Index: wp-content/themes/twentyseventeen/assets/css/editor-style.css
===================================================================
--- wp-content/themes/twentyseventeen/assets/css/editor-style.css	(revision 53101)
+++ wp-content/themes/twentyseventeen/assets/css/editor-style.css	(working copy)
@@ -579,3 +579,6 @@
 .rtl .mejs-offscreen {
 	right: -10000px;
 }
+.wp-block-button .wp-block-button__link {
+    font-size: inherit;
+}
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