Hi Jakub,
It is because the paddings added to the div made the total width of the 2 div more than 100%.
As you can see, if we disable the paddings, the layout would be normal:
https://www.screencast.com/t/ovgA6KeWj
1. Add this CSS to remove the paddings:
.site-content .tutor-course-filter-wrapper>div {
padding: 0;
}
2. The filter wrapper’s max width is set to 1140px which I think is too narrow. It’s better to increase both the wrapper max width and the container width at customizer > layout > container.