revolution slider -css-unwanted elements

Hi,

I added some border to my rev slider whith this code:

#rev_slider_20_2_wrapper :before,
#rev_slider_20_2_wrapper :after,
#rev_slider_20_2 :before,
#rev_slider_20_2 :after {

position: absolute;
content: “”;
z-index: 30;

/* adjust border color here */

background-image:url(“https://futuristgames.be/wp-content/themes/futur/images/vr-patern.jpg”);

}

#rev_slider_20_2_wrapper :before {

display: inline-block;
position: absolute;
bottom:-5vw;
right: calc(50% - 0.5px);
left: calc(0.5 - 50%);
width: calc(50% - 0.5px);
height: calc(26%);

-webkit-transform: skewY(10deg);
transform: skewY(10deg);

    border-top: 2px solid #9826fb;
  }

#rev_slider_20_2_wrapper :after {

display: inline-block;
position: absolute;
bottom:-5vw;
right: calc(50% - 0.5px);
left: calc(50% - 0.5px);
width: calc(50% - 0.5px);
height: calc(26%);

-webkit-transform: skewY(-10deg);
transform: skewY(-10deg);

    border-top: 2px solid #9826fb;
  }

#rev_slider_20_2 :before {

   display: inline-block;

position: absolute;
background:#111;
top:-5vw;
right: calc(50% - 0.5px);
left: calc(0.5 - 50%);
width: calc(50% - 0.5px);
height: calc(10%);

-webkit-transform: skewY(10deg);
transform: skewY(10deg);

}

#rev_slider_20_2 :after {

display: inline-block;
position: absolute;
background:#111;
top:-5vw;
right: calc(50% - 0.5px);
left: calc(50% - 0.5px);
width: calc(50% - 0.5px);
height: calc(10%);

-webkit-transform: skewY(-10deg);
transform: skewY(-10deg);

but I got some unwanted elements border in my navigation element: arrows, bullet point …

How to do to avoid that?

Thank you very much