file difference page is covered by a full page black shadow

Hi,

Wordfence detected changes in files in a plugin. When I click on “See how the file has changed” it opens a new tab, where the two versions of the file are compared, the page is very very dark and hard to read. screenshot

Looks like the dark colour is caused by CSS in file:
/?_wfsf=diff&nonce=36ed2af332&file=wp-content%2Fplugins%2Fphoto-gallery%2Fjs%2Fbwg_gallery_box.js&cType=plugin&cKey=photo-gallery%2Fphoto-gallery.php&cName=Photo%20Gallery&cVersion=1.2.82

body {
font-family: ‘Signika Negative’,sans-serif;
font-size: 16px;
background-color: #333;
}

https://wordpress.org/plugins/wordfence/