refactor: pass-through containers in BS5 only (#3960)

NEWS.md

@@ -2,7 +2,7 @@
 
 ## Breaking changes
 
-* Both `conditionalPanel()` and `uiOutput()` are now styled with `display: contents` by default. This means that the elements they contain are positioned as if they were direct children of the parent container holding the `conditionalPanel()` or `uiOutput()`. This is probably what most users intend when they use these functions, but it may break apps that applied styles directly to the container elements created by these two functions. In that case, you may include CSS rules to set `display: block` for the `.shiny-panel-conditional` or `.shiny-html-output` classes. (#3957)
+* Both `conditionalPanel()` and `uiOutput()` are now styled with `display: contents` by default in Shiny apps that use Bootstrap 5. This means that the elements they contain are positioned as if they were direct children of the parent container holding the `conditionalPanel()` or `uiOutput()`. This is probably what most users intend when they use these functions, but it may break apps that applied styles directly to the container elements created by these two functions. In that case, you may include CSS rules to set `display: block` for the `.shiny-panel-conditional` or `.shiny-html-output` classes. (#3957, #3960)
 
 ## New features and improvements
 

inst/www/shared/shiny_scss/shiny.bootstrap5.scss

@@ -37,3 +37,9 @@ $notification-content-action-color: RGB(var(--#{$prefix}primary-rgb, #{to-rgb($p
 $datepicker-disabled-color:         $dropdown-link-disabled-color !default;
 
 $shiny-file-active-shadow:          $input-focus-box-shadow !default;
+
+/* Treat conditional panels and uiOutput as "pass-through" containers */
+.shiny-panel-conditional,
+div:where(.shiny-html-output) {
+  display: contents;
+}

inst/www/shared/shiny_scss/shiny.scss

@@ -469,9 +469,3 @@ html.autoreload-enabled #shiny-disconnected-overlay.reloading {
   /* override anything bootstrap sets for `.nav` */
   display: none !important;
 }
-
-/* Conditional panels and uiOutput */
-.shiny-panel-conditional,
-div:where(.shiny-html-output) {
-  display: contents;
-}