Override styling on notebook close button to make it more subtle when delete...

Override styling on notebook close button to make it more subtle when delete annotation modal is open

src/annotator/components/NotebookModal.tsx

@@ -124,6 +124,13 @@ export default function NotebookModal({
             title="Close the Notebook"
             onClick={onClose}
             variant="dark"
+            classes={classnames(
+              // Remove the dark variant's background color to avoid
+              // interfering with modal overlays. Re-activate the dark variant's
+              // background color on hover.
+              // See https://github.com/hypothesis/client/issues/3676
+              '!bg-transparent enabled:hover:!bg-grey-3'
+            )}
           >
             <CancelIcon className="w-4 h-4" />
           </IconButton>