Scope styles in LayoutPane

Fixed: 430520387
Change-Id: Ic709b1505490445b998aeec7375ad2dc9c91165b
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6718253
Commit-Queue: Philip Pfaffe <[email protected]>
Reviewed-by: Ergün Erdoğmuş <[email protected]>

Author: pfaffe

front_end/panels/elements/LayoutPane.ts

@@ -283,8 +283,8 @@ const DEFAULT_VIEW: View = (input, output, target) => {
   // clang-format off
   render(html`
       <div style="min-width: min-content;" jslog=${VisualLogging.pane('layout').track({resize: true})}>
-        <style>${layoutPaneStyles}</style>
-        <style>${UI.inspectorCommonStyles}</style>
+        <style>@scope to (devtools-widget) { ${layoutPaneStyles} }</style>
+        <style>@scope to (devtools-widget) { ${UI.inspectorCommonStyles} }</style>
         <details open>
           <summary class="header"
             @keydown=${input.onSummaryKeyDown}