For layout work, I highly suggest https://flexboxfroggy.com https://flexboxfroggy.com and https://cssgridgarden.com https://cssgridgarden.com. You'll end up wit

For layout work, I highly suggest https://flexboxfroggy.com https://flexboxfroggy.com and https://cssgridgarden.com https://cssgridgarden.com. You'll end up with a strong understanding of both display: flex and display: grid. Once you know how to (ab)use these, much of modern css just drops out.