diff --git a/sources/_static/custom.css b/sources/_static/custom.css
index a351cb4..175d283 100644
--- a/sources/_static/custom.css
+++ b/sources/_static/custom.css
@@ -1,3 +1,16 @@
+/* External link tweak. */
+article a[href^="http"]::after {
+    content: "";
+    width: 11px;
+    height: 11px;
+    margin-left: 4px;
+    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='currentColor' viewBox='0 0 16 16'%3E%3Cpath fill-rule='evenodd' d='M8.636 3.5a.5.5 0 0 0-.5-.5H1.5A1.5 1.5 0 0 0 0 4.5v10A1.5 1.5 0 0 0 1.5 16h10a1.5 1.5 0 0 0 1.5-1.5V7.864a.5.5 0 0 0-1 0V14.5a.5.5 0 0 1-.5.5h-10a.5.5 0 0 1-.5-.5v-10a.5.5 0 0 1 .5-.5h6.636a.5.5 0 0 0 .5-.5z'/%3E%3Cpath fill-rule='evenodd' d='M16 .5a.5.5 0 0 0-.5-.5h-5a.5.5 0 0 0 0 1h3.793L6.146 9.146a.5.5 0 1 0 .708.708L15 1.707V5.5a.5.5 0 0 0 1 0v-5z'/%3E%3C/svg%3E");
+    background-position: center;
+    background-repeat: no-repeat;
+    background-size: contain;
+    display: inline-block;
+}
+
 /* Home page title. */
 section#base-de-connaissances-du-luma h1 {
     text-align: center;