Signal Dark uses CSS Grid for page-level layout and Flexbox for component-level alignment. The main content area supports three configurations: full-width, content with right sidebar, or content with left sidebar. Assign a module to sidebar-right or sidebar-left and the template creates the grid automatically — no layout parameter to toggle.
The grid collapses gracefully. At tablet width the sidebar stacks below the content. At mobile width the dual-tier navigation condenses into a hamburger menu, cards switch from multi-column to single-column, and tables become scrollable. Every breakpoint is handled in CSS — no JavaScript layout switching, no hidden duplicate markup.