Index: src/wp-content/themes/twentyseventeen/assets/css/blocks.css
===================================================================
--- src/wp-content/themes/twentyseventeen/assets/css/blocks.css	(revision 43845)
+++ src/wp-content/themes/twentyseventeen/assets/css/blocks.css	(working copy)
@@ -97,11 +97,14 @@
 	width: 100%;
 }
 
-/* Cover Image */
+/* Cover */
 
 .wp-block-cover-image.alignright,
+.wp-block-cover.alignright,
 .wp-block-cover-image.alignleft,
-.wp-block-cover-image.aligncenter {
+.wp-block-cover.alignleft,
+.wp-block-cover-image.aligncenter,
+.wp-block-cover.aligncenter {
 	display: flex;
 }
 
@@ -219,10 +222,24 @@
 	max-width: 100px;
 }
 
+/* Media & Text */
+
+.wp-block-media-text {
+	margin-bottom: 1.5em;
+}
+
 /*--------------------------------------------------------------
 5.0 Blocks - Widgets
 --------------------------------------------------------------*/
 
+/* Archives, Categories & Latest Posts */
+
+.wp-block-archives.aligncenter,
+.wp-block-categories.aligncenter,
+.wp-block-latest-posts.aligncenter {
+	text-align: center;
+}
+
 /* Comments */
 
 .wp-block-latest-comments article {
Index: src/wp-content/themes/twentyseventeen/assets/css/editor-blocks.css
===================================================================
--- src/wp-content/themes/twentyseventeen/assets/css/editor-blocks.css	(revision 43845)
+++ src/wp-content/themes/twentyseventeen/assets/css/editor-blocks.css	(working copy)
@@ -25,6 +25,10 @@
 	font-size: 0.9375rem;
 }
 
+.editor-default-block-appender input[type="text"].editor-default-block-appender__content {
+	font-family: "Libre Franklin", "Helvetica Neue", helvetica, arial, sans-serif;
+}
+
 .edit-post-visual-editor .editor-block-list__block {
 	color: #333;
 }
@@ -346,12 +350,14 @@
 
 /* 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: 740px;
+.editor-styles-wrapper {
+	max-width: 100% !important; /* Override where editor-style.css is affecting this. */
 }
 
+.wp-block {
+	max-width: 674px; /* Based on one-column post width; 644px + 30px to account for padding. */
+}
+
 /* Background color */
 
 .gutenberg-editor-page .editor-block-list__block {