Hello,  I understand that these features are mostly aesthetic but I think there's some neat things that can be accomplished for those of us looking to push character sheets further.  Right now we have the availability for animating properties in CSS but the roll20 sandbox is adding extensions that frankly restrict its usability.  As a discussion about them revealed The script parses the CSS and adds ".charsheet " before any content that comes after a "}" so this @keyframes mymove {0%{top: 0px;}100%{top: 100px;}} turns into this @keyframes mymove {0%{top: 0px;}.charsheet 100%{top: 100px;}.charsheet } This seems a bug and if fixed would allow us to make full use of animation besides cheating it to allow single-state animations.  As for allowing <video> tags, this is more a push to incorporate the superior .webm files into charactersheets. GIFs are frankly on their way out as a serious video file with their limited alpha channels, palette, and poorer compression. A webm file is a quarter the size of a gif without those same limitations and has broad browser support.