@Dustin_Wang Transformations on child elements does not affect the parent it’s the other way around.
You are exactly right that %s transforms could result in element dimensions with a fraction or so called half pixel which the browser display as semi-transparent.
The problem is not from your code It’s coming from the 50% translation that Twitch applies to the wrapper of the iframe which holds your code and therefore propagates and creates dimensions with a fraction. At the moment nobody has come to explain why this 50% translation is applied in the first place. It’s a minor visual bug and my guess is that twitch devs have more important work to do but hopefully they will address this problem at some point.