@eri "em" is relative to the current font size, so things like nesting can unexpectedly result in sizes scaling up. that's the only thing i can think of https://jsfiddle.net/vso9wnxr/1/
(did you fix this problem already? i don't see it on your site)
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.