system-fonts.css

v0.0.1

font-family with System Fonts.

CSS

font-family: -apple-system, BlinkMacSystemFont,         
             "Segoe UI",                                
             Roboto,                                    
             Ubuntu,                                    
             "Helvetica Neue", Helvetica, Arial,        
             
             "PingFang SC", "Hiragino Sans GB",        
             "Microsoft YaHei UI", "Microsoft YaHei",  
             "Source Han Sans CN",                    
             sans-serif;                              

Explanations

... will be added.