source: frontend/node_modules/tailwindcss/src/util/removeAlphaVariables.js

/**
 * This function removes any uses of CSS variables used as an alpha channel
 *
 * This is required for selectors like `:visited` which do not allow
 * changes in opacity or external control using CSS variables.
 *
 * @param {import('postcss').Container} container
 * @param {string[]} toRemove
 */
export function removeAlphaVariables(container, toRemove) {
  container.walkDecls((decl) => {
    if (toRemove.includes(decl.prop)) {
      decl.remove()

      return
    }

    for (let varName of toRemove) {
      if (decl.value.includes(`/ var(${varName})`)) {
        decl.value = decl.value.replace(`/ var(${varName})`, '')
      } else if (decl.value.includes(`/ var(${varName}, 1)`)) {
        decl.value = decl.value.replace(`/ var(${varName}, 1)`, '')
      }
    }
  })
}