Multiple CSS classes

I have the following:

input.bg:hover {

...

}

I'm using the above following: <input type=开发者_如何学Go"submit" class="bg" value="ttttttt"/> now how to modify the class, so I can use <input type="submit" class="bg-small" value="cccccccc"/> ?

I need to add .bg-small into this css class, but I don't know how. I've been trying the following:

input.bg:hover .bg-small:hover {

...

}

Did you mean this ?

input.BG:hover, input.BG-SMALL:hover {
.....
}

So when you move your mouse over the normal input or submit input, they has the same effect

input.BG:hover, input.BG-SMALL:hover {

...

}

I'm not sure what you mean, but if you want the same class properties from BG for BG-SMALL, you can set

input.BG:hover, input.BG-SMALL:hover {
}

or just use the same class for the inputs if there's no difference.