How to use the @theme-ui/presets.tailwind.sizes function in @theme-ui/presets

light: {
        text: tailwind.colors.gray[8],
        heading: tailwind.colors.black,
        primary: tailwind.colors.orange[7],
        background: tailwind.colors.gray[1],
        divider: tailwind.colors.gray[2],
        textMuted: tailwind.colors.gray[6],
        icon_brightest: tailwind.colors.gray[2],
        icon_darker: tailwind.colors.gray[4],
        icon_darkest: tailwind.colors.gray[6],
      },
    },
  },
  breakpoints: [`400px`, `600px`, `900px`, `1200px`, `1600px`],
  sizes: {
    ...tailwind.sizes,
    "1/2": `50%`,
    "1/3": `33.333333%`,
    "2/3": `66.666667%`,
    "1/4": `25%`,
    "2/4": `50%`,
    "3/4": `75%`,
    "1/5": `20%`,
    "2/5": `40%`,
    "3/5": `60%`,
    "4/5": `80%`,
    "1/6": `16.666667%`,
    "2/6": `33.333333%`,
    "3/6": `50%`,
    "4/6": `66.666667%`,
    "5/6": `83.333333%`,
    "1/12": `8.333333%`,