Anderson Shindy Oki

Upgrade mantine to v7.x

1

# Description The main change on the Mantine V7 is that they removed the usage of Emotion and now all the customizations diretly from CSS in JS is not recommended,...

Closes #87. We currently try to parse the value to int assuming it is required, but it can be omitted to fallback as default as empty in the subtitles.

# Description When trying to parse an SSAFile from string using `pysubs2.SSAFile.from_string(text)` where the content of the Events of `Layer` is an empty string that represents a single layer, mostly...