Remove sidebar on mobile

Hi there!

I am having trouble hiding the sidebar on mobile. I am using the visual composer wigetised sidebar. I have added the following css from a few earlier posts:

@media (max-width: 767px) {
.post .td-main-sidebar {
display: none;
}
}

It is still showing up. I am using the infinite-scroll within a block13.

Thanks!

I finally got it to work adding the following lines to the custom css>advanced css>phones in the theme panel.

.wpb_widgetised_column {
display: none;
}