--- a/browser/components/downloads/content/downloadsOverlay.xul
+++ b/browser/components/downloads/content/downloadsOverlay.xul
@@ -148,17 +148,18 @@
                 </vbox>
               </hbox>
               <hbox id="downloadsFooterButtons">
                 <button id="downloadsHistory"
                         class="downloadsPanelFooterButton"
                         label="&downloadsHistory.label;"
                         accesskey="&downloadsHistory.accesskey;"
                         flex="1"
-                        oncommand="DownloadsPanel.showDownloadsHistory();"/>
+                        oncommand="DownloadsPanel.showDownloadsHistory();"
+                        pack="start"/>
               </hbox>
             </stack>
           </vbox>
         </panelview>
 
         <panelview id="downloadsPanel-blockedSubview"
                    descriptionheightworkaround="true"
                    class="PanelUI-subView"

--- a/browser/themes/shared/customizableui/panelUI.inc.css
+++ b/browser/themes/shared/customizableui/panelUI.inc.css
@@ -218,22 +218,28 @@ panelview {
 #PanelUI-popup .panel-subview-body {
   margin: -4px;
   padding: 4px 4px;
 }
 
 .subviewbutton.panel-subview-footer {
   box-sizing: border-box;
   min-height: 41px;
-  padding: 11px 12px;
+}
+
+.cui-widget-panelview menuitem.subviewbutton.panel-subview-footer {
+  margin: 4px 0 0;
 }
 
-.cui-widget-panelview .subviewbutton.panel-subview-footer {
-  margin: 4px 0 0;
-  -moz-box-pack: center;
+.cui-widget-panelview .subviewbutton.panel-subview-footer > .menu-text {
+  -moz-box-flex: 1;
+}
+
+.cui-widget-panelview .subviewbutton.panel-subview-footer .menu-accel-container {
+  -moz-box-pack: end;
 }
 
 #appMenu-popup > arrowscrollbox > autorepeatbutton,
 #PanelUI-popup > arrowscrollbox > autorepeatbutton {
   display: none;
 }
 
 #appMenu-popup > arrowscrollbox > scrollbox,
@@ -379,17 +385,18 @@ panel[photon] > .panel-arrowcontainer > 
   padding: 0;
 }
 
 panelview[id^=PanelUI-webext-] {
   overflow: hidden;
 }
 
 panelview:not([mainview]) .toolbarbutton-text,
-.cui-widget-panel toolbarbutton:not([wrap]) > .toolbarbutton-text {
+.cui-widget-panel toolbarbutton:not([wrap]) > .toolbarbutton-text,
+#overflowMenu-customize-button > .toolbarbutton-text {
   text-align: start;
   display: -moz-box;
 }
 
 .cui-widget-panel > .panel-arrowcontainer > .panel-arrowcontent {
   padding: 4px 0;
 }
 
@@ -1204,17 +1211,16 @@ panelview .toolbarbutton-1,
 }
 
 .subviewbutton:focus {
   outline: 0;
 }
 
 .subviewbutton > .toolbarbutton-text {
   padding: 0;
-  padding-inline-start: 24px; /* This is 16px for the icon + 8px for the padding as defined above. */
 }
 
 .subviewbutton > .menu-right,
 .subviewbutton > .menu-accel-container > .menu-iconic-accel,
 .subviewbutton > .menu-iconic-left,
 .subviewbutton > .menu-iconic-text {
   padding-bottom: 0;
   padding-top: 0;

--- a/browser/themes/shared/downloads/downloads.inc.css
+++ b/browser/themes/shared/downloads/downloads.inc.css
@@ -87,18 +87,18 @@
   background-color: #0568ba;
 }
 
 .downloadsPanelFooterButton > .button-box {
   padding: 0;
 }
 
 #downloadsHistory {
-  padding-inline-start: 10px;
-  padding-inline-end: 10px;
+  padding-inline-start: 14px;
+  padding-inline-end: 14px;
 }
 
 @item@ > toolbarseparator {
   margin: 10px 0;
 }
 
 @item@:hover > toolbarseparator {
   margin: 0;

--- a/toolkit/themes/windows/global/menu.css
+++ b/toolkit/themes/windows/global/menu.css
@@ -53,17 +53,16 @@ menuitem.spell-suggestion {
 .menu-text,
 .menu-iconic-text {
   margin: 0px !important;
   padding: 1px 0px;
   color: inherit;
 }
 
 .menu-text {
-  padding-inline-start: 1.45em !important;
   -moz-appearance: menuitemtext;
 }
 
 .menu-text,
 .menu-iconic-text {
   font-weight: inherit;
   margin-inline-start: 2px !important;
   padding-inline-end: 2px;
@@ -80,17 +79,16 @@ menucaption > .menu-iconic-text {
   color: GrayText;
   margin-inline-start: 1ex !important;
 }
 
 .menu-accel,
 .menu-iconic-accel {
   color: inherit;
   margin-inline-start: 0.74em !important;
-  margin-inline-end: 1.35em !important;
 }
 
 .menu-iconic-left {
   min-width: 1.45em;
 }
 
 .menu-iconic-icon {
   width: 16px;