diff --git a/TODOS.md b/TODOS.md
index 1847489..a4eb9c6 100644
--- a/TODOS.md
+++ b/TODOS.md
@@ -23,6 +23,9 @@
 - [ ] Reconsider `"menus": {}` opt-out: it currently discards all page frontmatter
       menus (with only a warning). Decide whether empty config should instead just
       suppress the auto-generated menu while still honoring frontmatter.
+- [ ] asset css files not  automatically  included in site.
+  - should we at least warn about them?
+- [ ] warn if stylesheet url starts with /assets  (and is therefore invalid).
 - [ ] warn when heading levels are skipped in a toc.
 - [ ] extract `[TOC]` from `.md` body (or at least from  the start.)
 
diff --git a/defaults/layouts/partials/styles.html b/defaults/layouts/partials/styles.html
index 78c4e7b..356ed90 100644
--- a/defaults/layouts/partials/styles.html
+++ b/defaults/layouts/partials/styles.html
@@ -230,4 +230,5 @@ label.margin-toggle:not(.sidenote-number) {
 }
 </style>
 {{/params.stylesheets}}
-{{#params.stylesheets}}<link rel="stylesheet" href="{{.|rel_url}}">{{/params.stylesheets}}
+{{#params.stylesheets}}<link rel="stylesheet" href="{{.|rel_url}}">
+{{/params.stylesheets}}
diff --git a/site/assets/css/main.css b/site/assets/css/main.css
new file mode 100644
index 0000000..f49e8f2
--- /dev/null
+++ b/site/assets/css/main.css
@@ -0,0 +1,28 @@
+body>header {
+  background: var(--pico-primary-background);
+  position: sticky;
+  top: 0;
+
+  nav>ul li a {
+    color: var(--pico-primary-inverse);
+  }
+}
+
+/* TODO: Should probaby use a container for the page content like Odin does */
+.toc {
+  position: fixed;
+  height: calc(100vh - 116px);
+  width: 280px;
+  top: 116px;
+  left: 0;
+  overflow-y: auto;
+
+  & ul {
+    flex-direction: column;
+  }
+}
+
+main>article {
+  width: 60%;
+  margin: auto;
+}
\ No newline at end of file
diff --git a/site/thor.json b/site/thor.json
index 00ce1b1..8960571 100644
--- a/site/thor.json
+++ b/site/thor.json
@@ -20,7 +20,8 @@
       "name": "Spencer Brower"
     },
     "stylesheets": [
-      "https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.blue.min.css"
+      "https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.blue.min.css",
+      "/css/main.css"
     ]
   }
 }
\ No newline at end of file