A SharePoint Framework (SPFx) Application Customizer that applies a responsive 3-column grid layout to SharePoint Modern pages. Provides a Fluent-styled floating toolbar and modal panel for live column-width configuration, persisted via localStorage.
Open this sample in the gallery (popup panel): Open in gallery
Source: https://github.com/pnp/sp-dev-fx-extensions/tree/main/samples/js-application-layout-customizer