TopBar causes "Largest Contentful Paint" Problem

Hi, I am a fun of your theme more than 4 years.

It seems that rendering of the Kalium top bar is taking longer than necessary processing time, causing delays.

I'm not a professional so I don't know the details, but why does it take 1,200 milliseconds even though the top bar consists of simple text? If possible, I would like you to simplify the rendering.

https://idle-planet.jp/%e5%a6%82%e6%9c%88%e3%81%b2%e3%82%81%e3%81%8b/%e3%81%b2%e3%82%81%e3%81%8b%e3%81%ae%e3%83%92%e3%83%a1%e3%82%b4%e3%83%88-%e5%a6%82%e6%9c%88%e3%81%b2%e3%82%81%e3%81%8b/