/* Main Columns Layout */
.main-columns {
  display: flex;
  gap: 24px;
  align-items: flex-start;
}

.left-column {
  flex: 2 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.right-column {
  flex: 1 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

@media (max-width: 900px) {
  .main-columns {
    flex-direction: column;
    gap: 0;
  }
  .left-column, .right-column {
    width: 100%;
    gap: 20px;
  }
}
:root {
  --primary-color: #4a6fa5;
  --primary-dark: #3a5a8a;
  --secondary-color: #6c757d;
  --success-color: #28a745;
  --danger-color: #dc3545;
  --light-color: #f8f9fa;
  --dark-color: #343a40;
  --border-color: #dee2e6;
  --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f5f7fa;
  padding: 0;
  margin: 0;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

header {
  text-align: center;
  margin-bottom: 30px;
}

h1 {
  color: var(--primary-color);
  font-size: 2.5rem;
  margin-bottom: 10px;
}

h1 i {
  margin-right: 10px;
}

.subtitle {
  color: var(--secondary-color);
  font-size: 1.1rem;
}

.card {
  background: white;
  border-radius: 8px;
  box-shadow: var(--card-shadow);
  padding: 20px;
  margin-bottom: 20px;
}

/* Upload Section */
.upload-section {
  text-align: center;
}

.file-upload {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
  margin-bottom: 15px;
}

.upload-btn {
  position: relative;
  display: inline-block;
  padding: 10px 20px;
  background-color: var(--primary-color);
  color: white;
  border-radius: 5px;
  cursor: pointer;
  transition: var(--transition);
}

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

.upload-btn input[type="file"] {
  position: absolute;
  left: 0;
  top: 0;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

#fileName {
  color: var(--secondary-color);
  font-size: 0.9rem;
}

.stats-container {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-top: 15px;
}

.stat-item {
  background: #f8f9fa;
  padding: 10px 15px;
  border-radius: 5px;
  font-size: 0.9rem;
}

.stat-item strong {
  color: var(--primary-color);
}

/* Filter Section */
.filter-section h2 {
  margin-bottom: 15px;
  color: var(--primary-color);
  font-size: 1.3rem;
}

.filter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
}

.filter-group {
  display: flex;
  flex-direction: column;
}

.filter-group label {
  margin-bottom: 5px;
  font-weight: 500;
  color: var(--secondary-color);
}

.filter-group input,
.filter-group select {
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 0.95rem;
}

.filter-group select {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' 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: 1em;
}

/* Playlist Section */
.playlist-section h2 {
  color: var(--primary-color);
  font-size: 1.3rem;
  margin-bottom: 15px;
}

.playlist-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
  gap: 10px;
}

.playlist-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 15px;
}

.select-controls {
  display: flex;
  align-items: center;
}

.selection-count {
  font-weight: 500;
  color: var(--primary-color);
  min-width: 120px;
}

.playlist-actions {
  display: flex;
  gap: 10px;
}

.btn {
  padding: 8px 16px;
  border-radius: 4px;
  font-weight: 500;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
  border: none;
}

.btn i {
  font-size: 0.9rem;
}

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

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

.btn.secondary {
  background-color: var(--light-color);
  color: var(--secondary-color);
  border: 1px solid var(--border-color);
}

.btn.secondary:hover {
  background-color: #e9ecef;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Song List */
.song-list-container {
  border: 1px solid var(--border-color);
  border-radius: 4px;
  overflow: hidden;
}

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
  color: var(--secondary-color);
  text-align: center;
}

.empty-state i {
  font-size: 3rem;
  margin-bottom: 15px;
  color: #e9ecef;
}

#songTable {
  width: 100%;
  border-collapse: collapse;
}

#songTable thead {
  background-color: var(--primary-color);
  color: white;
}

#songTable th {
  padding: 12px 15px;
  text-align: left;
  font-weight: 500;
  position: sticky;
  top: 0;
}

#songTable th i {
  margin-left: 5px;
}

#songTable tbody tr {
  border-bottom: 1px solid var(--border-color);
}

#songTable tbody tr:nth-child(even) {
  background-color: #f8f9fa;
}

#songTable tbody tr:hover {
  background-color: #e9ecef;
}

#songTable td {
  padding: 12px 15px;
  vertical-align: middle;
}

.checkbox-container {
  display: flex;
  align-items: center;
  cursor: pointer;
  user-select: none;
}

.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.checkmark {
  height: 18px;
  width: 18px;
  background-color: white;
  border: 1px solid var(--border-color);
  border-radius: 3px;
  margin-right: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.checkbox-container:hover input ~ .checkmark {
  background-color: #f1f1f1;
}

.checkbox-container input:checked ~ .checkmark {
  background-color: var(--primary-color);
  border-color: var(--primary-color);
}

.checkmark:after {
  content: "";
  display: none;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  margin-bottom: 2px;
}

.checkbox-container input:checked ~ .checkmark:after {
  display: block;
}

/* Playlist Footer */
.playlist-footer {
  margin-top: 15px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 15px;
}

.status-message {
  color: var(--secondary-color);
  font-size: 0.9rem;
}

.status-message.success {
  color: var(--success-color);
}

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

.playlist-options {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 15px;
}

.playlist-name {
  display: flex;
  align-items: center;
  gap: 8px;
}

.playlist-name input {
  padding: 6px 10px;
  border: 1px solid var(--border-color);
  border-radius: 4px;
}

/* Footer */
footer {
  text-align: center;
  margin-top: 30px;
  color: var(--secondary-color);
  font-size: 0.9rem;
}

footer i {
  color: var(--danger-color);
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 15px;
  }

  h1 {
    font-size: 2rem;
  }

  .filter-grid {
    grid-template-columns: 1fr;
  gap: 10px;
  margin-bottom: 10px;
  }

  .playlist-controls {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .playlist-actions {
    width: 100%;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  #songTable {
    display: block;
    overflow-x: auto;
  }
}

/* Loading spinner */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
}

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

/* Preview Section Styles */
.preview-section {
  margin-bottom: 20px;
}

.preview-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 15px;
  gap: 15px;
}

.preview-list-container {
  border: 1px solid var(--border-color);
  border-radius: 4px;
  max-height: 200px;
  overflow-y: auto;
  margin-bottom: 15px;
}

.preview-list-container table {
  width: 100%;
  border-collapse: collapse;
}

.preview-list-container th {
  background-color: var(--primary-color);
  color: white;
  padding: 8px 12px;
  text-align: left;
  position: sticky;
  top: 0;
}

.preview-list-container td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--border-color);
}

.preview-list-container tr:nth-child(even) {
  background-color: #f8f9fa;
}

.preview-actions {
  display: flex;
  justify-content: flex-end;
}

.remove-preview-item {
  color: var(--danger-color);
  cursor: pointer;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .preview-controls {
    flex-direction: column;
    align-items: flex-start;
  }
  
  #addToPreviewBtn {
    width: 100%;
  }
}