Working with the Classic Editor:

Two editors in Squarespace — Fluid Engine (current drag-and-drop grid system) and Classic Editor (older inline system)
Classic Editor is still used for — Event pages and Blog pages; most other pages use Fluid Engine
How to spot Classic Editor — horizontal line system with plus marks appears instead of the "add a section" interface
Classic Editor works inline — blocks stack in a line rather than dragging freely; use spacers to create gaps between elements like side-by-side images
Classic Editor can also be added as a section within a Fluid Engine page via Add Section — useful when you need very precise, rigid spacing
Fluid Engine is more flexible but Classic Editor can sometimes hold layouts more consistently in place
Upgrading — if you build something in Classic Editor, Squarespace offers an upgrade button to convert it to Fluid Engine at any time
Most of the tutorial library focuses on Fluid Engine, but good to know Classic Editor exists for edge cases

Working in Classic Editor