Convert to container queries

[thomaswilburn]

We do a lot of small multiples in the rig, and that causes problems when the graphic is sized according to the viewport, so it makes visual choices like a big chart even though it's very small. By switching to container queries, we can avoid this completely. We may need to pick a standard wrapper class for charts to make that possible, or we can just continue hanging it on .graphic and make sure we use that consistently.

We can make this change when Safari 18 drops, since that will mean 2 major versions of support there, and it's the big laggard.