diff --git a/assets/style.css b/assets/style.css
index 352b4f4..8aa8850 100644
--- a/assets/style.css
+++ b/assets/style.css
@@ -133,6 +133,30 @@ pre {
     display: none;
 }
 
+aside {
+    padding: 5px;
+    border: solid 1px black;
+    margin-left: 2rem;
+    margin-right: 2rem;
+    margin-top: 35px;
+    margin-bottom: 35px;
+}
+
+aside > :first-child {
+    margin-top: 0;
+}
+
+aside > :last-child {
+    margin-bottom: 0;
+}
+
+.guide aside::before {
+    content: "➔";
+    float: left;
+    margin-right: 1ex;
+    margin-left: 5px;
+}
+
 @media print {
     header a {
         display: none;