diff --git a/static/css/app.css b/static/css/app.css
index 5827f44..ae33a79 100644
--- a/static/css/app.css
+++ b/static/css/app.css
@@ -1726,6 +1726,7 @@ body.reader-immersive.reader-show-bottom .reader-overlay  { bottom: var(--bar-h)
 
 /* Highlight marks */
 .reader-no-bold * { font-weight: normal !important; }
+.reader-content img { max-width: 100%; height: auto; display: block; }
 .epub-highlight { border-radius:2px; cursor:pointer; }
 .epub-highlight[data-color="yellow"] { background:rgba(241,196,15,.4); }
 .epub-highlight[data-color="green"]  { background:rgba(46,204,113,.35); }