Nested @supports {} problems; parsing material.grey-pink.min.css

[promptio]

Unhandled rejection Error: Error: Unexpected } (line 4548, char 1)

@supports (-webkit-appearance:none) {
.mdl-progress:not(.mdl-progress--indeterminate):not(.mdl-progress--indeterminate)>.auxbar,
.mdl-progress:not(.mdl-progress__indeterminate):not(.mdl-progress__indeterminate)>.auxbar {
background-image: linear-gradient(to right, rgba(66, 66, 66, .7), rgba(66, 66, 66, .7)), linear-gradient(to right, rgb(158, 158, 158), rgb(158, 158, 158));
-webkit-mask: url("data:image/svg+xml;base64,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");
mask: url("data:image/svg+xml;base64,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")
}
}

from: https://code.getmdl.io/1.1.3/material.grey-pink.min.css

Any thoughts? For now I am removing the @supports

[bohnna]

Any updates on this? @supports is pretty useful in email and I am unable to proceed without removing the css.