added mixin

assets/sass/_theme/_utils.sass

@@ -442,6 +442,26 @@ $space-unit: 4 !default
     font-display: swap
     src: $src
 
+@mixin sidebar
+    @include in-page-with-sidebar
+        @include media-breakpoint-down(desktop)
+            padding: 0 half($grid-gutter-sm)
+            margin-bottom: $spacing3
+        @include media-breakpoint-up(desktop)
+            @include container-margin-left
+            margin-top: 0
+            top: 0
+            left: 0
+            height: 100%
+            position: absolute
+            width: col-outside-container(4)
+            &:not(.paper-sidebar)> div
+                @include sticky($spacing1)
+            .toc-container
+                border-top: 1px solid $color-border
+                padding-top: $spacing1
+                position: static
+                margin-left: 0
 
 // Old browsers support
 

assets/sass/_theme/design-system/layout.sass

@@ -123,27 +123,4 @@ details
                 position: absolute
                 padding: 0
                 right: 0
-                top: 0
-
-.posts__page,
-.events__page,
-.papers__page
-    .section-sidebar
-        @include media-breakpoint-down(desktop)
-            padding: 0 half($grid-gutter-sm)
-            margin-bottom: $spacing3
-        @include media-breakpoint-up(desktop)
-            @include container-margin-left
-            margin-top: 0
-            top: 0
-            left: 0
-            height: 100%
-            position: absolute
-            width: col-outside-container(4)
-            &:not(.paper-sidebar)> div
-                @include sticky($spacing1)
-            .toc-container
-                border-top: 1px solid $color-border
-                padding-top: $spacing1
-                position: static
-                margin-left: 0
\ No newline at end of file
+                top: 0
\ No newline at end of file

assets/sass/_theme/sections/events.sass

@@ -258,4 +258,8 @@
                     @include h3
                 &:not(.event--with-image)
                     width: col(5)
-                    margin-left: offset(4)
\ No newline at end of file
+                    margin-left: offset(4)
+
+
+.event-sidebar
+    @include sidebar
\ No newline at end of file

assets/sass/_theme/sections/papers.sass

@@ -138,4 +138,7 @@
             display: block
         p
             @include meta
-            margin-top: $spacing0
\ No newline at end of file
+            margin-top: $spacing0
+
+.paper-sidebar
+    @include sidebar
\ No newline at end of file

assets/sass/_theme/sections/posts.sass

@@ -21,6 +21,9 @@
         @include meta
         color: $color-text-alt
 
+.post-sidebar
+    @include sidebar
+
 .posts__section,
 .authors__term,
 .posts_categories__term,