diff --git a/preview.css b/preview.css
index c1de137..40449c3 100644
--- a/preview.css
+++ b/preview.css
@@ -1,6 +1,11 @@
 html {
   font: 3mm tahoma,arial,helvetica,sans-serif;
   background-color: rgb(240, 240, 240);
+  box-sizing: border-box;
+}
+
+*, *:before, *:after {
+  box-sizing: inherit;
 }
 
 body {
@@ -35,6 +40,17 @@ a[href] img {
   border: none;
 }
 
+pre {
+  word-wrap: break-word;
+  word-break: break-all;
+}
+
+code {
+  display: block;
+  overflow: auto;
+  white-space: inherit;
+}
+
 #feedBody {
   border: 1px solid THreeDShadow;
   padding: 3em;