// tailwind 3
// export default {
  // plugins: [
    // plugin(function ({ addUtilities }) {

      addUtilities({
        '.appearance-clean': {
          'appearance': 'none',
          '-moz-appearance': 'textfield',
          '&::-webkit-inner-spin-button': {
            '-webkit-appearance': 'none',
          },
          '&::-webkit-outer-spin-button': {
            '-webkit-appearance': 'none',
          },
        },
      })

    // }),
  // ]
// }

/* tailwind v4 */
@layer utils {
  .appearance-clean {
    appearance: none;
    -webkit-appearance: none;
    &::-webkit-search-decoration,
    &::-webkit-search-cancel-button,
    &::-webkit-inner-spin-button,
    &::-webkit-outer-spin-button {
      -webkit-appearance: none;
    }
  }
}

<input type="number" class="appearance-clean" />