Yes.
> How many times you struggled with mingled CSS ?
Not enough times that I'd get blood pressure issues over it.
> I bet first one is far more common and costly task.
You lost your bet. Which was idiotic, I wouldn't argue web layouting to be a bigger issue if I didn't find it to be.
It seems your comment regarding ShadowDOM not helping layouting issues is not entirely true.
Take a look on:
polymer-grid-layout polymer-flex-layout polymer-layout
http://www.polymer-project.org/docs/elements/polymer-element...
Yes.
> How many times you struggled with mingled CSS ?
Not enough times that I'd get blood pressure issues over it.
> I bet first one is far more common and costly task.
You lost your bet. Which was idiotic, I wouldn't argue web layouting to be a bigger issue if I didn't find it to be.