This release switches our CSS selector engine from nwsapi to @asamuzakjp/dom-selector. The new engine is more actively maintained, and supports many new selectors: see the package's documentation for the full list. It also works better with shadow trees.
There is a potential of a performance regression due to this change. In our stress test benchmark, which runs most of these 273 selectors against this 128 KiB document, the new engine completes the benchmark only 0.25x as fast. However, we're hopeful that in more moderate usage this will not be a significant issue. Any help speeding up @asamuzakjp/dom-selector is appreciated, and feel free to open an issue if this has had a significant impact on your project.