You can modify the plugin CSS in the following path wp-content/plugins/contus-video-gallery/css/style.min.css, wp-content/plugins/contus-video-gallery/css/skins.min.css.
Could you show me exactly the section for title font and weight in widget (WP Video Gallery)? I think in wp-content/plugins/contus-video-gallery/css/style.min.css, because wp-content/plugins/contus-video-gallery/css/skins.min.css it’s something else.
Thanks.
Open the mentioned css file and find ‘font-family’ and change the font style. To change font weight search ‘font-weight’, for font size ‘font-size’.