Add 'error' page module using new mixins

scss/page/_main_page.scss

@@ -1,3 +1,4 @@
 @use '../utilities/main_utilities' as *;
 
-// Page specific stuff
+// Page specific stuff
+@use 'error/error';

scss/page/error/_error.scss

@@ -0,0 +1,25 @@
+@use '../../utilities/main_utilities' as *;
+
+.body--error{
+    display: flex !important;
+    align-items: center !important;
+    justify-content: center !important;
+    flex-direction: column !important;
+    height: 100% !important;
+    background: $color-bg;
+    color: $color-text;
+
+    @include color-scheme(dark) {
+        background: $color-bg--dark;
+        color: $color-text--dark;
+    }
+}
+
+.error-title{
+    font-size: 40px;
+    @include media($media-sm) { font-size: 80px; }
+}
+.error-text{
+    margin-top: 20px;
+    @include media($media-sm) { margin-top: 40px; }
+}