I can't get :last-child to work for the last element inside a dom-repeat...
I think it's because the template itself becomes the last-child...

You could just try :nth-last-child(2) instead of :last-child
Or :last-of-type.
Thanks for the workarounds. I was trying to turn off border-bottom on the last child... I swapped border-bottom for border-top and last-child for first-child.
Still seems like the last-child selector should work.
I'll close the issue if the polymer team doesn't consider it a bug. Perhaps it's in the docs somewhere?
:last-child won't work because the last child is the dom-repeat template.
+1 @miztroh, it shouldn't work this way, <template> is really last child, nothing wrong here.
Yes, :last-child refers to the element that is the last child of it's parent element, so <template is="dom-repeat"> would be the last child. https://developer.mozilla.org/en-US/docs/Web/CSS/%3Alast-child
You can user this:
Most helpful comment
Or
:last-of-type.