TV Series demo highlights wrong season tab

[davidsgrogan]

Hi @argyleink

https://chrome.dev/carousel/horizontal/series/

Clicking Season 1 and Season 2 works fine.

But try

• Click Season 1
• scroll to the right until you get to s01e07-s01e09
• I expected header tab to still be on Season 1, because you only see Season 1 episodes. No Season 2 episodes are visible
• but the header tab has moved to Season 2!

This is Canary 137.0.7119.0 with experimental web platform features enabled.

[philipwalton]

@flackr do you think this might be a Chrome bug?

Based on my reading of this line in the spec "Since markers themselves may represent just the start of the content (e.g. headers), we consider the active marker to be the first one which we are at or beyond the scroll position of." It seems like the demo code here is correct but the Chrome behavior is wrong. Can you confirm?

For context, the demo is only defining ::scroll-marker pseudo-elements on slides matching the .season-start class.