If you look at the console you’ll see an error like this:
Uncaught SecurityError: Failed to set the ‘cssText’ property on ‘CSSStyleDeclaration’: Refused to evaluate a string as CSS because ‘unsafe-eval’ is not an allowed source of style in the following Content Security Policy directive: “style-src ‘self’ ‘unsafe-inline’”.
This seems to be caused by Chrome’s experimental implementation of CSP 1.1. If you’ve enabled “Enable experimental Web Platform features” in chrome://flags, then that’s why this is happening to you.
The solution is simply to disable that flag.