Slide show Reponsive

Hi, I am trying to make my slideshow smaller and center it. I have set the configuration to be responsive at 70% but that didn’t worked. I also added this short code for the slideshow: [tribulant_slideshow layout=”responsive” resheight=”70″ resheighttype=”%” gallery_id=”1″]
That didn’t work either.
I also tried using CSS edit with the following code: #slideshow-wrappergallery1{
width: 70%;
}
The css works when I edit it on the website but it does not work on the CSS Edit.
Could you please help me?

https://wordpress.org/plugins/slideshow-gallery/