css: Make dark variant a little darker

src/_sass/_colors.scss

@@ -80,7 +80,7 @@ $on-colors: (

                                
                                
                                
                            
                                
                                    
                                        
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                                            }
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
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                                            // Private variables for dark background colors
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        83 -
                                        $-dark-background:                       #1F1F1F;
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        83 +
                                        $-dark-background:                       #181818;
                                        
                                        
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
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                                            $-dark-surface-1dp:                      mix(white, $-dark-background, 5%);
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
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                                            $-dark-surface-4dp:                      mix(white, $-dark-background, 9%);
                                        
                                        
                                            
                                            
                                            
                                            
                                        
                                    
                                
                                
                                
                            
                                
                                    
                                        
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                                            $-dark-surface-8dp:                      mix(white, $-dark-background, 12%);