Index: node_modules/postcss/lib/tokenize.js
===================================================================
--- node_modules/postcss/lib/tokenize.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss/lib/tokenize.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,266 @@
+'use strict'
+
+const SINGLE_QUOTE = "'".charCodeAt(0)
+const DOUBLE_QUOTE = '"'.charCodeAt(0)
+const BACKSLASH = '\\'.charCodeAt(0)
+const SLASH = '/'.charCodeAt(0)
+const NEWLINE = '\n'.charCodeAt(0)
+const SPACE = ' '.charCodeAt(0)
+const FEED = '\f'.charCodeAt(0)
+const TAB = '\t'.charCodeAt(0)
+const CR = '\r'.charCodeAt(0)
+const OPEN_SQUARE = '['.charCodeAt(0)
+const CLOSE_SQUARE = ']'.charCodeAt(0)
+const OPEN_PARENTHESES = '('.charCodeAt(0)
+const CLOSE_PARENTHESES = ')'.charCodeAt(0)
+const OPEN_CURLY = '{'.charCodeAt(0)
+const CLOSE_CURLY = '}'.charCodeAt(0)
+const SEMICOLON = ';'.charCodeAt(0)
+const ASTERISK = '*'.charCodeAt(0)
+const COLON = ':'.charCodeAt(0)
+const AT = '@'.charCodeAt(0)
+
+const RE_AT_END = /[\t\n\f\r "#'()/;[\\\]{}]/g
+const RE_WORD_END = /[\t\n\f\r !"#'():;@[\\\]{}]|\/(?=\*)/g
+const RE_BAD_BRACKET = /.[\r\n"'(/\\]/
+const RE_HEX_ESCAPE = /[\da-f]/i
+
+module.exports = function tokenizer(input, options = {}) {
+  let css = input.css.valueOf()
+  let ignore = options.ignoreErrors
+
+  let code, content, escape, next, quote
+  let currentToken, escaped, escapePos, n, prev
+
+  let length = css.length
+  let pos = 0
+  let buffer = []
+  let returned = []
+
+  function position() {
+    return pos
+  }
+
+  function unclosed(what) {
+    throw input.error('Unclosed ' + what, pos)
+  }
+
+  function endOfFile() {
+    return returned.length === 0 && pos >= length
+  }
+
+  function nextToken(opts) {
+    if (returned.length) return returned.pop()
+    if (pos >= length) return
+
+    let ignoreUnclosed = opts ? opts.ignoreUnclosed : false
+
+    code = css.charCodeAt(pos)
+
+    switch (code) {
+      case NEWLINE:
+      case SPACE:
+      case TAB:
+      case CR:
+      case FEED: {
+        next = pos
+        do {
+          next += 1
+          code = css.charCodeAt(next)
+        } while (
+          code === SPACE ||
+          code === NEWLINE ||
+          code === TAB ||
+          code === CR ||
+          code === FEED
+        )
+
+        currentToken = ['space', css.slice(pos, next)]
+        pos = next - 1
+        break
+      }
+
+      case OPEN_SQUARE:
+      case CLOSE_SQUARE:
+      case OPEN_CURLY:
+      case CLOSE_CURLY:
+      case COLON:
+      case SEMICOLON:
+      case CLOSE_PARENTHESES: {
+        let controlChar = String.fromCharCode(code)
+        currentToken = [controlChar, controlChar, pos]
+        break
+      }
+
+      case OPEN_PARENTHESES: {
+        prev = buffer.length ? buffer.pop()[1] : ''
+        n = css.charCodeAt(pos + 1)
+        if (
+          prev === 'url' &&
+          n !== SINGLE_QUOTE &&
+          n !== DOUBLE_QUOTE &&
+          n !== SPACE &&
+          n !== NEWLINE &&
+          n !== TAB &&
+          n !== FEED &&
+          n !== CR
+        ) {
+          next = pos
+          do {
+            escaped = false
+            next = css.indexOf(')', next + 1)
+            if (next === -1) {
+              if (ignore || ignoreUnclosed) {
+                next = pos
+                break
+              } else {
+                unclosed('bracket')
+              }
+            }
+            escapePos = next
+            while (css.charCodeAt(escapePos - 1) === BACKSLASH) {
+              escapePos -= 1
+              escaped = !escaped
+            }
+          } while (escaped)
+
+          currentToken = ['brackets', css.slice(pos, next + 1), pos, next]
+
+          pos = next
+        } else {
+          next = css.indexOf(')', pos + 1)
+          content = css.slice(pos, next + 1)
+
+          if (next === -1 || RE_BAD_BRACKET.test(content)) {
+            currentToken = ['(', '(', pos]
+          } else {
+            currentToken = ['brackets', content, pos, next]
+            pos = next
+          }
+        }
+
+        break
+      }
+
+      case SINGLE_QUOTE:
+      case DOUBLE_QUOTE: {
+        quote = code === SINGLE_QUOTE ? "'" : '"'
+        next = pos
+        do {
+          escaped = false
+          next = css.indexOf(quote, next + 1)
+          if (next === -1) {
+            if (ignore || ignoreUnclosed) {
+              next = pos + 1
+              break
+            } else {
+              unclosed('string')
+            }
+          }
+          escapePos = next
+          while (css.charCodeAt(escapePos - 1) === BACKSLASH) {
+            escapePos -= 1
+            escaped = !escaped
+          }
+        } while (escaped)
+
+        currentToken = ['string', css.slice(pos, next + 1), pos, next]
+        pos = next
+        break
+      }
+
+      case AT: {
+        RE_AT_END.lastIndex = pos + 1
+        RE_AT_END.test(css)
+        if (RE_AT_END.lastIndex === 0) {
+          next = css.length - 1
+        } else {
+          next = RE_AT_END.lastIndex - 2
+        }
+
+        currentToken = ['at-word', css.slice(pos, next + 1), pos, next]
+
+        pos = next
+        break
+      }
+
+      case BACKSLASH: {
+        next = pos
+        escape = true
+        while (css.charCodeAt(next + 1) === BACKSLASH) {
+          next += 1
+          escape = !escape
+        }
+        code = css.charCodeAt(next + 1)
+        if (
+          escape &&
+          code !== SLASH &&
+          code !== SPACE &&
+          code !== NEWLINE &&
+          code !== TAB &&
+          code !== CR &&
+          code !== FEED
+        ) {
+          next += 1
+          if (RE_HEX_ESCAPE.test(css.charAt(next))) {
+            while (RE_HEX_ESCAPE.test(css.charAt(next + 1))) {
+              next += 1
+            }
+            if (css.charCodeAt(next + 1) === SPACE) {
+              next += 1
+            }
+          }
+        }
+
+        currentToken = ['word', css.slice(pos, next + 1), pos, next]
+
+        pos = next
+        break
+      }
+
+      default: {
+        if (code === SLASH && css.charCodeAt(pos + 1) === ASTERISK) {
+          next = css.indexOf('*/', pos + 2) + 1
+          if (next === 0) {
+            if (ignore || ignoreUnclosed) {
+              next = css.length
+            } else {
+              unclosed('comment')
+            }
+          }
+
+          currentToken = ['comment', css.slice(pos, next + 1), pos, next]
+          pos = next
+        } else {
+          RE_WORD_END.lastIndex = pos + 1
+          RE_WORD_END.test(css)
+          if (RE_WORD_END.lastIndex === 0) {
+            next = css.length - 1
+          } else {
+            next = RE_WORD_END.lastIndex - 2
+          }
+
+          currentToken = ['word', css.slice(pos, next + 1), pos, next]
+          buffer.push(currentToken)
+          pos = next
+        }
+
+        break
+      }
+    }
+
+    pos++
+    return currentToken
+  }
+
+  function back(token) {
+    returned.push(token)
+  }
+
+  return {
+    back,
+    endOfFile,
+    nextToken,
+    position
+  }
+}