Style border-radius fillets
border-radius: upper left lower left upper right lower right;
elliptical design: border-radius attribute value can be divided into two sections separated by a slash abscissa value is preceded by a backslash, the vertical axis backslash written value, elliptical fillet similar before and after the slash are independent, and abbreviations are the same syntax. 0px / 0px or 0% / 0%
