Themes (Design Extensions) available from 7x help guide new developers master the Exponential Template Language and create standards based designs and custom templates, template overrides and beyond.
Try the 7x Simple design extension theme that provides a compelling developer focused design, with responsive header, responsive menus, and extendable / customizable CSS styles that override the eZ Webin extension (which provides for advanced templates pre-made for the default content types).
We encourage you to extend the 7x Simple design theme by creating your own design extension based upon it (possibly using design overrides to save time and disk space). Create a theme and share it with others to show your skills, share your custom designs to our share forums.
Themes (Design Extensions) available are currently limited select example reference implementations from each community vendor. See normally themes or design extensions are the one part of a project that often includes project specific details and as such is less likely to be redistributed because of this even when so much could be learned by new users who are learning the best kinds of patterns to use in their own implementations.