2
I don't know for sure - but this looks like a difference in the default settings between browsers. You might try setting the attributes for the input box and submit button instead of "assuming" their state.
You could try something like:
input
{
color: #781351;
background: #fee3ad;
border: 1px solid #781351
}
.submit input
{
color: #000;
background: #ffa20f;
border: 2px outset #d7b9c9
}
in your theme's style.css file. Although you'll want to change the colors from the example above since the colors I have here are shades of orange.