Caption under gallery image without affecting image size

I’m trying to get the image caption to sit below the image and found this CSS code, however the relative position keeps changing the size of the image but without it the caption is in the wrong place on some of the pages. Please help!

.wp-block-gallery .blocks-gallery-item figure {
    flex-direction: column;
}

.wp-block-gallery .blocks-gallery-item figcaption {
    position: relative;
    bottom: auto-flow;
    width: 100%;
    max-height: 100%;
    overflow: auto;
    padding: 10px 0 20px 0;
    color: #484848;
    text-align: justify;
    font-size: 15px;
    background: linear-gradient(0deg,rgba(0,0,0,0),rgba(0,0,0,0) 0%,transparent);
}

Also any idea how to disable CSS for a particular page?

The page I need help with: [log in to see the link]