diff --git a/Gemfile b/Gemfile
index 19767c3..7dabdb6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,7 +17,7 @@ gem 'tzinfo-data', platforms: [:mswin, :mingw, :jruby]
 gem 'require_all', '1.3.3'
 
 # Autoprefixer for all vendor-specific CSS attributes
-gem 'middleman-autoprefixer', '~>2.7.0'
+gem 'middleman-autoprefixer', '~>3.0.0'
 
 # Use sprokets for assets + compass
 gem 'middleman-compass', '4.0.1'
@@ -27,7 +27,7 @@ gem 'middleman-sprockets', '4.0.0'
 gem 'middleman-blog', '~> 4.0'
 
 # Boostrap as SASS
-gem 'bootstrap', '~> 4.0.0.alpha4'
+gem 'bootstrap', '~> 5.3.3'
 gem 'rails-assets-tether', '>= 1.1.0'
 gem 'sass', '3.4.19'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index a2a8b49..671cabd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,19 +1,19 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.2.7)
+    activesupport (4.2.11.3)
       i18n (~> 0.7)
-      json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.4.0)
-    autoprefixer-rails (6.3.7)
-      execjs
-    backports (3.6.8)
-    bootstrap (4.0.0.alpha4)
-      autoprefixer-rails (>= 6.0.3)
-      sass (>= 3.4.19)
+    addressable (2.8.7)
+      public_suffix (>= 2.0.2, < 7.0)
+    autoprefixer-rails (10.4.19.0)
+      execjs (~> 2)
+    backports (3.25.0)
+    bootstrap (5.3.3)
+      autoprefixer-rails (>= 9.1.0)
+      popper_js (>= 2.11.8, < 3)
     chunky_png (1.3.6)
     coffee-script (2.4.1)
       coffee-script-source
@@ -31,35 +31,33 @@ GEM
       sass (>= 3.3.0, < 3.5)
     compass-import-once (1.0.5)
       sass (>= 3.2, < 3.5)
-    concurrent-ruby (1.0.2)
+    concurrent-ruby (1.3.3)
     contracts (0.13.0)
-    dotenv (2.1.1)
+    dotenv (3.1.2)
     em-websocket (0.5.1)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     erubis (2.7.0)
     eventmachine (1.2.0.1)
-    execjs (2.7.0)
-    fast_blank (1.0.0)
-    fastimage (2.0.0)
-      addressable (~> 2)
-    ffi (1.9.14)
+    execjs (2.9.1)
+    fast_blank (1.0.1)
+    fastimage (2.3.1)
+    ffi (1.17.0)
     haml (5.1.2)
       temple (>= 0.8.0)
       tilt
     hamster (3.0.0)
       concurrent-ruby (~> 1.0)
-    hashie (3.4.4)
+    hashie (3.6.0)
     http_parser.rb (0.6.0)
     i18n (0.7.0)
     jquery-middleman (3.1.2)
       thor (>= 0.14, < 2.0)
-    json (1.8.3)
     kramdown (1.11.1)
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    memoist (0.14.0)
+    memoist (0.16.2)
     middleman (4.1.10)
       coffee-script (~> 2.2)
       compass-import-once (= 1.0.5)
@@ -68,9 +66,9 @@ GEM
       middleman-cli (= 4.1.10)
       middleman-core (= 4.1.10)
       sass (>= 3.4.0, < 4.0)
-    middleman-autoprefixer (2.7.0)
-      autoprefixer-rails (>= 6.3.1, < 7.0.0)
-      middleman-core (>= 3.3.3)
+    middleman-autoprefixer (3.0.0)
+      autoprefixer-rails (~> 10.0)
+      middleman-core (>= 4.0.0)
     middleman-blog (4.0.2)
       addressable (~> 2.3)
       middleman-core (~> 4.0)
@@ -115,48 +113,50 @@ GEM
     middleman-syntax (3.0.0)
       middleman-core (>= 3.2)
       rouge (~> 2.0)
-    minitest (5.9.0)
+    minitest (5.24.1)
     multi_json (1.12.1)
-    padrino-helpers (0.13.2)
+    padrino-helpers (0.13.3.4)
       i18n (~> 0.6, >= 0.6.7)
-      padrino-support (= 0.13.2)
+      padrino-support (= 0.13.3.4)
       tilt (>= 1.4.1, < 3)
-    padrino-support (0.13.2)
+    padrino-support (0.13.3.4)
       activesupport (>= 3.1)
-    parallel (1.9.0)
-    rack (1.6.4)
+    parallel (1.25.1)
+    popper_js (2.11.8)
+    public_suffix (6.0.1)
+    rack (1.6.13)
     rack-livereload (0.3.16)
       rack
     rails-assets-tether (1.1.1)
     rake (10.5.0)
-    rb-fsevent (0.9.7)
-    rb-inotify (0.9.7)
-      ffi (>= 0.5.0)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.11.1)
+      ffi (~> 1.0)
     redcarpet (3.3.3)
     require_all (1.3.3)
     rouge (2.0.5)
     sass (3.4.19)
-    servolux (0.12.0)
+    servolux (0.13.0)
     sprockets (3.7.0)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     temple (0.8.2)
     thor (0.19.1)
-    thread_safe (0.3.5)
+    thread_safe (0.3.6)
     tilt (1.4.1)
-    tzinfo (1.2.2)
+    tzinfo (1.2.11)
       thread_safe (~> 0.1)
-    uglifier (3.0.1)
+    uglifier (3.2.0)
       execjs (>= 0.3.0, < 3)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  bootstrap (~> 4.0.0.alpha4)
+  bootstrap (~> 5.3.3)
   jquery-middleman (= 3.1.2)
   middleman (~> 4.1.0)
-  middleman-autoprefixer (~> 2.7.0)
+  middleman-autoprefixer (~> 3.0.0)
   middleman-blog (~> 4.0)
   middleman-compass (= 4.0.1)
   middleman-gh-pages (~> 0.3.0)