Improve _FilePanel.scss (#9031)
Improve _FilePanel.scss (#9031)

Signed-off-by: Suguru Hirahara <4ee41141f41dad19127963eb65a2461cc3bc0d81@users.noreply.github.com>
matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk