diff --git a/custom.css b/custom.css
new file mode 100644
index 0000000..fb26489
--- /dev/null
+++ b/custom.css
@@ -0,0 +1,15 @@
+/* uhhm - the skin over portal's own stylesheet
+   (site.yaml `stylesheet`, loaded after main.css, so these rules win). */
+
+/* The way in sits beside the wordmark on every page. uhhm.no is read
+   and answered without an account, so the invitation is not shown.
+   Whoever edits the site still signs in at /auth/login directly, and
+   once signed in the nav keeps its name and its way out. */
+.session:has(a[href^="/auth/login"]) {
+  display: none;
+}
+
+/* Without :has(), the link alone goes and the empty nav stays. */
+.session a[href^="/auth/login"] {
+  display: none;
+}
diff --git a/site.yaml b/site.yaml
index 6d0b6da..20b5f10 100644
--- a/site.yaml
+++ b/site.yaml
@@ -5,6 +5,9 @@ hero:
   kind: module
   module: hero.js
 
+# The skin over portal's own stylesheet.
+stylesheet: custom.css
+
 # Mail goes out through gdo on this host, which sends over JMAP as
 # bl@uhhm.no; replies come back to the same address.
 mail: