fix

packages/app/src/server/routes/hackmd.js

@@ -73,9 +73,10 @@ module.exports = function(crowi, app) {
    */
   const loadStyles = function(req, res) {
 
+    const stylesCSSLineBreaksRemoved = hackmdFiles.stylesCSS.replace(/(\r\n|\n|\r)/gm, ''); // https://stackoverflow.com/questions/10805125/how-to-remove-all-line-breaks-from-a-string
     // generate definitions to replace
     const definitions = {
-      styles: hackmdFiles.stylesCSS,
+      styles: stylesCSSLineBreaksRemoved,
     };
     // inject styles to script
     const script = ejs.render(hackmdFiles.stylesJS, definitions);

packages/hackmd/src/hackmd-styles.js

@@ -19,7 +19,6 @@ const styles = '<%= styles %>'; // will be replaced by ejs
  */
 function insertStyle() {
   const element = document.createElement('style');
-  element.type = 'text/css';
   element.appendChild(document.createTextNode(unescape(styles)));
   document.getElementsByTagName('head')[0].appendChild(element);
 }