Custom card can't define property "px"

Hi hassio’s,

I’ve been stuck for two days trying to solve my problem with the custom day-countdown card, which i really want to be using in my lovelace I add the files to the www folder and re-direct to it via manage resources: /local/day-countdown.js

While adding the card to lovelace i get the following error? I can’t find anything via Google if someone else had the same issue with maybe a different card.

As soon as i think i have HomeAssistant figured out, i get into these problems, meh
All help is appreciated! Thanks

Did you read the README?

I did, yes