CSS Logical Shorthands

These days, it's a common practice to use logical flow-relative properties & values like `block-size` whenever possible. But the shorthand properties feel stuck in the past. It's surprising that a `size` shorthand can't set the `inline-size`, and the `inset` shorthand doesn't include `inset-block-start`. There are several proposals to move forward, but they've been stalled in the Working Group for several years – waiting for someone to do the necessary background research. Let's make it happen!