diff --git a/rtfd/public/html/index.css b/rtfd/public/html/index.css
index 7443cd6..fab050a 100644
--- a/rtfd/public/html/index.css
+++ b/rtfd/public/html/index.css
@@ -1,3 +1,11 @@
+/*
+block-size ← height
+inline-size ← width
+margin-block ← vspace
+padding-block[-start|end]
+padding-inline[-start|end]
+*/
+
 html {
 }
 
@@ -36,6 +44,10 @@ background-color: #033;
 margin-block: 4rem;
 }
 
+strong {
+color: red;
+}
+
 ol, ul {
 background-color: #303;
 }
@@ -50,5 +62,6 @@ color: #f77;
 
 footer {
 background-color: #003;
+padding: 1rem 2rem;
 text-align: end;
 }