In Drupal 7, I used contrib base themes like Bootstrap, Omega, or Zen as a starting point for most of the themes I created. Primarily, themers use base themes to improve accessibility, get more semantic markup, make responsive websites, and save time. The Drupal 8 theme system provides more accessible, semantic markup in core and is responsive out-of-the-box. It's the perfect time to try theming without a contrib base theme. If you're deciding how to structure your first Drupal 8 theme and which base theme to use, this is the talk for you. The talk will include: Overview of Drupal 8 core themes Tips for building a responsive theme from scratch Adding a grid system Responsive navigation Structuring CSS or SASS