Changing the width of the tabs in Mobile theme

Hello Experts,

In my application, I am trying to increase the width of tabs in the tab strip to make all the tabs of equal length. I am using an iPad layout with Mobile theme. By default, the width of each tab is automatically defined based on the text of the tab. In my case, I need to have fixed length for all the tabs, irrespective of their texts. I tried to add spaces in the tab text, but it didn't work.

Please advise if I can do this by using CSS code.I am attaching a screenshot of the tab strip for reference. Thanks in advance!