Build accessible interfaces with practical guides on semantics, ARIA, keyboard navigation, and testing. Implementation detail, not the argument.
The business case for accessibility has been made a thousand times. What is harder to find is the implementation detail, so this skips the argument and goes to the code.
Mobile stopped being a special case a decade ago. The hard parts now are viewport units that lie, forms that fight the keyboard, and devices with CPUs unlike yours.
Designing a Ghost theme is the easy part. The time goes into a handful of boundary problems where Ghost doesn't give you control, and none of them is documented.