diff --git a/common/head_tag.html b/common/head_tag.html
new file mode 100644
index 0000000..9ad0067
--- /dev/null
+++ b/common/head_tag.html
@@ -0,0 +1,6 @@
+<script>
+  if(!CSS.supports("(color: hsl(from white h s l))")){
+    window.unsupportedBrowser = true;
+    window.I18n.translations[I18n.locale].js.browser_update = 'The Horizon theme does not support your browser. Please update your browser, or <a href="?safe_mode=no_themes">switch to safe mode</a>.';
+  }
+</script>
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