diff --git a/assets/css/style.css b/assets/css/style.css
index 9708038..f639d6f 100644
--- a/assets/css/style.css
+++ b/assets/css/style.css
@@ -1382,3 +1382,18 @@ a.next-page-btn:hover {
 .content pre::-webkit-scrollbar-thumb:hover {
   background: #afb8c1 !important;
 }
+
+/* Line length. Running text is capped at about 80 characters per line.
+   Paragraphs and list items that hold an image, video, embed, table, code
+   block or other layout keep the full width of their container. */
+main :is(p, li):not(:has(img, video, iframe, table, pre, div)) {
+  max-width: 40em !important;
+}
+
+/* Keep centered paragraphs centered once they are narrower than their
+   container. */
+main .text-center p,
+main p.text-center {
+  margin-left: auto;
+  margin-right: auto;
+}