https://jgthms.com/web-design-in-4-minutes/

static/css/main.css

@@ -1,6 +1,8 @@
 body {
     display: flex;
     flex-flow: column wrap;
+    max-width: 50em;
+    line-height: 1.5em;
 }
 
 
@@ -14,6 +16,10 @@ img {
     max-width: 100%;
 }
 
+code, blockquote {
+    background: #eee;
+}
+
 /* Homepage */
 .intro > h1 {
     color: #212121;