/* Modern Dark Theme - Spotify-inspired AMOLED Design */

/* ==================== CSS Variables ==================== */
:root {
  /* Background Colors */
  --bg-primary: #000000;        /* Pure black (AMOLED) */
  --bg-secondary: #121212;      /* Dark gray (cards) */
  --bg-tertiary: #282828;       /* Medium gray (hover) */
  --bg-elevated: #181818;       /* Slightly elevated surfaces */
  
  /* Border & Divider Colors */
  --border-color: #535353;
  --divider-color: #2A2A2A;
  
  /* Text Colors */
  --text-primary: #FFFFFF;
  --text-secondary: #B3B3B3;
  --text-tertiary: #6A6A6A;
  
  /* Accent Colors */
  --accent-primary: #1DB954;    /* Spotify green */
  --accent-hover: #1ED760;      /* Brighter green on hover */
  --accent-active: #169C46;     /* Darker green when active */
  
  /* Status Colors */
  --color-error: #E22134;
  --color-warning: #FFA500;
  --color-info: #3B82F6;
  --color-success: #1DB954;
  
  /* Spacing & Layout */
  --radius: 8px;
  --radius-sm: 4px;
  --radius-lg: 12px;
  --spacing: 16px;
  --spacing-sm: 8px;
  --spacing-lg: 24px;
  
  /* Transitions */
  --transition: 0.2s ease;
}

/* ==================== Base Styles ==================== */
* {
  box-sizing: border-box;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

/* ==================== Typography ==================== */
h1 {
  font-size: 32px;
  font-weight: 700;
  margin: 0 0 var(--spacing) 0;
  color: var(--text-primary);
}

h2 {
  font-size: 24px;
  font-weight: 700;
  margin: 0 0 var(--spacing) 0;
  color: var(--text-primary);
}

h3 {
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 var(--spacing-sm) 0;
  color: var(--text-primary);
}

p {
  margin: 0 0 var(--spacing-sm) 0;
}

/* ==================== Cards ==================== */
.card {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: var(--spacing);
  transition: background var(--transition);
}

.card:hover {
  background: var(--bg-tertiary);
}

.card-elevated {
  background: var(--bg-elevated);
}

/* ==================== Buttons ==================== */
.btn {
  border: none;
  border-radius: var(--radius);
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  display: inline-block;
  text-align: center;
}

.btn-primary {
  background: var(--accent-primary);
  color: var(--text-primary);
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: scale(1.02);
}

.btn-primary:active {
  background: var(--accent-active);
  transform: scale(0.98);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

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

.btn-sm {
  padding: 8px 16px;
  font-size: 14px;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 18px;
}

/* ==================== Inputs ==================== */
input[type="text"],
input[type="number"],
input[type="email"],
input[type="password"],
select,
textarea {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: var(--radius);
  padding: 12px;
  font-size: 16px;
  width: 100%;
  transition: border-color var(--transition);
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent-primary);
}

input::placeholder {
  color: var(--text-tertiary);
}

/* ==================== Progress Bars ==================== */
.progress-container {
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  height: 8px;
  overflow: hidden;
}

.progress-bar {
  background: var(--accent-primary);
  height: 100%;
  transition: width 0.3s ease;
  border-radius: var(--radius);
}

/* ==================== Status Badges ==================== */
.badge {
  display: inline-block;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-success {
  background: rgba(29, 185, 84, 0.2);
  color: var(--color-success);
}

.badge-error {
  background: rgba(226, 33, 52, 0.2);
  color: var(--color-error);
}

.badge-warning {
  background: rgba(255, 165, 0, 0.2);
  color: var(--color-warning);
}

.badge-info {
  background: rgba(59, 130, 246, 0.2);
  color: var(--color-info);
}

/* ==================== Navigation ==================== */
.nav {
  background: var(--bg-secondary);
  padding: var(--spacing);
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--divider-color);
}

.nav-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

/* ==================== Grid Layouts ==================== */
.grid {
  display: grid;
  gap: var(--spacing);
}

.grid-2 {
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
}

.grid-3 {
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
}

/* ==================== Playlist Cards ==================== */
.playlist-card {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: var(--spacing);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  color: var(--text-primary);
  display: block;
}

.playlist-card:hover {
  background: var(--bg-tertiary);
  transform: translateY(-2px);
}

.playlist-cover {
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--radius-sm);
  object-fit: cover;
  margin-bottom: var(--spacing-sm);
}

.playlist-name {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.playlist-meta {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ==================== Track Items ==================== */
.track-item {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  transition: background var(--transition);
  cursor: pointer;
}

.track-item:hover {
  background: var(--bg-tertiary);
}

.track-item.selected {
  background: rgba(29, 185, 84, 0.1);
  border: 1px solid var(--accent-primary);
}

/* ==================== Checkboxes ==================== */
input[type="checkbox"] {
  width: 20px;
  height: 20px;
  accent-color: var(--accent-primary);
  cursor: pointer;
}

/* ==================== Utility Classes ==================== */
.text-secondary {
  color: var(--text-secondary);
}

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

.text-accent {
  color: var(--accent-primary);
}

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing); }
.mb-3 { margin-bottom: var(--spacing-lg); }

.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing); }
.mt-3 { margin-top: var(--spacing-lg); }

.p-1 { padding: var(--spacing-sm); }
.p-2 { padding: var(--spacing); }
.p-3 { padding: var(--spacing-lg); }

/* ==================== Responsive ==================== */
@media (max-width: 768px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
  }
  
  h1 {
    font-size: 24px;
  }
  
  h2 {
    font-size: 20px;
  }
}