Index: node_modules/postcss-value-parser/lib/index.d.ts
===================================================================
--- node_modules/postcss-value-parser/lib/index.d.ts	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/index.d.ts	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,177 @@
+declare namespace postcssValueParser {
+  interface BaseNode {
+    /**
+     * The offset, inclusive, inside the CSS value at which the node starts.
+     */
+    sourceIndex: number;
+
+    /**
+     * The offset, exclusive, inside the CSS value at which the node ends.
+     */
+    sourceEndIndex: number;
+
+    /**
+     * The node's characteristic value
+     */
+    value: string;
+  }
+
+  interface ClosableNode {
+    /**
+     * Whether the parsed CSS value ended before the node was properly closed
+     */
+    unclosed?: true;
+  }
+
+  interface AdjacentAwareNode {
+    /**
+     * The token at the start of the node
+     */
+    before: string;
+
+    /**
+     * The token at the end of the node
+     */
+    after: string;
+  }
+
+  interface CommentNode extends BaseNode, ClosableNode {
+    type: "comment";
+  }
+
+  interface DivNode extends BaseNode, AdjacentAwareNode {
+    type: "div";
+  }
+
+  interface FunctionNode extends BaseNode, ClosableNode, AdjacentAwareNode {
+    type: "function";
+
+    /**
+     * Nodes inside the function
+     */
+    nodes: Node[];
+  }
+
+  interface SpaceNode extends BaseNode {
+    type: "space";
+  }
+
+  interface StringNode extends BaseNode, ClosableNode {
+    type: "string";
+
+    /**
+     * The quote type delimiting the string
+     */
+    quote: '"' | "'";
+  }
+
+  interface UnicodeRangeNode extends BaseNode {
+    type: "unicode-range";
+  }
+
+  interface WordNode extends BaseNode {
+    type: "word";
+  }
+
+  /**
+   * Any node parsed from a CSS value
+   */
+  type Node =
+    | CommentNode
+    | DivNode
+    | FunctionNode
+    | SpaceNode
+    | StringNode
+    | UnicodeRangeNode
+    | WordNode;
+
+  interface CustomStringifierCallback {
+    /**
+     * @param node The node to stringify
+     * @returns The serialized CSS representation of the node
+     */
+    (nodes: Node): string | undefined;
+  }
+
+  interface WalkCallback {
+    /**
+     * @param node  The currently visited node
+     * @param index The index of the node in the series of parsed nodes
+     * @param nodes The series of parsed nodes
+     * @returns Returning `false` will prevent traversal of descendant nodes (only applies if `bubble` was set to `true` in the `walk()` call)
+     */
+    (node: Node, index: number, nodes: Node[]): void | boolean;
+  }
+
+  /**
+   * A CSS dimension, decomposed into its numeric and unit parts
+   */
+  interface Dimension {
+    number: string;
+    unit: string;
+  }
+
+  /**
+   * A wrapper around a parsed CSS value that allows for inspecting and walking nodes
+   */
+  interface ParsedValue {
+    /**
+     * The series of parsed nodes
+     */
+    nodes: Node[];
+
+    /**
+     * Walk all parsed nodes, applying a callback
+     *
+     * @param callback A visitor callback that will be executed for each node
+     * @param bubble   When set to `true`, walking will be done inside-out instead of outside-in
+     */
+    walk(callback: WalkCallback, bubble?: boolean): this;
+  }
+
+  interface ValueParser {
+    /**
+     * Decompose a CSS dimension into its numeric and unit part
+     *
+     * @param value The dimension to decompose
+     * @returns An object representing `number` and `unit` part of the dimension or `false` if the decomposing fails
+     */
+    unit(value: string): Dimension | false;
+
+    /**
+     * Serialize a series of nodes into a CSS value
+     *
+     * @param nodes  The nodes to stringify
+     * @param custom A custom stringifier callback
+     * @returns The generated CSS value
+     */
+    stringify(nodes: Node | Node[], custom?: CustomStringifierCallback): string;
+
+    /**
+     * Walk a series of nodes, applying a callback
+     *
+     * @param nodes    The nodes to walk
+     * @param callback A visitor callback that will be executed for each node
+     * @param bubble   When set to `true`, walking will be done inside-out instead of outside-in
+     */
+    walk(nodes: Node[], callback: WalkCallback, bubble?: boolean): void;
+
+    /**
+     * Parse a CSS value into a series of nodes to operate on
+     *
+     * @param value The value to parse
+     */
+    new (value: string): ParsedValue;
+
+    /**
+     * Parse a CSS value into a series of nodes to operate on
+     *
+     * @param value The value to parse
+     */
+    (value: string): ParsedValue;
+  }
+}
+
+declare const postcssValueParser: postcssValueParser.ValueParser;
+
+export = postcssValueParser;
Index: node_modules/postcss-value-parser/lib/index.js
===================================================================
--- node_modules/postcss-value-parser/lib/index.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/index.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,28 @@
+var parse = require("./parse");
+var walk = require("./walk");
+var stringify = require("./stringify");
+
+function ValueParser(value) {
+  if (this instanceof ValueParser) {
+    this.nodes = parse(value);
+    return this;
+  }
+  return new ValueParser(value);
+}
+
+ValueParser.prototype.toString = function() {
+  return Array.isArray(this.nodes) ? stringify(this.nodes) : "";
+};
+
+ValueParser.prototype.walk = function(cb, bubble) {
+  walk(this.nodes, cb, bubble);
+  return this;
+};
+
+ValueParser.unit = require("./unit");
+
+ValueParser.walk = walk;
+
+ValueParser.stringify = stringify;
+
+module.exports = ValueParser;
Index: node_modules/postcss-value-parser/lib/parse.js
===================================================================
--- node_modules/postcss-value-parser/lib/parse.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/parse.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,321 @@
+var openParentheses = "(".charCodeAt(0);
+var closeParentheses = ")".charCodeAt(0);
+var singleQuote = "'".charCodeAt(0);
+var doubleQuote = '"'.charCodeAt(0);
+var backslash = "\\".charCodeAt(0);
+var slash = "/".charCodeAt(0);
+var comma = ",".charCodeAt(0);
+var colon = ":".charCodeAt(0);
+var star = "*".charCodeAt(0);
+var uLower = "u".charCodeAt(0);
+var uUpper = "U".charCodeAt(0);
+var plus = "+".charCodeAt(0);
+var isUnicodeRange = /^[a-f0-9?-]+$/i;
+
+module.exports = function(input) {
+  var tokens = [];
+  var value = input;
+
+  var next,
+    quote,
+    prev,
+    token,
+    escape,
+    escapePos,
+    whitespacePos,
+    parenthesesOpenPos;
+  var pos = 0;
+  var code = value.charCodeAt(pos);
+  var max = value.length;
+  var stack = [{ nodes: tokens }];
+  var balanced = 0;
+  var parent;
+
+  var name = "";
+  var before = "";
+  var after = "";
+
+  while (pos < max) {
+    // Whitespaces
+    if (code <= 32) {
+      next = pos;
+      do {
+        next += 1;
+        code = value.charCodeAt(next);
+      } while (code <= 32);
+      token = value.slice(pos, next);
+
+      prev = tokens[tokens.length - 1];
+      if (code === closeParentheses && balanced) {
+        after = token;
+      } else if (prev && prev.type === "div") {
+        prev.after = token;
+        prev.sourceEndIndex += token.length;
+      } else if (
+        code === comma ||
+        code === colon ||
+        (code === slash &&
+          value.charCodeAt(next + 1) !== star &&
+          (!parent ||
+            (parent && parent.type === "function" && parent.value !== "calc")))
+      ) {
+        before = token;
+      } else {
+        tokens.push({
+          type: "space",
+          sourceIndex: pos,
+          sourceEndIndex: next,
+          value: token
+        });
+      }
+
+      pos = next;
+
+      // Quotes
+    } else if (code === singleQuote || code === doubleQuote) {
+      next = pos;
+      quote = code === singleQuote ? "'" : '"';
+      token = {
+        type: "string",
+        sourceIndex: pos,
+        quote: quote
+      };
+      do {
+        escape = false;
+        next = value.indexOf(quote, next + 1);
+        if (~next) {
+          escapePos = next;
+          while (value.charCodeAt(escapePos - 1) === backslash) {
+            escapePos -= 1;
+            escape = !escape;
+          }
+        } else {
+          value += quote;
+          next = value.length - 1;
+          token.unclosed = true;
+        }
+      } while (escape);
+      token.value = value.slice(pos + 1, next);
+      token.sourceEndIndex = token.unclosed ? next : next + 1;
+      tokens.push(token);
+      pos = next + 1;
+      code = value.charCodeAt(pos);
+
+      // Comments
+    } else if (code === slash && value.charCodeAt(pos + 1) === star) {
+      next = value.indexOf("*/", pos);
+
+      token = {
+        type: "comment",
+        sourceIndex: pos,
+        sourceEndIndex: next + 2
+      };
+
+      if (next === -1) {
+        token.unclosed = true;
+        next = value.length;
+        token.sourceEndIndex = next;
+      }
+
+      token.value = value.slice(pos + 2, next);
+      tokens.push(token);
+
+      pos = next + 2;
+      code = value.charCodeAt(pos);
+
+      // Operation within calc
+    } else if (
+      (code === slash || code === star) &&
+      parent &&
+      parent.type === "function" &&
+      parent.value === "calc"
+    ) {
+      token = value[pos];
+      tokens.push({
+        type: "word",
+        sourceIndex: pos - before.length,
+        sourceEndIndex: pos + token.length,
+        value: token
+      });
+      pos += 1;
+      code = value.charCodeAt(pos);
+
+      // Dividers
+    } else if (code === slash || code === comma || code === colon) {
+      token = value[pos];
+
+      tokens.push({
+        type: "div",
+        sourceIndex: pos - before.length,
+        sourceEndIndex: pos + token.length,
+        value: token,
+        before: before,
+        after: ""
+      });
+      before = "";
+
+      pos += 1;
+      code = value.charCodeAt(pos);
+
+      // Open parentheses
+    } else if (openParentheses === code) {
+      // Whitespaces after open parentheses
+      next = pos;
+      do {
+        next += 1;
+        code = value.charCodeAt(next);
+      } while (code <= 32);
+      parenthesesOpenPos = pos;
+      token = {
+        type: "function",
+        sourceIndex: pos - name.length,
+        value: name,
+        before: value.slice(parenthesesOpenPos + 1, next)
+      };
+      pos = next;
+
+      if (name === "url" && code !== singleQuote && code !== doubleQuote) {
+        next -= 1;
+        do {
+          escape = false;
+          next = value.indexOf(")", next + 1);
+          if (~next) {
+            escapePos = next;
+            while (value.charCodeAt(escapePos - 1) === backslash) {
+              escapePos -= 1;
+              escape = !escape;
+            }
+          } else {
+            value += ")";
+            next = value.length - 1;
+            token.unclosed = true;
+          }
+        } while (escape);
+        // Whitespaces before closed
+        whitespacePos = next;
+        do {
+          whitespacePos -= 1;
+          code = value.charCodeAt(whitespacePos);
+        } while (code <= 32);
+        if (parenthesesOpenPos < whitespacePos) {
+          if (pos !== whitespacePos + 1) {
+            token.nodes = [
+              {
+                type: "word",
+                sourceIndex: pos,
+                sourceEndIndex: whitespacePos + 1,
+                value: value.slice(pos, whitespacePos + 1)
+              }
+            ];
+          } else {
+            token.nodes = [];
+          }
+          if (token.unclosed && whitespacePos + 1 !== next) {
+            token.after = "";
+            token.nodes.push({
+              type: "space",
+              sourceIndex: whitespacePos + 1,
+              sourceEndIndex: next,
+              value: value.slice(whitespacePos + 1, next)
+            });
+          } else {
+            token.after = value.slice(whitespacePos + 1, next);
+            token.sourceEndIndex = next;
+          }
+        } else {
+          token.after = "";
+          token.nodes = [];
+        }
+        pos = next + 1;
+        token.sourceEndIndex = token.unclosed ? next : pos;
+        code = value.charCodeAt(pos);
+        tokens.push(token);
+      } else {
+        balanced += 1;
+        token.after = "";
+        token.sourceEndIndex = pos + 1;
+        tokens.push(token);
+        stack.push(token);
+        tokens = token.nodes = [];
+        parent = token;
+      }
+      name = "";
+
+      // Close parentheses
+    } else if (closeParentheses === code && balanced) {
+      pos += 1;
+      code = value.charCodeAt(pos);
+
+      parent.after = after;
+      parent.sourceEndIndex += after.length;
+      after = "";
+      balanced -= 1;
+      stack[stack.length - 1].sourceEndIndex = pos;
+      stack.pop();
+      parent = stack[balanced];
+      tokens = parent.nodes;
+
+      // Words
+    } else {
+      next = pos;
+      do {
+        if (code === backslash) {
+          next += 1;
+        }
+        next += 1;
+        code = value.charCodeAt(next);
+      } while (
+        next < max &&
+        !(
+          code <= 32 ||
+          code === singleQuote ||
+          code === doubleQuote ||
+          code === comma ||
+          code === colon ||
+          code === slash ||
+          code === openParentheses ||
+          (code === star &&
+            parent &&
+            parent.type === "function" &&
+            parent.value === "calc") ||
+          (code === slash &&
+            parent.type === "function" &&
+            parent.value === "calc") ||
+          (code === closeParentheses && balanced)
+        )
+      );
+      token = value.slice(pos, next);
+
+      if (openParentheses === code) {
+        name = token;
+      } else if (
+        (uLower === token.charCodeAt(0) || uUpper === token.charCodeAt(0)) &&
+        plus === token.charCodeAt(1) &&
+        isUnicodeRange.test(token.slice(2))
+      ) {
+        tokens.push({
+          type: "unicode-range",
+          sourceIndex: pos,
+          sourceEndIndex: next,
+          value: token
+        });
+      } else {
+        tokens.push({
+          type: "word",
+          sourceIndex: pos,
+          sourceEndIndex: next,
+          value: token
+        });
+      }
+
+      pos = next;
+    }
+  }
+
+  for (pos = stack.length - 1; pos; pos -= 1) {
+    stack[pos].unclosed = true;
+    stack[pos].sourceEndIndex = value.length;
+  }
+
+  return stack[0].nodes;
+};
Index: node_modules/postcss-value-parser/lib/stringify.js
===================================================================
--- node_modules/postcss-value-parser/lib/stringify.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/stringify.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,48 @@
+function stringifyNode(node, custom) {
+  var type = node.type;
+  var value = node.value;
+  var buf;
+  var customResult;
+
+  if (custom && (customResult = custom(node)) !== undefined) {
+    return customResult;
+  } else if (type === "word" || type === "space") {
+    return value;
+  } else if (type === "string") {
+    buf = node.quote || "";
+    return buf + value + (node.unclosed ? "" : buf);
+  } else if (type === "comment") {
+    return "/*" + value + (node.unclosed ? "" : "*/");
+  } else if (type === "div") {
+    return (node.before || "") + value + (node.after || "");
+  } else if (Array.isArray(node.nodes)) {
+    buf = stringify(node.nodes, custom);
+    if (type !== "function") {
+      return buf;
+    }
+    return (
+      value +
+      "(" +
+      (node.before || "") +
+      buf +
+      (node.after || "") +
+      (node.unclosed ? "" : ")")
+    );
+  }
+  return value;
+}
+
+function stringify(nodes, custom) {
+  var result, i;
+
+  if (Array.isArray(nodes)) {
+    result = "";
+    for (i = nodes.length - 1; ~i; i -= 1) {
+      result = stringifyNode(nodes[i], custom) + result;
+    }
+    return result;
+  }
+  return stringifyNode(nodes, custom);
+}
+
+module.exports = stringify;
Index: node_modules/postcss-value-parser/lib/unit.js
===================================================================
--- node_modules/postcss-value-parser/lib/unit.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/unit.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,120 @@
+var minus = "-".charCodeAt(0);
+var plus = "+".charCodeAt(0);
+var dot = ".".charCodeAt(0);
+var exp = "e".charCodeAt(0);
+var EXP = "E".charCodeAt(0);
+
+// Check if three code points would start a number
+// https://www.w3.org/TR/css-syntax-3/#starts-with-a-number
+function likeNumber(value) {
+  var code = value.charCodeAt(0);
+  var nextCode;
+
+  if (code === plus || code === minus) {
+    nextCode = value.charCodeAt(1);
+
+    if (nextCode >= 48 && nextCode <= 57) {
+      return true;
+    }
+
+    var nextNextCode = value.charCodeAt(2);
+
+    if (nextCode === dot && nextNextCode >= 48 && nextNextCode <= 57) {
+      return true;
+    }
+
+    return false;
+  }
+
+  if (code === dot) {
+    nextCode = value.charCodeAt(1);
+
+    if (nextCode >= 48 && nextCode <= 57) {
+      return true;
+    }
+
+    return false;
+  }
+
+  if (code >= 48 && code <= 57) {
+    return true;
+  }
+
+  return false;
+}
+
+// Consume a number
+// https://www.w3.org/TR/css-syntax-3/#consume-number
+module.exports = function(value) {
+  var pos = 0;
+  var length = value.length;
+  var code;
+  var nextCode;
+  var nextNextCode;
+
+  if (length === 0 || !likeNumber(value)) {
+    return false;
+  }
+
+  code = value.charCodeAt(pos);
+
+  if (code === plus || code === minus) {
+    pos++;
+  }
+
+  while (pos < length) {
+    code = value.charCodeAt(pos);
+
+    if (code < 48 || code > 57) {
+      break;
+    }
+
+    pos += 1;
+  }
+
+  code = value.charCodeAt(pos);
+  nextCode = value.charCodeAt(pos + 1);
+
+  if (code === dot && nextCode >= 48 && nextCode <= 57) {
+    pos += 2;
+
+    while (pos < length) {
+      code = value.charCodeAt(pos);
+
+      if (code < 48 || code > 57) {
+        break;
+      }
+
+      pos += 1;
+    }
+  }
+
+  code = value.charCodeAt(pos);
+  nextCode = value.charCodeAt(pos + 1);
+  nextNextCode = value.charCodeAt(pos + 2);
+
+  if (
+    (code === exp || code === EXP) &&
+    ((nextCode >= 48 && nextCode <= 57) ||
+      ((nextCode === plus || nextCode === minus) &&
+        nextNextCode >= 48 &&
+        nextNextCode <= 57))
+  ) {
+    pos += nextCode === plus || nextCode === minus ? 3 : 2;
+
+    while (pos < length) {
+      code = value.charCodeAt(pos);
+
+      if (code < 48 || code > 57) {
+        break;
+      }
+
+      pos += 1;
+    }
+  }
+
+  return {
+    number: value.slice(0, pos),
+    unit: value.slice(pos)
+  };
+};
Index: node_modules/postcss-value-parser/lib/walk.js
===================================================================
--- node_modules/postcss-value-parser/lib/walk.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
+++ node_modules/postcss-value-parser/lib/walk.js	(revision 2058e5c694bb6097866a5fe6503c519e8f74970f)
@@ -0,0 +1,22 @@
+module.exports = function walk(nodes, cb, bubble) {
+  var i, max, node, result;
+
+  for (i = 0, max = nodes.length; i < max; i += 1) {
+    node = nodes[i];
+    if (!bubble) {
+      result = cb(node, i, nodes);
+    }
+
+    if (
+      result !== false &&
+      node.type === "function" &&
+      Array.isArray(node.nodes)
+    ) {
+      walk(node.nodes, cb, bubble);
+    }
+
+    if (bubble) {
+      cb(node, i, nodes);
+    }
+  }
+};