Escaped css selector names in SVGs break the parser

[Watercycle]

Version: 0.16.0

Given:

$oddSvg = <<<SVG
<svg>
    <defs>
        <style>
            .\37 15ca94c-fc50-4dc6-8356-e55b8cb855fa { fill: #1d526b; }
        </style>
    </defs>
</svg>
SVG;

(new enshrined\svgSanitize\Sanitizer())->sanitize($oddSvg); // => ""

Expected: There should be no changes. Actual: It returns an empty string.

Context: Apparently some SVG generators use UUID class names. According to the CSS spec class selectors can lead with escaped digits (TIL).

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I'm not sure I'll have time to look into the solution; but, wanted to file this so others know. Ideally any tools starting its CSS selectors with numbers should be thrown to the wolves.