Center content on error and single page layouts (#2060)

.changeset/little-garlics-begin.md

@@ -0,0 +1,5 @@
+---
+"@tabler/core": patch
+---
+
+Center content on error and single page layouts

src/pages/_layouts/error.html

@@ -3,7 +3,7 @@ layout: base
 body-class: border-top-wide border-primary d-flex flex-column
 ---
 
-<div class="page my-auto">
+<div class="page justify-content-center">
 	<div class="container-tight py-4">
 		{% assign error = site.data.errors[page.error] %}
 		{% assign header = error.header | default: 'Oops… You just found an error page' %}

src/pages/_layouts/single.html

@@ -3,7 +3,7 @@ layout: base
 body-class: d-flex flex-column
 ---
 
-<div class="page my-auto">
+<div class="page justify-content-center">
 	<div class="container container-{{ page.container-size | default: 'tight' }} py-4">
 
 		{% unless page.hide-logo %}