How can I make CSS level changes on my website?

[ZenoPageBuilder]

Hello @mystore123d

In Shopify Admin, you can go to Edit theme code, open file base.css and add this code at the bottom

.review-detail-wrapper {
    background-color: #F1EFE7 !important;
}

.review-detail-body::after {
    display: none !important;
}

The result

Hope that helps!