Use fonts.googleapis.com

It's working now...

layouts/partials/site_head.html

@@ -96,7 +96,7 @@
 
   {{/* We cannot use SRI with Google Fonts because the CSS is dynamically generated according to the user agent. */}}
   {{ with ($scr.Get "google_fonts") }}
-  <link rel="stylesheet" {{ printf "href=\"//fonts.proxy.ustclug.org/css?family=%s\"" . | safeHTMLAttr }}>
+  <link rel="stylesheet" {{ printf "href=\"//fonts.googleapis.com/css?family=%s\"" . | safeHTMLAttr }}>
   {{ end }}
 
   {{ $css_options := (dict "targetPath" "css/academic.css" "outputStyle" "compressed") }}