We have a brand to replace our old Options page (we’ll automatically redirect folks from the old page). This new page delves into the structure of our Sass files, default variables and customizing them, maps and loops we use, functions, colors, and of course or global Sass options. It also includes a new section to explain how we build our components via Sass maps and loops, specifically our modifier classes (e.g., .btn-danger).. Just over two months ago we shipped our first beta for Bootstrap 4, and now we’re ready to share our second with you. We’ve improved customization, documentation, build tooling, and naming inconsistencies all while fixing hella bugs.. Two years in the making, we finally have our first beta release of Bootstrap 4. In that time, we’ve broken all the things at least twenty-seven times over with nearly 5,000 commits, 650+ files changed, 67,000 lines added, and 82,000 lines deleted..