Hi,
First, before we talk about CSS, you have another problem to solve first:
monosnap.com/file/US3sTtZelC5PKh278VgXcA9dJtGnYG
All the modules on your sidebar have the same classes for their title.
So it's not possible at the moment to have one CSS to customize the title of one module there without affecting the others in the same position.
Each module has a module class suffix setting that you can use in order to configure different classes for different modules so that you can do such thing.
So first please try that and check the HTML of the modules with your browser to check that the classes are different for each module so that you can style them independently.
Otherwise, you might need to check with your template provider what they recommend to do.
Once you have a specific class for the cart module, you can just use such CSS:
.XXX h3{
//your CSS
}
where XXX is that specific class name. And for your CSS, you can do something like that:
stackoverflow.com/questions/735394/add-i...left-of-text-via-css