diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index e255495..eca3bbd 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -29,7 +29,7 @@ jobs:
     - name: Install and Build 🔧
       run: |
         pip3 install --upgrade jupyter
-        npm install -g mermaid.cli
+        npm install -g @mermaid-js/mermaid-cli
         export JEKYLL_ENV=production
         bundle exec jekyll build
     - name: Deploy 🚀
diff --git a/Gemfile b/Gemfile
index 5b6bb41..8918584 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,6 @@ group :jekyll_plugins do
     gem 'jekyll-archives-v2'
     gem 'jekyll-email-protect'
     gem 'jekyll-feed'
-    gem 'jekyll-get-json'
     gem 'jekyll-imagemagick'
     gem 'jekyll-jupyter-notebook'
     gem 'jekyll-link-attributes'
diff --git a/Gemfile.lock b/Gemfile.lock
index e2888c9..4c1125d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -63,7 +63,6 @@ GEM
     cssminify2 (2.1.0)
     csv (3.3.5)
     date (3.5.1)
-    deep_merge (1.2.2)
     drb (2.2.3)
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)
@@ -144,9 +143,6 @@ GEM
     jekyll-email-protect (1.1.0)
     jekyll-feed (0.17.0)
       jekyll (>= 3.7, < 5.0)
-    jekyll-get-json (1.0.0)
-      deep_merge (~> 1.2)
-      jekyll (>= 3.0)
     jekyll-imagemagick (1.4.0)
       jekyll (>= 3.4)
     jekyll-jupyter-notebook (0.0.6)
@@ -296,7 +292,6 @@ DEPENDENCIES
   jekyll-archives-v2
   jekyll-email-protect
   jekyll-feed
-  jekyll-get-json
   jekyll-imagemagick
   jekyll-jupyter-notebook
   jekyll-link-attributes
@@ -332,7 +327,6 @@ CHECKSUMS
   cssminify2 (2.1.0) sha256=406a0b95fdaab60132c6f1fbb47b4a30f9572d2ef523f806fb94a530d78c2bb1
   csv (3.3.5) sha256=6e5134ac3383ef728b7f02725d9872934f523cb40b961479f69cf3afa6c8e73f
   date (3.5.1) sha256=750d06384d7b9c15d562c76291407d89e368dda4d4fff957eb94962d325a0dc0
-  deep_merge (1.2.2) sha256=83ced3a3d7f95f67de958d2ce41b1874e83c8d94fe2ddbff50c8b4b82323563a
   drb (2.2.3) sha256=0b00d6fdb50995fe4a45dea13663493c841112e4068656854646f418fda13373
   em-websocket (0.5.3) sha256=f56a92bde4e6cb879256d58ee31f124181f68f8887bd14d53d5d9a292758c6a8
   eventmachine (1.2.7) sha256=994016e42aa041477ba9cff45cbe50de2047f25dd418eba003e84f0d16560972
@@ -367,7 +361,6 @@ CHECKSUMS
   jekyll-archives-v2 (0.0.6) sha256=207aad14a5c09cbb673744e9e012318da66be9163f1abe1e450820d600a94904
   jekyll-email-protect (1.1.0) sha256=00d620939c710788ae3f71188ef913e0aa7ff0a5a39f48249213ea6215558c8d
   jekyll-feed (0.17.0) sha256=689aab16c877949bb9e7a5c436de6278318a51ecb974792232fd94d8b3acfcc3
-  jekyll-get-json (1.0.0) sha256=f6b076a93de9cace89a88617b494bea10e6dbb86331c293d663d37d9b9ae7522
   jekyll-imagemagick (1.4.0) sha256=dcf4ae46ffbeabfac584a5256821e39fc5fae8d651fd5c4a56fef3a2061a7ef4
   jekyll-jupyter-notebook (0.0.6) sha256=33f757eaad9035bebc5309e23ce2274db089ae8a0d002a53c3acbc5265d322cd
   jekyll-link-attributes (1.0.1) sha256=c88e6742ea1ee0442a49ac183f89ad68b194bf9bffe1b05e0cc308dbaebd3e23
diff --git a/_config.yml b/_config.yml
index e1b07cd..6bed674 100644
--- a/_config.yml
+++ b/_config.yml
@@ -7,7 +7,7 @@ first_name: Farhad
 middle_name:
 last_name: Allian
 email: allianfarhad@gmail.com
-description: Farhad Allian's personal website. > # the ">" symbol means to ignore newlines until "footer_text:"
+description: Farhad Allian's personal website.
 
 footer_text: >
 #  Powered by <a href="https://jekyllrb.com/" target="_blank">Jekyll</a> with <a href="https://github.com/alshedivat/al-folio">al-folio</a> theme.
@@ -62,9 +62,9 @@ max_width: 790px
 # Open Graph & Schema.org
 # -----------------------------------------------------------------------------
 # Display links to the page with a preview object on social media.
-serve_og_meta: false # Include Open Graph meta tags in the HTML head
+serve_og_meta: true # Include Open Graph meta tags in the HTML head
 serve_schema_org: false # Include Schema.org in the HTML head
-og_image: # The site-wide (default for all links) Open Graph preview image
+og_image: https://www.farhadallian.co.uk/assets/img/favicon_io/android-chrome-512x512.png
 
 # -----------------------------------------------------------------------------
 # Social integration
@@ -199,7 +199,6 @@ plugins:
   - jekyll-archives-v2
   - jekyll-email-protect
   - jekyll-feed
-  - jekyll-get-json
   - jekyll-imagemagick
   - jekyll-jupyter-notebook
   - jekyll-link-attributes
diff --git a/_includes/header.html b/_includes/header.html
index 1d3d79f..55fc004 100644
--- a/_includes/header.html
+++ b/_includes/header.html
@@ -80,8 +80,8 @@
 
           {% if site.search_enabled %}
           <li class="nav-item">
-            <a class="nav-link" href="#" id="search-link" title="Search">
-              <i class="fas fa-search"></i>
+            <a class="nav-link" href="#" id="search-link" aria-label="Open search">
+              <i class="fas fa-search" aria-hidden="true"></i>
             </a>
           </li>
           {% endif %}
@@ -90,9 +90,9 @@
           <!-- Toggle theme mode -->
           <li class="nav-item">
             <div class="toggle-container">
-              <a id="light-toggle">
-                <i class="fas fa-moon"></i>
-                <i class="fas fa-sun"></i>
+              <a id="light-toggle" aria-label="Toggle theme">
+                <i class="fas fa-moon" aria-hidden="true"></i>
+                <i class="fas fa-sun" aria-hidden="true"></i>
               </a>
             </div>
           </li>
diff --git a/_layouts/about.html b/_layouts/about.html
index 72a0b28..bcb2de8 100644
--- a/_layouts/about.html
+++ b/_layouts/about.html
@@ -23,10 +23,11 @@ <h1 class="post-title">
                 {%- assign profile_image_class = "img-fluid z-depth-1 rounded" -%}
               {% endif %}
 
+              {%- capture profile_image_alt %}Profile photo of {{ site.first_name }} {{ site.last_name }}{% endcapture -%}
               {% include figure.html
               path=profile_image_path
               class=profile_image_class
-              alt=page.profile.image
+              alt=profile_image_alt
               width="480"
               height="468" -%}
             {% endif -%}
diff --git a/_layouts/default.html b/_layouts/default.html
index 9b67975..224ee70 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -7,13 +7,9 @@
   <!-- Head -->
   <head>
     {%- if page.redirect -%}
-      <meta rel="canonical" http-equiv="refresh" content="3; url={{ site.baseurl }}/" />
+      <meta http-equiv="refresh" content="3; url={{ site.baseurl }}/" />
     {%- endif -%}
     {% include head.html %}
-    <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1">
-    <meta name="description" content="{{ page.description | default: site.description }}">
-    <link rel="canonical" href="{{ site.url }}">
   </head>
 
   <!-- Body -->
@@ -26,9 +22,9 @@
     {%- include header.html %}
 
     <!-- Content -->
-    <div class="container mt-5">
+    <main class="container mt-5">
       {{ content }}
-    </div>
+    </main>
 
     <!-- Footer -->
     {%- include footer.html %}
diff --git a/_plugins/external-posts.rb b/_plugins/external-posts.rb
index 469ace3..7a0baf2 100644
--- a/_plugins/external-posts.rb
+++ b/_plugins/external-posts.rb
@@ -20,12 +20,12 @@ def generate(site)
           raise "Invalid RSS URL scheme for external source '#{name}': #{url}"
         end
 
-        p "Fetching external posts from #{name}:"
-        xml = HTTParty.get(uri.to_s).body
+        Jekyll.logger.info "ExternalPosts:", "Fetching from #{name}"
+        xml = HTTParty.get(uri.to_s, timeout: 10).body
         feed = Feedjira.parse(xml)
 
         feed.entries.each do |e|
-          p "...fetching #{e.url}"
+          Jekyll.logger.info "ExternalPosts:", "Fetching #{e.url}"
 
           slug = e.title
                   .downcase
diff --git a/assets/js/theme.js b/assets/js/theme.js
index 380e24c..4f22319 100644
--- a/assets/js/theme.js
+++ b/assets/js/theme.js
@@ -56,7 +56,7 @@ let setHighlight = (theme) => {
 
 let setGiscusTheme = (theme) => {
   const iframe = document.querySelector("iframe.giscus-frame");
-  if (!iframe) return;
+  if (!iframe || !iframe.contentWindow) return;
   iframe.contentWindow.postMessage(
     { giscus: { setConfig: { theme: theme } } },
     "https://giscus.app"
diff --git a/robots.txt b/robots.txt
index 509128e..7a48656 100644
--- a/robots.txt
+++ b/robots.txt
@@ -4,4 +4,4 @@ permalink: /robots.txt
 User-agent: *
 Disallow:
 
-Sitemap: https://farhadallian.co.uk/sitemap.xml
+Sitemap: https://www.farhadallian.co.uk/sitemap.xml