diff --git a/settings/org-settings.el b/settings/org-settings.el
index 7803d19c..3be2e057 100644
--- a/settings/org-settings.el
+++ b/settings/org-settings.el
@@ -1066,90 +1066,80 @@ Uses function `my-org-headline-string-element'"
   (setq org-html-doctype "html5")
   (setq org-html-html5-fancy t)
   (setq org-html-validation-link nil)          ;; remove the "Validate" link at the bottom of the page
-  (setq org-html-mathjax-options
-        '((path "https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS_HTML")
-          ;;(path "/js/MathJax-master/MathJax.js?config=TeX-AMS_HTML")
-          (scale "100")
+  (setq org-html-mathjax-options               ;; variables used in `org-html-mathjax-template'
+        '((path "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-svg.js")
+          (scale "1.0")
           (align "center")
           (font "TeX")
-          (linebreaks "false")
-          (autonumber "AMS")
+          (overflow "overflow")
+          (tags "ams")
           (indent "0em")
           (multlinewidth "85%")
           (tagindent ".8em")
           (tagside "right")))                  ;; #+HTML_MATHJAX: align: left indent: 5em tagside: left font: Neo-Euler
   ;; http://docs.mathjax.org/en/latest/input/tex/macros/
-  (setq org-html-mathjax-template "<script type=\"text/x-mathjax-config\">
-    MathJax.Ajax.config.path[\"Contrib\"] = \"https://cdn.mathjax.org/mathjax/contrib\";
-    MathJax.Hub.Register.StartupHook(\"TeX Jax Ready\",function () {
-        MathJax.Hub.Insert(MathJax.InputJax.TeX.Definitions.macros,{
-            cancel: [\"Extension\",\"cancel\"],
-            bcancel: [\"Extension\",\"cancel\"],
-            xcancel: [\"Extension\",\"cancel\"],
-            cancelto: [\"Extension\",\"cancel\"]
-        });
-    });
-    MathJax.Hub.Config({
-        extensions: [\"[Contrib]/siunitx/siunitx.js\"],
-        displayAlign: \"%ALIGN\",
-        displayIndent: \"%INDENT\",
-
-        \"HTML-CSS\": { scale: %SCALE,
-                        linebreaks: { automatic: \"%LINEBREAKS\" },
-                        webFont: \"%FONT\"
-                       },
-        SVG: {scale: %SCALE,
-              linebreaks: { automatic: \"%LINEBREAKS\" },
-              font: \"%FONT\"},
-        NativeMML: {scale: %SCALE},
-        TeX: { equationNumbers: {autoNumber: \"%AUTONUMBER\"},
-               MultLineWidth: \"%MULTLINEWIDTH\",
-               TagSide: \"%TAGSIDE\",
-               TagIndent: \"%TAGINDENT\",
-               Macros: {
-                         ti: [\"{_\\\\text{#1}}\",1],
-                         ho: [\"{^\\\\text{#1}}\",1],
-                         field: [\"\\\\mathbb{#1}\",1],
-                         fC: \"{\\\\field{C}}\",
-                         fN: \"{\\\\field{N}}\",
-                         fR: \"{\\\\field{R}}\",
-                         fQ: \"{\\\\field{Q}}\",
-                         fI: \"{\\\\field{I}}\",
-                         fZ: \"{\\\\field{Z}}\",
-                         qed: \"{\\\\blacksquare}\",
-                         T: \"{\\\\mathrm{T}}\",
-                         dif: \"{\\\\,\\\\mathop{}\\\\!\\\\mathrm{d}}\",
-                         norm: [\"{\\\\lVert{}#1\\\\rVert}\",1],
-                         abs: [\"{\\\\lvert{}#1\\\\rvert}\",1],
-                         corresponds: \"{{\\\\kern0em\\\\raise{.5ex}{\\\\Large\\\\hat{}}\\\\kern-.73em\\\\raise{-.2ex}{=}}\\\\ }\",
-                         dt: [\"{\\\\overset{{\\\\large\\\\bf{}.}}{#1}}\",1],
-                         ddt: [\"{\\\\overset{{\\\\large\\\\bf{}.\\\\hspace{-0.1ex}.}}{#1}}\",1],
-                         Eval: [\"{\\\\left.#1\\\\phantom{\\\\Big|}\\\\!\\\\!\\\\right\\\\rvert_{#2}^{#3}}\",3],
-                         tensor: [\"{\\\\mathbf{#1}}\",1],
-                         tensorI: [\"{\\\\underline{\\\\mathbf{#1}}}\",1],
-                         tensorII: [\"{\\\\underline{\\\\underline{\\\\mathbf{#1}}}}\",1],
-                         tensorIII: [\"{\\\\underset{\\\\raise{.5ex}{\\\\Large\\\\tilde{\\\\small{}3}}}{\\\\mathbf{#1}}}\",1],
-                         tensorIV: [\"{\\\\underset{\\\\raise{.5ex}{\\\\Large\\\\tilde{\\\\small{}4}}}{\\\\mathbf{#1}}}\",1],
-                         tensori: [\"{\\\\overrightarrow{#1}}\",1],
-                         tensorii: [\"{\\\\overleftrightarrow{#1}}\",1],
-                         tensoriii: [\"{\\\\overrightarrow{\\\\overleftrightarrow{#1}}}\",1],
-                         tensoriv: [\"{\\\\overleftrightarrow{\\\\overleftrightarrow{#1}}}\",1],
-                         rank: \"{\\\\mathop{\\\\mathrm{rank}}}\",
-                         tr: \"{\\\\mathop{\\\\mathrm{tr}}}\",
-                         dev: \"{\\\\mathop{\\\\mathrm{dev}}}\",
-                         var: \"{\\\\mathop{\\\\mathrm{var}}}\",
-                         grad: \"{\\\\mathop{\\\\mathrm{grad}}}\",
-                         divergence: \"{\\\\mathop{\\\\mathrm{div}}}\",
-                         rot: \"{\\\\mathop{\\\\mathrm{rot}}}\",
-                         diag: \"{\\\\mathop{\\\\mathrm{diag}}}\",
-                         adjungate: \"{\\\\mathop{\\\\mathrm{adj}}}\",
-                         EUR: \"{\\\\text{€}}\"
-               }
-             }
-});
+  ;; TODO: old config v2 to v3
+  ;; variable ONLY in upper-case!
+  (setq org-html-mathjax-template "
+<script>
+MathJax = {
+  chtml: {
+    scale: %SCALE
+  },
+  svg: {
+    scale: %SCALE
+  },
+  tex: {
+    inlineMath: [['\\\\(', '\\\\)']],
+    tags: \"%TAGS\",
+    multlineWidth: \"%MULTLINEWIDTH\",
+    tagSide: \"$TAGSIDE\",
+    tagIndent: \"%TAGINDENT\",
+    macros: {
+      ti: [\"{_\\\\text{#1}}\",1],
+      ho: [\"{^\\\\text{#1}}\",1],
+      field: [\"\\\\mathbb{#1}\",1],
+      fC: \"{\\\\field{C}}\",
+      fN: \"{\\\\field{N}}\",
+      fR: \"{\\\\field{R}}\",
+      fQ: \"{\\\\field{Q}}\",
+      fI: \"{\\\\field{I}}\",
+      fZ: \"{\\\\field{Z}}\",
+      qed: \"{\\\\blacksquare}\",
+      T: \"{\\\\mathrm{T}}\",
+      dif: \"{\\\\,\\\\mathop{}\\\\!\\\\mathrm{d}}\",
+      norm: [\"{\\\\lVert{}#1\\\\rVert}\",1],
+      abs: [\"{\\\\lvert{}#1\\\\rvert}\",1],
+      corresponds: \"{{\\\\kern0em\\\\raise{.5ex}{\\\\Large\\\\hat{}}\\\\kern-.73em\\\\raise{-.2ex}{=}}\\\\ }\",
+      dt: [\"{\\\\overset{{\\\\large\\\\bf{}.}}{#1}}\",1],
+      ddt: [\"{\\\\overset{{\\\\large\\\\bf{}.\\\\hspace{-0.1ex}.}}{#1}}\",1],
+      Eval: [\"{\\\\left.#1\\\\phantom{\\\\Big|}\\\\!\\\\!\\\\right\\\\rvert_{#2}^{#3}}\",3],
+      tensor: [\"{\\\\mathbf{#1}}\",1],
+      tensorI: [\"{\\\\underline{\\\\mathbf{#1}}}\",1],
+      tensorII: [\"{\\\\underline{\\\\underline{\\\\mathbf{#1}}}}\",1],
+      tensorIII: [\"{\\\\underset{\\\\raise{.5ex}{\\\\Large\\\\tilde{\\\\small{}3}}}{\\\\mathbf{#1}}}\",1],
+      tensorIV: [\"{\\\\underset{\\\\raise{.5ex}{\\\\Large\\\\tilde{\\\\small{}4}}}{\\\\mathbf{#1}}}\",1],
+      tensori: [\"{\\\\overrightarrow{#1}}\",1],
+      tensorii: [\"{\\\\overleftrightarrow{#1}}\",1],
+      tensoriii: [\"{\\\\overrightarrow{\\\\overleftrightarrow{#1}}}\",1],
+      tensoriv: [\"{\\\\overleftrightarrow{\\\\overleftrightarrow{#1}}}\",1],
+      rank: \"{\\\\mathop{\\\\mathrm{rank}}}\",
+      tr: \"{\\\\mathop{\\\\mathrm{tr}}}\",
+      dev: \"{\\\\mathop{\\\\mathrm{dev}}}\",
+      var: \"{\\\\mathop{\\\\mathrm{var}}}\",
+      grad: \"{\\\\mathop{\\\\mathrm{grad}}}\",
+      divergence: \"{\\\\mathop{\\\\mathrm{div}}}\",
+      rot: \"{\\\\mathop{\\\\mathrm{rot}}}\",
+      diag: \"{\\\\mathop{\\\\mathrm{diag}}}\",
+      adjungate: \"{\\\\mathop{\\\\mathrm{adj}}}\",
+      EUR: \"{\\\\text{€}}\"
+    }
+  }
+};
 </script>
-<script type=\"text/javascript\"
-        src=\"%PATH\"></script>")
+<script type=\"text/javascript\" id=\"MathJax-script\" async
+  src=\"%PATH\"></script>
+")
   )
 
 (use-package ox-latex