I have just been playing with the featherlight plugin and it works really nicely except for one small glitch. On very narrow images the “next” button pushes the dimensions out and brings up a scroll bar. So the image keeps jumping around as you hover over it. I found a solution by reducing the font-size on the arrow from 80px down to 40px. It’s in featherlight.gallery.min.css - you might need to unminify the css file first.
.featherlight-next span,
.featherlight-previous span {
display: none;
position: absolute;
top: 50%;
left: 5%;
width: 82%;
text-align: center;
font-size: 40px;
line-height: 80px;
margin-top: -40px;
text-shadow: 0 0 5px #fff;
color: #fff;
font-style: normal;
font-weight: 400;
}
While I was there I also changed the background to be darker and give more contrast.
.featherlight-next:hover,
.featherlight-previous:hover {
background: rgba(0, 0, 0, 0.4);
}
Before:
After: