CSS Variable timing issue

[katemenkhaus]

Description

When theming iron-doc-viewer there seems to be a timing issue of when the css variables are being loaded. In order for the css variables to be styled in chrome the link import has to be before the custom styles.

Expected outcome

If the link import of iron-doc-viewer is after the custom styles the custom styles should still be applied.

Live Demo

https://menkhaus-ge.github.io/css-variable-test/index_styled.html
https://menkhaus-ge.github.io/css-variable-test/index_notStyled.html
https://github.com/Menkhaus-ge/css-variable-test

Browsers Affected

• Canary
• Chrome
• Firefox
• Safari 9
• Edge
• IE 11

[katemenkhaus]

seems to be the same issue here PolymerElements/paper-styles#93