Index: src/wp-content/themes/twentysixteen/css/editor-blocks.css
===================================================================
--- src/wp-content/themes/twentysixteen/css/editor-blocks.css	(revision 58395)
+++ src/wp-content/themes/twentysixteen/css/editor-blocks.css	(working copy)
@@ -262,18 +262,14 @@
 
 /* Captions */
 
-[class^="wp-block-"] figcaption {
+figure[class*="wp-block-"] > figcaption {
 	color: #686868;
 	font-style: italic;
 	line-height: 1.6153846154;
 	padding-top: 0.5384615385em;
-	text-align: left;
+	text-align: start;
 }
 
-.rtl [class^="wp-block-"] figcaption {
-	text-align: right;
-}
-
 /*--------------------------------------------------------------
 3.0 Blocks - Common Blocks
 --------------------------------------------------------------*/
Index: src/wp-content/themes/twentysixteen/css/editor-style.css
===================================================================
--- src/wp-content/themes/twentysixteen/css/editor-style.css	(revision 58395)
+++ src/wp-content/themes/twentysixteen/css/editor-style.css	(working copy)
@@ -313,19 +313,22 @@
 .mce-item-table th,
 table caption {
 	border-width: 0 1px 1px 0;
-	font-size: 16px;
 	font-weight: 700;
 	padding: 7px;
-	text-align: left;
+	text-align: start;
 	vertical-align: baseline;
 }
 
+table caption {
+	font-weight: normal;
+}
+
 table td,
 .mce-item-table td {
 	border-width: 0 1px 1px 0;
-	font-size: 16px;
 	padding: 7px;
 	vertical-align: baseline;
+	text-align: start;
 }
 
 img {
@@ -502,6 +505,10 @@
  * 8.0 - RTL
  */
 
+[dir="rtl"] body {
+	font-family: Arial, Tahoma, sans-serif;
+}
+
 .rtl blockquote {
 	border: 0 solid #1a1a1a;
 	border-right-width: 4px;
@@ -533,9 +540,3 @@
 	margin-right: 24px;
 	margin-left: auto;
 }
-
-.rtl table th,
-.rtl .mce-item-table th,
-.rtl table caption {
-	text-align: right;
-}