Support inline css / Polymer style modules

[w-p]

Feature Request.

Currently, processing the example below produces an error styles.html:17:1: missing '{'. Stripping the tags, of course, solves the immediate problem. Additionally, the :root block is removed entirely without error or notice.

Polymer style modules are declared within tags. Myth doesn't like tags. Polymer handles var, calc and other such declarations but does not handle prefixes. Support for Polymer style modules in myth would be awesome.

<dom-module id='my-styles'>
    <template>
    <style>
    :root {
        --green:    seagreen;
        --red:      darkred;
    }
    div, span {
        display: flex;
        width: calc(100% / 2);
        background-color: var(--green);
    }
    </style>
    </template>
</dom-module>