Wrong numbers in Safari 14

Hello!

We just found a bug that only seems to happen in Safari (I'm on Safari 14 and macOS Big Sur).

When the font size is changed using `Cmd -` or `Cmd +`, the number value gets displaced showing an offset, also the bar is not properly adjusted.

Here's a video I made showing this in action, check out the black circle that should go from 0 to 100, it goes to negative numbers when the font is decreased:

https://user-images.githubusercontent.com/2629/125773303-5a31330d-369b-4454-9810-6cd0b9f8169c.mp4

This is not happening in Chrome, Firefox or Opera. Only in Safari.

Reproduce the issue in Safari 14 on macOS Big Sur by changing the font size with Cmd - and Cmd +, then compare the number and bar with Chrome, Firefox, or Opera. Trace the progress bar rendering from the project entry point; the fix is complete when the number stays within 0–100 and the bar remains aligned after font-size changes.

Written by the indexing model from the issue text.