diff --git a/app-proto/main.css b/app-proto/main.css
index 46bdf84..a1ff9da 100644
--- a/app-proto/main.css
+++ b/app-proto/main.css
@@ -24,7 +24,7 @@ body {
   display: flex;
   flex-direction: column;
   float: left;
-  width: 450px;
+  width: 500px;
   height: 100vh;
   margin: 0px;
   padding: 0px;
@@ -128,6 +128,11 @@ details[open]:has(li) .element-switch::after {
   font-style: italic;
 }
 
+.observable-type {
+  padding: 2px 8px 0px 8px;
+  font-size: 10pt;
+}
+
 .observable.invalid-constraint {
   color: var(--text-invalid);
 }
diff --git a/app-proto/src/outline.rs b/app-proto/src/outline.rs
index d2f9058..f341357 100644
--- a/app-proto/src/outline.rs
+++ b/app-proto/src/outline.rs
@@ -68,6 +68,7 @@ fn ObservableOutlineItem(observable_key: ObservableKey, element_key: ElementKey)
     view! {
         li(class=class.get()) {
             div(class="observable-label") { (other_subject_label) }
+            div(class="observable-type") { "Inversive distance" }
             ObservableInput(observable=observable)
             div(class="status")
         }