diff --git a/src/wp-activate.php b/src/wp-activate.php
index 103df0364e973..4631f8f252d50 100644
--- a/src/wp-activate.php
+++ b/src/wp-activate.php
@@ -101,12 +101,16 @@ function do_activate_header() {
 function wpmu_activate_stylesheet() {
 	?>
 	<style>
-		.wp-activate-container { width: 90%; margin: 0 auto; }
-		.wp-activate-container form { margin-top: 2em; }
-		#submit, #key { width: 100%; font-size: 24px; box-sizing: border-box; }
+		.wp-activate-container { max-width: 1280px; width: 100%; margin: 0 auto; text-align: start; background: #fff; color: #333; padding: 1.5rem; box-sizing: border-box; }
+		.wp-activate-container form { margin: 1.5rem 0; }
+		.wp-activate-container a { color: #2271b1; }
+		.wp-activate-container p { font-size: 18px; }
+		#submit, #key { font-size: 24px; box-sizing: border-box; }
+		#key { width: 100%; }
+		#submit { width: auto; }
 		#language { margin-top: 0.5em; }
-		.wp-activate-container .error { background: #f66; color: #333; }
-		span.h3 { padding: 0 8px; font-size: 1.3em; font-weight: 600; }
+		.wp-activate-container .error { background: #f86; color: #333; }
+		span.h3 { font-weight: 600; }
 	</style>
 	<?php
 }
@@ -166,7 +170,7 @@ function wpmu_activate_stylesheet() {
 			?>
 			<h2><?php _e( 'An error occurred during the activation' ); ?></h2>
 			<?php if ( is_wp_error( $result ) ) : ?>
-				<p><?php echo esc_html( $result->get_error_message() ); ?></p>
+				<p class="error"><?php echo esc_html( $result->get_error_message() ); ?></p>
 			<?php endif; ?>
 			<?php
 		} else {