Unicode has superscript versions of numerical characters. These are however not always rendered correctly (e.g. they are currently broken on MacOSX and iOS with the default font). The reason is because the superscript character 1-3 are defined in separate code blocks from characters 0, 4-9. On Apple products, the default font has superscript characters 1-3 but falls back to a different font for the other numbers.
A simple fix would be for Apple to add the other superscript characters to the default font (or remove 1-3 and fallback for all superscript characters, but that might break software which doesn't implemenent font fallback).
This is a test page. You can compare how your browser renders with the default font vs screenshots of what I'm getting.
Some superscript numbers don't line up:
Your browser: x⁰, x¹, x², x³, x⁴, x⁵, x⁶, x⁷, x⁸, x⁹.
Screenshot of mine:
As a result, some of the following lines look like x^(ab), others look like x^a^b, and others just look broken.
Your browser:
x⁰⁰, x⁰¹, x⁰², x⁰³, x⁰⁴, x⁰⁵, x⁰⁶, x⁰⁷, x⁰⁸, x⁰⁹
x¹⁰, x¹¹, x¹², x¹³, x¹⁴, x¹⁵, x¹⁶, x¹⁷, x¹⁸, x¹⁹
x²⁰, x²¹, x²², x²³, x²⁴, x²⁵, x²⁶, x²⁷, x²⁸, x²⁹
x³⁰, x³¹, x³², x³³, x³⁴, x³⁵, x³⁶, x³⁷, x³⁸, x³⁹
x⁴⁰, x⁴¹, x⁴², x⁴³, x⁴⁴, x⁴⁵, x⁴⁶, x⁴⁷, x⁴⁸, x⁴⁹
x⁵⁰, x⁵¹, x⁵², x⁵³, x⁵⁴, x⁵⁵, x⁵⁶, x⁵⁷, x⁵⁸, x⁵⁹
x⁶⁰, x⁶¹, x⁶², x⁶³, x⁶⁴, x⁶⁵, x⁶⁶, x⁶⁷, x⁶⁸, x⁶⁹
x⁷⁰, x⁷¹, x⁷², x⁷³, x⁷⁴, x⁷⁵, x⁷⁶, x⁷⁷, x⁷⁸, x⁷⁹
x⁸⁰, x⁸¹, x⁸², x⁸³, x⁸⁴, x⁸⁵, x⁸⁶, x⁸⁷, x⁸⁸, x⁸⁹
x⁹⁰, x⁹¹, x⁹², x⁹³, x⁹⁴, x⁹⁵, x⁹⁶, x⁹⁷, x⁹⁸, x⁹⁹
Screenshot of mine:
Why do I care? Some Wikipedia pages use numerical superscript characters and can lead to mistakes!
Thanks to @FakeUnicode and @AlecMuffett for helping figure out what's going on!
* Unicode is working as designed here. It's unfortunate that related characters are in separate blocks since fonts are typically designed to cover specific set of blocks. A font can cherry-pick characters from any block.