(CSS) update stylesheets for recent changes.

this will fix a new visual bug with the rounded outside corners on tabs.

uc-tabs.css

@@ -128,7 +128,7 @@
 #TabsToolbar .tabbrowser-tab :is(.tab-stack, .tab-background, .tab-content, .tab-loading-burst) {
     border-top-right-radius: 5px !important;
     border-top-left-radius: 5px !important;
-    overflow: hidden;
+    overflow: clip;
 }
 
 /* unround top left/right corner for first/last tab.
@@ -365,11 +365,6 @@ which could represent a security risk if you accidentally use the wrong containe
     .tabbrowser-tab .tab-stack::after {
         display: none !important;
     }
-
-    #TabsToolbar .tabbrowser-tab,
-    #TabsToolbar .tabbrowser-tab .tab-stack {
-        overflow: hidden !important;
-    }
 }
 
 /* style the loading burst that triggers when tab loading finishes */
@@ -382,6 +377,10 @@ which could represent a security risk if you accidentally use the wrong containe
     backface-visibility: hidden;
 }
 
+:root[sessionrestored] .tab-loading-burst[pinned]::before {
+	margin-inline-start: calc((var(--pinned-tab-width, 36px) / 2) - 2.5%) !important;
+}
+
 /* this is all the convoluted z-index stuff I was talking about — how tab depth is controlled. */
 
 /* default position is for tabs to be stacked on top of the tab to their left.

userChrome.au.css

@@ -394,6 +394,11 @@ we can continue using opacity as the transition property. */
         opacity: 1;
     }
 
+    .tabbrowser-tab {
+        overflow: revert;
+        -moz-box-pack: center;
+    }
+
     /* make unpinned tabs stretch to fill the whole tab bar */
     .tabbrowser-tab[fadein]:not([style*="max-width"]) {
         max-width: var(--tab-max-width, 225px);