/* ==========================================================================
   1. ДИЗАЙН-ТОКЕНЫ (ПЕРЕМЕННЫЕ)
   ========================================================================== */
:root {
  /* Шрифты */
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Space Mono', monospace;

  /* Базовая темная тема (по умолчанию) */
  --bg-primary: oklch(0.14 0.01 260);
  --bg-surface: oklch(0.18 0.01 260);
  --bg-surface-hover: oklch(0.22 0.01 260);

  --border-subtle: oklch(0.25 0.01 260);
  --border-focus: oklch(0.65 0.15 250);

  --text-primary: oklch(0.96 0.01 260);
  --text-secondary: oklch(0.65 0.02 260);
  --text-tertiary: oklch(0.45 0.02 260);

  --accent: oklch(0.85 0.12 85);
  --accent-glow: oklch(0.85 0.12 85 / 0.15);

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
  --bg-primary: oklch(0.97 0.005 85);
  --bg-surface: oklch(1 0 0);
  --bg-surface-hover: oklch(0.94 0.005 85);

  --border-subtle: oklch(0.88 0.01 85);
  --border-focus: oklch(0.45 0.15 250);
  
  --text-primary: oklch(0.18 0.02 260);
  --text-secondary: oklch(0.45 0.02 260);
  --text-tertiary: oklch(0.65 0.02 260);

  --accent: oklch(0.55 0.15 45);
  --accent-glow: oklch(0.55 0.15 45 / 0.12);
}

/* ==========================================================================
   2. БАЗОВЫЙ LAYOUT
   ========================================================================== */
body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  transition: background-color var(--transition-smooth), color var(--transition-smooth);
  display: flex;
  justify-content: center;
  padding: 1.5rem;
}

.app-layout {
  width: 100%;
  max-width: 680px;
  min-height: calc(100vh - 3rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 2.5rem;
}

/* ==========================================================================
   3. HEADER
   ========================================================================== */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-subtle);
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.logo__symbol {
  color: var(--accent);
  font-size: 0.8rem;
  animation: pulse-slow 4s infinite ease-in-out;
}

.btn-ghost {
  font-size: 0.875rem;
  color: var(--text-secondary);
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background-color: var(--bg-surface);
}

.app-main {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* ==========================================================================
   4. СЕКЦИЯ ТАЙМЕРА
   ========================================================================== */
.timer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.75rem;
  text-align: center;
}

.timer-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.timer-modes {
  display: flex;
  gap: 0.25rem;
  background-color: var(--bg-surface);
  padding: 0.25rem;
  border-radius: 9999px;
  border: 1px solid var(--border-subtle);  
}

.mode-btn {
  padding: 0.4rem 1rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 9999px;
  transition: all var(--transition-fast);
}

.mode-btn.is-active {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  box-shadow: 0 2px 8px rgba(0,0,0, 0.15);
}

.timer-digits {
  font-family: var(--font-mono);
  font-size: clamp(4rem, 12vw, 6.5rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.timer-status {
  font-size: 0.875rem;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 500;
}

.timer-controls {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.btn-primary {
  background-color: var(--text-primary);
  color: var(--bg-primary);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.75rem 2.25rem;
  border-radius: 9999px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

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

.btn-secondary {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 1.2rem;
  transition: all var(--transition-fast);
}

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

/* ==========================================================================
   5. ВИЗУАЛИЗАТОР (CANVAS)
   ========================================================================== */
.visualizer-section {
  width: 100%;
  height: 64px;
  background-color: var(--bg-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  overflow: hidden;
  position: relative;
}

#visualizer-canvas {
  width: 100%;
  height: 100%;
}

/* ==========================================================================
   6. МИКШЕР ЗВУКА
   ========================================================================== */
.mixer-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.section-title {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05rem;
  color: var(--text-tertiary);
}

.channels-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr); /* Ровно 2 равные колонки */
  gap: 0.875rem;
}

/* На мобильных экранах (уже 520px) перестраиваем в 1 колонку */
@media (max-width: 520px) {
  .channels-grid {
    grid-template-columns: 1fr;
  }
}

.sound-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.sound-card:hover {
  background-color: var(--bg-surface-hover);
}

.sound-card__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
}

.sound-card__name {
  font-weight: 500;
}

.sound-card__value {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

/* Стилизация слайдеров громкости (Cross-browser) */
.custom-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--border-subtle);
  border-radius: 9999px;
  outline: none;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.custom-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--text-primary);
  border: 2px solid var(--bg-surface);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
  transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.custom-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--text-primary);
  border: 2px solid var(--bg-surface);
  box-shadow: 0 1px 4px rgba(0,0,0,0.3);
  transition: transform var(--transition-fast);
}

.custom-slider:hover::-webkit-slider-thumb {
  transform: scale(1.2);
  background: var(--accent);
}

.custom-slider:focus {
  outline: none;
}

.master-bar {
  display: flex;
  justify-content: flex-end;
}

/* ==========================================================================
   7. FOOTER & SHORTCUTS
   ========================================================================== */
.app-footer {
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  justify-content: center;
}

.shortcuts-hint {
  display: flex;
  gap: 1.25rem;
  font-size: 0.75rem;
  color: var(--text-tertiary);
}

kbd {
  font-family: var(--font-mono);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
}

/* Анимации */
@keyframes pulse-slow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.85); }
}

/* Доступность: видимый фокус для клавиатуры */
:focus-visible {
  outline: 2px solid var(--border-focus);
  outline-offset: 3px;
}