Designing navigation is an art in itself, and designers become better at it with experience. It’s all about using good information architecture: “the art of expressing a model or concept of information used in activities that require explicit details of complex systems.”
We’ve scientifically determined the maximum amount of time that you should need to make a layout work in CSS: it’s 47 minutes. When your time is up, we’ll even give you the table code you need. Take three minutes to build a table. And ten minutes to get a donut. Bill the client for an hour. Done.