--- a/devtools/client/shared/components/tabs/tabs.css
+++ b/devtools/client/shared/components/tabs/tabs.css
@@ -76,20 +76,16 @@
   border-bottom: 1px solid var(--theme-splitter-color);
   background: var(--theme-tab-toolbar-background);
 }
 
 .theme-dark .tabs .tabs-menu-item,
 .theme-light .tabs .tabs-menu-item {
   margin: 0;
   padding: 0;
-  border-style: solid;
-  border-width: 0;
-  border-inline-start-width: 1px;
-  border-color: var(--theme-splitter-color);
   color: var(--theme-content-color1);
 }
 
 .theme-dark .tabs .tabs-menu-item:last-child,
 .theme-light:not(.theme-firebug) .tabs .tabs-menu-item:last-child {
   border-inline-end-width: 1px;
 }
 
@@ -103,22 +99,16 @@
   background-color: var(--theme-toolbar-hover);
 }
 
 .theme-dark .tabs .tabs-menu-item:hover:active:not(.is-active),
 .theme-light .tabs .tabs-menu-item:hover:active:not(.is-active) {
   background-color: var(--theme-toolbar-hover-active);
 }
 
-.theme-dark .tabs .tabs-menu-item.is-active,
-.theme-light .tabs .tabs-menu-item.is-active {
-  background-color: var(--theme-selection-background);
-  color: var(--theme-selection-color);
-}
-
 /* Dark Theme */
 
 .theme-dark .tabs .tabs-menu-item {
   color: var(--theme-body-color-alt);
 }
 
 .theme-dark .tabs .tabs-menu-item:hover:not(.is-active) {
   color: var(--theme-focus-outline-color);