how to modify select options length

[chinatea]

want to modify select options length. you can follow below action

you can define yourself attribute group,but if the optins length is long. which can’t disply well under IE, you can modify it in prestashop\themes\prestashop\css\global.css
modify #primary_block form#buy_block label,#primary_block form#buy_block select{ display:block; width:47%; float:left;
}
to
#primary_block form#buy_block label,#primary_block form#buy_block{ display:block; float:left;
}
#primary_block form#buy_block select{ display:block; width:80%; float:left;
}

for the example, please visit: http://oilpaintingbank.com