diff --git a/Gemfile b/Gemfile
index 788c7a91..ebedacbd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,6 @@ gem 'kramdown'
 gem 'mime-types'
 gem 'nokogiri'
 gem 'rouge'
-gem 'sass'
 gem 'systemu'
 
 group :test do
@@ -20,6 +19,7 @@ group :development do
 end
 
 group :nanoc do
+  gem 'nanoc-dart-sass'
   gem 'nanoc-live'
 end
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 2ab481c8..83bc1307 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -27,6 +27,7 @@ GEM
       http_parser.rb (~> 0)
     eventmachine (1.2.7)
     ffi (1.14.2)
+    google-protobuf (3.21.12)
     http_parser.rb (0.8.0)
     immutable-ruby (0.2.0)
       concurrent-ruby (~> 1.1)
@@ -80,6 +81,9 @@ GEM
       slow_enumerator_tools (~> 1.0)
       tty-platform (~> 0.2)
       zeitwerk (~> 2.1)
+    nanoc-dart-sass (1.0.3)
+      nanoc-core (~> 4.12)
+      sass-embedded (~> 1.56)
     nanoc-deploying (1.0.2)
       nanoc-checking (~> 1.0)
       nanoc-cli (~> 4.11, >= 4.11.15)
@@ -120,11 +124,9 @@ GEM
       strscan (>= 3.0.9)
     rouge (4.2.1)
     ruby-progressbar (1.13.0)
-    sass (3.7.4)
-      sass-listen (~> 4.0.0)
-    sass-listen (4.0.0)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
+    sass-embedded (1.58.0)
+      google-protobuf (~> 3.21)
+      rake (>= 10.0.0)
     set (1.1.0)
     slow_enumerator_tools (1.1.0)
     sorted_set (1.0.3)
@@ -152,12 +154,12 @@ DEPENDENCIES
   minitest
   minitest-reporters
   nanoc (~> 4.12)
+  nanoc-dart-sass
   nanoc-live
   nokogiri
   puma (~> 6.4)
   rake
   rouge
-  sass
   systemu
 
 BUNDLED WITH
diff --git a/Rules b/Rules
index 4d1901cd..b102aa25 100644
--- a/Rules
+++ b/Rules
@@ -17,11 +17,11 @@ postprocess do
   create_search_index
 end
 
-compile '/assets/css/*/' do
-  if item.identifier =~ %r{/_[^/]+/$}
+compile '/assets/css/**/*' do
+  if item.identifier.to_s =~ %r{/_\w+\.scss$}
     # don't compile partials
   else
-    filter :sass, :syntax => :scss, :style => :compressed
+    filter :dart_sass, :syntax => :scss, :style => :compressed
     filter :relativize_paths, type: :css
   end
 end
@@ -57,15 +57,15 @@ compile '*' do
 end
 
 
-route '/assets/css/*/' do
-  if item.identifier =~ %r{/_[^/]+/$}
+route '/assets/css/**/*' do
+  if item.identifier.to_s =~ %r{/_\w+\.scss$}
     # don't route partials
   else
     item.identifier.chop + '.css'
   end
 end
 
-route '/assets/*/' do
+route '/assets/**/*' do
   item.identifier.to_s.chop + '.' + item[:extension]
 end
 
diff --git a/content/assets/css/_application.scss b/content/assets/css/_application.scss
index 409870b8..37eb392b 100644
--- a/content/assets/css/_application.scss
+++ b/content/assets/css/_application.scss
@@ -1,6 +1,11 @@
 //
 // Application Template
 // --------------------------------------------------
+@mixin font-awesome($unicode) {
+  font-family: "Font Awesome 5 Free";
+  font-weight: 900;
+  content: $unicode;
+}
 
 .table {
   width: 100%;
diff --git a/content/assets/css/_mixins.scss b/content/assets/css/_mixins.scss
deleted file mode 100644
index ea1d2982..00000000
--- a/content/assets/css/_mixins.scss
+++ /dev/null
@@ -1,9 +0,0 @@
-//
-// Mixins
-// --------------------------------------------------
-
-@mixin font-awesome($unicode) {
-  font-family: "Font Awesome 5 Free";
-  font-weight: 900;
-  content: $unicode;
-}
diff --git a/content/assets/css/_typography.scss b/content/assets/css/_typography.scss
index eb11c78c..54200c07 100644
--- a/content/assets/css/_typography.scss
+++ b/content/assets/css/_typography.scss
@@ -40,7 +40,7 @@ h3 {
   margin: 0;
   padding: 12px 0 8px 0;
   i {
-    margin-right: $base-unit/4;
+    margin-right: calc($base-unit / 4);
   }
 }
 
@@ -50,7 +50,7 @@ h5 {
 }
 
 p, pre, table {
-  margin: 0 0 $base-unit/1.5 0;
+  margin: 0 0 calc($base-unit / 1.5) 0;
 }
 
 a {
diff --git a/content/assets/css/style.scss b/content/assets/css/style.scss
index 564f2dec..e62b0a0f 100644
--- a/content/assets/css/style.scss
+++ b/content/assets/css/style.scss
@@ -7,7 +7,6 @@
 @import "../../dist/highlightjs/styles/github.css";
 @import "variables";
 @import "colorscheme";
-@import "mixins";
 @import "typography";
 @import "syntax";
 @import "template";