Your example gets stuck at building for some reason, have tried to open it but haven't been able to. However, based on the description, I believe the problem is because you're putting the border on the tr element.

We apply sticky styles directly to td and th elements. This is for two main reasons:

1. Some browsers currently have a bug where you cannot apply sticky to thead, tbody, or tr elements directly. To get around this, we apply the styles to the individual cells.

2. We must apply sticky positioning to cells for fixed columns, since they are fixed both from the bottom and the left/right. Applying the positioning to cells unilaterally instead of mixing/matching sticky positioning on cells, rows, headers and footers makes things much easier for us in the code.

This means that you'll have to apply the styles directly to cells for them to work, unfortunately 😕 This could change in the future as the browsers fix their sticky implementations, but as of now I wouldn't count on it.

We should cover this in the "styling the table" section in the docs.