I was all excited over Polymer and starting developing a web app. I soon found out that Firefox fails loading the site correctly, see this SO post for details:
Polymer: Layout screwed up in Firefox, fine in Chrome
Then, I downloaded the latest version of Chrome on an iPhone 4 (iOS7) and the same thing for iPhone 6 (iOS8) and tried the website. I see the same errors as I see on Firefox (please see the link above).
In other words - going to my Polymer based website using Chrome for iOS fails just as bad as Firefox fails.
As I also noted in my other SO question linked above, I was expecting it to work in all browser due to "polyfill", but that doesn't seem to help.
Am I missing something?
Note: Using Chrome for Android works fine, no errors there.
As I mentioned in the other thread, it's impossible to polyfill CSS scoping. Chrome on iOS is not actually Chrome, it's built using the iOS WebView (an old one at that), meaning there's no native Shadow DOM and no CSS scoping. The Shadow DOM polyfill does properly wrap DOM API methods like querySelector and getElementById, so you do get limited encapsulation, in that respect. But for CSS, the only thing the polyfill can do is rename your selectors, so :host .blah gets renamed to x-foo .blah and appended to a style tag in the head. It means you need to still write defensive CSS (as you do today) and avoid very loose selectors because they will be applied.