diff --git a/diary/2020-04-22.md b/diary/2020-04-22.md
index adc1d37c..308f8eff 100644
--- a/diary/2020-04-22.md
+++ b/diary/2020-04-22.md
@@ -134,6 +134,10 @@ ins.addition, .substitution ins {
     background-color: #d4fcbc;
 }
 
+mark.selected {
+    background-color: #ddf;
+}
+
 q.comment {
     display: block;
     float: right;
@@ -164,7 +168,7 @@ q.comment::before, q.comment::after {
     clear: both;
 }
 
-q.comment::before {
+p q.comment::before {
     /* Add an arrow pointing back to the line. */
     width: 0;
     height: -0.5rem;
@@ -176,6 +180,30 @@ q.comment::before {
     margin-top: calc(-0.5rem - 1.195px);
 }
 
+ins q.comment::before {
+    border-right-color: #ceebab;
+}
+
+ins q.comment {
+    background-color: #d4fcbc;
+}
+
+del q.comment::before {
+    border-right-color: #daa;
+}
+
+del q.comment {
+    background-color: #fbb;
+}
+
+mark q.comment::before {
+    border-right-color: #ddf;
+}
+
+mark q.comment {
+    background-color: #eef;
+}
+
 q.comment q.comment::before {
     /* don't add arrow on nested comments. */
     border: none;