How to format text in dropdown options

How can I format the text in my dropdown options?

When I created my combo, everything worked and looked fine. When I took my module and placed it on the corporate website, the text of the options (the list that shows up when you click on the down arrow) now appears larger than needed and centered (no longer left aligned).

Evidently something in the css files of the corporate website has messed up the options list in the combo box. What style is used to affect this part of the combo box?

.dhx_combo_list { - container for options list
.dhx_combo_list div { - option