css - Why was the background color of the two input different? -

As can be seen, I have not specified the background color of the input, but one is gray, the other is white Why, why?

  & lt; Style & gt; .bank {border: 1px solid # 888888; Font-family: Trebuchet MS, Helvetica, Sense-Serif; Font-size: 130%; font-weight: bold; Margin: 3px; Padding: 2px; } & Lt; / Style & gt; & Lt; Input type = "button" class = "bacon" value = "answer your question" / & gt; & Lt; Input type = "button" value = "hello button" /> By specifying a limit on the button  
 

, this default operating-system-specific removal button On the styles, it is being brought back to some default (which looks gray)

You can remove it from your class by entering border in action.