.overlay-panel {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 10000;
  align-items: center;
  justify-content: center;
}

.overlay-panel-content {
  background: white;
  border-radius: 12px;
  max-width: 1200px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.overlay-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 30px;
  border-bottom: 1px solid #e1e4e8;
}

.overlay-panel-header h3 {
  margin: 0;
  font-size: 24px;
  color: #2c3e50;
}

.close-overlay-panel {
  background: none;
  border: none;
  font-size: 32px;
  color: #95a5a6;
  cursor: pointer;
  padding: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.2s;
}

.close-overlay-panel:hover {
  color: #2c3e50;
}

.data-source-manager {
  padding: 20px 30px;
}

.data-source-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.data-source-header h2 {
  font-size: 24px;
  margin: 0;
  color: #2c3e50;
}

.data-source-header .header-actions {
  display: flex;
  gap: 12px;
}

.btn-add-source {
  background: #3498db;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.2s;
}

.btn-add-source:hover {
  background: #2980b9;
}

.btn-relationship {
  background: #9b59b6;
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.2s;
}

.btn-relationship:hover {
  background: #8e44ad;
}

.data-source-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.data-source-card {
  background: white;
  border: 1px solid #e1e4e8;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  transition: transform 0.2s, box-shadow 0.2s;
}

.data-source-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.source-icon {
  font-size: 32px;
  margin-bottom: 10px;
}

.data-source-card h3 {
  font-size: 16px;
  margin: 0 0 10px 0;
  color: #2c3e50;
  font-weight: 600;
}

.source-status {
  font-size: 13px;
  color: #7f8c8d;
  margin-bottom: 12px;
}

.source-stats {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 13px;
  color: #95a5a6;
  margin-bottom: 15px;
  padding: 10px 0;
  border-top: 1px solid #ecf0f1;
  border-bottom: 1px solid #ecf0f1;
}

.source-actions {
  display: flex;
  gap: 8px;
}

.source-actions button {
  flex: 1;
  padding: 8px;
  border: 1px solid #dfe4e8;
  background: white;
  border-radius: 4px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.2s;
}

.btn-refresh {
  color: #3498db;
}

.btn-refresh:hover {
  background: #3498db;
  color: white;
  border-color: #3498db;
}

.btn-configure:hover {
  background: #95a5a6;
  color: white;
  border-color: #95a5a6;
}

.btn-remove {
  color: #e74c3c;
  flex: 0 0 40px;
}

.btn-remove:hover {
  background: #e74c3c;
  color: white;
  border-color: #e74c3c;
}

.empty-state {
  grid-column: 1 / -1;
  text-align: center;
  padding: 60px 20px;
  color: #95a5a6;
}

.empty-state p {
  margin: 8px 0;
  font-size: 14px;
}

.empty-state p:first-child {
  font-size: 16px;
  color: #7f8c8d;
  font-weight: 500;
}

@media (max-width: 768px) {
  .data-source-grid {
    grid-template-columns: 1fr;
  }
  
  .data-source-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 15px;
  }
}