Hello,
Add this code to the Theme Settings > Custom CSS > Global:
.sidebar-container .promo-banner-wrapper {
position: relative;
}
.sidebar-container .promo-banner-wrapper:after,
.sidebar-container .promo-banner-wrapper:before {
content: "";
position: absolute;
-webkit-box-shadow: 0 15px 10px rgba(0,0,0,.6);
box-shadow: 0 15px 10px rgba(0,0,0,.6);
left: 5px;
right: 50%;
bottom: 8px;
height: 30%;
border-radius: inherit;
-webkit-transform-origin: 0 0;
-moz-transform-origin: 0 0;
-ms-transform-origin: 0 0;
transform-origin: 0 0;
-webkit-transform: skewY(-6deg);
-ms-transform: skewY(-6deg);
transform: skewY(-6deg);
}
.sidebar-container .promo-banner-wrapper:after {
left: 50%;
right: 5px;
-webkit-transform: skewY(6deg);
-ms-transform: skewY(6deg);
transform: skewY(6deg);
-webkit-transform-origin: 100% 0;
-moz-transform-origin: 100% 0;
-ms-transform-origin: 100% 0;
transform-origin: 100% 0;
}
.sidebar-container .promo-banner {
z-index: 1;
}
Best Regards