Carousal and Slideshow adjustments to size/arrows

Site URL: https://www.cedarbuiltgreenhouses.com/arrow-test-page

Hello anyone or TuanPhan (hopefully 🙂 ),

Having some issues with these gallery options. Need a bit of code to fix 

Carousal: Need darker grey backdrop behind white arrows

Slideshow: Can’t see thumbnails as the top photo is too large. Tried adding spacers as above but it didn’t work. Can I reduce the height of the image on top of the slideshow so that the thumbnails are more accessible? (Also would like the darker grey backdrop behind white arrows on this too )

Q1. Add to Design > Custom CSS

/* carousel arrows darker */
.sqs-gallery-controls .previous, .sqs-gallery-controls .next {
    background-color: rgba(0,0,0,0.75) !important;
}

Q2. Add to Design > Custom CSS

/* Gallery size */
div#block-yui_3_17_2_1_1619114881682_7992 {
    width: 70%;
    margin: 0 auto;
}