diff --git a/_static/css/custom.css b/_static/css/custom.css
index f17f4799c..713d9a11c 100644
--- a/_static/css/custom.css
+++ b/_static/css/custom.css
@@ -48,6 +48,7 @@
     --search-credits-link-color: #4392c5; /* derived from --link-color */
 
     --highlight-background-color: #f5ffe1;
+    --highlight-background-emph-color: #dbe6c3;
     --highlight-default-color: #404040;
     --highlight-comment-color: #408090;
     --highlight-keyword-color: #007020;
@@ -133,6 +134,7 @@
 
         /* Colors taken from the Godot script editor with the Adaptive theme */
         --highlight-background-color: #202531;
+        --highlight-background-emph-color: #2d3444;
         --highlight-default-color: rgba(255, 255, 255, 0.85);
         --highlight-comment-color: rgba(204, 206, 211, 0.5);
         --highlight-keyword-color: #ff7085;
@@ -536,6 +538,11 @@ code,
     background-color: var(--highlight-background-color);
 }
 
+/* Emphasized lines */
+.highlight .hll {
+    background-color: var(--highlight-background-emph-color);
+}
+
 .highlight .gh /* Generic.Heading */,
 .highlight .gu /* Generic.Subheading */,
 .highlight .go /* Generic.Output */,