Push system-ui further down the stack, fix #12966

Author: CL-Jeremy

web_src/less/_base.less

@@ -1,6 +1,6 @@
 :root {
   /* documented customizable variables */
-  --fonts-proportional: system-ui, -apple-system, "Segoe UI", "Roboto", "Helvetica Neue", "Arial", "Noto Sans", "Liberation Sans", sans-serif;
+  --fonts-proportional: -apple-system, "Segoe UI", system-ui, "Roboto", "Helvetica Neue", "Arial", "Noto Sans", "Liberation Sans", sans-serif;
   --fonts-monospace: "SFMono-Regular", "Menlo", "Monaco", "Consolas", "Liberation Mono", "Courier New", monospace;
   --fonts-emoji: system-emoji;
   /* other variables */

web_src/less/_font_i18n.less

@@ -36,7 +36,7 @@ each(@fonts, {
     "HiraginoSans-:{W2,W4,W5,W6}", "Hiragino Kaku Gothic ProN :{W3,W6}",
     .shs("JP")[], .shs("J")[], .noto("JP")[], .shs("")[],
     /* https://acetaminophen.hatenablog.com/entry/2016/02/15/225009 */
-    "Yu Gothic :{Regular,Medium,Medium,Bold}", "YuGothic :{Regular,Medium,Medium,Bold}",
+    "Yu Gothic :{Regular,Medium,Bold}", "YuGothic :{Regular,Medium,Bold}",
     "Droid Sans Japanese:{}", "Meiryo:{, Bold}", "MS PGothic:{}";
   @zh-cn:
     .pingfang("SC")[],
@@ -51,6 +51,7 @@ each(@fonts, {
   @zh-hk:
     .pingfang("HK")[],
     .shs("HK")[], .shs("HC")[], .noto("HK")[], .shs("TC")[], .noto("TC")[],
+    "HiraginoSansTC-:{W3,W6}", "Hiragino Sans TC :{W3,W6}",
     "Microsoft JhengHei:{ Light,, Bold}", "Heiti TC :{Light,Medium}", "PMingLiU_HKSCS:{}", "PMingLiU:{}";
   @ko:
     "AppleSDGothicNeo-:{Light,Regular,Medium,Semibold}",