Hi
Try to add the following codes into “Oldcar options > custom code > javascript code”
jQuery(document).ready(function($){
function resetMain(){
var sidebarWidth=$('#sidebar').width();
var mainWidth=$(window).width()-sidebarWidth-60;
if($(window).width()> 1023){
$('#main').css('width',mainWidth+'px');
}else{
$('#main').css('width','auto');
}
}
resetMain();
$(window).resize(function(){
resetMain();
});
});
If you found any issues after you added this code, please let me know, I will keep improve.
Also, after I release the next version and you update the theme in the future, you can remove the additional code above.
Thanks for your feedback!