diff --git a/routes/css.cpp b/routes/css.cpp
index 4e5ffee..9935314 100644
--- a/routes/css.cpp
+++ b/routes/css.cpp
@@ -45,6 +45,10 @@ html {
     padding: 10px;
     overflow-wrap: break-word;
 }
+pre {
+    /* https://stackoverflow.com/a/248013 */
+    white-space: pre-wrap;
+}
 
 img {
     object-fit: cover;