diff --git a/media/tabs.css b/media/tabs.css
index 93f22dd..fa8f90a 100644
--- a/media/tabs.css
+++ b/media/tabs.css
@@ -160,6 +160,16 @@ button.marker:focus-visible {
     outline-offset: -1px;
 }
 
+/* The pin leans over while it is only an offer; once the tab is really pinned it
+   stands upright, so the state reads apart from the hover affordance. */
+button.pin svg {
+    transition: transform 80ms ease-out;
+}
+
+button.pin.on svg {
+    transform: rotate(-45deg);
+}
+
 /* An unsaved file shows a dot, which the close button replaces on hover. */
 .dirty {
     flex: 0 0 auto;