{"action":"opened","issue":{"url":"https://api.github.com/repos/Polymer/docs/issues/865","labels_url":"https://api.github.com/repos/Polymer/docs/issues/865/labels{/name}","comments_url":"https://api.github.com/repos/Polymer/docs/issues/865/comments","events_url":"https://api.github.com/repos/Polymer/docs/issues/865/events","html_url":"https://github.com/Polymer/docs/issues/865","id":53787055,"number":865,"title":"Styling reference: should mention shim-shadowdom per implications for main page styles","user":{"login":"ebidel","id":238208,"avatar_url":"https://avatars.githubusercontent.com/u/238208?v=3","gravatar_id":"","url":"https://api.github.com/users/ebidel","html_url":"https://github.com/ebidel","followers_url":"https://api.github.com/users/ebidel/followers","following_url":"https://api.github.com/users/ebidel/following{/other_user}","gists_url":"https://api.github.com/users/ebidel/gists{/gist_id}","starred_url":"https://api.github.com/users/ebidel/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ebidel/subscriptions","organizations_url":"https://api.github.com/users/ebidel/orgs","repos_url":"https://api.github.com/users/ebidel/repos","events_url":"https://api.github.com/users/ebidel/events{/privacy}","received_events_url":"https://api.github.com/users/ebidel/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-01-08T19:01:11Z","updated_at":"2015-01-08T19:01:11Z","closed_at":null,"body":"If users put `shim-shadowdom` on their main page stylesheet, this can be a source of perf hit. Especially if the stylesheet is large. One optimization is to separate out SD rules from the bulk of the page css and throw it in another file that does use `shim-shadowdom`."}}