3.9.6

* Fix invisible icons on desktop notifications and the startup page (regression on 3.9.4)
* Use more visible color for scrollbar thumb on some theme including "Dark".
* Add a new expert choice for new child tab from existing tab: simulating Firefox's default behavior `browser.tabs.insertRelatedAfterCurrent`=`true`.
* Fixup tree structure correctly when a new tab is inserted middle of a tree by `browser.tabs.insertAfterCurrent`=`true`.
* Update the title of a group tab more certainly.
* Clear wrongly memorized "Ctrl key is pressed down" state after tab open/close to avoid unstable behavior after some operations.
* Introduce new placeholders for bookmark folder name to bookmark multiple tabs.
  * `%GROUP%`: the title of the parent tab if it is a group tab, otherwise blank.
  * `%HOURS%`: hours of the time in two digits.
  * `%MINUTES%`: minutes of the time in two digits.
  * `%SECONDS%`: seconds of the time in two digits.
  * `%MILLISECONDS%`: milliseconds of the time in three digits.
  * `%ANY(value1, value2, ...)%`: the first effective value in the given list.
* Allow to pin group tabs.
  * It will leave an alias group tab at its original position.
  * Drag-and-drop onto pinned group tab is treated as the action on the alias group tab.
* API: add a new notification message type [`try-handle-newtab`](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#suppress-handling-of-new-tabs-by-tst) to allow helper addons to override TST's behavior of opened tab handling.

3.9.5

Update `de` locale by [SammysHP](https://github.com/SammysHP). Thanks!

3.9.3

* Use the name of the parent "group tab" as the default folder name for the "Bookmark This Tree" command, if possible.
* Detect tabs as opened from bookmarks correctly on Firefox 105 and later.
* Never load pending tabs after they are moved across windows more certainly.
* Update `ru` locale by [wvxwxvw](https://github.com/wvxwxvw). Thanks!

3.9.2

* Fix hanging after a tree is moved across windows via drag and drop. (regression on 3.9.0)
* Keep tabs shifted when the mouse cursor moves onto the scrollbar.
* Becomes more safe for invalid value of distance to shift tabs for auto-shown scrollbar.

3.9.1

* Fix incompatibility with user styles including `@media` and pseudo elements.
* Expose options for experts: shifting of tabs avoiding covered by the auto-shown scrollbar.
* Shift tabs to avoid auto-shown scrollbar, only on hover around the scrollbar by default.

3.9.0

* Windows for tabs detached from an existing window inherits the size and state ("maximized" or "fullscreen") from the source window like Firefox does.
* Reduce some edge case problems (like infinite loop, stop working, and so on) around re-layouting and synchronization of the sidebar contents.
* Update indent level and parent information correctly for descendant tabs orphaned by tab detaching via any operation ouside of TST.
* Imitate tab focus behavior about Firefox's `browser.tabs.insertRelatedAfterCurrent` and `browser.tabs.selectOwnerOnClose` more correctly.
* Never load pending tabs after they are moved across windows.
* Fix unexpected fail of drag-and-drop of selected multiple trees after drag-and-drop across windows.
* Open `about:reader` URL bookmarks with their original URL (because addons cannot open `about:reader` URLs.)
* Always expose the "Manage Devices..." item under the "Send Tree to Device" menu [in the tab context menu, if it is running on Fennec](https://github.com/piroor/treestyletab/issues/3174).
* Brush up wording of "other tabs" in Japanese locale.
* Reset configs more safely with the "Reset" in the options page.
* Change the method to keep space to show auto-hidden scrollbar: using `margin` instead of `padding` in `tab-item-substance`.
* Never change coloring of auto-hidden scroll bar.
* Reintroduce support for `@import` rule in user styles.
* Totally reconstruct [API to insert extra contents to TST's sidebar area](https://github.com/piroor/treestyletab/wiki/Extra-Tab-Contents-API). Now we can insert arbitrary UI element above/below all tabs, and track events about keyboard input and focus.
* Respond to a [`get-tree`](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#get-tree-information) request more certainly even if it is requested with a `Tab.id` and from a `tabs.onCreated` listener.
* Add a new log module `sidebar/tst-api-frontend`.
* Update `zh_CN` locale by [NightSharp](https://github.com/NightSharp). Thanks!

3.8.26

* Make some user styles written for old versions of TST effective. See [the related issue](https://github.com/piroor/treestyletab/issues/3153) also for more details.
* Prevent zoom-in/out by pinch-in/out on macOS.
* Add a secret option `enableWorkaroundForBug1763420_reloadMaskImage` for an ability to deactivate a workaround for the [missing icons problem](https://github.com/piroor/treestyletab/issues/3142).
* Update `ru` locale by [wvxwxvw](https://github.com/wvxwxvw). Thanks!

3.8.25

* Restructure options about new tabs behavior to make more understandable.
* Introduce workaround for [missing icons problem](https://github.com/piroor/treestyletab/issues/3142).
* Add special favicons for blocked pages.
* Update `fr` locale by [tbertels](https://github.com/tbertels). Thanks!

3.8.24

* Shift twisties in tabs to avoid covered by the scrollbar, on macOS, Linux and Windows 11.
* Keep label of group tabs correctly after they are moved.
* Send `tab-mouseover` and other notifications to helper addons correctly after the sidebar is reopened.
* Better auto-sizing of the dialog for confirmation on grouping of tabs.
* Deactivate a workaround of problems around wrong coordinates of `dragend` events on Firefox 99 and 100 (the [bug 1767165](https://bugzilla.mozilla.org/show_bug.cgi?id=1767165)) on other versions.
* API improvement: Add a new notification message type [`new-tab-processed`](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#when-the-tst-finishes-its-handling-for-a-newly-opened-tab) to handle new independent tabs.

3.8.23

Introduce a workaround of problems around wrong coordinates of `dragend` events on Firefox 99 and later (the [bug 1767165](https://bugzilla.mozilla.org/show_bug.cgi?id=1767165)). It reduces unexpected detaching of tabs especially on a rightside placed sidebar. This workaround can be disabled by unchecking `enableWorkaroundForBug1767165_fixDragEndCoordinates` via TST Options - "Development" - "All Configs".