Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The ::-ms-tooltip CSS pseudo-element is a Microsoft extension that applies one or more styles to the tooltip of a slider <input type="range">.
::-ms-tooltip{...}
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https://developer.mozilla.org/en-US/docs/Web/CSS/::-ms-tooltip