actually use the global font everywhere (#1384)

edit/edit.css

@@ -5,7 +5,6 @@
 body {
   margin: 0;
   height: 100vh;
-  font: 12px arial,sans-serif;
 }
 
 a {

global.css

@@ -4,18 +4,18 @@ html#stylus #header *:not(#\1transition-suppressor) {
    * Using \1 to simplify js code because \0 is converted to \xFFFD per spec. */
   transition: none !important;
 }
-body {
+:root {
-  font: normal 12px Arial, system-ui, sans-serif;
+  --family: Arial, "Helvetica Neue", Helvetica, system-ui, sans-serif;
+}
+body {
+  font: normal 12px var(--family);
 }
-
 body:lang(ja) {
   font-family: Arial, 'Meiryo UI', 'MS Gothic', system-ui, sans-serif;
 }
-
 body:lang(zh-CN) {
   font-family: Arial, 'Microsoft YaHei UI', 'Microsoft YaHei', system-ui, sans-serif;
 }
-
 body:lang(zh-TW),
 body:lang(zh-HK) {
   font-family: Arial, 'Microsoft JhengHei UI', 'Microsoft JhengHei', system-ui, sans-serif;

install-usercss/install-usercss.css

@@ -119,8 +119,6 @@ h1 {
 }
 
 .install {
-  font-family: Arial, "DejaVu Sans", Verdana, Geneva, sans-serif;
-  font-size: 14px;
   background-color: hsl(0, 0%, 33%);
   color: #eee;
   border-radius: 4px;

manage/manage.css

@@ -962,7 +962,7 @@ a:hover {
 }
 
 #manage\.newUI\.sort {
-  font-family: 'sorticon', Arial;
+  font-family: 'sorticon', var(--family);
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
 }

popup/popup.css

@@ -11,8 +11,6 @@ html, body {
 
 body {
   width: 252px;
-  font-size: 12px;
-  font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;
   margin: 0;
 }