🐛(frontend) fix collaboration cursor

- The collaboration slider is not fully shown when a user is at the very
top of the document

src/frontend/apps/impress/src/features/docs/doc-editor/components/BlockNoteEditor.tsx

@@ -176,7 +176,11 @@ export const BlockNoteEditor = ({ doc, provider }: BlockNoteEditorProps) => {
   }, [setEditor, editor]);
 
   return (
-    <Box $css={cssEditor(readOnly)}>
+    <Box
+      $padding={{ top: 'md' }}
+      $background="white"
+      $css={cssEditor(readOnly)}
+    >
       {errorAttachment && (
         <Box $margin={{ bottom: 'big' }}>
           <TextErrors

src/frontend/apps/impress/src/features/docs/doc-header/components/DocHeader.tsx

@@ -64,7 +64,12 @@ export const DocHeader = ({ doc }: DocHeaderProps) => {
             </Text>
           </Box>
         )}
-        <Box $direction="row" $align="center" $width="100%">
+        <Box
+          $direction="row"
+          $align="center"
+          $width="100%"
+          $padding={{ bottom: 'xs' }}
+        >
           <Box
             $direction="row"
             $justify="space-between"
@@ -98,7 +103,7 @@ export const DocHeader = ({ doc }: DocHeaderProps) => {
             <DocToolBox doc={doc} />
           </Box>
         </Box>
-        <HorizontalSeparator $withPadding={true} />
+        <HorizontalSeparator $withPadding={false} />
       </Box>
     </>
   );