diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9d771af7ae8b544fce111477d1da814d4f958061..380a99d55dee788f91830c21018c82873ca005b1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,9 @@
 image: omalaspinas/pandoc:latest
 
+variables:
+  GIT_SUBMODULE_STRATEGY: recursive
+
+
 before_script:
    ##
    ## Install ssh-agent if not already installed, it is required by Docker.
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000000000000000000000000000000000..822f448577fd54bc1a81827516065bc405f49fb7
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "css/tufte-css"]
+	path = css/tufte-css
+	url = https://github.com/edwardtufte/tufte-css.git
diff --git a/Makefile b/Makefile
index 47639cc2d7affb9ba26c1d5c1c1350478b27d18b..c07dc3a3ef7ad1602877876114adcb2677ff7f72 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ PDFOPTIONS += --number-sections
 PDFOPTIONS += --template=./default.latex
 
 HTMLOPTIONS += -t html5
-HTMLOPTIONS += -c css/styling.css
+HTMLOPTIONS += -c css/tufte-css/tufte.css
 HTMLOPTIONS += --self-contained
 
 all: base_2.pdf base_1.pdf intro.pdf index.html
diff --git a/css/tufte-css b/css/tufte-css
new file mode 160000
index 0000000000000000000000000000000000000000..c414b9117d5b39bdb747a172822333fc1043aee3
--- /dev/null
+++ b/css/tufte-css
@@ -0,0 +1 @@
+Subproject commit c414b9117d5b39bdb747a172822333fc1043aee3