diff --git a/html/book.css b/html/book.css
index 86339c1..6fee7e1 100644
--- a/html/book.css
+++ b/html/book.css
@@ -49,11 +49,20 @@ h2 {
   text-align: center;
 }
 
+figure {
+  text-align: center;
+}
+
 pre, table {
   overflow: scroll;
   width: 100%;
 }
 
+caption {
+  font-weight: bold;
+  margin-bottom: 20px;
+}
+
 pre {
   line-height: 1em;
 }