diff --git a/doc/themes/scikit-learn/static/nature.css_t b/doc/themes/scikit-learn/static/nature.css_t
index 05546aba61a06..2049a2e9ab618 100644
--- a/doc/themes/scikit-learn/static/nature.css_t
+++ b/doc/themes/scikit-learn/static/nature.css_t
@@ -342,7 +342,7 @@ div.bodywrapper h1 {
     text-align: center;
     background-color: #cde8ef;
     font-family: Helvetica, Arial, sans-serif;
-    font-size: 250%;
+    font-size: 190%;
     border-radius: 0 15px 0 15px;
     -moz-border-radius: 0 15px 0 15px;
 }