The Sidebar Collapses icon shows a rounded rectangular sidebar split into a light main panel and a dark vertical section, with a rounded right-pointing wedge inside. Drawn in the flat style on a 48px grid, its chunky rounded forms support a friendly illustrative look at larger sizes. Use it for collapsible sidebars, navigation toggles, dashboard layouts, and responsive interface controls. It belongs to Plump Flat set in the Plump family.