diff --git a/browser/themes/shared/toolbarbuttons.css b/browser/themes/shared/toolbarbuttons.css
index 94b1a2a841d8fd47a491616d52e5bf544f0c0bf9..9e98266b98c6b66fed26fec12fa3391fc5fcc79b 100644
--- a/browser/themes/shared/toolbarbuttons.css
+++ b/browser/themes/shared/toolbarbuttons.css
@@ -13,20 +13,6 @@
     --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-touch);
     --bookmark-block-padding: 7px;
   }
-  @media (width <= 900px) {
-    --toolbarbutton-padding-outer: var(--toolbarbutton-padding-outer-narrow);
-  }
-  @media (width <= 800px) {
-    --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-narrow);
-    &:where([uidensity="touch"]) {
-      --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-touch-narrow);
-    }
-  }
-  /* 700px is just above half of the popular 1366px screen width, so two browser
-     windows put next to each other will be below this threshold. */
-  @media (width <= 700px) {
-    --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-compact);
-  }
   &:where([uidensity="compact"]) {
     --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-compact);
     --bookmark-block-padding: 1px;
@@ -123,9 +109,7 @@
 #TabsToolbar {
   /* Override the inner padding to ensure the dimensions match the tabs, but also making sure
      different types of buttons (combined-buttons-dropmarker or text) still look correct. */
-  @media (width > 900px) {
     --toolbarbutton-padding-inner: calc((var(--tab-min-height) - 16px) / 2);
-  }
 }
 
 /* Primary toolbar buttons */
@@ -205,8 +189,8 @@ toolbar .toolbarbutton-1 {
 
   > .toolbarbutton-icon {
     /* horizontal padding + actual icon width */
-    width: calc(2 * var(--toolbarbutton-padding-inner) + 16px);
-    height: calc(2 * var(--toolbarbutton-padding-inner) + 16px);
+    width: calc(2 * var(--toolbarbutton-padding-inner) + var(--zen-toolbar-button-size, 16px));
+    height: calc(2 * var(--toolbarbutton-padding-inner) + var(--zen-toolbar-button-size, 16px));
   }
 
   > .toolbarbutton-text {
@@ -216,7 +200,7 @@ toolbar .toolbarbutton-1 {
      * height as the button icons and the same vertical padding, but as a minimum,
      * because otherwise an increase in text sizes would break things.
      */
-    min-height: calc(16px + 2 * var(--toolbarbutton-padding-inner));
+    min-height: calc(var(--zen-toolbar-button-size, 16px) + 2 * var(--toolbarbutton-padding-inner));
 
     @media (-moz-platform: macos) {
       padding-top: calc(var(--toolbarbutton-padding-inner) + 1px);
@@ -326,7 +310,7 @@ toolbar .toolbaritem-combined-buttons {
 #nav-bar-overflow-button {
   list-style-image: url("chrome://global/skin/icons/chevron.svg");
 
-  #nav-bar:not([overflowing], [nonemptyoverflow], [customizing]) > & {
+  toolbar:not([overflowing], [nonemptyoverflow], [customizing]) > & {
     display: none;
   }
 
@@ -536,7 +520,7 @@ toolbarbutton.bookmark-item:not(.subviewbutton) {
      */
     align-items: stretch;
     > .toolbarbutton-icon {
-      height: auto;
+      margin-top: auto; margin-bottom: auto;
     }
     > .toolbarbutton-badge-stack {
       align-items: center;
