On "Override Global Settings" for a specific slide... There

On "Override Global Settings" for a specific slide...

There is no way to control the CSS from within the interface

Secondly, I have a website where I want the Slide-In to come in above the menu. The Menu is Set to Z-Index of 100 to work properly with the site.

.art-nav
{
background: #282A22;
background: linear-gradient(top, #131410 0, #414436 100%) no-repeat;
background: -webkit-linear-gradient(top, #131410 0, #414436 100%) no-repeat;
background: -moz-linear-gradient(top, #131410 0, #414436 100%) no-repeat;
background: -o-linear-gradient(top, #131410 0, #414436 100%) no-repeat;
background: -ms-linear-gradient(top, #131410 0, #414436 100%) no-repeat;
background: linear-gradient(top, #131410 0, #414436 100%) no-repeat;
-svg-background: linear-gradient(top, #131410 0, #414436 100%) no-repeat;
border-top:3px solid #282A22;
padding:5px 5px 0;
margin:0 auto;
position: relative;
z-index: 100;
font-size: 0;
}

But I cannot seem to change the Z-Index of the Slide-In.... No matter what I set it to in the CSS:

.wdsi-slide {
position: fixed;
/*top: -1000000000;*/
left: 0;
width: 100%;
visibility: hidden;
-webkit-transition: all 1s;
-moz-transition: all 1s;
-ms-transition: all 1s;
-o-transition: all 1s;
transition: all 1s;
z-index: 999999;

The Slide still moves in behind the menu...

Please help me make the Slide show up above the Menu...