The core-style demo currently looks different in IE11 compared to Chrome/Firefox. The numbers in the cards have different colors assigned in IE11. Shouldn't the result be equal in all supported browsers?

Having a detailed research I ended up here:
Polymer/polymer#1052 (comment)

I am understanding it right: Core-style simply shares bits of CSS across elements?

If this is so I can use something like SASS or LESS, right? And simply share a partial or variables across my elements styling?

May be I can ask the question in this way: is core-style intended for the developers that want or are forced to use vanilla CSS for styling?

I cant think of a scenario where a preprocessor like SASS would't fit a use-case that core-style does.

Simpler core-style

view-source:https://www.polymer-project.org/components/core-style/demo.html
view-source:https://www.polymer-project.org/components/core-style/my-theme.html
view-source:https://www.polymer-project.org/components/core-style/elements.html

Would be less confusing if elements.html used inline <style> tags and my-theme.html <core-style>

Using multiple core-styles with the same id can't be good considering vulcanizing etc.

2x <core-style id="my-toolbar">
2x <core-style id="my-panel">

The idea is to allow local customization of the variables in producers.

An example use case would be:

1. adding a paper input on an blue toolbar
2. I'd like to make it's colors white so they look ok on the blue background
3. all while keeping the global paper-inputs colors unaltered.

Since there are already customization vars in the producer, I'd prefer not to write a ton of CSS all over again, but to reuse the existing producer with new, local, variables.

Sample API:

<!-- global params -->
<script>
  CoreStyle.g.myColor = red;
</script>

<!-- parameterized producer -->
<core-style id="myProducer">
  selector {
    color: {{g.myColor}}; /* default to CoreStyle.params.myColor */
  }
</core-style>

<!-- refined producer -->
<core-style refines="myProducer" select=".css-selector">
  g.myColor = red; // local parameter just for this instance
</core-style>

The select=".css-selector" could be used to target a subset of elements that have a paired consumer, so it can be applied selectively.

If the select attribute would be missing the refinement would apply globally.

Hi there.

I read the core-style docs and saw the following sentence:

It kind of looked like that the period shouldn't be there and that this sentence really wants to say: "Using core-style in HTML Imports is currently not supported.".

Since I think that using core-style inside HTML Imports is the actual win, I wanted to open an issue and ask what the status of this thing is.

But when we look at the source file where the actual documentation is written, we see this: https://github.com/Polymer/core-style/blob/master/core-style.html#L20-L22

So it seems that core-component-page breaks that paragraph (and using core-style in HTML Imports is supported). I haven't looked at the exact issue yet, but I have a feeling that it has something to do with the @import in the sentence.

The core-style consumers are added in global refMap but are never removed.
Looks like a function to undo registerRef() is missing in detached

unregisterRef: function() {
    var idx = this.refMap[this.ref].indexOf(this);
    if(idx >= 0)
        this.refMap[this.ref].splice(idx, 1);
}

This is an issue because this prevents all the template instances of elements using core-style from being deallocated.

Since updating to 0.5.1, I'm getting the error "WebComponents is not defined", coming from core-style.html on line 268. It seems to work in Chrome, the error only appears in Firefox. What might cause this?

https://github.com/Polymer/core-style/blob/master/core-style.html#L268

It would be pretty neat if core-style could, instead of embedding a string of CSS within the core-style tag, include 1 or many link rel stylesheets that point to actual CSS files.

Looks like any space outside the parenthesis is converted to  

  <core-style id="main">
    body {background-color:#000000;}
  </core-style>

It's working fine on FF and Safari, but not on Chrome.
Here is the generated result:

<core-style id="main" hidden="">
"body&nbsp;{background-color:#000000;}"
</core-style>

ex.

<style is="core-style" type="polymer/style">
    .span::before { content: "<script>alert(1)</script>"; }
</style>

Using today to do that will alert since it just has random HTML inside it which is both slower for the parser, and will interpret stuff inside it as tags. Instead it should work as above.

See dart-archive/core-elements#122