Restricting width of input text boxes

I've searched the internet and these forums for my answer but can't seem to find one. Does anyone know...is it possible to restrict the size of your input type="text" boxes? I've used size="2" and maxlength="2" and it still won't get any smaller. I have 3 input type="text boxes side by side. The first one is for 2 digits and the next 2 are for 3 digits. But they all 3 look the same size. I've also tried using width:20px; and different pixel lengths to get it size down. But it just won't get any smaller. I want to make it clear to the users filling out my form that there are 2 digits in the first box and then 3 digits in the next 2. Is this possible to make those boxes smaller? I've also set the font-size to 11px.