 0 -1px 1px rgba(0,0,0,0.5);
  top: 10px;
  z-index: 2;
}

[data-theme="retro2"] .gauge-section::before { left: 12px; }
[data-theme="retro2"] .gauge-section::after { right: 12px; }


[data-theme="retro2"] .string-btn {
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 -1px 0 rgba(0,0,0,0.3),
    0 2px 6px rgba(0,0,0,0.4);
}

[data-theme="vanta3"] .string-btn {
  background: rgba(22, 20, 14, 0.92);
  border-color: rgba(110, 100, 80, 0.85);
  color: #a09070;
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 -1px 0 rgba(0,0,0,0.4),
    0 2px 8px rgba(0,0,0,0.6);
}

[data-theme="vanta3"] .string-btn:hover {
  background: rgba(34, 30, 20, 0.95);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

[data-theme="retro2"] .string-btn.playing {
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.2),
    0 0 12px rgba(212,162,78,0.3);
}

[data-theme="retro2"] .note-name {
  text-shadow: 0 1px 2px rgba(0,0,0,0.5), 0 0 20px rgba(212,162,78,0.1);
}

/* Hide the gold accent dot in the gauge center pivot */
[data-theme="retro2"] .gauge-center-glow {
  fill: #1e1e20;
  opacity: 0.5;
}

[data-theme="retro2"] .mic-button {
  color: #0c0c0e;
  background: linear-gradient(180deg, #e8c06a 0%, #d4a24e 50%, #b8862e 100%);
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.3),
    inset 0 -1px 0 rgba(0,0,0,0.2),
    0 2px 8px rgba(0,0,0,0.5);
  border: 1px solid rgba(255,255,255,0.1);
  text-shadow: 0 1px 0 rgba(255,255,255,0.15);
}

[data-theme="retro2"] .mic-button:active {
  box-shadow: inset 0 2px 6px rgba(0,0,0,0.4);
}

[data-theme="retro2"] .step-card,
[data-theme="retro2"] .feature-card,
[data-theme="retro2"] .tuning-group {
  box-shadow:
    inset 0 1px 0 rgba(255,255,255,0.04),
    0 2px 8px rgba(0,0,0,0.4);
}

/* ========== IN-TUNE INDICATOR ========== */
.in-tune-overlay {
  position: absolute;
  top: 12px;
  right: 12px;
  z-index: 10;
  opacity: 1;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.in-tune-overlay.hidden {
  opacity: 0;
}

.in-tune-check {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-success);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: in-tune-pop 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 0 16px rgba(var(--color-accent-rgb), 0.5);
  position: relative;
}

.in-tune-check::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 2px solid var(--color-success);
  animation: in-tune-ripple 0.8s ease-out forwards;
}

@keyframes in-tune-ripple {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(2); opacity: 0; }
}

.in-tune-check svg {
  width: 22px;
  height: 22px;
  stroke: white;
  stroke-width: 3;
  fill: none;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ========== IN-TUNE BLOOM EFFECT ========== */
.in-tune-bloom {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 5;
  opacity: 0;
  background: radial-gradient(
    ellipse at 50% 35%,
    var(--color-success) 0%,
    transparent 70%
  );
  transform: scale(0.3);
  will-change: opacity, transform;
}

.in-tune-bloom.bloom-active {
  animation: bloom-pulse 800ms ease-out forwards;
}

@keyframes bloom-pulse {
  0% {
    opacity: 0;
    transform: scale(0.3);
  }
  30% {
    opacity: 0.3;
    transform: scale(0.8);
  }
  60% {
    opacity: 0.2;
    transform: scale(1.1);
  }
  100% {
    opacity: 0;
    transform: scale(1.2);
  }
}

/* ========== ANIMATIONS ========== */
@keyframes pulse-ring {
  0%, 100% {
    box-shadow: var(--glow-accent), inset 0 1px 3px rgba(0,0,0,0.1), 0 0 0 0 rgba(var(--color-accent-rgb), 0.2);
  }
  50% {
    box-shadow: var(--glow-strong), inset 0 1px 3px rgba(0,0,0,0.1), 0 0 0 8px rgba(var(--color-accent-rgb), 0);
  }
}

@keyframes pulse-border {
  0%, 100% {
    border-color: var(--color-accent);
    box-shadow: var(--glow-accent);
  }
  50% {
    border-color: rgba(var(--color-accent-rgb), 0.4);
    box-shadow: none;
  }
}

@keyframes in-tune-pop {
  0% { transform: scale(0); opacity: 0; }
  60% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes mic-pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.15); opacity: 0.7; }
}

@keyframes ripple-out {
  0% { box-shadow: 0 0 0 0 rgba(var(--color-accent-rgb), 0.4); }
  100% { box-shadow: 0 0 0 12px rgba(var(--color-accent-rgb), 0); }
}

/* ========== VIEW MODE TOGGLE ========== */
.view-mode-toggle {
  display: flex;
  gap: 0;
  background: transparent;
  border-radius: var(--radius-full);
  padding: 0;
  margin-bottom: 4px;
  width: fit-content;
  align-self: center;
  opacity: 0.5;
  transition: opacity var(--transition-fast);
}

.view-mode-toggle:hover {
  opacity: 0.8;
}

.view-mode-btn {
  padding: 6px 20px;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  color: var(--color-text-secondary);
  font-family: var(--font-display);
  font-size: 0.65rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.view-mode-btn.active {
  color: var(--color-text-primary);
}

.view-mode-btn:not(.active):hover {
  color: var(--color-text-primary);
}

/* ========== STROBE TUNER ========== */
.strobe-container {
  width: 100%;
  max-width: 300px;
  aspect-ratio: 5 / 3;
  margin-top: -4px;
}

.strobe-container canvas {
  width: 100%;
  height: 100%;
  display: block;
  border-radius: var(--radius-sm);
}

/* ========== ADVANCED SETTINGS ========== */
.advanced-section {
  display: flex;
  flex-direction: column;
}

.advanced-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 12px 0 0;
}

.advanced-panel[hidden] {
  display: none;
}

/* Reset to Defaults button */
.reset-defaults-btn {
  align-self: flex-end;
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  background: transparent;
  color: var(--color-text-secondary);
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.reset-defaults-btn:hover {
  color: var(--color-text-primary);
  border-color: var(--color-text-secondary);
}

.reset-defaults-btn:active {
  transform: scale(0.95);
}

/* Help icon tooltips */
.label-with-help {
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.help-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1px solid var(--color-text-secondary);
  color: var(--color-text-secondary);
  font-family: var(--font-primary);
  font-size: 0.6rem;
  font-weight: 700;
  cursor: help;
  position: relative;
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.help-icon:hover {
  color: var(--color-text-primary);
  border-color: var(--color-text-primary);
}

.help-icon::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  width: max-content;
  max-width: 220px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  color: var(--color-text-primary);
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 400;
  line-height: 1.45;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
  z-index: 20;
  white-space: normal;
}

.help-icon:hover::after {
  opacity: 1;
}

/* Keep tooltip on screen for left-aligned labels */
.help-icon::before {
  content: '';
  position: absolute;
  bottom: calc(100% + 2px);
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: var(--color-bg-secondary);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
  z-index: 21;
}

.help-icon:hover::before {
  opacity: 1;
}

.setting-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 14px;
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  border: var(--card-border-style);
  backdrop-filter: var(--card-backdrop);
  -webkit-backdrop-filter: var(--card-backdrop);
}

.setting-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-display);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

.setting-value {
  font-family: var(--font-primary);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text-accent);
}

.setting-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: var(--color-gauge-track);
  outline: none;
  transition: background var(--transition-fast);
}

.setting-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-accent);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.setting-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-accent);
  cursor: pointer;
  border: none;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.setting-presets {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.preset-btn {
  padding: 4px 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  background: transparent;
  color: var(--color-text-secondary);
  font-family: var(--font-primary);
  font-size: 0.7rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.preset-btn.active,
.preset-btn:hover {
  background: var(--color-btn-active-bg);
  color: var(--color-btn-active-text);
  border-color: var(--color-btn-active-bg);
}

.setting-select {
  appearance: none;
  -webkit-appearance: none;
  width: 100%;
  padding: 10px 36px 10px 12px;
  border: 1px solid var(--color-select-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-primary);
  font-family: var(--font-display);
  font-size: 0.85rem;
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23888' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
}

.setting-select option {
  background: var(--color-bg-secondary);
  color: var(--color-text-primary);
}

.setting-sub {
  display: flex;
  align-items: center;
  gap: 8px;
}

.setting-label-small {
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
}

.setting-select-small {
  appearance: none;
  -webkit-appearance: none;
  flex: 1;
  padding: 6px 28px 6px 10px;
  border: 1px solid var(--color-select-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-primary);
  font-family: var(--font-primary);
  font-size: 0.8rem;
  cursor: pointer;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23888' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.setting-select-small option {
  background: var(--color-bg-secondary);
  color: var(--color-text-primary);
}

.custom-tuning-strings {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

.custom-tuning-strings select {
  width: 60px;
  padding: 6px 4px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-primary);
  font-family: var(--font-primary);
  font-size: 0.75rem;
  text-align: center;
  appearance: none;
  -webkit-appearance: none;
}

.custom-tuning-controls {
  display: flex;
  gap: 6px;
}

.custom-tuning-save {
  display: flex;
  gap: 6px;
}

.setting-input {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid var(--color-select-border);
  border-radius: var(--radius-sm);
  background: var(--color-select-bg);
  color: var(--color-text-primary);
  font-family: var(--font-display);
  font-size: 0.8rem;
}

.setting-input::placeholder {
  color: var(--color-text-secondary);
  opacity: 0.6;
}

.small-btn {
  padding: 6px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg-card);
  color: var(--color-text-secondary);
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.small-btn:hover {
  color: var(--color-text-primary);
  border-color: var(--color-text-secondary);
}

.small-btn.primary {
  background: var(--color-accent);
  color: var(--color-bg-primary);
  border-color: var(--color-accent);
}

.small-btn.primary:hover {
  opacity: 0.9;
}

.custom-tuning-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.custom-tuning-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 6px 10px;
  background: rgba(var(--color-accent-rgb), 0.06);
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--color-text-primary);
}

.custom-tuning-item-info {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.custom-tuning-item-notes {
  font-family: var(--font-primary);
  font-size: 0.7rem;
  color: var(--color-text-secondary);
}

.custom-tuning-delete {
  background: none;
  border: none;
  color: var(--color-danger);
  cursor: pointer;
  font-size: 0.8rem;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast);
  flex-shrink: 0;
}

.custom-tuning-delete:hover {
  background: rgba(255, 0, 0, 0.1);
}

/* ========== FOCUS MODE ========== */
#app > * {
  transition: filter 0.6s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

#app.focus-mode > *:not(.gauge-section):not(.strings-section):not(.mic-button):not(.focus-hint) {
  filter: blur(6px);
  opacity: 0.12;
  user-select: none;
  cursor: pointer;
}

#app.focus-mode .gauge-section {
  box-shadow: var(--shadow-card), 0 0 90px rgba(var(--color-accent-rgb), 0.30);
}

.focus-hint {
  text-align: center;
  font-family: var(--font-display);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity 0.4s ease, max-height 0.4s ease;
  pointer-events: none;
}

#app.focus-mode .focus-hint {
  opacity: 0.5;
  max-height: 2em;
  margin-top: 2px;
}

/* ========== SEO CONTENT SECTIONS ========== */
.seo-section {
  padding: 24px 0 0;
  border-top: 1px solid var(--color-border);
  margin-top: 8px;
}

.seo-heading {
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 4vw, 1.3rem);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

/* Steps Grid */
.steps-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.step-card {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 2px 12px;
  align-items: start;
  padding: 14px;
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  border: var(--card-border-style);
  backdrop-filter: var(--card-backdrop);
  -webkit-backdrop-filter: var(--card-backdrop);
}

.step-icon {
  width: 36px;
  height: 36px;
  grid-row: 1 / 3;
  align-self: center;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(var(--color-accent-rgb), 0.1);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
}

.step-icon svg {
  width: 18px;
  height: 18px;
}

.step-title {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 4px;
}

.step-desc {
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--color-text-secondary);
}

/* Tunings Grid */
.tunings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.tuning-group {
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  border: var(--card-border-style);
  padding: 14px;
  backdrop-filter: var(--card-backdrop);
  -webkit-backdrop-filter: var(--card-backdrop);
}

.tuning-group-title {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-text-accent);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.tuning-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.tuning-list li {
  font-size: 0.8rem;
  color: var(--color-text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.tuning-notes {
  font-family: var(--font-primary);
  font-size: 0.7rem;
  color: var(--color-text-secondary);
  white-space: nowrap;
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.feature-card {
  padding: 14px;
  background: var(--color-bg-card);
  border-radius: var(--radius-md);
  border: var(--card-border-style);
  backdrop-filter: var(--card-backdrop);
  -webkit-backdrop-filter: var(--card-backdrop);
}

.feature-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(var(--color-accent-rgb), 0.1);
  border-radius: var(--radius-sm);
  color: var(--color-accent);
  margin-bottom: 10px;
}

.feature-icon svg {
  width: 18px;
  height: 18px;
}

.feature-title {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 4px;
}

.feature-desc {
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--color-text-secondary);
}

/* Footer */
.site-footer {
  padding: 20px 0;
  border-top: 1px solid var(--color-border);
  margin-top: 8px;
  text-align: center;
}

.footer-text {
  font-size: 0.75rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 480px) {
  .tunings-grid,
  .features-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 768px) {
  #app {
    padding: 32px 24px;
    gap: 24px;
    justify-content: center;
  }

  .gauge-section {
    padding: 28px 24px 20px;
  }

  .gauge-container {
    max-width: 340px;
  }

  .note-name {
    font-size: 5.5rem;
  }

  .string-btn {
    width: 64px;
    height: 64px;
    font-size: 0.9rem;
  }
}

@media (min-width: 1024px) {
  #app {
    padding: 40px 32px;
    gap: 28px;
  }
}

/* ========== ACCESSIBILITY ========== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

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