I don't entirely understand this, but I think horizontal and vertical are often treated differently in CSS, yes? Like an item without width or height set will

I don't entirely understand this, but I think horizontal and vertical are often treated differently in CSS, yes? Like an item without width or height set will in some cases have width constrained by it's parent element, but height will not be (and can even cause parent element to grow). And I feel like it would end up weird and not what you wanted if it wasn't that way. I may not have this exactly right, but i have an intuition that width and height are treated differently by CSS, and the aspect-ratio example is a consequence of some other fundamental rule/principle, not something unique to aspect-ratio. Maybe someone else can explain this more specifically.