Index: wp-content/themes/twentyten/editor-style-rtl.css
===================================================================
--- wp-content/themes/twentyten/editor-style-rtl.css	(revision 59114)
+++ wp-content/themes/twentyten/editor-style-rtl.css	(working copy)
@@ -27,3 +27,8 @@
 	text-align: right;
 	margin: 0 0 24px -1px;
 }
+/* Details block */
+details p{
+	font-size: 12px;
+    line-height: 18px;
+}
\ No newline at end of file
Index: wp-content/themes/twentyten/editor-style.css
===================================================================
--- wp-content/themes/twentyten/editor-style.css	(revision 59114)
+++ wp-content/themes/twentyten/editor-style.css	(working copy)
@@ -295,3 +295,8 @@
 .wp-smiley {
 	margin: 0;
 }
+/* Details block */
+details p{
+	font-size: 12px;
+    line-height: 18px;
+}
\ No newline at end of file