Fullscreen Slider : Captions with 3 buttons in a row?

Hello,

I´d like to place 3 buttons in a row (one button next to each other)
inside a caption of the fullscreen slider.

Since I need 3 or more buttons, and since I´d like to have more options designing them,
I tried to put button shortcodes inside the caption text box, rather than using the default “add buttons” option.
It works so far, but I got two issues:

1. I can´t place the buttons in one line.
The solution I found in another thread was modifying the css like this:
.avia-button-center {
display: inline;
padding: 0 5px;
}
This works well on a normal content page, but it does not work with captions.

2. The text in the buttons gets underlined, when used in the captions. This is not the case when using them on a normal page either.

Any hint would be greatly appreciated!
Btw.: The site is still offline, so I cannot give you any link now.

Best regards & thanks in advance!