diff --git a/_config.yml b/_config.yml
index 4c593e0..a4b4c79 100644
--- a/_config.yml
+++ b/_config.yml
@@ -26,8 +26,8 @@ impressum_path:  # set to path to include impressum link in the footer, use the
 # -----------------------------------------------------------------------------
 
 # code highlighter theme
-highlight_theme_light: github   # https://github.com/jwarby/jekyll-pygments-themes
-highlight_theme_dark: native    # https://github.com/jwarby/jekyll-pygments-themes
+highlight_theme_light: tango   # assets/stylesheets/
+highlight_theme_dark: zenburn  #  assets/stylesheets/
 
 # repo color theme
 repo_theme_light: default       # https://github.com/anuraghazra/github-readme-stats/blob/master/themes/README.md
@@ -174,9 +174,9 @@ markdown: Pandoc
 highlighter: rouge
 #pandoc:
 #  extensions:
-#    - filter: mermaid-filter
 #    - filter: mathjax-pandoc-filter
 #    - '-Mmathjax.centerDisplayMath' # center display math
+#    - filter: mermaid-filter
 
 # Includes & excludes
 include: ['_pages']
diff --git a/_includes/head.html b/_includes/head.html
index 75c9b34..c48d71d 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -11,11 +11,12 @@
     <link rel="stylesheet" type="text/css" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700|Roboto+Slab:100,300,400,500,700|Material+Icons">
 
     <!-- Code Syntax Highlighting -->
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/jwarby/jekyll-pygments-themes@master/{{ site.highlight_theme_light | append: '.css' }}" media="" id="highlight_theme_light" />
+    <!---<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/jwarby/jekyll-pygments-themes@master/{{ site.highlight_theme_light | append: '.css' }}" media="" id="highlight_theme_light" /> -->
+    <link rel="stylesheet" href="/assets/stylesheets/{{ site.highlight_theme_light | append: '.css' }}" media="" id="highlight_theme_light" />
 
-    <!-- Styles -->
-    {% if site.icon.size <= 4 %}
-    <link rel="shortcut icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>{{ site.icon }}</text></svg>">
+      <!-- Styles -->
+      {% if site.icon.size <= 4 %}
+      <link rel="shortcut icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>{{ site.icon }}</text></svg>">
     {% elsif site.icon != blank %}
     <link rel="shortcut icon" href="{{ site.icon | prepend: '/assets/img/' | relative_url}}"/>
     {% endif %}
@@ -24,7 +25,7 @@
     
     <!-- Dark Mode -->
     {% if site.enable_darkmode %}
-    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/jwarby/jekyll-pygments-themes@master/{{ site.highlight_theme_dark | append: '.css' }}" media="none" id="highlight_theme_dark" />
+    <link rel="stylesheet" href="/assets/stylesheets/{{ site.highlight_theme_dark | append: '.css' }}" media="" id="highlight_theme_dark" />
 
     <script src="{{ '/assets/js/theme.js' | relative_url }}"></script>
     <script src="{{ '/assets/js/dark_mode.js' | relative_url }}"></script>
diff --git a/_projects/spectra.md b/_projects/spectra.md
index 3c3de51..6a5bc6d 100644
--- a/_projects/spectra.md
+++ b/_projects/spectra.md
@@ -9,6 +9,10 @@ category: thesis
 
 ![Caption](/assets/img/spectra.png 'Spectra caption')
 
+$$
+E = mc^2 \frac{42}{10^5}
+$$
+
 ![Caption](/assets/img/spectra.png 'Spectra caption'){class="img-fluid rounded z-depth-1"}
 
 ![Caption](/assets/img/spectra.png 'Spectra caption'){:class="img-fluid rounded z-depth-1"}