/* ==========================================
   CSS Reset & Base Styles
   ========================================== */

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

:root {
  /* Spotify-inspired color palette */
  --color-bg-primary: #121212;
  --color-bg-secondary: #181818;
  --color-bg-elevated: #282828;
  --color-accent: #1DB954;
  --color-accent-hover: #1ed760;
  --color-text-primary: #FFFFFF;
  --color-text-secondary: #B3B3B3;
  --color-error: #E22134;
  --color-warning: #FFA726;
  
  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  
  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.4);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
}

body {
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

/* ==========================================
   App Container Layout
   ========================================== */

.app-container {
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100vh;
  height: 100dvh; /* Dynamic viewport height for mobile */
  overflow: hidden;
}

.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md);
  background-color: var(--color-bg-secondary);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  flex-shrink: 0;
}

.app-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
}

.header-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.app-main {
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* ==========================================
   Screen Management
   ========================================== */

.screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  background-color: var(--color-bg-primary);
  display: none;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.screen.active {
  display: block;
  opacity: 1;
}

/* ==========================================
   Button Styles
   ========================================== */

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  outline: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-text-primary);
  padding: 12px 32px;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 700;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover, .btn-primary:active {
  background-color: var(--color-accent-hover);
  transform: scale(1.05);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-text-primary);
  padding: 10px 24px;
  border: 2px solid var(--color-text-secondary);
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all var(--transition-fast);
}

.btn-secondary:hover, .btn-secondary:active {
  border-color: var(--color-text-primary);
  background-color: rgba(255, 255, 255, 0.1);
}

.btn-text {
  color: var(--color-text-secondary);
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 600;
  transition: color var(--transition-fast);
}

.btn-text:hover, .btn-text:active {
  color: var(--color-text-primary);
}

.icon-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  color: var(--color-text-secondary);
  font-size: 1.2rem;
  transition: all var(--transition-fast);
}

.icon-btn:hover, .icon-btn:active {
  color: var(--color-text-primary);
  background-color: rgba(255, 255, 255, 0.1);
}

/* ==========================================
   Welcome/Auth Screen
   ========================================== */

.welcome-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-lg);
  text-align: center;
}

.welcome-icon {
  font-size: 5rem;
  margin-bottom: var(--spacing-lg);
  animation: float 3s ease-in-out infinite;
  position: relative;
  width: 160px;
  height: 160px;
}

.welcome-icon::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #8B5CF6 0%, #EC4899 100%);
  border-radius: 8px;
  mix-blend-mode: screen;
  opacity: 0.9;
  pointer-events: none;
  filter: drop-shadow(0 0 30px rgba(139, 92, 246, 0.6))
          drop-shadow(0 0 50px rgba(236, 72, 153, 0.5));
  transition: all 0.5s ease;
}

.welcome-icon:hover::before {
  opacity: 1;
  filter: drop-shadow(0 0 40px rgba(139, 92, 246, 0.8))
          drop-shadow(0 0 60px rgba(236, 72, 153, 0.7));
}

.welcome-cassette {
  width: 160px;
  height: 160px;
  object-fit: contain;
  filter: brightness(0) invert(1);
  transition: all 0.5s ease;
  position: relative;
  z-index: 1;
}

.welcome-icon:hover .welcome-cassette {
  transform: scale(1.1);
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.welcome-container h2 {
  font-size: 1.8rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.welcome-container p {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  max-width: 400px;
  line-height: 1.6;
}

/* ==========================================
   Loading Screen
   ========================================== */

.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  padding: var(--spacing-lg);
}

.spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.1);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-container p {
  margin-top: var(--spacing-lg);
  color: var(--color-text-secondary);
  font-size: 0.95rem;
}

/* ==========================================
   Empty States
   ========================================== */

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xl);
  text-align: center;
  color: var(--color-text-secondary);
  min-height: 300px;
}

.empty-state p {
  font-size: 1.1rem;
  margin-bottom: var(--spacing-md);
}

.empty-state-subtitle {
  font-size: 0.9rem !important;
  margin-bottom: var(--spacing-lg) !important;
}

/* ==========================================
   Bottom Navigation
   ========================================== */

.bottom-nav {
  display: flex;
  background-color: var(--color-bg-secondary);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 8px 0;
  flex-shrink: 0;
}

.nav-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 8px;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.nav-btn.active {
  color: var(--color-accent);
}

.nav-icon {
  font-size: 1.5rem;
  margin-bottom: 4px;
}

.nav-label {
  font-size: 0.7rem;
  font-weight: 600;
}

/* ==========================================
   Context Menu
   ========================================== */

.context-menu {
  position: fixed;
  background-color: var(--color-bg-elevated);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-sm) 0;
  z-index: 1000;
  min-width: 200px;
  max-width: 300px;
}

.context-menu-header {
  padding: 8px 20px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: var(--spacing-sm);
}

.context-menu-divider {
  height: 1px;
  background-color: rgba(255, 255, 255, 0.1);
  margin: var(--spacing-sm) 0;
}

.context-menu-item {
  width: 100%;
  padding: 12px 20px;
  text-align: left;
  color: var(--color-text-primary);
  font-size: 0.95rem;
  transition: background-color var(--transition-fast);
}

.context-menu-item:hover, .context-menu-item:active {
  background-color: rgba(255, 255, 255, 0.1);
}

.context-menu-separator {
  height: 1px;
  background-color: rgba(255, 255, 255, 0.1);
  margin: var(--spacing-sm) 0;
}

/* ==========================================
   Toast Notifications
   ========================================== */

.toast-container {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  pointer-events: none;
}

.toast {
  background-color: var(--color-bg-elevated);
  color: var(--color-text-primary);
  padding: 12px 20px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.9rem;
  animation: toastIn 0.3s ease;
  pointer-events: all;
  max-width: 300px;
}

.toast.error {
  background-color: var(--color-error);
}

.toast.success {
  background-color: var(--color-accent);
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ==========================================
   Utility Classes
   ========================================== */

.hidden {
  display: none !important;
}

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

.text-secondary {
  color: var(--color-text-secondary);
}

.truncate {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}