diff --git a/README.md b/README.md
index 8615038..3077091 100644
--- a/README.md
+++ b/README.md
@@ -37,8 +37,8 @@ The format is mostly markdown, except for these modifications:
   - multi-line content allowed.
   - the prefix `@=latex=` will display its content in pdf only. There is no html-prefix equivalent.
 
-- Use `####` to create paragraph like sections. These sections are displayed in the margin. Like an index for quick reference. In mobile html they are normal `h4` headings.
-  - Of course `#`, `##`, and `###` are translated to `h1` to `h3` headings
+- Use `####` to create paragraphs and `#####` for paragraph-like sections. The latter are displayed in the margin. Like an index for quick reference. In mobile html they are normal `h5` headings.
+  - Of course `#`, `##`, and `###` translate to `h1` to `h3` headings.
 
 - You can add a reference-id to a title by adding `{#label}` after the title, e.g., `## Title {#title}`
   - other than that, all titles have implicit labels where spaces are replaced with dashes `My Title` becomes `my-title`
diff --git a/bin/custom.css b/bin/custom.css
index 9b9bbe6..d94267b 100755
--- a/bin/custom.css
+++ b/bin/custom.css
@@ -1,6 +1,7 @@
 @font-face { font-family: 'Roboto'; src: url(fonts/Roboto-Regular.otf); }  /* only h1-6, thus no italic */
 @font-face { font-family: 'Piazzolla'; src: url(fonts/Piazzolla.ttf); }
 @font-face { font-family: 'Piazzolla'; font-style: italic; src: url(fonts/Piazzolla-Italic.ttf); }
+@font-face { font-family: 'Iosevka'; src: url(fonts/iosevka-ss04-regular.ttf); }
 
 body {
   font-family: Piazzolla, Helvetica Neue, sans-serif;
@@ -10,6 +11,11 @@ b,strong { font-weight: 600; }
 h1,h2,h3,h4,h5,h6,.topnav {
   font-family: Roboto, Helvetica Neue, sans-serif;
 }
+pre, pre > code {
+  margin-left: 0.1em;
+  font-family: Iosevka, Menlo, Consolas, Courier, monospace;
+  font-size: 1rem;
+}
 #subtitle { margin-top: inherit; }
 @media (prefers-color-scheme: dark) {
     body { background: #17110E; color: #DDD; font-weight: 500; }
@@ -68,23 +74,28 @@ div.topnav {
 }
 
 /* Margin-Sections */
-p + .h4-spacer {
+p + .h5-spacer {
     margin-top: 2.2rem;
 }
-h4 {
-    display: none;
+h4,h5 {
     font-size: 1.4em;
     margin-bottom: 1rem;
 }
-h4 + p { margin-top: 0; }
+h4 + p, h5 + p { margin-top: 0; }
+h5 { display: none; }
 @media (max-width: 760px) {
-    .h4-spacer { display: none; }
-    h4 { display: inherit; }
-    h4 + p>.marginnote, h4 + p>.sidenote {
+    .h5-spacer { display: none; }
+    h5 { display: inherit; }
+    h5 + p>.marginnote, h5 + p>.sidenote {
         display: none;
     }
 }
 
+/* Support for Checkbox-Lists */
+input[type='checkbox'] { width: 1.4em; height: 1.4em; margin: 0 .5em 0 0; }
+li.checkbox { text-indent: -1.4em; }
+li.checkbox::marker { content: ''; }
+
 /* Override original Tufte CSS */
 
 p {
diff --git a/src/common-preamble.tex b/src/common-preamble.tex
index 8a20b5f..bb68e39 100755
--- a/src/common-preamble.tex
+++ b/src/common-preamble.tex
@@ -15,6 +15,7 @@
 \usepackage{url}
 \usepackage{graphicx}
 \usepackage{microtype}
+\usepackage{mathabx}
 
 \setmainfont[
   Path           = fonts/,
@@ -31,6 +32,7 @@
 ]{Roboto-Regular}
 \setmonofont[
   Path           = fonts/,
+  Scale          = 0.8,
   BoldFont       = {iosevka-ss04-bold},
   ItalicFont     = {iosevka-ss04-italic},
   BoldItalicFont = {iosevka-ss04-bolditalic}
@@ -61,6 +63,8 @@
 \renewcommand\allcapsspacing[1]{{\addfontfeature{LetterSpace=15}#1}}
 \renewcommand\smallcapsspacing[1]{{\addfontfeature{LetterSpace=10}#1}}
 
+\renewcommand\subsubsection\paragraph
+
 \newcommand{\marginsection}[1]{
   \if@noskipsec\leavevmode\fi \par
   \paragraph{}
diff --git a/src/rules-html-post.sed b/src/rules-html-post.sed
index c9d7a85..53ce0ce 100755
--- a/src/rules-html-post.sed
+++ b/src/rules-html-post.sed
@@ -1,3 +1,7 @@
 # Sectioning
 s?<h2?</section><section><h2?g
 s?</section><section><h2 class="no-sect"?<h2?g
+
+# TODO: define good option to toggle between non-/editable checkboxes
+#s?<li><input type="checkbox" disabled=""?<li><input type="checkbox"?g
+s?<li><input type="checkbox"?<li class="checkbox"><input type="checkbox"?g
diff --git a/src/rules-html-pre.sed b/src/rules-html-pre.sed
index 704c74f..846ae9c 100755
--- a/src/rules-html-pre.sed
+++ b/src/rules-html-pre.sed
@@ -3,8 +3,8 @@ s?\\,?<span style="white-space:nowrap">\&thinsp;</span>?g
 s?\\~?\&nbsp;?g
 
 # Margin note
-s?####[[:space:]]*\(.*\)$?<p class="h4-spacer"></p>\
-#### \1\
+s?#####[[:space:]]*\(.*\)$?<p class="h5-spacer"></p>\
+##### \1\
 @== \1 ==@?g
 
 # Use this to show margin notes inline
diff --git a/src/rules-tex-post.sed b/src/rules-tex-post.sed
index d52623a..9120b58 100755
--- a/src/rules-tex-post.sed
+++ b/src/rules-tex-post.sed
@@ -2,4 +2,10 @@
 s?@=\(latex\)\{0,1\}=[[:space:]]*?\\marginnote{?g
 s?[[:space:]]*==@?}?g
 # scale images
-s?\\marginnote{\\includegraphics?\\marginnote{\\includegraphics[width=1\\linewidth]?g
+s?\\marginnote{\\includegraphics?\\marginnote{\\includegraphics\[width=1\\linewidth\]?g
+
+# For proper clickable check boxes we need to increment the name ids :-/
+#s?\\item\[\$\\square\$\]?\\item\[\\CheckBox{}\]?g
+#s?\\item\[\$\\boxtimes\$\]?\\item\[\\CheckBox\[checked\]{}\]?g
+# OR
+s?\\item\[\$\\square\$\]?\\item\[\$\\Box\$\]?g
diff --git a/src/rules-tex-pre.sed b/src/rules-tex-pre.sed
index 73ec582..00d9f56 100755
--- a/src/rules-tex-pre.sed
+++ b/src/rules-tex-pre.sed
@@ -6,4 +6,4 @@ s?<dt>?\\item[?g
 s?</dt>?] ?g
 s?<dd>??g
 s?</dd>??g
-s?####[[:space:]]*\(.*\)$?\\marginsection{\1}?g
+s?#####[[:space:]]*\(.*\)$?\\marginsection{\1}?g