You're tasked with creating a webpage that should adapt to various screen sizes. How would you manage the content placement within the body to ensure responsiveness?

Implementing CSS Grid or Flexbox for layout management is a modern approach to design responsive web layouts. These techniques allow for fluid grid systems, which adapt to varying screen sizes without requiring separate designs for each size. Fixed widths are not responsive, designing different versions for each screen size isn't scalable or efficient, and adding more pages doesn't directly address responsiveness.