Text misalignment when using '@' followed by a number in Inter font

[leonschwanitz]

Describe the bug
When using the Inter font, entering an @ symbol followed by a number causes the text to shift upward. This issue was observed during login on the website https://authenticator.cursor.sh/. For example, typing test@2 triggers the problem.

To Reproduce
Steps to reproduce the behavior:

Navigate to https://authenticator.cursor.sh/.

In the login field, enter any text followed by @ and a number (e.g., test@2).

Observe the text shifting upward.

Expected behavior
The text should remain aligned consistently without any unexpected shifts, regardless of the input.

Additional context
The issue might relate to how the font handles specific character combinations. This behavior could be problematic in login forms and other input fields where such combinations are common.

[kepstin]

This behaviour is part of the calt (Contextual Alternatives) feature of Inter, which is enabled by default. It provides alternate rendering of certain glyphs based on context (i.e. depending on other characters are nearby).

The calt feature is intended for use with "script" fonts which need to replace certain character glyphs so they all join smoothly, but Inter is overloading (misusing?) the feature it to do other types of replacements.

If you are using Inter as a web font, you can use the CSS font-feature-settings: "calt" off; to disable this. (Firefox supports putting this in the @font-face rule to affect only one font, but this doesn't work in Chrome where you have to apply the property to HTML elements instead, and it will affect all fonts).

I personally think that most of the things that Inter does by default via the calt feature aren't suitable to be enabled by default for a general purpose font, but should instead be off-by-default optional features.