Libadwaita 1.5
The GNOME Project has published a release of the Libadwaita 1.5 library, which includes a set of components for user interface styling that conforms to the GNOME HIG (Human Interface Guidelines). The library includes ready-made widgets and objects for building GNOME-style applications that can adapt to any screen size. The library code is written in C and distributed under the LGPL 2.1+ license.
Major change
The major change in libadwaita 1.5 is the redesign of adaptive widgets to create dialogs that adapt to the size of the visible area. Unlike traditional dialogs, which are placed in separate windows, the new dialogs are generated client-side, rendered inside existing windows, and cannot extend beyond the parent window.