Hide caption/title only mouseover

For small devices I want to hide the image text (caption) completley and make it only show at mouseover.

I found this snippet for the flex-slider that works perfect if added in child-theme css

.metaslider-flex li .caption {
    display: none;
}
.metaslider-flex li:hover .caption {
    display: block;
}

Does anyone have the similar code that works for the Nivo-slider? I cant figure it out since it seems to be diffrent coded.

Can I request the hiding/unhiding for only mouseover be a feature for each slide setting in next versions plz?

https://ww.wp.xz.cn/plugins/ml-slider/