Hi Arthur,
It looks like to me that you want the tabs to take up the entire area. I don't know this template, but they probably expand to accomodated the length of the text.
When you change the text does the size of the gap change? If it does you're going to have to change the css to expand the tabs to widths that will fill the spaces exactly.
Everything that controls this is in menu.css.
You could fix this by creating a module suffix for the menu module with custom css that will override the menu.css Or if you know how, a template override.
docs.joomla.org/How_to_override_the_outp...rom_the_Joomla!_core
I don't understand the white padding you want to remove, because the padding is transparent. But if you want to remove the lines between the buttons you would remove the background image from here.
.menu-dropdown li.level1 {
background: url("../images/menu_dropdown_level1.png") no-repeat scroll 100% 0 transparent;
padding: 0 2px 3px 0;
}
You would need to rewrite the li definitions in the menu.css to change the way that menu displays.
Cheers,
Ed
PS. Just for clarification, if you're using firebug and you find the css file has a weird name like this one
www.yootheme.com/demo/themes/joomla/2012...emplate-3b8030c2.css It's because it is in a compiled (cached) directory and isn't the real style sheet you need to change.
