* Added support of nesting CSS for a capture.
* Added support of referrer policy related attributes when performing a capture.
* Reworked `capture.referrerPolicy` to provide default referrer policy, or provide dominant referrer policy by prepending "+".
* Fixed some bad referrer handling cases for downgrading requests for a capture.
* Fixed script error when `Rewrite styles` is `(Advanced) tidy` for an external or imported CSS for a headless capture.
* Fixed missing resources inside an at-rule like `layer` when `Style images` is `Save used` for a capture.
* Fixed `:root` and `:scope` CSS rules not correctly handled when `Rewrite styles` is `Tidy` for a capture.
* Fixed an issue that constructed stylesheets are not captured in Firefox.
* Fixed downloading linked files and in-depth capture of hyperlink elements in an SVG or MathML for a capture.
* Fixed broken version 3 sitemap.
* Fixed missing links in an embedded SVG or MathML for sitemap.
* Fixed misleading links of `a[download], area[download], iframe[srcdoc]` elements for sitemap.
* Miscellaneous optimization of the internal code and unit test suite.