/ makes the display image clickable to zoom
    // makes the modal clickable to un-zoom

    // restricting the max height of image to the definition box
    // TODO this one line of code seems to reflow the document, causing noticeable delay in the js
    // https://stackoverflow.com/questions/45960181/what-is-the-fastest-way-to-get-height-width-of-unstyled-element-in-javascript
    // https://stackoverflow.com/questions/19815810/avoiding-html-document-reflows/19816067#19816067

    // this appears to be t