Hello @Valholy, if you are looking to build a Shiny application with a more flexible layout I suggest the yonder package. I built the package, in part, to tackle situations like these.
You would most likely be interested in the container(), columns(), column(), and flexbox() functions. Flex box is a CSS layout system and is quite powerful. An introduction to flex box can be found here https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Flexible_Box_Layout/Basic_Concepts_of_Flexbox. The yonder::flexbox() function is a helper function to apply flex box styling to elements of an application. I tried to make the ?flexbox help page accessible for new developers, so check out the page in addition to any online resources.
You might also like the height() and width() utilities to help specify fixed or relative element sizes.