center on vertical .item-pagination responsive

Site URL: https://briancullenfurniture.squarespace.com/lighting/wallsconce

I would like to know how I can keep the ".item-pagination" navigation arrows centered vertically

pass: BCF-light230522

Thanks

Vertically on page or slideshow?

Hi Tuan, slideshow

someone who can help?

Allso, i need it to always be aligned with the width of the line 

I also have a problem when I move the image further to the right and it shows a gray bar on the right side.

/* Item pagination  prev next */
@media screen and (min-width:900px) {#page .item-pagination--prev-next{
 width:1224px;
 margin-left:165px;
 padding-right:65px;
 margin-right:217px;
 padding-left:89px;
}
}