I've made a year progress bar

Although the year is starting, I made a little site that shows us the progress of the year in percentage, it's not useful, but I find it nice !

Note that I do not take into account the bisextile years, maybe coming soon !

I'm happy if I can have some tips, or feedback to improve my code !

The website : https://adscud.github.io/progryear/
The repo : https://github.com/adscud/progryear