3.8.12

* Update scrollability status of the tab bar even if there are some "hidden via WebExtensions API, but visible by CSS hack" tabs.
* Reduce (deactivate) mis-detection of the sidebar position on some unstable cases: leftside non-primary and high-dpi screen.
* Use an info icon same to the one in the Proton theme of Firefox itself, for network error pages.
* Suppress unexpected expansion after a parent tab lost its focus, while tab swhiching via Ctrl-Tab.
* Open the options page when some drag-and-drop options are chosen in the shorthand menu on the toolbar icon.
* Reload the sidebar automatically for unexpected fatal error while its initialization, to reduce failing of sidebar initialization.
* Update `ru` locale by [wvxwxvw](https://github.com/wvxwxvw). Thanks!
* Update `ko` locale by [OctopusET](https://github.com/OctopusET). Thanks!
* Update `zh_CN` locale by [NightSharp](https://github.com/NightSharp). Thanks!

3.8.11

Never show unexpected confirmation about "Right Side" appearance for the sidebar panel shown at the left side.

3.8.10

Show a confirmation to apply "Right Side" appearance for the sidebar panel shown at the right side when it is initially detected.

3.8.9

* Apply appearance matching to sidebar position (left or right) automatically by default. After you switch the siderbar position, you need to reopen TST's sidebar panel to apply  matching apperance.
* Introduce an expert option to allow detach dragged tab from the window even if it is dropped near the sidebar, for people using `privacy.resistFingerprinting`=`true`.
* Better tree restoration on browser startup, if the delay to detect duplicated tabs is configured for recent versions of Firefox.
* Better compatibility with addons which reopen the initial tab of a new window immediately (e.g. Temporary Containers).
* Import and export all configs more safely with sanitization of device specific config keys.
* API improvement: introduce new notifications [`tabbar-overflow` and `tabbar-underflow`](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#when-the-tab-bar-becomes-scrollable-or-unscrollable).
* API improvement: [`scrolled` notification](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#messages-notified-by-mouse-wheel-rotation) now provides new property `overflow` indicating overflow state of the tab bar.
* Update `ru` locale by [wvxwxvw](https://github.com/wvxwxvw). Thanks!

3.8.8

* Clear indentation of left tabs correctly after multiple ancestors are closed at a time.
* Allow to drop Firefox's native tabs to TST's sidebar. (regression on recent versions)
* Give static `aria-label` for in-tab button elements. This change should improve compatibility with some voice recognition systems including Dragon.

3.8.7

* Fix odd appearance of the Photon theme. (regression on 3.8.5)
* Calculate total height of visible tabs more safely.

3.8.6

Fix visual corruption on very old versions of Firefox. (regression on  3.8.5)

3.8.5

* Breaking change around DOM structure of tabs:
  * Each tab now has `tab-item-substance` as a mid-level container between `tab-item` and tab content elements like `tab-favicon`.
    If you use any custom user styles, [`>` (child combinator)](https://developer.mozilla.org/en-US/docs/Web/CSS/Child_combinator) after `tab-item` in selectors need to be removed.
* Open bookmarks including `about:newtab` correctly.
* Init list of external addons for permissions correctly.
* Reduce annoying errors in the error console.
* API improvement: introduce a new place `indent` [to insert extra tab contents](https://github.com/piroor/treestyletab/wiki/Extra-Tab-Contents-API#how-to-insert-extra-contents-to-tabs).
* API improvement: introduce [`parent`, `parent-of-<id>`, `root` and `root-of-<id>` keywords to get tabs based on tree structures](https://github.com/piroor/treestyletab/wiki/API-for-other-addons#basics-to-specify-tabs).

3.8.4

* Update overflow state of tabs more correctly to avoid unexpected covering of the bottom most tab with the new tab button.
* Update visibility of tab context menu items correctly even if it the initial run.
* Restore tree structure more correctly for tabs reopened via Shift-Ctrl-T after closing of multiple tabs at a time.
* Allow to override size of pinned tabs area (`--pinned-tabs-area-size`), subpanel area (`--subpanel-area-size`), and new tab button area (`--after-tabs-area-size`) easily by overriding these variables with custom user style.
* Rescue errors of options UI initialization, and reveal options UI even if some options don't work.
* Don't close the new tab button long-press menu on mouseup. (regression on 3.8.2)
* Restore lost compatibility with user styles containing `--multiselected-color`. (regression on 3.8.2)

3.8.3

* Recontstruct "Proton" theme for better compatibility with Firefox's themes, dark mode of the platform, and GTK theme.
* Avoid needless 1sec delay of confirmation dialogs.
* Update `ru` locale by [wvxwxvw](https://github.com/wvxwxvw). Thanks!