Index: src/wp-content/themes/twentyfifteen/css/blocks.css
===================================================================
--- src/wp-content/themes/twentyfifteen/css/blocks.css	(revision 43866)
+++ src/wp-content/themes/twentyfifteen/css/blocks.css	(working copy)
@@ -59,6 +59,19 @@
 	}
 }
 
+/* Alignments */
+
+[class^="wp-block-"].alignleft,
+[class^="wp-block-"] .alignleft {
+	margin-right: 1em;
+}
+
+[class^="wp-block-"].alignright,
+[class^="wp-block-"] .alignright {
+	margin-left: 1em;
+}
+
+
 /*--------------------------------------------------------------
 2.0 Blocks - Common Blocks
 --------------------------------------------------------------*/
@@ -82,10 +95,12 @@
 	width: 100%;
 }
 
-/* Cover Image */
+/* Cover */
 
 .wp-block-cover-image .wp-block-cover-image-text,
-.wp-block-cover-image h2 {
+.wp-block-cover .wp-block-cover-text,
+.wp-block-cover-image h2,
+.wp-block-cover h2 {
 	font-size: 29px;
 	line-height: 1.2069;
 }
@@ -187,8 +202,11 @@
 /* Cover Image */
 
 .wp-block-cover-image.aligncenter,
+.wp-block-cover.aligncenter,
 .wp-block-cover-image.alignleft,
-.wp-block-cover-image.alignright {
+.wp-block-cover.alignleft,
+.wp-block-cover-image.alignright,
+.wp-block-cover.alignright {
 	display: flex;
 }
 
@@ -439,10 +457,29 @@
 	max-width: 100%;
 }
 
+/* Media & Text */
+
+.wp-block-media-text {
+	margin-bottom: 1.6em;
+}
+
+.wp-block-media-text *:last-child {
+	margin-bottom: 0;
+}
+
 /*--------------------------------------------------------------
 5.0 Blocks - Widgets
 --------------------------------------------------------------*/
 
+/* Archives, Categories & Latest Posts */
+
+.wp-block-archives.aligncenter,
+.wp-block-categories.aligncenter,
+.wp-block-latest-posts.aligncenter {
+	list-style-position: inside;
+	text-align: center;
+}
+
 /* Latest Comments */
 
 .wp-block-latest-comments {
Index: src/wp-content/themes/twentyfifteen/css/editor-blocks.css
===================================================================
--- src/wp-content/themes/twentyfifteen/css/editor-blocks.css	(revision 43866)
+++ src/wp-content/themes/twentyfifteen/css/editor-blocks.css	(working copy)
@@ -305,12 +305,14 @@
 
 /* Main column width */
 
-body.gutenberg-editor-page .edit-post-visual-editor .editor-post-title__block,
-body.gutenberg-editor-page .edit-post-visual-editor .editor-default-block-appender,
-body.gutenberg-editor-page .edit-post-visual-editor .editor-block-list__block {
-	max-width: 690px; /* 660px + 30px for the editor padding */
+.editor-styles-wrapper {
+	max-width: 100% !important; /* Override where editor-style.css is affecting this. */
 }
 
+.wp-block {
+	max-width: 690px; /* 660px + 30px to account for padding. */
+}
+
 /* Link styles */
 
 .edit-post-visual-editor a,
@@ -556,15 +558,16 @@
 	}
 }
 
-/* Cover Image */
+/* Cover */
 
 .edit-post-visual-editor .editor-block-list__block .wp-block-cover-image p,
-.wp-block-cover-image h2 {
+.edit-post-visual-editor .editor-block-list__block .wp-block-cover p,
+.wp-block-cover-image h2,
+.wp-block-cover h2 {
 	font-size: 29px;
 	line-height: 1.2069;
 }
 
-
 /* File */
 
 .wp-block-file .editor-rich-text__tinymce {
@@ -764,11 +767,26 @@
 	max-width: 100%;
 }
 
+/* Media & Text */
 
+.wp-block-media-text *:last-child {
+	margin-bottom: 0;
+}
+
+
 /*--------------------------------------------------------------
 6.0 Blocks - Widgets
 --------------------------------------------------------------*/
 
+/* Archives, Categories & Latest Posts */
+
+[data-align="center"] .wp-block-archives ul,
+[data-align="center"] .wp-block-categories ul,
+[data-align="center"] .wp-block-latest-posts ul {
+	list-style-position: inside;
+}
+
+
 /* Latest Comments */
 
 .wp-block-latest-comments {