But, Widgets!
We started showing non-styled non-widgets because it's important
to realize that custom elements are a primitive. The idea
is not to lock users into a framework, but the opposite, to unleash
creativity.
But it's not fun to start at the bottom, so the Polymer
team is working on a nicely styled widget set to blaze the trail.
Click the drawer button in the upper-left corner.
Notes for the advanced:
The particular custom elements used here are not yet canonical,
they are just examples. A key takeaway is that the underlying
implementations are easily modified without necessarily impacting
the app itself.
For example, these layout tools use absolute positioning. Soon, we will
have superior objects that use, for example, flex-box or CSS grids. Those
improved elements can just drop in.