diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 5908513..b5fe956 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -4054,6 +4054,13 @@
   .tabbrowser-tab[selected="true"] {
     -moz-window-dragging: drag;
     --tab-max-width: 100%;
+    width: var(--tab-max-width) !important;
+    margin-inline-start: calc(var(--tab-shadow-max-size) * -1) !important;
+  }
+
+  .tabbrowser-tab[selected="true"][pinned="true"] {
+    -moz-box-flex: 100;
+    max-width: var(--tab-max-width) !important;
   }
 
   .tabbrowser-tab[selected="true"] .tab-label-container {
@@ -4082,6 +4089,24 @@
   .tab-label-container[pinned] {
     width: unset !important;
   }
+
+  @supports -moz-bool-pref("browser.tabs.tabmanager.enabled") {
+    :root:not([tabsintitlebar="true"]) #tabbrowser-tabs:not([overflow="true"], [hashiddentabs]) ~ #alltabs-button,
+    :root:not([tabsintitlebar="true"])
+      #tabbrowser-tabs[hasadjacentnewtabbutton]:not([overflow="true"])
+      ~ #new-tab-button {
+      display: -moz-box !important;
+    }
+  }
+  #tabbrowser-tabs:not([positionpinnedtabs]) > #tabbrowser-arrowscrollbox {
+    padding-inline: 12.5px !important;
+  }
+
+  #tabbrowser-tabs[haspinnedtabs]:not([positionpinnedtabs])
+    > #tabbrowser-arrowscrollbox
+    > .tabbrowser-tab[first-visible-unpinned-tab] {
+    --inline-tab-padding: 0 !important;
+  }
 }
 /*= Tab Bar - Connect to window ==============================================*/
 @supports -moz-bool-pref("userChrome.tab.connect_to_window") {
diff --git a/src/tabbar/_as_titlebar.scss b/src/tabbar/_as_titlebar.scss
index b9b7459..40ef1a8 100644
--- a/src/tabbar/_as_titlebar.scss
+++ b/src/tabbar/_as_titlebar.scss
@@ -14,6 +14,14 @@ spacer[part="overflow-end-indicator"],
 .tabbrowser-tab[selected="true"] {
   -moz-window-dragging: drag;
   --tab-max-width: 100%;
+  width: var(--tab-max-width) !important;
+
+  margin-inline-start: calc(var(--tab-shadow-max-size) * -1) !important;
+  // padding-inline-start: calc(var(--tab-shadow-max-size) + 1px) !important;
+}
+.tabbrowser-tab[selected="true"][pinned="true"] {
+  -moz-box-flex: 100;
+  max-width: var(--tab-max-width) !important;
 }
 .tabbrowser-tab[selected="true"] .tab-label-container {
   margin-inline: 0 !important;
@@ -41,3 +49,45 @@ spacer[part="overflow-end-indicator"],
 .tab-label-container[pinned] {
   width: unset !important;
 }
+
+
+// @supports not -moz-bool-pref("browser.tabs.tabmanager.enabled") {
+//   #tabbrowser-tabs:not([overflow="true"], [hashiddentabs]) ~ #alltabs-button {
+//     display: none;
+//   }
+//   #tabbrowser-tabs:not([overflow="true"])[using-closing-tabs-spacer] ~ #alltabs-button {
+//     // temporary space to keep a tab's close button under the cursor
+//     display: -moz-box;
+//     visibility: hidden;
+//   }
+// }
+//
+// #tabbrowser-tabs[hasadjacentnewtabbutton]:not([overflow="true"]) ~ #new-tab-button,
+// #tabbrowser-tabs[overflow="true"] > #tabbrowser-arrowscrollbox > #tabbrowser-arrowscrollbox-periphery > #tabs-newtab-button,
+// #tabbrowser-tabs:not([hasadjacentnewtabbutton]) > #tabbrowser-arrowscrollbox > #tabbrowser-arrowscrollbox-periphery > #tabs-newtab-button,
+// #TabsToolbar[customizing="true"] #tabs-newtab-button {
+//   display: none;
+// }
+//
+// #tabbrowser-tabs[positionpinnedtabs] > #tabbrowser-arrowscrollbox::part(scrollbox) {
+//   // Add padding to match the shadow's blur radius so the
+//   //  shadow doesn't get clipped when either the first or
+//   //  last tab is selected
+//   padding-inline: var(--tab-shadow-max-size); // 6px
+// }
+//
+// #tabbrowser-tabs[haspinnedtabs]:not([positionpinnedtabs]) > #tabbrowser-arrowscrollbox > .tabbrowser-tab[first-visible-unpinned-tab] {
+//   margin-inline-start: 12px !important;
+// }
+@include Option("browser.tabs.tabmanager.enabled") {
+  :root:not([tabsintitlebar="true"]) #tabbrowser-tabs:not([overflow="true"], [hashiddentabs]) ~ #alltabs-button,
+  :root:not([tabsintitlebar="true"]) #tabbrowser-tabs[hasadjacentnewtabbutton]:not([overflow="true"]) ~ #new-tab-button {
+    display: -moz-box !important;
+  }
+}
+#tabbrowser-tabs:not([positionpinnedtabs]) > #tabbrowser-arrowscrollbox {
+  padding-inline: 12.5px !important;
+}
+#tabbrowser-tabs[haspinnedtabs]:not([positionpinnedtabs]) > #tabbrowser-arrowscrollbox > .tabbrowser-tab[first-visible-unpinned-tab] {
+  --inline-tab-padding: 0 !important;
+}