In osu-md.less, this rule style[1] removes padding left in ordered list. But in this rule style[2], pseudo element `::before` is used as marker or counter and has minimal width 30px. So we use this as left padding size. [1] https://github.com/ppy/osu-web/blob/5b0e3ac3ffce6b1aff8c9a8794db56603e885ef8/resources/assets/less/bem/osu-md.less#L196-L200 [2] https://github.com/ppy/osu-web/blob/5b0e3ac3ffce6b1aff8c9a8794db56603e885ef8/resources/assets/less/bem/osu-md.less#L210-L219
Reference : https://github.com/ppy/osu-web/blob/5b0e3ac3ffce6b1aff8c9a8794db56603e885ef8/resources/assets/less/bem/osu-md.less#L193-L194