Your own custom CSS is floating this right (even in ltr) so Use this code...
html[dir="ltr"] .sprocket-strips-container-ar > li {
float: left ;
}
Make sure it is AFTER your existing statement.
To create a custom CSS compatible with Gantry 5 please read this
http://docs.gantry.org/gantry5/tutorials/adding-a-custom-style-sheet
.
Remember to recompile CSS from base outline too.
Regards, Mark.