--- a/browser/extensions/formautofill/skin/shared/editProfile.css
+++ b/browser/extensions/formautofill/skin/shared/editProfile.css
@@ -32,17 +32,17 @@ label > span {
 
 input,
 select {
   flex: 1 0 auto;
   width: 9em;
 }
 
 option {
-  padding: 6px;
+  padding: 5px 10px;
 }
 
 textarea {
   resize: none;
 }
 
 button {
   padding: 3px 2em;

--- a/toolkit/themes/shared/in-content/common.inc.css
+++ b/toolkit/themes/shared/in-content/common.inc.css
@@ -190,16 +190,27 @@ xul|menulist {
   -moz-border-top-colors: none !important;
   -moz-border-right-colors: none !important;
   -moz-border-bottom-colors: none !important;
   -moz-border-left-colors: none !important;
   border-radius: 2px;
   background-color: var(--in-content-page-background);
 }
 
+html|select:not([size]):not([multiple]) {
+  background-image: url("chrome://global/skin/in-content/dropdown.svg#dropdown");
+  background-position: right 3px center;
+  background-repeat: no-repeat;
+  background-size: auto 18px;
+  font-size: inherit;
+  padding-inline-start: 5px;
+  padding-inline-end: 24px;
+  text-overflow: ellipsis;
+}
+
 html|button:enabled:hover,
 html|select:not([size]):not([multiple]):enabled:hover,
 xul|button:not([disabled="true"]):hover,
 xul|colorpicker[type="button"]:not([disabled="true"]):hover,
 xul|menulist:not([disabled="true"]):hover {
   background-color: var(--in-content-box-background-hover);
 }