postcss,(plugins): nanocss, postcss-preset-env

42 files changed, 3266 insertions, 0 deletions

diff --git a/node_modules/csso/lib/clean/Atrule.js b/node_modules/csso/lib/clean/Atrule.js
new file mode 100644
index 00000000..236d122d
--- /dev/null
+++ b/node_modules/csso/lib/clean/Atrule.js
@@ -0,0 +1,69 @@
+import { keyword as resolveKeyword } from 'css-tree';
+import { hasNoChildren } from './utils.js';
+
+export default function cleanAtrule(node, item, list) {
+    if (node.block) {
+        // otherwise removed at-rule don't prevent @import for removal
+        if (this.stylesheet !== null) {
+            this.stylesheet.firstAtrulesAllowed = false;
+        }
+
+        if (hasNoChildren(node.block)) {
+            list.remove(item);
+            return;
+        }
+    }
+
+    switch (node.name) {
+        case 'charset':
+            if (hasNoChildren(node.prelude)) {
+                list.remove(item);
+                return;
+            }
+
+            // if there is any rule before @charset -> remove it
+            if (item.prev) {
+                list.remove(item);
+                return;
+            }
+
+            break;
+
+        case 'import':
+            if (this.stylesheet === null || !this.stylesheet.firstAtrulesAllowed) {
+                list.remove(item);
+                return;
+            }
+
+            // if there are some rules that not an @import or @charset before @import
+            // remove it
+            list.prevUntil(item.prev, function(rule) {
+                if (rule.type === 'Atrule') {
+                    if (rule.name === 'import' || rule.name === 'charset') {
+                        return;
+                    }
+                }
+
+                this.root.firstAtrulesAllowed = false;
+                list.remove(item);
+
+                return true;
+            }, this);
+
+            break;
+
+        default: {
+            const name = resolveKeyword(node.name).basename;
+
+            if (name === 'keyframes' ||
+                name === 'media' ||
+                name === 'supports') {
+
+                // drop at-rule with no prelude
+                if (hasNoChildren(node.prelude) || hasNoChildren(node.block)) {
+                    list.remove(item);
+                }
+            }
+        }
+    }
+};
diff --git a/node_modules/csso/lib/clean/Comment.js b/node_modules/csso/lib/clean/Comment.js
new file mode 100644
index 00000000..7744c6ba
--- /dev/null
+++ b/node_modules/csso/lib/clean/Comment.js
@@ -0,0 +1,3 @@
+export default function cleanComment(data, item, list) {
+    list.remove(item);
+};
diff --git a/node_modules/csso/lib/clean/Declaration.js b/node_modules/csso/lib/clean/Declaration.js
new file mode 100644
index 00000000..36af5a85
--- /dev/null
+++ b/node_modules/csso/lib/clean/Declaration.js
@@ -0,0 +1,14 @@
+import { property } from 'css-tree';
+
+export default function cleanDeclartion(node, item, list) {
+    if (node.value.children && node.value.children.isEmpty) {
+        list.remove(item);
+        return;
+    }
+
+    if (property(node.property).custom) {
+        if (/\S/.test(node.value.value)) {
+            node.value.value = node.value.value.trim();
+        }
+    }
+};
diff --git a/node_modules/csso/lib/clean/Raw.js b/node_modules/csso/lib/clean/Raw.js
new file mode 100644
index 00000000..b9ec0ae9
--- /dev/null
+++ b/node_modules/csso/lib/clean/Raw.js
@@ -0,0 +1,9 @@
+import { isNodeChildrenList } from './utils.js';
+
+export default function cleanRaw(node, item, list) {
+    // raw in stylesheet or block children
+    if (isNodeChildrenList(this.stylesheet, list) ||
+        isNodeChildrenList(this.block, list)) {
+        list.remove(item);
+    }
+};
diff --git a/node_modules/csso/lib/clean/Rule.js b/node_modules/csso/lib/clean/Rule.js
new file mode 100644
index 00000000..c4b02d2f
--- /dev/null
+++ b/node_modules/csso/lib/clean/Rule.js
@@ -0,0 +1,100 @@
+import { walk, keyword } from 'css-tree';
+import { hasNoChildren } from './utils.js';
+
+const { hasOwnProperty } = Object.prototype;
+const skipUsageFilteringAtrule = new Set(['keyframes']);
+
+function cleanUnused(selectorList, usageData) {
+    selectorList.children.forEach((selector, item, list) => {
+        let shouldRemove = false;
+
+        walk(selector, function(node) {
+            // ignore nodes in nested selectors
+            if (this.selector === null || this.selector === selectorList) {
+                switch (node.type) {
+                    case 'SelectorList':
+                        // TODO: remove toLowerCase when pseudo selectors will be normalized
+                        // ignore selectors inside :not()
+                        if (this.function === null || this.function.name.toLowerCase() !== 'not') {
+                            if (cleanUnused(node, usageData)) {
+                                shouldRemove = true;
+                            }
+                        }
+                        break;
+
+                    case 'ClassSelector':
+                        if (usageData.whitelist !== null &&
+                            usageData.whitelist.classes !== null &&
+                            !hasOwnProperty.call(usageData.whitelist.classes, node.name)) {
+                            shouldRemove = true;
+                        }
+                        if (usageData.blacklist !== null &&
+                            usageData.blacklist.classes !== null &&
+                            hasOwnProperty.call(usageData.blacklist.classes, node.name)) {
+                            shouldRemove = true;
+                        }
+                        break;
+
+                    case 'IdSelector':
+                        if (usageData.whitelist !== null &&
+                            usageData.whitelist.ids !== null &&
+                            !hasOwnProperty.call(usageData.whitelist.ids, node.name)) {
+                            shouldRemove = true;
+                        }
+                        if (usageData.blacklist !== null &&
+                            usageData.blacklist.ids !== null &&
+                            hasOwnProperty.call(usageData.blacklist.ids, node.name)) {
+                            shouldRemove = true;
+                        }
+                        break;
+
+                    case 'TypeSelector':
+                        // TODO: remove toLowerCase when type selectors will be normalized
+                        // ignore universal selectors
+                        if (node.name.charAt(node.name.length - 1) !== '*') {
+                            if (usageData.whitelist !== null &&
+                                usageData.whitelist.tags !== null &&
+                                !hasOwnProperty.call(usageData.whitelist.tags, node.name.toLowerCase())) {
+                                shouldRemove = true;
+                            }
+                            if (usageData.blacklist !== null &&
+                                usageData.blacklist.tags !== null &&
+                                hasOwnProperty.call(usageData.blacklist.tags, node.name.toLowerCase())) {
+                                shouldRemove = true;
+                            }
+                        }
+                        break;
+                }
+            }
+        });
+
+        if (shouldRemove) {
+            list.remove(item);
+        }
+    });
+
+    return selectorList.children.isEmpty;
+}
+
+export default function cleanRule(node, item, list, options) {
+    if (hasNoChildren(node.prelude) || hasNoChildren(node.block)) {
+        list.remove(item);
+        return;
+    }
+
+    // avoid usage filtering for some at-rules
+    if (this.atrule && skipUsageFilteringAtrule.has(keyword(this.atrule.name).basename)) {
+        return;
+    }
+
+    const { usage } = options;
+
+    if (usage && (usage.whitelist !== null || usage.blacklist !== null)) {
+        cleanUnused(node.prelude, usage);
+
+        if (hasNoChildren(node.prelude)) {
+            list.remove(item);
+            return;
+        }
+    }
+};
diff --git a/node_modules/csso/lib/clean/TypeSelector.js b/node_modules/csso/lib/clean/TypeSelector.js
new file mode 100644
index 00000000..416b495d
--- /dev/null
+++ b/node_modules/csso/lib/clean/TypeSelector.js
@@ -0,0 +1,19 @@
+// remove useless universal selector
+export default function cleanTypeSelector(node, item, list) {
+    const name = item.data.name;
+
+    // check it's a non-namespaced universal selector
+    if (name !== '*') {
+        return;
+    }
+
+    // remove when universal selector before other selectors
+    const nextType = item.next && item.next.data.type;
+    if (nextType === 'IdSelector' ||
+        nextType === 'ClassSelector' ||
+        nextType === 'AttributeSelector' ||
+        nextType === 'PseudoClassSelector' ||
+        nextType === 'PseudoElementSelector') {
+        list.remove(item);
+    }
+};
diff --git a/node_modules/csso/lib/clean/WhiteSpace.js b/node_modules/csso/lib/clean/WhiteSpace.js
new file mode 100644
index 00000000..870befb1
--- /dev/null
+++ b/node_modules/csso/lib/clean/WhiteSpace.js
@@ -0,0 +1,3 @@
+export default function cleanWhitespace(node, item, list) {
+    list.remove(item);
+};
diff --git a/node_modules/csso/lib/clean/index.js b/node_modules/csso/lib/clean/index.js
new file mode 100644
index 00000000..4faa73a6
--- /dev/null
+++ b/node_modules/csso/lib/clean/index.js
@@ -0,0 +1,28 @@
+import { walk } from 'css-tree';
+import Atrule from './Atrule.js';
+import Comment from './Comment.js';
+import Declaration from './Declaration.js';
+import Raw from './Raw.js';
+import Rule from './Rule.js';
+import TypeSelector from './TypeSelector.js';
+import WhiteSpace from './WhiteSpace.js';
+
+const handlers = {
+    Atrule,
+    Comment,
+    Declaration,
+    Raw,
+    Rule,
+    TypeSelector,
+    WhiteSpace
+};
+
+export default function(ast, options) {
+    walk(ast, {
+        leave(node, item, list) {
+            if (handlers.hasOwnProperty(node.type)) {
+                handlers[node.type].call(this, node, item, list, options);
+            }
+        }
+    });
+};
diff --git a/node_modules/csso/lib/clean/utils.js b/node_modules/csso/lib/clean/utils.js
new file mode 100644
index 00000000..ca1d57c8
--- /dev/null
+++ b/node_modules/csso/lib/clean/utils.js
@@ -0,0 +1,7 @@
+export function hasNoChildren(node) {
+    return !node || !node.children || node.children.isEmpty;
+}
+
+export function isNodeChildrenList(node, list) {
+    return node !== null && node.children === list;
+}
diff --git a/node_modules/csso/lib/compress.js b/node_modules/csso/lib/compress.js
new file mode 100644
index 00000000..4c4fb4fc
--- /dev/null
+++ b/node_modules/csso/lib/compress.js
@@ -0,0 +1,196 @@
+import { List, clone, walk } from 'css-tree';
+import { buildIndex } from './usage.js';
+import clean from './clean/index.js';
+import replace from './replace/index.js';
+import restructure from './restructure/index.js';
+
+function readChunk(input, specialComments) {
+    const children = new List();
+    let nonSpaceTokenInBuffer = false;
+    let protectedComment;
+
+    input.nextUntil(input.head, (node, item, list) => {
+        if (node.type === 'Comment') {
+            if (!specialComments || node.value.charAt(0) !== '!') {
+                list.remove(item);
+                return;
+            }
+
+            if (nonSpaceTokenInBuffer || protectedComment) {
+                return true;
+            }
+
+            list.remove(item);
+            protectedComment = node;
+
+            return;
+        }
+
+        if (node.type !== 'WhiteSpace') {
+            nonSpaceTokenInBuffer = true;
+        }
+
+        children.insert(list.remove(item));
+    });
+
+    return {
+        comment: protectedComment,
+        stylesheet: {
+            type: 'StyleSheet',
+            loc: null,
+            children
+        }
+    };
+}
+
+function compressChunk(ast, firstAtrulesAllowed, num, options) {
+    options.logger(`Compress block #${num}`, null, true);
+
+    let seed = 1;
+
+    if (ast.type === 'StyleSheet') {
+        ast.firstAtrulesAllowed = firstAtrulesAllowed;
+        ast.id = seed++;
+    }
+
+    walk(ast, {
+        visit: 'Atrule',
+        enter(node) {
+            if (node.block !== null) {
+                node.block.id = seed++;
+            }
+        }
+    });
+    options.logger('init', ast);
+
+    // remove redundant
+    clean(ast, options);
+    options.logger('clean', ast);
+
+    // replace nodes for shortened forms
+    replace(ast, options);
+    options.logger('replace', ast);
+
+    // structure optimisations
+    if (options.restructuring) {
+        restructure(ast, options);
+    }
+
+    return ast;
+}
+
+function getCommentsOption(options) {
+    let comments = 'comments' in options ? options.comments : 'exclamation';
+
+    if (typeof comments === 'boolean') {
+        comments = comments ? 'exclamation' : false;
+    } else if (comments !== 'exclamation' && comments !== 'first-exclamation') {
+        comments = false;
+    }
+
+    return comments;
+}
+
+function getRestructureOption(options) {
+    if ('restructure' in options) {
+        return options.restructure;
+    }
+
+    return 'restructuring' in options ? options.restructuring : true;
+}
+
+function wrapBlock(block) {
+    return new List().appendData({
+        type: 'Rule',
+        loc: null,
+        prelude: {
+            type: 'SelectorList',
+            loc: null,
+            children: new List().appendData({
+                type: 'Selector',
+                loc: null,
+                children: new List().appendData({
+                    type: 'TypeSelector',
+                    loc: null,
+                    name: 'x'
+                })
+            })
+        },
+        block
+    });
+}
+
+export default function compress(ast, options) {
+    ast = ast || { type: 'StyleSheet', loc: null, children: new List() };
+    options = options || {};
+
+    const compressOptions = {
+        logger: typeof options.logger === 'function' ? options.logger : function() {},
+        restructuring: getRestructureOption(options),
+        forceMediaMerge: Boolean(options.forceMediaMerge),
+        usage: options.usage ? buildIndex(options.usage) : false
+    };
+    const output = new List();
+    let specialComments = getCommentsOption(options);
+    let firstAtrulesAllowed = true;
+    let input;
+    let chunk;
+    let chunkNum = 1;
+    let chunkChildren;
+
+    if (options.clone) {
+        ast = clone(ast);
+    }
+
+    if (ast.type === 'StyleSheet') {
+        input = ast.children;
+        ast.children = output;
+    } else {
+        input = wrapBlock(ast);
+    }
+
+    do {
+        chunk = readChunk(input, Boolean(specialComments));
+        compressChunk(chunk.stylesheet, firstAtrulesAllowed, chunkNum++, compressOptions);
+        chunkChildren = chunk.stylesheet.children;
+
+        if (chunk.comment) {
+            // add \n before comment if there is another content in output
+            if (!output.isEmpty) {
+                output.insert(List.createItem({
+                    type: 'Raw',
+                    value: '\n'
+                }));
+            }
+
+            output.insert(List.createItem(chunk.comment));
+
+            // add \n after comment if chunk is not empty
+            if (!chunkChildren.isEmpty) {
+                output.insert(List.createItem({
+                    type: 'Raw',
+                    value: '\n'
+                }));
+            }
+        }
+
+        if (firstAtrulesAllowed && !chunkChildren.isEmpty) {
+            const lastRule = chunkChildren.last;
+
+            if (lastRule.type !== 'Atrule' ||
+               (lastRule.name !== 'import' && lastRule.name !== 'charset')) {
+                firstAtrulesAllowed = false;
+            }
+        }
+
+        if (specialComments !== 'exclamation') {
+            specialComments = false;
+        }
+
+        output.appendList(chunkChildren);
+    } while (!input.isEmpty);
+
+    return {
+        ast
+    };
+};
diff --git a/node_modules/csso/lib/index.js b/node_modules/csso/lib/index.js
new file mode 100644
index 00000000..66ccf2b8
--- /dev/null
+++ b/node_modules/csso/lib/index.js
@@ -0,0 +1,131 @@
+import { version } from './version.js';
+import * as syntax from './syntax.js';
+import * as utils from './utils.js';
+
+const { parse, generate, compress } = syntax;
+
+function debugOutput(name, options, startTime, data) {
+    if (options.debug) {
+        console.error(`## ${name} done in %d ms\n`, Date.now() - startTime);
+    }
+
+    return data;
+}
+
+function createDefaultLogger(level) {
+    let lastDebug;
+
+    return function logger(title, ast) {
+        let line = title;
+
+        if (ast) {
+            line = `[${((Date.now() - lastDebug) / 1000).toFixed(3)}s] ${line}`;
+        }
+
+        if (level > 1 && ast) {
+            let css = generate(ast);
+
+            // when level 2, limit css to 256 symbols
+            if (level === 2 && css.length > 256) {
+                css = css.substr(0, 256) + '...';
+            }
+
+            line += `\n  ${css}\n`;
+        }
+
+        console.error(line);
+        lastDebug = Date.now();
+    };
+}
+
+function buildCompressOptions(options) {
+    options = { ...options };
+
+    if (typeof options.logger !== 'function' && options.debug) {
+        options.logger = createDefaultLogger(options.debug);
+    }
+
+    return options;
+}
+
+function runHandler(ast, options, handlers) {
+    if (!Array.isArray(handlers)) {
+        handlers = [handlers];
+    }
+
+    handlers.forEach(fn => fn(ast, options));
+}
+
+function minify(context, source, options) {
+    options = options || {};
+
+    const filename = options.filename || '<unknown>';
+    let result;
+
+    // parse
+    const ast = debugOutput('parsing', options, Date.now(),
+        parse(source, {
+            context,
+            filename,
+            positions: Boolean(options.sourceMap)
+        })
+    );
+
+    // before compress handlers
+    if (options.beforeCompress) {
+        debugOutput('beforeCompress', options, Date.now(),
+            runHandler(ast, options, options.beforeCompress)
+        );
+    }
+
+    // compress
+    const compressResult = debugOutput('compress', options, Date.now(),
+        compress(ast, buildCompressOptions(options))
+    );
+
+    // after compress handlers
+    if (options.afterCompress) {
+        debugOutput('afterCompress', options, Date.now(),
+            runHandler(compressResult, options, options.afterCompress)
+        );
+    }
+
+    // generate
+    if (options.sourceMap) {
+        result = debugOutput('generate(sourceMap: true)', options, Date.now(), (() => {
+            const tmp = generate(compressResult.ast, { sourceMap: true });
+
+            tmp.map._file = filename; // since other tools can relay on file in source map transform chain
+            tmp.map.setSourceContent(filename, source);
+
+            return tmp;
+        })());
+    } else {
+        result = debugOutput('generate', options, Date.now(), {
+            css: generate(compressResult.ast),
+            map: null
+        });
+    }
+
+    return result;
+}
+
+function minifyStylesheet(source, options) {
+    return minify('stylesheet', source, options);
+}
+
+function minifyBlock(source, options) {
+    return minify('declarationList', source, options);
+}
+
+export {
+    version,
+    utils,
+
+    // main methods
+    minifyStylesheet as minify,
+    minifyBlock,
+
+    // css syntax parser/walkers/generator/etc
+    syntax
+};
diff --git a/node_modules/csso/lib/replace/Atrule.js b/node_modules/csso/lib/replace/Atrule.js
new file mode 100644
index 00000000..98f3248d
--- /dev/null
+++ b/node_modules/csso/lib/replace/Atrule.js
@@ -0,0 +1,9 @@
+import { keyword as resolveKeyword } from 'css-tree';
+import compressKeyframes from './atrule/keyframes.js';
+
+export default function(node) {
+    // compress @keyframe selectors
+    if (resolveKeyword(node.name).basename === 'keyframes') {
+        compressKeyframes(node);
+    }
+};
diff --git a/node_modules/csso/lib/replace/AttributeSelector.js b/node_modules/csso/lib/replace/AttributeSelector.js
new file mode 100644
index 00000000..3821530c
--- /dev/null
+++ b/node_modules/csso/lib/replace/AttributeSelector.js
@@ -0,0 +1,28 @@
+// Can unquote attribute detection
+// Adopted implementation of Mathias Bynens
+// https://github.com/mathiasbynens/mothereff.in/blob/master/unquoted-attributes/eff.js
+const blockUnquoteRx = /^(-?\d|--)|[\u0000-\u002c\u002e\u002f\u003A-\u0040\u005B-\u005E\u0060\u007B-\u009f]/;
+
+function canUnquote(value) {
+    if (value === '' || value === '-') {
+        return false;
+    }
+
+    return !blockUnquoteRx.test(value);
+}
+
+export default function(node) {
+    const attrValue = node.value;
+
+    if (!attrValue || attrValue.type !== 'String') {
+        return;
+    }
+
+    if (canUnquote(attrValue.value)) {
+        node.value = {
+            type: 'Identifier',
+            loc: attrValue.loc,
+            name: attrValue.value
+        };
+    }
+};
diff --git a/node_modules/csso/lib/replace/Dimension.js b/node_modules/csso/lib/replace/Dimension.js
new file mode 100644
index 00000000..edb00388
--- /dev/null
+++ b/node_modules/csso/lib/replace/Dimension.js
@@ -0,0 +1,63 @@
+import { packNumber } from './Number.js';
+
+const MATH_FUNCTIONS = new Set([
+    'calc',
+    'min',
+    'max',
+    'clamp'
+]);
+const LENGTH_UNIT = new Set([
+    // absolute length units
+    'px',
+    'mm',
+    'cm',
+    'in',
+    'pt',
+    'pc',
+
+    // relative length units
+    'em',
+    'ex',
+    'ch',
+    'rem',
+
+    // viewport-percentage lengths
+    'vh',
+    'vw',
+    'vmin',
+    'vmax',
+    'vm'
+]);
+
+export default function compressDimension(node, item) {
+    const value = packNumber(node.value);
+
+    node.value = value;
+
+    if (value === '0' && this.declaration !== null && this.atrulePrelude === null) {
+        const unit = node.unit.toLowerCase();
+
+        // only length values can be compressed
+        if (!LENGTH_UNIT.has(unit)) {
+            return;
+        }
+
+        // issue #362: shouldn't remove unit in -ms-flex since it breaks flex in IE10/11
+        // issue #200: shouldn't remove unit in flex since it breaks flex in IE10/11
+        if (this.declaration.property === '-ms-flex' ||
+            this.declaration.property === 'flex') {
+            return;
+        }
+
+        // issue #222: don't remove units inside calc
+        if (this.function && MATH_FUNCTIONS.has(this.function.name)) {
+            return;
+        }
+
+        item.data = {
+            type: 'Number',
+            loc: node.loc,
+            value
+        };
+    }
+};
diff --git a/node_modules/csso/lib/replace/Number.js b/node_modules/csso/lib/replace/Number.js
new file mode 100644
index 00000000..3420812d
--- /dev/null
+++ b/node_modules/csso/lib/replace/Number.js
@@ -0,0 +1,40 @@
+const OMIT_PLUSSIGN = /^(?:\+|(-))?0*(\d*)(?:\.0*|(\.\d*?)0*)?$/;
+const KEEP_PLUSSIGN = /^([\+\-])?0*(\d*)(?:\.0*|(\.\d*?)0*)?$/;
+const unsafeToRemovePlusSignAfter = new Set([
+    'Dimension',
+    'Hash',
+    'Identifier',
+    'Number',
+    'Raw',
+    'UnicodeRange'
+]);
+
+export function packNumber(value, item) {
+    // omit plus sign only if no prev or prev is safe type
+    const regexp = item && item.prev !== null && unsafeToRemovePlusSignAfter.has(item.prev.data.type)
+        ? KEEP_PLUSSIGN
+        : OMIT_PLUSSIGN;
+
+    // 100 -> '100'
+    // 00100 -> '100'
+    // +100 -> '100'
+    // -100 -> '-100'
+    // 0.123 -> '.123'
+    // 0.12300 -> '.123'
+    // 0.0 -> ''
+    // 0 -> ''
+    // -0 -> '-'
+    value = String(value).replace(regexp, '$1$2$3');
+
+    if (value === '' || value === '-') {
+        value = '0';
+    }
+    // FIXME: is it solution simplier?
+    // value = String(Number(value)).replace(/^(-?)0+\./, '$1.');
+
+    return value;
+}
+
+export function Number(node) {
+    node.value = packNumber(node.value);
+};
diff --git a/node_modules/csso/lib/replace/Percentage.js b/node_modules/csso/lib/replace/Percentage.js
new file mode 100644
index 00000000..4a2d70e8
--- /dev/null
+++ b/node_modules/csso/lib/replace/Percentage.js
@@ -0,0 +1,37 @@
+import { lexer } from 'css-tree';
+import { packNumber } from './Number.js';
+
+const blacklist = new Set([
+    // see https://github.com/jakubpawlowicz/clean-css/issues/957
+    'width',
+    'min-width',
+    'max-width',
+    'height',
+    'min-height',
+    'max-height',
+
+    // issue #410: Don’t remove units in flex-basis value for (-ms-)flex shorthand
+    // issue #362: shouldn't remove unit in -ms-flex since it breaks flex in IE10/11
+    // issue #200: shouldn't remove unit in flex since it breaks flex in IE10/11
+    'flex',
+    '-ms-flex'
+]);
+
+export default function compressPercentage(node, item) {
+    node.value = packNumber(node.value);
+
+    if (node.value === '0' && this.declaration && !blacklist.has(this.declaration.property)) {
+        // try to convert a number
+        item.data = {
+            type: 'Number',
+            loc: node.loc,
+            value: node.value
+        };
+
+        // that's ok only when new value matches on length
+        if (!lexer.matchDeclaration(this.declaration).isType(item.data, 'length')) {
+            // otherwise rollback changes
+            item.data = node;
+        }
+    }
+};
diff --git a/node_modules/csso/lib/replace/Url.js b/node_modules/csso/lib/replace/Url.js
new file mode 100644
index 00000000..00149218
--- /dev/null
+++ b/node_modules/csso/lib/replace/Url.js
@@ -0,0 +1,4 @@
+export default function(node) {
+    // convert `\\` to `/`
+    node.value = node.value.replace(/\\/g, '/');
+};
diff --git a/node_modules/csso/lib/replace/Value.js b/node_modules/csso/lib/replace/Value.js
new file mode 100644
index 00000000..05d1d57b
--- /dev/null
+++ b/node_modules/csso/lib/replace/Value.js
@@ -0,0 +1,26 @@
+import { property as resolveName } from 'css-tree';
+import font from './property/font.js';
+import fontWeight from './property/font-weight.js';
+import background from './property/background.js';
+import border from './property/border.js';
+import outline from './property/border.js';
+
+const handlers = {
+    'font': font,
+    'font-weight': fontWeight,
+    'background': background,
+    'border': border,
+    'outline': outline
+};
+
+export default function compressValue(node) {
+    if (!this.declaration) {
+        return;
+    }
+
+    const property = resolveName(this.declaration.property);
+
+    if (handlers.hasOwnProperty(property.basename)) {
+        handlers[property.basename](node);
+    }
+};
diff --git a/node_modules/csso/lib/replace/atrule/keyframes.js b/node_modules/csso/lib/replace/atrule/keyframes.js
new file mode 100644
index 00000000..62e6aef7
--- /dev/null
+++ b/node_modules/csso/lib/replace/atrule/keyframes.js
@@ -0,0 +1,21 @@
+export default function(node) {
+    node.block.children.forEach((rule) => {
+        rule.prelude.children.forEach((simpleselector) => {
+            simpleselector.children.forEach((data, item) => {
+                if (data.type === 'Percentage' && data.value === '100') {
+                    item.data = {
+                        type: 'TypeSelector',
+                        loc: data.loc,
+                        name: 'to'
+                    };
+                } else if (data.type === 'TypeSelector' && data.name === 'from') {
+                    item.data = {
+                        type: 'Percentage',
+                        loc: data.loc,
+                        value: '0'
+                    };
+                }
+            });
+        });
+    });
+};
diff --git a/node_modules/csso/lib/replace/color.js b/node_modules/csso/lib/replace/color.js
new file mode 100644
index 00000000..7f3db13d
--- /dev/null
+++ b/node_modules/csso/lib/replace/color.js
@@ -0,0 +1,498 @@
+import { lexer } from 'css-tree';
+import { packNumber } from './Number.js';
+
+// http://www.w3.org/TR/css3-color/#svg-color
+const NAME_TO_HEX = {
+    'aliceblue': 'f0f8ff',
+    'antiquewhite': 'faebd7',
+    'aqua': '0ff',
+    'aquamarine': '7fffd4',
+    'azure': 'f0ffff',
+    'beige': 'f5f5dc',
+    'bisque': 'ffe4c4',
+    'black': '000',
+    'blanchedalmond': 'ffebcd',
+    'blue': '00f',
+    'blueviolet': '8a2be2',
+    'brown': 'a52a2a',
+    'burlywood': 'deb887',
+    'cadetblue': '5f9ea0',
+    'chartreuse': '7fff00',
+    'chocolate': 'd2691e',
+    'coral': 'ff7f50',
+    'cornflowerblue': '6495ed',
+    'cornsilk': 'fff8dc',
+    'crimson': 'dc143c',
+    'cyan': '0ff',
+    'darkblue': '00008b',
+    'darkcyan': '008b8b',
+    'darkgoldenrod': 'b8860b',
+    'darkgray': 'a9a9a9',
+    'darkgrey': 'a9a9a9',
+    'darkgreen': '006400',
+    'darkkhaki': 'bdb76b',
+    'darkmagenta': '8b008b',
+    'darkolivegreen': '556b2f',
+    'darkorange': 'ff8c00',
+    'darkorchid': '9932cc',
+    'darkred': '8b0000',
+    'darksalmon': 'e9967a',
+    'darkseagreen': '8fbc8f',
+    'darkslateblue': '483d8b',
+    'darkslategray': '2f4f4f',
+    'darkslategrey': '2f4f4f',
+    'darkturquoise': '00ced1',
+    'darkviolet': '9400d3',
+    'deeppink': 'ff1493',
+    'deepskyblue': '00bfff',
+    'dimgray': '696969',
+    'dimgrey': '696969',
+    'dodgerblue': '1e90ff',
+    'firebrick': 'b22222',
+    'floralwhite': 'fffaf0',
+    'forestgreen': '228b22',
+    'fuchsia': 'f0f',
+    'gainsboro': 'dcdcdc',
+    'ghostwhite': 'f8f8ff',
+    'gold': 'ffd700',
+    'goldenrod': 'daa520',
+    'gray': '808080',
+    'grey': '808080',
+    'green': '008000',
+    'greenyellow': 'adff2f',
+    'honeydew': 'f0fff0',
+    'hotpink': 'ff69b4',
+    'indianred': 'cd5c5c',
+    'indigo': '4b0082',
+    'ivory': 'fffff0',
+    'khaki': 'f0e68c',
+    'lavender': 'e6e6fa',
+    'lavenderblush': 'fff0f5',
+    'lawngreen': '7cfc00',
+    'lemonchiffon': 'fffacd',
+    'lightblue': 'add8e6',
+    'lightcoral': 'f08080',
+    'lightcyan': 'e0ffff',
+    'lightgoldenrodyellow': 'fafad2',
+    'lightgray': 'd3d3d3',
+    'lightgrey': 'd3d3d3',
+    'lightgreen': '90ee90',
+    'lightpink': 'ffb6c1',
+    'lightsalmon': 'ffa07a',
+    'lightseagreen': '20b2aa',
+    'lightskyblue': '87cefa',
+    'lightslategray': '789',
+    'lightslategrey': '789',
+    'lightsteelblue': 'b0c4de',
+    'lightyellow': 'ffffe0',
+    'lime': '0f0',
+    'limegreen': '32cd32',
+    'linen': 'faf0e6',
+    'magenta': 'f0f',
+    'maroon': '800000',
+    'mediumaquamarine': '66cdaa',
+    'mediumblue': '0000cd',
+    'mediumorchid': 'ba55d3',
+    'mediumpurple': '9370db',
+    'mediumseagreen': '3cb371',
+    'mediumslateblue': '7b68ee',
+    'mediumspringgreen': '00fa9a',
+    'mediumturquoise': '48d1cc',
+    'mediumvioletred': 'c71585',
+    'midnightblue': '191970',
+    'mintcream': 'f5fffa',
+    'mistyrose': 'ffe4e1',
+    'moccasin': 'ffe4b5',
+    'navajowhite': 'ffdead',
+    'navy': '000080',
+    'oldlace': 'fdf5e6',
+    'olive': '808000',
+    'olivedrab': '6b8e23',
+    'orange': 'ffa500',
+    'orangered': 'ff4500',
+    'orchid': 'da70d6',
+    'palegoldenrod': 'eee8aa',
+    'palegreen': '98fb98',
+    'paleturquoise': 'afeeee',
+    'palevioletred': 'db7093',
+    'papayawhip': 'ffefd5',
+    'peachpuff': 'ffdab9',
+    'peru': 'cd853f',
+    'pink': 'ffc0cb',
+    'plum': 'dda0dd',
+    'powderblue': 'b0e0e6',
+    'purple': '800080',
+    'rebeccapurple': '639',
+    'red': 'f00',
+    'rosybrown': 'bc8f8f',
+    'royalblue': '4169e1',
+    'saddlebrown': '8b4513',
+    'salmon': 'fa8072',
+    'sandybrown': 'f4a460',
+    'seagreen': '2e8b57',
+    'seashell': 'fff5ee',
+    'sienna': 'a0522d',
+    'silver': 'c0c0c0',
+    'skyblue': '87ceeb',
+    'slateblue': '6a5acd',
+    'slategray': '708090',
+    'slategrey': '708090',
+    'snow': 'fffafa',
+    'springgreen': '00ff7f',
+    'steelblue': '4682b4',
+    'tan': 'd2b48c',
+    'teal': '008080',
+    'thistle': 'd8bfd8',
+    'tomato': 'ff6347',
+    'turquoise': '40e0d0',
+    'violet': 'ee82ee',
+    'wheat': 'f5deb3',
+    'white': 'fff',
+    'whitesmoke': 'f5f5f5',
+    'yellow': 'ff0',
+    'yellowgreen': '9acd32'
+};
+
+const HEX_TO_NAME = {
+    '800000': 'maroon',
+    '800080': 'purple',
+    '808000': 'olive',
+    '808080': 'gray',
+    '00ffff': 'cyan',
+    'f0ffff': 'azure',
+    'f5f5dc': 'beige',
+    'ffe4c4': 'bisque',
+    '000000': 'black',
+    '0000ff': 'blue',
+    'a52a2a': 'brown',
+    'ff7f50': 'coral',
+    'ffd700': 'gold',
+    '008000': 'green',
+    '4b0082': 'indigo',
+    'fffff0': 'ivory',
+    'f0e68c': 'khaki',
+    '00ff00': 'lime',
+    'faf0e6': 'linen',
+    '000080': 'navy',
+    'ffa500': 'orange',
+    'da70d6': 'orchid',
+    'cd853f': 'peru',
+    'ffc0cb': 'pink',
+    'dda0dd': 'plum',
+    'f00': 'red',
+    'ff0000': 'red',
+    'fa8072': 'salmon',
+    'a0522d': 'sienna',
+    'c0c0c0': 'silver',
+    'fffafa': 'snow',
+    'd2b48c': 'tan',
+    '008080': 'teal',
+    'ff6347': 'tomato',
+    'ee82ee': 'violet',
+    'f5deb3': 'wheat',
+    'ffffff': 'white',
+    'ffff00': 'yellow'
+};
+
+function hueToRgb(p, q, t) {
+    if (t < 0) {
+        t += 1;
+    }
+    if (t > 1) {
+        t -= 1;
+    }
+    if (t < 1 / 6) {
+        return p + (q - p) * 6 * t;
+    }
+    if (t < 1 / 2) {
+        return q;
+    }
+    if (t < 2 / 3) {
+        return p + (q - p) * (2 / 3 - t) * 6;
+    }
+    return p;
+}
+
+function hslToRgb(h, s, l, a) {
+    let r;
+    let g;
+    let b;
+
+    if (s === 0) {
+        r = g = b = l; // achromatic
+    } else {
+        const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+        const p = 2 * l - q;
+
+        r = hueToRgb(p, q, h + 1 / 3);
+        g = hueToRgb(p, q, h);
+        b = hueToRgb(p, q, h - 1 / 3);
+    }
+
+    return [
+        Math.round(r * 255),
+        Math.round(g * 255),
+        Math.round(b * 255),
+        a
+    ];
+}
+
+function toHex(value) {
+    value = value.toString(16);
+
+    return value.length === 1 ? '0' + value : value;
+}
+
+function parseFunctionArgs(functionArgs, count, rgb) {
+    let cursor = functionArgs.head;
+    let args = [];
+    let wasValue = false;
+
+    while (cursor !== null) {
+        const { type, value } = cursor.data;
+
+        switch (type) {
+            case 'Number':
+            case 'Percentage':
+                if (wasValue) {
+                    return;
+                }
+
+                wasValue = true;
+                args.push({
+                    type,
+                    value: Number(value)
+                });
+
+                break;
+
+            case 'Operator':
+                if (value === ',') {
+                    if (!wasValue) {
+                        return;
+                    }
+                    wasValue = false;
+                } else if (wasValue || value !== '+') {
+                    return;
+                }
+
+                break;
+
+            default:
+                // something we couldn't understand
+                return;
+        }
+
+        cursor = cursor.next;
+    }
+
+    if (args.length !== count) {
+        // invalid arguments count
+        // TODO: remove those tokens
+        return;
+    }
+
+    if (args.length === 4) {
+        if (args[3].type !== 'Number') {
+            // 4th argument should be a number
+            // TODO: remove those tokens
+            return;
+        }
+
+        args[3].type = 'Alpha';
+    }
+
+    if (rgb) {
+        if (args[0].type !== args[1].type || args[0].type !== args[2].type) {
+            // invalid color, numbers and percentage shouldn't be mixed
+            // TODO: remove those tokens
+            return;
+        }
+    } else {
+        if (args[0].type !== 'Number' ||
+            args[1].type !== 'Percentage' ||
+            args[2].type !== 'Percentage') {
+            // invalid color, for hsl values should be: number, percentage, percentage
+            // TODO: remove those tokens
+            return;
+        }
+
+        args[0].type = 'Angle';
+    }
+
+    return args.map(function(arg) {
+        let value = Math.max(0, arg.value);
+
+        switch (arg.type) {
+            case 'Number':
+                // fit value to [0..255] range
+                value = Math.min(value, 255);
+                break;
+
+            case 'Percentage':
+                // convert 0..100% to value in [0..255] range
+                value = Math.min(value, 100) / 100;
+
+                if (!rgb) {
+                    return value;
+                }
+
+                value = 255 * value;
+                break;
+
+            case 'Angle':
+                // fit value to (-360..360) range
+                return (((value % 360) + 360) % 360) / 360;
+
+            case 'Alpha':
+                // fit value to [0..1] range
+                return Math.min(value, 1);
+        }
+
+        return Math.round(value);
+    });
+}
+
+export function compressFunction(node, item) {
+    let functionName = node.name;
+    let args;
+
+    if (functionName === 'rgba' || functionName === 'hsla') {
+        args = parseFunctionArgs(node.children, 4, functionName === 'rgba');
+
+        if (!args) {
+            // something went wrong
+            return;
+        }
+
+        if (functionName === 'hsla') {
+            args = hslToRgb(...args);
+            node.name = 'rgba';
+        }
+
+        if (args[3] === 0) {
+            // try to replace `rgba(x, x, x, 0)` to `transparent`
+            // always replace `rgba(0, 0, 0, 0)` to `transparent`
+            // otherwise avoid replacement in gradients since it may break color transition
+            // http://stackoverflow.com/questions/11829410/css3-gradient-rendering-issues-from-transparent-to-white
+            const scopeFunctionName = this.function && this.function.name;
+
+            if ((args[0] === 0 && args[1] === 0 && args[2] === 0) ||
+                !/^(?:to|from|color-stop)$|gradient$/i.test(scopeFunctionName)) {
+
+                item.data = {
+                    type: 'Identifier',
+                    loc: node.loc,
+                    name: 'transparent'
+                };
+
+                return;
+            }
+        }
+
+        if (args[3] !== 1) {
+            // replace argument values for normalized/interpolated
+            node.children.forEach((node, item, list) => {
+                if (node.type === 'Operator') {
+                    if (node.value !== ',') {
+                        list.remove(item);
+                    }
+                    return;
+                }
+
+                item.data = {
+                    type: 'Number',
+                    loc: node.loc,
+                    value: packNumber(args.shift())
+                };
+            });
+
+            return;
+        }
+
+        // otherwise convert to rgb, i.e. rgba(255, 0, 0, 1) -> rgb(255, 0, 0)
+        functionName = 'rgb';
+    }
+
+    if (functionName === 'hsl') {
+        args = args || parseFunctionArgs(node.children, 3, false);
+
+        if (!args) {
+            // something went wrong
+            return;
+        }
+
+        // convert to rgb
+        args = hslToRgb(...args);
+        functionName = 'rgb';
+    }
+
+    if (functionName === 'rgb') {
+        args = args || parseFunctionArgs(node.children, 3, true);
+
+        if (!args) {
+            // something went wrong
+            return;
+        }
+
+        item.data = {
+            type: 'Hash',
+            loc: node.loc,
+            value: toHex(args[0]) + toHex(args[1]) + toHex(args[2])
+        };
+
+        compressHex(item.data, item);
+    }
+}
+
+export function compressIdent(node, item) {
+    if (this.declaration === null) {
+        return;
+    }
+
+    let color = node.name.toLowerCase();
+
+    if (NAME_TO_HEX.hasOwnProperty(color) &&
+        lexer.matchDeclaration(this.declaration).isType(node, 'color')) {
+        const hex = NAME_TO_HEX[color];
+
+        if (hex.length + 1 <= color.length) {
+            // replace for shorter hex value
+            item.data = {
+                type: 'Hash',
+                loc: node.loc,
+                value: hex
+            };
+        } else {
+            // special case for consistent colors
+            if (color === 'grey') {
+                color = 'gray';
+            }
+
+            // just replace value for lower cased name
+            node.name = color;
+        }
+    }
+}
+
+export function compressHex(node, item) {
+    let color = node.value.toLowerCase();
+
+    // #112233 -> #123
+    if (color.length === 6 &&
+        color[0] === color[1] &&
+        color[2] === color[3] &&
+        color[4] === color[5]) {
+        color = color[0] + color[2] + color[4];
+    }
+
+    if (HEX_TO_NAME[color]) {
+        item.data = {
+            type: 'Identifier',
+            loc: node.loc,
+            name: HEX_TO_NAME[color]
+        };
+    } else {
+        node.value = color;
+    }
+}
diff --git a/node_modules/csso/lib/replace/index.js b/node_modules/csso/lib/replace/index.js
new file mode 100644
index 00000000..de90ee46
--- /dev/null
+++ b/node_modules/csso/lib/replace/index.js
@@ -0,0 +1,32 @@
+import { walk } from 'css-tree';
+import Atrule from './Atrule.js';
+import AttributeSelector from './AttributeSelector.js';
+import Value from './Value.js';
+import Dimension from './Dimension.js';
+import Percentage from './Percentage.js';
+import { Number } from './Number.js';
+import Url from './Url.js';
+import { compressHex, compressIdent, compressFunction } from './color.js';
+
+const handlers = {
+    Atrule,
+    AttributeSelector,
+    Value,
+    Dimension,
+    Percentage,
+    Number,
+    Url,
+    Hash: compressHex,
+    Identifier: compressIdent,
+    Function: compressFunction
+};
+
+export default function(ast) {
+    walk(ast, {
+        leave(node, item, list) {
+            if (handlers.hasOwnProperty(node.type)) {
+                handlers[node.type].call(this, node, item, list);
+            }
+        }
+    });
+};
diff --git a/node_modules/csso/lib/replace/property/background.js b/node_modules/csso/lib/replace/property/background.js
new file mode 100644
index 00000000..847a8cff
--- /dev/null
+++ b/node_modules/csso/lib/replace/property/background.js
@@ -0,0 +1,50 @@
+import { List } from 'css-tree';
+
+export default function compressBackground(node) {
+    function flush() {
+        if (!buffer.length) {
+            buffer.unshift(
+                {
+                    type: 'Number',
+                    loc: null,
+                    value: '0'
+                },
+                {
+                    type: 'Number',
+                    loc: null,
+                    value: '0'
+                }
+            );
+        }
+
+        newValue.push.apply(newValue, buffer);
+
+        buffer = [];
+    }
+
+    let newValue = [];
+    let buffer = [];
+
+    node.children.forEach((node) => {
+        if (node.type === 'Operator' && node.value === ',') {
+            flush();
+            newValue.push(node);
+            return;
+        }
+
+        // remove defaults
+        if (node.type === 'Identifier') {
+            if (node.name === 'transparent' ||
+                node.name === 'none' ||
+                node.name === 'repeat' ||
+                node.name === 'scroll') {
+                return;
+            }
+        }
+
+        buffer.push(node);
+    });
+
+    flush();
+    node.children = new List().fromArray(newValue);
+};
diff --git a/node_modules/csso/lib/replace/property/border.js b/node_modules/csso/lib/replace/property/border.js
new file mode 100644
index 00000000..c470b66f
--- /dev/null
+++ b/node_modules/csso/lib/replace/property/border.js
@@ -0,0 +1,16 @@
+export default function compressBorder(node) {
+    node.children.forEach((node, item, list) => {
+        if (node.type === 'Identifier' && node.name.toLowerCase() === 'none') {
+            if (list.head === list.tail) {
+                // replace `none` for zero when `none` is a single term
+                item.data = {
+                    type: 'Number',
+                    loc: node.loc,
+                    value: '0'
+                };
+            } else {
+                list.remove(item);
+            }
+        }
+    });
+};
diff --git a/node_modules/csso/lib/replace/property/font-weight.js b/node_modules/csso/lib/replace/property/font-weight.js
new file mode 100644
index 00000000..3b901d33
--- /dev/null
+++ b/node_modules/csso/lib/replace/property/font-weight.js
@@ -0,0 +1,22 @@
+export default function compressFontWeight(node) {
+    const value = node.children.head.data;
+
+    if (value.type === 'Identifier') {
+        switch (value.name) {
+            case 'normal':
+                node.children.head.data = {
+                    type: 'Number',
+                    loc: value.loc,
+                    value: '400'
+                };
+                break;
+            case 'bold':
+                node.children.head.data = {
+                    type: 'Number',
+                    loc: value.loc,
+                    value: '700'
+                };
+                break;
+        }
+    }
+};
diff --git a/node_modules/csso/lib/replace/property/font.js b/node_modules/csso/lib/replace/property/font.js
new file mode 100644
index 00000000..38e903a2
--- /dev/null
+++ b/node_modules/csso/lib/replace/property/font.js
@@ -0,0 +1,30 @@
+export default function compressFont(node) {
+    const list = node.children;
+
+    list.forEachRight(function(node, item) {
+        if (node.type === 'Identifier') {
+            if (node.name === 'bold') {
+                item.data = {
+                    type: 'Number',
+                    loc: node.loc,
+                    value: '700'
+                };
+            } else if (node.name === 'normal') {
+                const prev = item.prev;
+
+                if (prev && prev.data.type === 'Operator' && prev.data.value === '/') {
+                    this.remove(prev);
+                }
+
+                this.remove(item);
+            }
+        }
+    });
+
+    if (list.isEmpty) {
+        list.insert(list.createItem({
+            type: 'Identifier',
+            name: 'normal'
+        }));
+    }
+};
diff --git a/node_modules/csso/lib/restructure/1-mergeAtrule.js b/node_modules/csso/lib/restructure/1-mergeAtrule.js
new file mode 100644
index 00000000..e00e4d32
--- /dev/null
+++ b/node_modules/csso/lib/restructure/1-mergeAtrule.js
@@ -0,0 +1,106 @@
+import { List, walk, keyword as resolveKeyword } from 'css-tree';
+
+const { hasOwnProperty } = Object.prototype;
+
+function addRuleToMap(map, item, list, single) {
+    const node = item.data;
+    const name = resolveKeyword(node.name).basename;
+    const id = node.name.toLowerCase() + '/' + (node.prelude ? node.prelude.id : null);
+
+    if (!hasOwnProperty.call(map, name)) {
+        map[name] = Object.create(null);
+    }
+
+    if (single) {
+        delete map[name][id];
+    }
+
+    if (!hasOwnProperty.call(map[name], id)) {
+        map[name][id] = new List();
+    }
+
+    map[name][id].append(list.remove(item));
+}
+
+function relocateAtrules(ast, options) {
+    const collected = Object.create(null);
+    let topInjectPoint = null;
+
+    ast.children.forEach(function(node, item, list) {
+        if (node.type === 'Atrule') {
+            const name = resolveKeyword(node.name).basename;
+
+            switch (name) {
+                case 'keyframes':
+                    addRuleToMap(collected, item, list, true);
+                    return;
+
+                case 'media':
+                    if (options.forceMediaMerge) {
+                        addRuleToMap(collected, item, list, false);
+                        return;
+                    }
+                    break;
+            }
+
+            if (topInjectPoint === null &&
+                name !== 'charset' &&
+                name !== 'import') {
+                topInjectPoint = item;
+            }
+        } else {
+            if (topInjectPoint === null) {
+                topInjectPoint = item;
+            }
+        }
+    });
+
+    for (const atrule in collected) {
+        for (const id in collected[atrule]) {
+            ast.children.insertList(
+                collected[atrule][id],
+                atrule === 'media' ? null : topInjectPoint
+            );
+        }
+    }
+};
+
+function isMediaRule(node) {
+    return node.type === 'Atrule' && node.name === 'media';
+}
+
+function processAtrule(node, item, list) {
+    if (!isMediaRule(node)) {
+        return;
+    }
+
+    const prev = item.prev && item.prev.data;
+
+    if (!prev || !isMediaRule(prev)) {
+        return;
+    }
+
+    // merge @media with same query
+    if (node.prelude &&
+        prev.prelude &&
+        node.prelude.id === prev.prelude.id) {
+        prev.block.children.appendList(node.block.children);
+        list.remove(item);
+
+        // TODO: use it when we can refer to several points in source
+        // prev.loc = {
+        //     primary: prev.loc,
+        //     merged: node.loc
+        // };
+    }
+}
+
+export default function rejoinAtrule(ast, options) {
+    relocateAtrules(ast, options);
+
+    walk(ast, {
+        visit: 'Atrule',
+        reverse: true,
+        enter: processAtrule
+    });
+};
diff --git a/node_modules/csso/lib/restructure/2-initialMergeRuleset.js b/node_modules/csso/lib/restructure/2-initialMergeRuleset.js
new file mode 100644
index 00000000..c49abaa0
--- /dev/null
+++ b/node_modules/csso/lib/restructure/2-initialMergeRuleset.js
@@ -0,0 +1,53 @@
+import { walk } from 'css-tree';
+import {
+    unsafeToSkipNode,
+    isEqualSelectors,
+    isEqualDeclarations,
+    addSelectors,
+    hasSimilarSelectors
+} from './utils.js';
+
+function processRule(node, item, list) {
+    const selectors = node.prelude.children;
+    const declarations = node.block.children;
+
+    list.prevUntil(item.prev, function(prev) {
+        // skip non-ruleset node if safe
+        if (prev.type !== 'Rule') {
+            return unsafeToSkipNode.call(selectors, prev);
+        }
+
+        const prevSelectors = prev.prelude.children;
+        const prevDeclarations = prev.block.children;
+
+        // try to join rulesets with equal pseudo signature
+        if (node.pseudoSignature === prev.pseudoSignature) {
+            // try to join by selectors
+            if (isEqualSelectors(prevSelectors, selectors)) {
+                prevDeclarations.appendList(declarations);
+                list.remove(item);
+                return true;
+            }
+
+            // try to join by declarations
+            if (isEqualDeclarations(declarations, prevDeclarations)) {
+                addSelectors(prevSelectors, selectors);
+                list.remove(item);
+                return true;
+            }
+        }
+
+        // go to prev ruleset if has no selector similarities
+        return hasSimilarSelectors(selectors, prevSelectors);
+    });
+}
+
+// NOTE: direction should be left to right, since rulesets merge to left
+// ruleset. When direction right to left unmerged rulesets may prevent lookup
+// TODO: remove initial merge
+export default function initialMergeRule(ast) {
+    walk(ast, {
+        visit: 'Rule',
+        enter: processRule
+    });
+};
diff --git a/node_modules/csso/lib/restructure/3-disjoinRuleset.js b/node_modules/csso/lib/restructure/3-disjoinRuleset.js
new file mode 100644
index 00000000..02ec5e1f
--- /dev/null
+++ b/node_modules/csso/lib/restructure/3-disjoinRuleset.js
@@ -0,0 +1,42 @@
+import { List, walk } from 'css-tree';
+
+function processRule(node, item, list) {
+    const selectors = node.prelude.children;
+
+    // generate new rule sets:
+    // .a, .b { color: red; }
+    // ->
+    // .a { color: red; }
+    // .b { color: red; }
+
+    // while there are more than 1 simple selector split for rulesets
+    while (selectors.head !== selectors.tail) {
+        const newSelectors = new List();
+
+        newSelectors.insert(selectors.remove(selectors.head));
+
+        list.insert(list.createItem({
+            type: 'Rule',
+            loc: node.loc,
+            prelude: {
+                type: 'SelectorList',
+                loc: node.prelude.loc,
+                children: newSelectors
+            },
+            block: {
+                type: 'Block',
+                loc: node.block.loc,
+                children: node.block.children.copy()
+            },
+            pseudoSignature: node.pseudoSignature
+        }), item);
+    }
+}
+
+export default function disjoinRule(ast) {
+    walk(ast, {
+        visit: 'Rule',
+        reverse: true,
+        enter: processRule
+    });
+};
diff --git a/node_modules/csso/lib/restructure/4-restructShorthand.js b/node_modules/csso/lib/restructure/4-restructShorthand.js
new file mode 100644
index 00000000..41acb515
--- /dev/null
+++ b/node_modules/csso/lib/restructure/4-restructShorthand.js
@@ -0,0 +1,425 @@
+import { List, generate, walk } from 'css-tree';
+
+const REPLACE = 1;
+const REMOVE = 2;
+const TOP = 0;
+const RIGHT = 1;
+const BOTTOM = 2;
+const LEFT = 3;
+const SIDES = ['top', 'right', 'bottom', 'left'];
+const SIDE = {
+    'margin-top': 'top',
+    'margin-right': 'right',
+    'margin-bottom': 'bottom',
+    'margin-left': 'left',
+
+    'padding-top': 'top',
+    'padding-right': 'right',
+    'padding-bottom': 'bottom',
+    'padding-left': 'left',
+
+    'border-top-color': 'top',
+    'border-right-color': 'right',
+    'border-bottom-color': 'bottom',
+    'border-left-color': 'left',
+    'border-top-width': 'top',
+    'border-right-width': 'right',
+    'border-bottom-width': 'bottom',
+    'border-left-width': 'left',
+    'border-top-style': 'top',
+    'border-right-style': 'right',
+    'border-bottom-style': 'bottom',
+    'border-left-style': 'left'
+};
+const MAIN_PROPERTY = {
+    'margin': 'margin',
+    'margin-top': 'margin',
+    'margin-right': 'margin',
+    'margin-bottom': 'margin',
+    'margin-left': 'margin',
+
+    'padding': 'padding',
+    'padding-top': 'padding',
+    'padding-right': 'padding',
+    'padding-bottom': 'padding',
+    'padding-left': 'padding',
+
+    'border-color': 'border-color',
+    'border-top-color': 'border-color',
+    'border-right-color': 'border-color',
+    'border-bottom-color': 'border-color',
+    'border-left-color': 'border-color',
+    'border-width': 'border-width',
+    'border-top-width': 'border-width',
+    'border-right-width': 'border-width',
+    'border-bottom-width': 'border-width',
+    'border-left-width': 'border-width',
+    'border-style': 'border-style',
+    'border-top-style': 'border-style',
+    'border-right-style': 'border-style',
+    'border-bottom-style': 'border-style',
+    'border-left-style': 'border-style'
+};
+
+class TRBL {
+    constructor(name) {
+        this.name = name;
+        this.loc = null;
+        this.iehack = undefined;
+        this.sides = {
+            'top': null,
+            'right': null,
+            'bottom': null,
+            'left': null
+        };
+    }
+
+    getValueSequence(declaration, count) {
+        const values = [];
+        let iehack = '';
+        const hasBadValues = declaration.value.type !== 'Value' || declaration.value.children.some(function(child) {
+            let special = false;
+
+            switch (child.type) {
+                case 'Identifier':
+                    switch (child.name) {
+                        case '\\0':
+                        case '\\9':
+                            iehack = child.name;
+                            return;
+
+                        case 'inherit':
+                        case 'initial':
+                        case 'unset':
+                        case 'revert':
+                            special = child.name;
+                            break;
+                    }
+                    break;
+
+                case 'Dimension':
+                    switch (child.unit) {
+                        // is not supported until IE11
+                        case 'rem':
+
+                        // v* units is too buggy across browsers and better
+                        // don't merge values with those units
+                        case 'vw':
+                        case 'vh':
+                        case 'vmin':
+                        case 'vmax':
+                        case 'vm': // IE9 supporting "vm" instead of "vmin".
+                            special = child.unit;
+                            break;
+                    }
+                    break;
+
+                case 'Hash': // color
+                case 'Number':
+                case 'Percentage':
+                    break;
+
+                case 'Function':
+                    if (child.name === 'var') {
+                        return true;
+                    }
+
+                    special = child.name;
+                    break;
+
+                default:
+                    return true;  // bad value
+            }
+
+            values.push({
+                node: child,
+                special,
+                important: declaration.important
+            });
+        });
+
+        if (hasBadValues || values.length > count) {
+            return false;
+        }
+
+        if (typeof this.iehack === 'string' && this.iehack !== iehack) {
+            return false;
+        }
+
+        this.iehack = iehack; // move outside
+
+        return values;
+    }
+
+    canOverride(side, value) {
+        const currentValue = this.sides[side];
+
+        return !currentValue || (value.important && !currentValue.important);
+    }
+
+    add(name, declaration) {
+        function attemptToAdd() {
+            const sides = this.sides;
+            const side = SIDE[name];
+
+            if (side) {
+                if (side in sides === false) {
+                    return false;
+                }
+
+                const values = this.getValueSequence(declaration, 1);
+
+                if (!values || !values.length) {
+                    return false;
+                }
+
+                // can mix only if specials are equal
+                for (const key in sides) {
+                    if (sides[key] !== null && sides[key].special !== values[0].special) {
+                        return false;
+                    }
+                }
+
+                if (!this.canOverride(side, values[0])) {
+                    return true;
+                }
+
+                sides[side] = values[0];
+
+                return true;
+            } else if (name === this.name) {
+                const values = this.getValueSequence(declaration, 4);
+
+                if (!values || !values.length) {
+                    return false;
+                }
+
+                switch (values.length) {
+                    case 1:
+                        values[RIGHT] = values[TOP];
+                        values[BOTTOM] = values[TOP];
+                        values[LEFT] = values[TOP];
+                        break;
+
+                    case 2:
+                        values[BOTTOM] = values[TOP];
+                        values[LEFT] = values[RIGHT];
+                        break;
+
+                    case 3:
+                        values[LEFT] = values[RIGHT];
+                        break;
+                }
+
+                // can mix only if specials are equal
+                for (let i = 0; i < 4; i++) {
+                    for (const key in sides) {
+                        if (sides[key] !== null && sides[key].special !== values[i].special) {
+                            return false;
+                        }
+                    }
+                }
+
+                for (let i = 0; i < 4; i++) {
+                    if (this.canOverride(SIDES[i], values[i])) {
+                        sides[SIDES[i]] = values[i];
+                    }
+                }
+
+                return true;
+            }
+        }
+
+        if (!attemptToAdd.call(this)) {
+            return false;
+        }
+
+        // TODO: use it when we can refer to several points in source
+        // if (this.loc) {
+        //     this.loc = {
+        //         primary: this.loc,
+        //         merged: declaration.loc
+        //     };
+        // } else {
+        //     this.loc = declaration.loc;
+        // }
+        if (!this.loc) {
+            this.loc = declaration.loc;
+        }
+
+        return true;
+    }
+
+    isOkToMinimize() {
+        const top = this.sides.top;
+        const right = this.sides.right;
+        const bottom = this.sides.bottom;
+        const left = this.sides.left;
+
+        if (top && right && bottom && left) {
+            const important =
+                top.important +
+                right.important +
+                bottom.important +
+                left.important;
+
+            return important === 0 || important === 4;
+        }
+
+        return false;
+    }
+
+    getValue() {
+        const result = new List();
+        const sides = this.sides;
+        const values = [
+            sides.top,
+            sides.right,
+            sides.bottom,
+            sides.left
+        ];
+        const stringValues = [
+            generate(sides.top.node),
+            generate(sides.right.node),
+            generate(sides.bottom.node),
+            generate(sides.left.node)
+        ];
+
+        if (stringValues[LEFT] === stringValues[RIGHT]) {
+            values.pop();
+            if (stringValues[BOTTOM] === stringValues[TOP]) {
+                values.pop();
+                if (stringValues[RIGHT] === stringValues[TOP]) {
+                    values.pop();
+                }
+            }
+        }
+
+        for (let i = 0; i < values.length; i++) {
+            result.appendData(values[i].node);
+        }
+
+        if (this.iehack) {
+            result.appendData({
+                type: 'Identifier',
+                loc: null,
+                name: this.iehack
+            });
+        }
+
+        return {
+            type: 'Value',
+            loc: null,
+            children: result
+        };
+    }
+
+    getDeclaration() {
+        return {
+            type: 'Declaration',
+            loc: this.loc,
+            important: this.sides.top.important,
+            property: this.name,
+            value: this.getValue()
+        };
+    }
+}
+
+function processRule(rule, shorts, shortDeclarations, lastShortSelector) {
+    const declarations = rule.block.children;
+    const selector = rule.prelude.children.first.id;
+
+    rule.block.children.forEachRight(function(declaration, item) {
+        const property = declaration.property;
+
+        if (!MAIN_PROPERTY.hasOwnProperty(property)) {
+            return;
+        }
+
+        const key = MAIN_PROPERTY[property];
+        let shorthand;
+        let operation;
+
+        if (!lastShortSelector || selector === lastShortSelector) {
+            if (key in shorts) {
+                operation = REMOVE;
+                shorthand = shorts[key];
+            }
+        }
+
+        if (!shorthand || !shorthand.add(property, declaration)) {
+            operation = REPLACE;
+            shorthand = new TRBL(key);
+
+            // if can't parse value ignore it and break shorthand children
+            if (!shorthand.add(property, declaration)) {
+                lastShortSelector = null;
+                return;
+            }
+        }
+
+        shorts[key] = shorthand;
+        shortDeclarations.push({
+            operation,
+            block: declarations,
+            item,
+            shorthand
+        });
+
+        lastShortSelector = selector;
+    });
+
+    return lastShortSelector;
+}
+
+function processShorthands(shortDeclarations, markDeclaration) {
+    shortDeclarations.forEach(function(item) {
+        const shorthand = item.shorthand;
+
+        if (!shorthand.isOkToMinimize()) {
+            return;
+        }
+
+        if (item.operation === REPLACE) {
+            item.item.data = markDeclaration(shorthand.getDeclaration());
+        } else {
+            item.block.remove(item.item);
+        }
+    });
+}
+
+export default function restructBlock(ast, indexer) {
+    const stylesheetMap = {};
+    const shortDeclarations = [];
+
+    walk(ast, {
+        visit: 'Rule',
+        reverse: true,
+        enter(node) {
+            const stylesheet = this.block || this.stylesheet;
+            const ruleId = (node.pseudoSignature || '') + '|' + node.prelude.children.first.id;
+            let ruleMap;
+            let shorts;
+
+            if (!stylesheetMap.hasOwnProperty(stylesheet.id)) {
+                ruleMap = {
+                    lastShortSelector: null
+                };
+                stylesheetMap[stylesheet.id] = ruleMap;
+            } else {
+                ruleMap = stylesheetMap[stylesheet.id];
+            }
+
+            if (ruleMap.hasOwnProperty(ruleId)) {
+                shorts = ruleMap[ruleId];
+            } else {
+                shorts = {};
+                ruleMap[ruleId] = shorts;
+            }
+
+            ruleMap.lastShortSelector = processRule.call(this, node, shorts, shortDeclarations, ruleMap.lastShortSelector);
+        }
+    });
+
+    processShorthands(shortDeclarations, indexer.declaration);
+};
diff --git a/node_modules/csso/lib/restructure/6-restructBlock.js b/node_modules/csso/lib/restructure/6-restructBlock.js
new file mode 100644
index 00000000..7d5e8572
--- /dev/null
+++ b/node_modules/csso/lib/restructure/6-restructBlock.js
@@ -0,0 +1,308 @@
+import {
+    walk,
+    generate,
+    property as resolveProperty,
+    keyword as resolveKeyword
+} from 'css-tree';
+
+let fingerprintId = 1;
+const dontRestructure = new Set([
+    'src' // https://github.com/afelix/csso/issues/50
+]);
+
+const DONT_MIX_VALUE = {
+    // https://developer.mozilla.org/en-US/docs/Web/CSS/display#Browser_compatibility
+    'display': /table|ruby|flex|-(flex)?box$|grid|contents|run-in/i,
+    // https://developer.mozilla.org/en/docs/Web/CSS/text-align
+    'text-align': /^(start|end|match-parent|justify-all)$/i
+};
+
+const SAFE_VALUES = {
+    cursor: [
+        'auto', 'crosshair', 'default', 'move', 'text', 'wait', 'help',
+        'n-resize', 'e-resize', 's-resize', 'w-resize',
+        'ne-resize', 'nw-resize', 'se-resize', 'sw-resize',
+        'pointer', 'progress', 'not-allowed', 'no-drop', 'vertical-text', 'all-scroll',
+        'col-resize', 'row-resize'
+    ],
+    overflow: [
+        'hidden', 'visible', 'scroll', 'auto'
+    ],
+    position: [
+        'static', 'relative', 'absolute', 'fixed'
+    ]
+};
+
+const NEEDLESS_TABLE = {
+    'border-width': ['border'],
+    'border-style': ['border'],
+    'border-color': ['border'],
+    'border-top': ['border'],
+    'border-right': ['border'],
+    'border-bottom': ['border'],
+    'border-left': ['border'],
+    'border-top-width': ['border-top', 'border-width', 'border'],
+    'border-right-width': ['border-right', 'border-width', 'border'],
+    'border-bottom-width': ['border-bottom', 'border-width', 'border'],
+    'border-left-width': ['border-left', 'border-width', 'border'],
+    'border-top-style': ['border-top', 'border-style', 'border'],
+    'border-right-style': ['border-right', 'border-style', 'border'],
+    'border-bottom-style': ['border-bottom', 'border-style', 'border'],
+    'border-left-style': ['border-left', 'border-style', 'border'],
+    'border-top-color': ['border-top', 'border-color', 'border'],
+    'border-right-color': ['border-right', 'border-color', 'border'],
+    'border-bottom-color': ['border-bottom', 'border-color', 'border'],
+    'border-left-color': ['border-left', 'border-color', 'border'],
+    'margin-top': ['margin'],
+    'margin-right': ['margin'],
+    'margin-bottom': ['margin'],
+    'margin-left': ['margin'],
+    'padding-top': ['padding'],
+    'padding-right': ['padding'],
+    'padding-bottom': ['padding'],
+    'padding-left': ['padding'],
+    'font-style': ['font'],
+    'font-variant': ['font'],
+    'font-weight': ['font'],
+    'font-size': ['font'],
+    'font-family': ['font'],
+    'list-style-type': ['list-style'],
+    'list-style-position': ['list-style'],
+    'list-style-image': ['list-style']
+};
+
+function getPropertyFingerprint(propertyName, declaration, fingerprints) {
+    const realName = resolveProperty(propertyName).basename;
+
+    if (realName === 'background') {
+        return propertyName + ':' + generate(declaration.value);
+    }
+
+    const declarationId = declaration.id;
+    let fingerprint = fingerprints[declarationId];
+
+    if (!fingerprint) {
+        switch (declaration.value.type) {
+            case 'Value':
+                const special = {};
+                let vendorId = '';
+                let iehack = '';
+                let raw = false;
+
+                declaration.value.children.forEach(function walk(node) {
+                    switch (node.type) {
+                        case 'Value':
+                        case 'Brackets':
+                        case 'Parentheses':
+                            node.children.forEach(walk);
+                            break;
+
+                        case 'Raw':
+                            raw = true;
+                            break;
+
+                        case 'Identifier': {
+                            const { name } = node;
+
+                            if (!vendorId) {
+                                vendorId = resolveKeyword(name).vendor;
+                            }
+
+                            if (/\\[09]/.test(name)) {
+                                iehack = RegExp.lastMatch;
+                            }
+
+                            if (SAFE_VALUES.hasOwnProperty(realName)) {
+                                if (SAFE_VALUES[realName].indexOf(name) === -1) {
+                                    special[name] = true;
+                                }
+                            } else if (DONT_MIX_VALUE.hasOwnProperty(realName)) {
+                                if (DONT_MIX_VALUE[realName].test(name)) {
+                                    special[name] = true;
+                                }
+                            }
+
+                            break;
+                        }
+
+                        case 'Function': {
+                            let { name } = node;
+
+                            if (!vendorId) {
+                                vendorId = resolveKeyword(name).vendor;
+                            }
+
+                            if (name === 'rect') {
+                                // there are 2 forms of rect:
+                                //   rect(<top>, <right>, <bottom>, <left>) - standart
+                                //   rect(<top> <right> <bottom> <left>) – backwards compatible syntax
+                                // only the same form values can be merged
+                                const hasComma = node.children.some((node) =>
+                                    node.type === 'Operator' && node.value === ','
+                                );
+
+                                if (!hasComma) {
+                                    name = 'rect-backward';
+                                }
+                            }
+
+                            special[name + '()'] = true;
+
+                            // check nested tokens too
+                            node.children.forEach(walk);
+
+                            break;
+                        }
+
+                        case 'Dimension': {
+                            const { unit } = node;
+
+                            if (/\\[09]/.test(unit)) {
+                                iehack = RegExp.lastMatch;
+                            }
+
+                            switch (unit) {
+                                // is not supported until IE11
+                                case 'rem':
+
+                                // v* units is too buggy across browsers and better
+                                // don't merge values with those units
+                                case 'vw':
+                                case 'vh':
+                                case 'vmin':
+                                case 'vmax':
+                                case 'vm': // IE9 supporting "vm" instead of "vmin".
+                                    special[unit] = true;
+                                    break;
+                            }
+
+                            break;
+                        }
+                    }
+                });
+
+                fingerprint = raw
+                    ? '!' + fingerprintId++
+                    : '!' + Object.keys(special).sort() + '|' + iehack + vendorId;
+                break;
+
+            case 'Raw':
+                fingerprint = '!' + declaration.value.value;
+                break;
+
+            default:
+                fingerprint = generate(declaration.value);
+        }
+
+        fingerprints[declarationId] = fingerprint;
+    }
+
+    return propertyName + fingerprint;
+}
+
+function needless(props, declaration, fingerprints) {
+    const property = resolveProperty(declaration.property);
+
+    if (NEEDLESS_TABLE.hasOwnProperty(property.basename)) {
+        const table = NEEDLESS_TABLE[property.basename];
+
+        for (const entry of table) {
+            const ppre = getPropertyFingerprint(property.prefix + entry, declaration, fingerprints);
+            const prev = props.hasOwnProperty(ppre) ? props[ppre] : null;
+
+            if (prev && (!declaration.important || prev.item.data.important)) {
+                return prev;
+            }
+        }
+    }
+}
+
+function processRule(rule, item, list, props, fingerprints) {
+    const declarations = rule.block.children;
+
+    declarations.forEachRight(function(declaration, declarationItem) {
+        const { property } = declaration;
+        const fingerprint = getPropertyFingerprint(property, declaration, fingerprints);
+        const prev = props[fingerprint];
+
+        if (prev && !dontRestructure.has(property)) {
+            if (declaration.important && !prev.item.data.important) {
+                props[fingerprint] = {
+                    block: declarations,
+                    item: declarationItem
+                };
+
+                prev.block.remove(prev.item);
+
+                // TODO: use it when we can refer to several points in source
+                // declaration.loc = {
+                //     primary: declaration.loc,
+                //     merged: prev.item.data.loc
+                // };
+            } else {
+                declarations.remove(declarationItem);
+
+                // TODO: use it when we can refer to several points in source
+                // prev.item.data.loc = {
+                //     primary: prev.item.data.loc,
+                //     merged: declaration.loc
+                // };
+            }
+        } else {
+            const prev = needless(props, declaration, fingerprints);
+
+            if (prev) {
+                declarations.remove(declarationItem);
+
+                // TODO: use it when we can refer to several points in source
+                // prev.item.data.loc = {
+                //     primary: prev.item.data.loc,
+                //     merged: declaration.loc
+                // };
+            } else {
+                declaration.fingerprint = fingerprint;
+
+                props[fingerprint] = {
+                    block: declarations,
+                    item: declarationItem
+                };
+            }
+        }
+    });
+
+    if (declarations.isEmpty) {
+        list.remove(item);
+    }
+}
+
+export default function restructBlock(ast) {
+    const stylesheetMap = {};
+    const fingerprints = Object.create(null);
+
+    walk(ast, {
+        visit: 'Rule',
+        reverse: true,
+        enter(node, item, list) {
+            const stylesheet = this.block || this.stylesheet;
+            const ruleId = (node.pseudoSignature || '') + '|' + node.prelude.children.first.id;
+            let ruleMap;
+            let props;
+
+            if (!stylesheetMap.hasOwnProperty(stylesheet.id)) {
+                ruleMap = {};
+                stylesheetMap[stylesheet.id] = ruleMap;
+            } else {
+                ruleMap = stylesheetMap[stylesheet.id];
+            }
+
+            if (ruleMap.hasOwnProperty(ruleId)) {
+                props = ruleMap[ruleId];
+            } else {
+                props = {};
+                ruleMap[ruleId] = props;
+            }
+
+            processRule.call(this, node, item, list, props, fingerprints);
+        }
+    });
+};
diff --git a/node_modules/csso/lib/restructure/7-mergeRuleset.js b/node_modules/csso/lib/restructure/7-mergeRuleset.js
new file mode 100644
index 00000000..8a4d5438
--- /dev/null
+++ b/node_modules/csso/lib/restructure/7-mergeRuleset.js
@@ -0,0 +1,86 @@
+import { walk } from 'css-tree';
+import { unsafeToSkipNode, isEqualDeclarations} from './utils.js';
+
+/*
+    At this step all rules has single simple selector. We try to join by equal
+    declaration blocks to first rule, e.g.
+
+    .a { color: red }
+    b { ... }
+    .b { color: red }
+    ->
+    .a, .b { color: red }
+    b { ... }
+*/
+
+function processRule(node, item, list) {
+    const selectors = node.prelude.children;
+    const declarations = node.block.children;
+    const nodeCompareMarker = selectors.first.compareMarker;
+    const skippedCompareMarkers = {};
+
+    list.nextUntil(item.next, function(next, nextItem) {
+        // skip non-ruleset node if safe
+        if (next.type !== 'Rule') {
+            return unsafeToSkipNode.call(selectors, next);
+        }
+
+        if (node.pseudoSignature !== next.pseudoSignature) {
+            return true;
+        }
+
+        const nextFirstSelector = next.prelude.children.head;
+        const nextDeclarations = next.block.children;
+        const nextCompareMarker = nextFirstSelector.data.compareMarker;
+
+        // if next ruleset has same marked as one of skipped then stop joining
+        if (nextCompareMarker in skippedCompareMarkers) {
+            return true;
+        }
+
+        // try to join by selectors
+        if (selectors.head === selectors.tail) {
+            if (selectors.first.id === nextFirstSelector.data.id) {
+                declarations.appendList(nextDeclarations);
+                list.remove(nextItem);
+                return;
+            }
+        }
+
+        // try to join by properties
+        if (isEqualDeclarations(declarations, nextDeclarations)) {
+            const nextStr = nextFirstSelector.data.id;
+
+            selectors.some((data, item) => {
+                const curStr = data.id;
+
+                if (nextStr < curStr) {
+                    selectors.insert(nextFirstSelector, item);
+                    return true;
+                }
+
+                if (!item.next) {
+                    selectors.insert(nextFirstSelector);
+                    return true;
+                }
+            });
+
+            list.remove(nextItem);
+            return;
+        }
+
+        // go to next ruleset if current one can be skipped (has no equal specificity nor element selector)
+        if (nextCompareMarker === nodeCompareMarker) {
+            return true;
+        }
+
+        skippedCompareMarkers[nextCompareMarker] = true;
+    });
+}
+
+export default function mergeRule(ast) {
+    walk(ast, {
+        visit: 'Rule',
+        enter: processRule
+    });
+};
diff --git a/node_modules/csso/lib/restructure/8-restructRuleset.js b/node_modules/csso/lib/restructure/8-restructRuleset.js
new file mode 100644
index 00000000..c9cbf094
--- /dev/null
+++ b/node_modules/csso/lib/restructure/8-restructRuleset.js
@@ -0,0 +1,176 @@
+import { List, walk } from 'css-tree';
+import {
+    unsafeToSkipNode,
+    isEqualSelectors,
+    compareDeclarations,
+    addSelectors
+} from './utils.js';
+
+function calcSelectorLength(list) {
+    return list.reduce((res, data) => res + data.id.length + 1, 0) - 1;
+}
+
+function calcDeclarationsLength(tokens) {
+    let length = 0;
+
+    for (const token of tokens) {
+        length += token.length;
+    }
+
+    return (
+        length +          // declarations
+        tokens.length - 1 // delimeters
+    );
+}
+
+function processRule(node, item, list) {
+    const avoidRulesMerge = this.block !== null ? this.block.avoidRulesMerge : false;
+    const selectors = node.prelude.children;
+    const block = node.block;
+    const disallowDownMarkers = Object.create(null);
+    let allowMergeUp = true;
+    let allowMergeDown = true;
+
+    list.prevUntil(item.prev, function(prev, prevItem) {
+        const prevBlock = prev.block;
+        const prevType = prev.type;
+
+        if (prevType !== 'Rule') {
+            const unsafe = unsafeToSkipNode.call(selectors, prev);
+
+            if (!unsafe && prevType === 'Atrule' && prevBlock) {
+                walk(prevBlock, {
+                    visit: 'Rule',
+                    enter(node) {
+                        node.prelude.children.forEach((data) => {
+                            disallowDownMarkers[data.compareMarker] = true;
+                        });
+                    }
+                });
+            }
+
+            return unsafe;
+        }
+
+        if (node.pseudoSignature !== prev.pseudoSignature) {
+            return true;
+        }
+
+        const prevSelectors = prev.prelude.children;
+
+        allowMergeDown = !prevSelectors.some((selector) =>
+            selector.compareMarker in disallowDownMarkers
+        );
+
+        // try prev ruleset if simpleselectors has no equal specifity and element selector
+        if (!allowMergeDown && !allowMergeUp) {
+            return true;
+        }
+
+        // try to join by selectors
+        if (allowMergeUp && isEqualSelectors(prevSelectors, selectors)) {
+            prevBlock.children.appendList(block.children);
+            list.remove(item);
+
+            return true;
+        }
+
+        // try to join by properties
+        const diff = compareDeclarations(block.children, prevBlock.children);
+
+        // console.log(diff.eq, diff.ne1, diff.ne2);
+
+        if (diff.eq.length) {
+            if (!diff.ne1.length && !diff.ne2.length) {
+                // equal blocks
+                if (allowMergeDown) {
+                    addSelectors(selectors, prevSelectors);
+                    list.remove(prevItem);
+                }
+
+                return true;
+            } else if (!avoidRulesMerge) { /* probably we don't need to prevent those merges for @keyframes
+                                              TODO: need to be checked */
+
+                if (diff.ne1.length && !diff.ne2.length) {
+                    // prevBlock is subset block
+                    const selectorLength = calcSelectorLength(selectors);
+                    const blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    if (allowMergeUp && selectorLength < blockLength) {
+                        addSelectors(prevSelectors, selectors);
+                        block.children.fromArray(diff.ne1);
+                    }
+                } else if (!diff.ne1.length && diff.ne2.length) {
+                    // node is subset of prevBlock
+                    const selectorLength = calcSelectorLength(prevSelectors);
+                    const blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    if (allowMergeDown && selectorLength < blockLength) {
+                        addSelectors(selectors, prevSelectors);
+                        prevBlock.children.fromArray(diff.ne2);
+                    }
+                } else {
+                    // diff.ne1.length && diff.ne2.length
+                    // extract equal block
+                    const newSelector = {
+                        type: 'SelectorList',
+                        loc: null,
+                        children: addSelectors(prevSelectors.copy(), selectors)
+                    };
+                    const newBlockLength = calcSelectorLength(newSelector.children) + 2; // selectors length + curly braces length
+                    const blockLength = calcDeclarationsLength(diff.eq); // declarations length
+
+                    // create new ruleset if declarations length greater than
+                    // ruleset description overhead
+                    if (blockLength >= newBlockLength) {
+                        const newItem = list.createItem({
+                            type: 'Rule',
+                            loc: null,
+                            prelude: newSelector,
+                            block: {
+                                type: 'Block',
+                                loc: null,
+                                children: new List().fromArray(diff.eq)
+                            },
+                            pseudoSignature: node.pseudoSignature
+                        });
+
+                        block.children.fromArray(diff.ne1);
+                        prevBlock.children.fromArray(diff.ne2overrided);
+
+                        if (allowMergeUp) {
+                            list.insert(newItem, prevItem);
+                        } else {
+                            list.insert(newItem, item);
+                        }
+
+                        return true;
+                    }
+                }
+            }
+        }
+
+        if (allowMergeUp) {
+            // TODO: disallow up merge only if any property interception only (i.e. diff.ne2overrided.length > 0);
+            // await property families to find property interception correctly
+            allowMergeUp = !prevSelectors.some((prevSelector) =>
+                selectors.some((selector) =>
+                    selector.compareMarker === prevSelector.compareMarker
+                )
+            );
+        }
+
+        prevSelectors.forEach((data) => {
+            disallowDownMarkers[data.compareMarker] = true;
+        });
+    });
+}
+
+export default function restructRule(ast) {
+    walk(ast, {
+        visit: 'Rule',
+        reverse: true,
+        enter: processRule
+    });
+};
diff --git a/node_modules/csso/lib/restructure/index.js b/node_modules/csso/lib/restructure/index.js
new file mode 100644
index 00000000..62c93528
--- /dev/null
+++ b/node_modules/csso/lib/restructure/index.js
@@ -0,0 +1,35 @@
+import prepare from './prepare/index.js';
+import mergeAtrule from './1-mergeAtrule.js';
+import initialMergeRuleset from './2-initialMergeRuleset.js';
+import disjoinRuleset from './3-disjoinRuleset.js';
+import restructShorthand from './4-restructShorthand.js';
+import restructBlock from './6-restructBlock.js';
+import mergeRuleset from './7-mergeRuleset.js';
+import restructRuleset from './8-restructRuleset.js';
+
+export default function(ast, options) {
+    // prepare ast for restructing
+    const indexer = prepare(ast, options);
+    options.logger('prepare', ast);
+
+    mergeAtrule(ast, options);
+    options.logger('mergeAtrule', ast);
+
+    initialMergeRuleset(ast);
+    options.logger('initialMergeRuleset', ast);
+
+    disjoinRuleset(ast);
+    options.logger('disjoinRuleset', ast);
+
+    restructShorthand(ast, indexer);
+    options.logger('restructShorthand', ast);
+
+    restructBlock(ast);
+    options.logger('restructBlock', ast);
+
+    mergeRuleset(ast);
+    options.logger('mergeRuleset', ast);
+
+    restructRuleset(ast);
+    options.logger('restructRuleset', ast);
+};
diff --git a/node_modules/csso/lib/restructure/prepare/createDeclarationIndexer.js b/node_modules/csso/lib/restructure/prepare/createDeclarationIndexer.js
new file mode 100644
index 00000000..227f8abf
--- /dev/null
+++ b/node_modules/csso/lib/restructure/prepare/createDeclarationIndexer.js
@@ -0,0 +1,31 @@
+import { generate } from 'css-tree';
+
+class Index {
+    constructor() {
+        this.map = new Map();
+    }
+    resolve(str) {
+        let index = this.map.get(str);
+
+        if (index === undefined) {
+            index = this.map.size + 1;
+            this.map.set(str, index);
+        }
+
+        return index;
+    }
+};
+
+export default function createDeclarationIndexer() {
+    const ids = new Index();
+
+    return function markDeclaration(node) {
+        const id = generate(node);
+
+        node.id = ids.resolve(id);
+        node.length = id.length;
+        node.fingerprint = null;
+
+        return node;
+    };
+};
diff --git a/node_modules/csso/lib/restructure/prepare/index.js b/node_modules/csso/lib/restructure/prepare/index.js
new file mode 100644
index 00000000..fc08082e
--- /dev/null
+++ b/node_modules/csso/lib/restructure/prepare/index.js
@@ -0,0 +1,41 @@
+import { walk, generate, keyword as resolveKeyword } from 'css-tree';
+import createDeclarationIndexer from './createDeclarationIndexer.js';
+import processSelector from './processSelector.js';
+
+export default function prepare(ast, options) {
+    const markDeclaration = createDeclarationIndexer();
+
+    walk(ast, {
+        visit: 'Rule',
+        enter(node) {
+            node.block.children.forEach(markDeclaration);
+            processSelector(node, options.usage);
+        }
+    });
+
+    walk(ast, {
+        visit: 'Atrule',
+        enter(node) {
+            if (node.prelude) {
+                node.prelude.id = null; // pre-init property to avoid multiple hidden class for generate
+                node.prelude.id = generate(node.prelude);
+            }
+
+            // compare keyframe selectors by its values
+            // NOTE: still no clarification about problems with keyframes selector grouping (issue #197)
+            if (resolveKeyword(node.name).basename === 'keyframes') {
+                node.block.avoidRulesMerge = true;  /* probably we don't need to prevent those merges for @keyframes
+                                                       TODO: need to be checked */
+                node.block.children.forEach(function(rule) {
+                    rule.prelude.children.forEach(function(simpleselector) {
+                        simpleselector.compareMarker = simpleselector.id;
+                    });
+                });
+            }
+        }
+    });
+
+    return {
+        declaration: markDeclaration
+    };
+};
diff --git a/node_modules/csso/lib/restructure/prepare/processSelector.js b/node_modules/csso/lib/restructure/prepare/processSelector.js
new file mode 100644
index 00000000..55a4fed8
--- /dev/null
+++ b/node_modules/csso/lib/restructure/prepare/processSelector.js
@@ -0,0 +1,97 @@
+import { generate } from 'css-tree';
+import specificity from './specificity.js';
+
+const nonFreezePseudoElements = new Set([
+    'first-letter',
+    'first-line',
+    'after',
+    'before'
+]);
+const nonFreezePseudoClasses = new Set([
+    'link',
+    'visited',
+    'hover',
+    'active',
+    'first-letter',
+    'first-line',
+    'after',
+    'before'
+]);
+
+export default function processSelector(node, usageData) {
+    const pseudos = new Set();
+
+    node.prelude.children.forEach(function(simpleSelector) {
+        let tagName = '*';
+        let scope = 0;
+
+        simpleSelector.children.forEach(function(node) {
+            switch (node.type) {
+                case 'ClassSelector':
+                    if (usageData && usageData.scopes) {
+                        const classScope = usageData.scopes[node.name] || 0;
+
+                        if (scope !== 0 && classScope !== scope) {
+                            throw new Error('Selector can\'t has classes from different scopes: ' + generate(simpleSelector));
+                        }
+
+                        scope = classScope;
+                    }
+
+                    break;
+
+                case 'PseudoClassSelector': {
+                    const name = node.name.toLowerCase();
+
+                    if (!nonFreezePseudoClasses.has(name)) {
+                        pseudos.add(`:${name}`);
+                    }
+
+                    break;
+                }
+
+                case 'PseudoElementSelector': {
+                    const name = node.name.toLowerCase();
+
+                    if (!nonFreezePseudoElements.has(name)) {
+                        pseudos.add(`::${name}`);
+                    }
+
+                    break;
+                }
+
+                case 'TypeSelector':
+                    tagName = node.name.toLowerCase();
+                    break;
+
+                case 'AttributeSelector':
+                    if (node.flags) {
+                        pseudos.add(`[${node.flags.toLowerCase()}]`);
+                    }
+
+                    break;
+
+                case 'Combinator':
+                    tagName = '*';
+                    break;
+            }
+        });
+
+        simpleSelector.compareMarker = specificity(simpleSelector).toString();
+        simpleSelector.id = null; // pre-init property to avoid multiple hidden class
+        simpleSelector.id = generate(simpleSelector);
+
+        if (scope) {
+            simpleSelector.compareMarker += ':' + scope;
+        }
+
+        if (tagName !== '*') {
+            simpleSelector.compareMarker += ',' + tagName;
+        }
+    });
+
+    // add property to all rule nodes to avoid multiple hidden class
+    node.pseudoSignature = pseudos.size > 0
+        ? [...pseudos].sort().join(',')
+        : false;
+};
diff --git a/node_modules/csso/lib/restructure/prepare/specificity.js b/node_modules/csso/lib/restructure/prepare/specificity.js
new file mode 100644
index 00000000..6fa4e5ab
--- /dev/null
+++ b/node_modules/csso/lib/restructure/prepare/specificity.js
@@ -0,0 +1,131 @@
+import { parse } from 'css-tree';
+
+function ensureSelectorList(node) {
+    if (node.type === 'Raw') {
+        return parse(node.value, { context: 'selectorList' });
+    }
+
+    return node;
+}
+
+function maxSpecificity(a, b) {
+    for (let i = 0; i < 3; i++) {
+        if (a[i] !== b[i]) {
+            return a[i] > b[i] ? a : b;
+        }
+    }
+
+    return a;
+}
+
+function maxSelectorListSpecificity(selectorList) {
+    return ensureSelectorList(selectorList).children.reduce(
+        (result, node) => maxSpecificity(specificity(node), result),
+        [0, 0, 0]
+    );
+}
+
+// §16. Calculating a selector’s specificity
+// https://www.w3.org/TR/selectors-4/#specificity-rules
+function specificity(simpleSelector) {
+    let A = 0;
+    let B = 0;
+    let C = 0;
+
+    // A selector’s specificity is calculated for a given element as follows:
+    simpleSelector.children.forEach((node) => {
+        switch (node.type) {
+            // count the number of ID selectors in the selector (= A)
+            case 'IdSelector':
+                A++;
+                break;
+
+            // count the number of class selectors, attributes selectors, ...
+            case 'ClassSelector':
+            case 'AttributeSelector':
+                B++;
+                break;
+
+            // ... and pseudo-classes in the selector (= B)
+            case 'PseudoClassSelector':
+                switch (node.name.toLowerCase()) {
+                    // The specificity of an :is(), :not(), or :has() pseudo-class is replaced
+                    // by the specificity of the most specific complex selector in its selector list argument.
+                    case 'not':
+                    case 'has':
+                    case 'is':
+                    // :matches() is used before it was renamed to :is()
+                    // https://github.com/w3c/csswg-drafts/issues/3258
+                    case 'matches':
+                    // Older browsers support :is() functionality as prefixed pseudo-class :any()
+                    // https://developer.mozilla.org/en-US/docs/Web/CSS/:is
+                    case '-webkit-any':
+                    case '-moz-any': {
+                        const [a, b, c] = maxSelectorListSpecificity(node.children.first);
+
+                        A += a;
+                        B += b;
+                        C += c;
+
+                        break;
+                    }
+
+                    // Analogously, the specificity of an :nth-child() or :nth-last-child() selector
+                    // is the specificity of the pseudo class itself (counting as one pseudo-class selector)
+                    // plus the specificity of the most specific complex selector in its selector list argument (if any).
+                    case 'nth-child':
+                    case 'nth-last-child': {
+                        const arg = node.children.first;
+
+                        if (arg.type === 'Nth' && arg.selector) {
+                            const [a, b, c] = maxSelectorListSpecificity(arg.selector);
+
+                            A += a;
+                            B += b + 1;
+                            C += c;
+                        } else {
+                            B++;
+                        }
+
+                        break;
+                    }
+
+                    // The specificity of a :where() pseudo-class is replaced by zero.
+                    case 'where':
+                        break;
+
+                    // The four Level 2 pseudo-elements (::before, ::after, ::first-line, and ::first-letter) may,
+                    // for legacy reasons, be represented using the <pseudo-class-selector> grammar,
+                    // with only a single ":" character at their start.
+                    // https://www.w3.org/TR/selectors-4/#single-colon-pseudos
+                    case 'before':
+                    case 'after':
+                    case 'first-line':
+                    case 'first-letter':
+                        C++;
+                        break;
+
+                    default:
+                        B++;
+                }
+                break;
+
+            // count the number of type selectors ...
+            case 'TypeSelector':
+                // ignore the universal selector
+                if (!node.name.endsWith('*')) {
+                    C++;
+                }
+                break;
+
+            // ... and pseudo-elements in the selector (= C)
+            case 'PseudoElementSelector':
+                C++;
+                break;
+        }
+    });
+
+    return [A, B, C];
+};
+
+export default specificity;
diff --git a/node_modules/csso/lib/restructure/utils.js b/node_modules/csso/lib/restructure/utils.js
new file mode 100644
index 00000000..792cc59b
--- /dev/null
+++ b/node_modules/csso/lib/restructure/utils.js
@@ -0,0 +1,142 @@
+const { hasOwnProperty } = Object.prototype;
+
+export function isEqualSelectors(a, b) {
+    let cursor1 = a.head;
+    let cursor2 = b.head;
+
+    while (cursor1 !== null && cursor2 !== null && cursor1.data.id === cursor2.data.id) {
+        cursor1 = cursor1.next;
+        cursor2 = cursor2.next;
+    }
+
+    return cursor1 === null && cursor2 === null;
+}
+
+export function isEqualDeclarations(a, b) {
+    let cursor1 = a.head;
+    let cursor2 = b.head;
+
+    while (cursor1 !== null && cursor2 !== null && cursor1.data.id === cursor2.data.id) {
+        cursor1 = cursor1.next;
+        cursor2 = cursor2.next;
+    }
+
+    return cursor1 === null && cursor2 === null;
+}
+
+export function compareDeclarations(declarations1, declarations2) {
+    const result = {
+        eq: [],
+        ne1: [],
+        ne2: [],
+        ne2overrided: []
+    };
+
+    const fingerprints = Object.create(null);
+    const declarations2hash = Object.create(null);
+
+    for (let cursor = declarations2.head; cursor; cursor = cursor.next)  {
+        declarations2hash[cursor.data.id] = true;
+    }
+
+    for (let cursor = declarations1.head; cursor; cursor = cursor.next)  {
+        const data = cursor.data;
+
+        if (data.fingerprint) {
+            fingerprints[data.fingerprint] = data.important;
+        }
+
+        if (declarations2hash[data.id]) {
+            declarations2hash[data.id] = false;
+            result.eq.push(data);
+        } else {
+            result.ne1.push(data);
+        }
+    }
+
+    for (let cursor = declarations2.head; cursor; cursor = cursor.next)  {
+        const data = cursor.data;
+
+        if (declarations2hash[data.id]) {
+            // when declarations1 has an overriding declaration, this is not a difference
+            // unless no !important is used on prev and !important is used on the following
+            if (!hasOwnProperty.call(fingerprints, data.fingerprint) ||
+                (!fingerprints[data.fingerprint] && data.important)) {
+                result.ne2.push(data);
+            }
+
+            result.ne2overrided.push(data);
+        }
+    }
+
+    return result;
+}
+
+export function addSelectors(dest, source) {
+    source.forEach((sourceData) => {
+        const newStr = sourceData.id;
+        let cursor = dest.head;
+
+        while (cursor) {
+            const nextStr = cursor.data.id;
+
+            if (nextStr === newStr) {
+                return;
+            }
+
+            if (nextStr > newStr) {
+                break;
+            }
+
+            cursor = cursor.next;
+        }
+
+        dest.insert(dest.createItem(sourceData), cursor);
+    });
+
+    return dest;
+}
+
+// check if simpleselectors has no equal specificity and element selector
+export function hasSimilarSelectors(selectors1, selectors2) {
+    let cursor1 = selectors1.head;
+
+    while (cursor1 !== null) {
+        let cursor2 = selectors2.head;
+
+        while (cursor2 !== null) {
+            if (cursor1.data.compareMarker === cursor2.data.compareMarker) {
+                return true;
+            }
+
+            cursor2 = cursor2.next;
+        }
+
+        cursor1 = cursor1.next;
+    }
+
+    return false;
+}
+
+// test node can't to be skipped
+export function unsafeToSkipNode(node) {
+    switch (node.type) {
+        case 'Rule':
+            // unsafe skip ruleset with selector similarities
+            return hasSimilarSelectors(node.prelude.children, this);
+
+        case 'Atrule':
+            // can skip at-rules with blocks
+            if (node.block) {
+                // unsafe skip at-rule if block contains something unsafe to skip
+                return node.block.children.some(unsafeToSkipNode, this);
+            }
+            break;
+
+        case 'Declaration':
+            return false;
+    }
+
+    // unsafe by default
+    return true;
+}
diff --git a/node_modules/csso/lib/syntax.js b/node_modules/csso/lib/syntax.js
new file mode 100644
index 00000000..724bd0fb
--- /dev/null
+++ b/node_modules/csso/lib/syntax.js
@@ -0,0 +1,60 @@
+import { fork, string, url, tokenTypes as TYPE } from 'css-tree';
+import compress from './compress.js';
+import specificity from './restructure/prepare/specificity.js';
+
+function encodeString(value) {
+    const stringApostrophe = string.encode(value, true);
+    const stringQuote = string.encode(value);
+
+    return stringApostrophe.length < stringQuote.length
+        ? stringApostrophe
+        : stringQuote;
+}
+
+const {
+    lexer,
+    tokenize,
+    parse,
+    generate,
+    walk,
+    find,
+    findLast,
+    findAll,
+    fromPlainObject,
+    toPlainObject
+} = fork({
+    node: {
+        String: {
+            generate(node) {
+                this.token(TYPE.String, encodeString(node.value));
+            }
+        },
+        Url: {
+            generate(node) {
+                const encodedUrl = url.encode(node.value);
+                const string = encodeString(node.value);
+
+                this.token(TYPE.Url,
+                    encodedUrl.length <= string.length + 5 /* "url()".length */
+                        ? encodedUrl
+                        : 'url(' + string + ')'
+                );
+            }
+        }
+    }
+});
+
+export {
+    lexer,
+    tokenize,
+    parse,
+    generate,
+    walk,
+    find,
+    findLast,
+    findAll,
+    fromPlainObject,
+    toPlainObject,
+    specificity,
+    compress
+};
diff --git a/node_modules/csso/lib/usage.js b/node_modules/csso/lib/usage.js
new file mode 100644
index 00000000..1618e931
--- /dev/null
+++ b/node_modules/csso/lib/usage.js
@@ -0,0 +1,71 @@
+const { hasOwnProperty } = Object.prototype;
+
+function buildMap(list, caseInsensitive) {
+    const map = Object.create(null);
+
+    if (!Array.isArray(list)) {
+        return null;
+    }
+
+    for (let name of list) {
+        if (caseInsensitive) {
+            name = name.toLowerCase();
+        }
+
+        map[name] = true;
+    }
+
+    return map;
+}
+
+function buildList(data) {
+    if (!data) {
+        return null;
+    }
+
+    const tags = buildMap(data.tags, true);
+    const ids = buildMap(data.ids);
+    const classes = buildMap(data.classes);
+
+    if (tags === null &&
+        ids === null &&
+        classes === null) {
+        return null;
+    }
+
+    return {
+        tags,
+        ids,
+        classes
+    };
+}
+
+export function buildIndex(data) {
+    let scopes = false;
+
+    if (data.scopes && Array.isArray(data.scopes)) {
+        scopes = Object.create(null);
+
+        for (let i = 0; i < data.scopes.length; i++) {
+            const list = data.scopes[i];
+
+            if (!list || !Array.isArray(list)) {
+                throw new Error('Wrong usage format');
+            }
+
+            for (const name of list) {
+                if (hasOwnProperty.call(scopes, name)) {
+                    throw new Error(`Class can't be used for several scopes: ${name}`);
+                }
+
+                scopes[name] = i + 1;
+            }
+        }
+    }
+
+    return {
+        whitelist: buildList(data),
+        blacklist: buildList(data.blacklist),
+        scopes
+    };
+}
diff --git a/node_modules/csso/lib/utils.js b/node_modules/csso/lib/utils.js
new file mode 100644
index 00000000..d41b7756
--- /dev/null
+++ b/node_modules/csso/lib/utils.js
@@ -0,0 +1,2 @@
+export { default as processSelector } from './restructure/prepare/processSelector.js';
+export * from './restructure/utils.js';
diff --git a/node_modules/csso/lib/version.js b/node_modules/csso/lib/version.js
new file mode 100644
index 00000000..dde3a83f
--- /dev/null
+++ b/node_modules/csso/lib/version.js
@@ -0,0 +1,5 @@
+import { createRequire } from 'module';
+
+const require = createRequire(import.meta.url);
+
+export const { version } = require('../package.json');