Previously, we recommended that a <style> element should be placed inside an element’s <dom-module> but outside of its template. This is still supported, but we’ve now optimized placing styles within the template itself, so having the <style> tag outside of the template will be slower. We will be updating all of the elements provided by the Polymer team to match this new recommended behavior as well.
robdodson
commented
9 years ago
https://blog.polymer-project.org/announcements/2015/08/13/1.1-release/
Previously, we recommended that a
<style>element should be placed inside an element’s<dom-module>but outside of its template. This is still supported, but we’ve now optimized placing styles within the template itself, so having the<style>tag outside of the template will be slower. We will be updating all of the elements provided by the Polymer team to match this new recommended behavior as well.