When a document uses normalize.css and inline svg, it's not possible to set an svg element's overflow via CSS through a simple class selector. The overflow value is always overridden by the svg:not(:root) override, unless !important or other means of artificially raising the specificity of the selector are used.

Maybe this override could be accomplished by doing, instead:

svg {
  overflow: hidden;
}

svg:root {
  overflow: visible;
}

This would still require that the user artificially increases the specificity of a selector if they really do mean to override the overflow of an svg root in css, but I suspect that is a much more unlikely use case.