Extend border to both edges

1 hour ago, Avenue43 said:

I am trying to get the border I have added to top of related products to extend all the way to the edges.

 

site: https://marigold-aqua-rwmn.squarespace.com/

Add these code on Custom CSS panel in Website > Utilities > Website Tools > Custom CSS.

[data-section-id="652dc6ae891148306eb297de"] {
    overflow: hidden;
}
[data-section-id="652dc6ae891148306eb297de"] .products.collection-content-wrapper .ProductItem-summary {
    position: relative !important;
}
[data-section-id="652dc6ae891148306eb297de"] .products.collection-content-wrapper .ProductItem-summary:after {
    content: "";
    position: absolute;
    width: 100vw;
    height: 2px;
    background: #000;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    box-sizing: border-box;
}