diff --git a/src/Middleware.js b/src/Middleware.js
index faf234f..1d7df2c 100644
--- a/src/Middleware.js
+++ b/src/Middleware.js
@@ -1,6 +1,6 @@
 import {MS, MOZ, WEBKIT, RULESET, KEYFRAMES, DECLARATION} from './Enum.js'
-import {match, charat, substr, strlen, sizeof, replace, combine} from './Utility.js'
-import {copy, tokenize} from './Tokenizer.js'
+import {match, charat, substr, strlen, sizeof, replace, combine, filter, assign} from './Utility.js'
+import {copy, lift, tokenize} from './Tokenizer.js'
 import {serialize} from './Serializer.js'
 import {prefix} from './Prefixer.js'
 
@@ -49,18 +49,22 @@ export function prefixer (element, index, children, callback) {
 					return serialize([copy(element, {value: replace(element.value, '@', '@' + WEBKIT)})], callback)
 				case RULESET:
 					if (element.length)
-						return combine(element.props, function (value) {
-							switch (match(value, /(::plac\w+|:read-\w+)/)) {
+						return combine(children = element.props, function (value) {
+							switch (match(value, callback = /(::plac\w+|:read-\w+)/)) {
 								// :read-(only|write)
 								case ':read-only': case ':read-write':
-									return serialize([copy(element, {props: [replace(value, /:(read-\w+)/, ':' + MOZ + '$1')]})], callback)
+									lift(copy(element, {props: [replace(value, /:(read-\w+)/, ':' + MOZ + '$1')]}))
+									lift(copy(element, {props: [value]}))
+									assign(element, {props: filter(children, callback)})
+									break
 								// :placeholder
 								case '::placeholder':
-									return serialize([
-										copy(element, {props: [replace(value, /:(plac\w+)/, ':' + WEBKIT + 'input-$1')]}),
-										copy(element, {props: [replace(value, /:(plac\w+)/, ':' + MOZ + '$1')]}),
-										copy(element, {props: [replace(value, /:(plac\w+)/, MS + 'input-$1')]})
-									], callback)
+									lift(copy(element, {props: [replace(value, /:(plac\w+)/, ':' + WEBKIT + 'input-$1')]}))
+									lift(copy(element, {props: [replace(value, /:(plac\w+)/, ':' + MOZ + '$1')]}))
+									lift(copy(element, {props: [replace(value, /:(plac\w+)/, MS + 'input-$1')]}))
+									lift(copy(element, {props: [value]}))
+									assign(element, {props: filter(children, callback)})
+									break
 							}
 
 							return ''
diff --git a/src/Parser.js b/src/Parser.js
index 68c5c02..e7472be 100644
--- a/src/Parser.js
+++ b/src/Parser.js
@@ -64,7 +64,7 @@ export function parse (value, root, parent, rule, rules, rulesets, pseudo, point
 			case 47:
 				switch (peek()) {
 					case 42: case 47:
-						append(comment(commenter(next(), caret()), root, parent), declarations)
+						append(comment(commenter(next(), caret()), root, parent, declarations), declarations)
 						break
 					default:
 						characters += '/'
@@ -81,13 +81,13 @@ export function parse (value, root, parent, rule, rules, rulesets, pseudo, point
 					// ;
 					case 59 + offset: if (ampersand == -1) characters = replace(characters, /\f/g, '')
 						if (property > 0 && (strlen(characters) - length))
-							append(property > 32 ? declaration(characters + ';', rule, parent, length - 1) : declaration(replace(characters, ' ', '') + ';', rule, parent, length - 2), declarations)
+							append(property > 32 ? declaration(characters + ';', rule, parent, length - 1, declarations) : declaration(replace(characters, ' ', '') + ';', rule, parent, length - 2, declarations), declarations)
 						break
 					// @ ;
 					case 59: characters += ';'
 					// { rule/at-rule
 					default:
-						append(reference = ruleset(characters, root, parent, index, offset, rules, points, type, props = [], children = [], length), rulesets)
+						append(reference = ruleset(characters, root, parent, index, offset, rules, points, type, props = [], children = [], length, rulesets), rulesets)
 
 						if (character === 123)
 							if (offset === 0)
@@ -96,7 +96,7 @@ export function parse (value, root, parent, rule, rules, rulesets, pseudo, point
 								switch (atrule === 99 && charat(characters, 3) === 110 ? 100 : atrule) {
 									// d l m s
 									case 100: case 108: case 109: case 115:
-										parse(value, reference, reference, rule && append(ruleset(value, reference, reference, 0, 0, rules, points, type, rules, props = [], length), children), rules, children, length, points, rule ? props : children)
+										parse(value, reference, reference, rule && append(ruleset(value, reference, reference, 0, 0, rules, points, type, rules, props = [], length, children), children), rules, children, length, points, rule ? props : children)
 										break
 									default:
 										parse(characters, reference, reference, reference, [''], children, 0, points, children)
@@ -154,9 +154,10 @@ export function parse (value, root, parent, rule, rules, rulesets, pseudo, point
  * @param {string[]} props
  * @param {string[]} children
  * @param {number} length
+ * @param {object[]} siblings
  * @return {object}
  */
-export function ruleset (value, root, parent, index, offset, rules, points, type, props, children, length) {
+export function ruleset (value, root, parent, index, offset, rules, points, type, props, children, length, siblings) {
 	var post = offset - 1
 	var rule = offset === 0 ? rules : ['']
 	var size = sizeof(rule)
@@ -166,17 +167,18 @@ export function ruleset (value, root, parent, index, offset, rules, points, type
 			if (z = trim(j > 0 ? rule[x] + ' ' + y : replace(y, /&\f/g, rule[x])))
 				props[k++] = z
 
-	return node(value, root, parent, offset === 0 ? RULESET : type, props, children, length)
+	return node(value, root, parent, offset === 0 ? RULESET : type, props, children, length, siblings)
 }
 
 /**
  * @param {number} value
  * @param {object} root
  * @param {object?} parent
+ * @param {object[]} siblings
  * @return {object}
  */
-export function comment (value, root, parent) {
-	return node(value, root, parent, COMMENT, from(char()), substr(value, 2, -2), 0)
+export function comment (value, root, parent, siblings) {
+	return node(value, root, parent, COMMENT, from(char()), substr(value, 2, -2), 0, siblings)
 }
 
 /**
@@ -184,8 +186,9 @@ export function comment (value, root, parent) {
  * @param {object} root
  * @param {object?} parent
  * @param {number} length
+ * @param {object[]} siblings
  * @return {object}
  */
-export function declaration (value, root, parent, length) {
-	return node(value, root, parent, DECLARATION, substr(value, 0, length), substr(value, length + 1, -1), length)
+export function declaration (value, root, parent, length, siblings) {
+	return node(value, root, parent, DECLARATION, substr(value, 0, length), substr(value, length + 1, -1), length, siblings)
 }
diff --git a/src/Serializer.js b/src/Serializer.js
index 0c1ffa3..cad20d4 100644
--- a/src/Serializer.js
+++ b/src/Serializer.js
@@ -1,5 +1,5 @@
 import {IMPORT, LAYER, COMMENT, RULESET, DECLARATION, KEYFRAMES} from './Enum.js'
-import {strlen, sizeof} from './Utility.js'
+import {strlen} from './Utility.js'
 
 /**
  * @param {object[]} children
@@ -8,9 +8,8 @@ import {strlen, sizeof} from './Utility.js'
  */
 export function serialize (children, callback) {
 	var output = ''
-	var length = sizeof(children)
 
-	for (var i = 0; i < length; i++)
+	for (var i = 0; i < children.length; i++)
 		output += callback(children[i], i, children, callback) || ''
 
 	return output
@@ -29,7 +28,7 @@ export function stringify (element, index, children, callback) {
 		case IMPORT: case DECLARATION: return element.return = element.return || element.value
 		case COMMENT: return ''
 		case KEYFRAMES: return element.return = element.value + '{' + serialize(element.children, callback) + '}'
-		case RULESET: element.value = element.props.join(',')
+		case RULESET: if (!strlen(element.value = element.props.join(','))) return ''
 	}
 
 	return strlen(children = serialize(element.children, callback)) ? element.return = element.value + '{' + children + '}' : ''
diff --git a/src/Tokenizer.js b/src/Tokenizer.js
index dd482ce..201fb51 100644
--- a/src/Tokenizer.js
+++ b/src/Tokenizer.js
@@ -14,10 +14,11 @@ export var characters = ''
  * @param {string} type
  * @param {string[] | string} props
  * @param {object[] | string} children
+ * @param {object[]} siblings
  * @param {number} length
  */
-export function node (value, root, parent, type, props, children, length) {
-	return {value: value, root: root, parent: parent, type: type, props: props, children: children, line: line, column: column, length: length, return: ''}
+export function node (value, root, parent, type, props, children, length, siblings) {
+	return {value: value, root: root, parent: parent, type: type, props: props, children: children, line: line, column: column, length: length, return: '', siblings: siblings}
 }
 
 /**
@@ -26,7 +27,17 @@ export function node (value, root, parent, type, props, children, length) {
  * @return {object}
  */
 export function copy (root, props) {
-	return assign(node('', null, null, '', null, null, 0), root, {length: -root.length}, props)
+	return assign(node('', null, null, '', null, null, 0, root.siblings), root, {length: -root.length}, props)
+}
+
+/**
+ * @param {object} root
+ */
+export function lift (root) {
+	while (root.root)
+		root = copy(root.root, {children: [root]})
+
+	append(root, root.siblings)
 }
 
 /**
diff --git a/src/Utility.js b/src/Utility.js
index 702fe6e..8357dbc 100644
--- a/src/Utility.js
+++ b/src/Utility.js
@@ -113,3 +113,12 @@ export function append (value, array) {
 export function combine (array, callback) {
 	return array.map(callback).join('')
 }
+
+/**
+ * @param {string[]} array
+ * @param {RegExp} pattern
+ * @return {string[]}
+ */
+export function filter (array, pattern) {
+	return array.filter(function (value) { return !match(value, pattern) })
+}
diff --git a/test/Middleware.js b/test/Middleware.js
index 596c8e9..3167d0b 100644
--- a/test/Middleware.js
+++ b/test/Middleware.js
@@ -3,9 +3,23 @@ import {compile, serialize, stringify, middleware, rulesheet, prefixer, namespac
 const stack = []
 
 describe('Middleware', () => {
-	test('rulesheet', () => {
-  	serialize(compile(`@import url('something.com/file.css');.user{ h1 {width:0;} @media{width:1;}@keyframes name{from{width:0;}to{width:1;}}}@keyframes empty{}`), middleware([prefixer, stringify, rulesheet(value => stack.push(value))]))
-  	expect(stack).to.deep.equal([
+  test('rulesheet', () => {
+    serialize(compile(`
+      @import url('something.com/file.css');
+      .user{ h1 {width:0;}
+      @media{width:1;}
+      @keyframes name{from{width:0;}to{width:1;}}}
+      @keyframes empty{}
+      @supports (display: grid) {
+        @media (min-width: 500px){
+          .a::placeholder{color: red;}
+        }
+      }
+      @media (min-width: 500px) {
+        a:read-only{color:red;}
+      }
+    `), middleware([prefixer, stringify, rulesheet(value => stack.push(value))]))
+    expect(stack).to.deep.equal([
       `@import url('something.com/file.css');`,
       `.user h1{width:0;}`,
       `@media{.user{width:1;}}`,
@@ -13,11 +27,17 @@ describe('Middleware', () => {
       `@keyframes name{from{width:0;}to{width:1;}}`,
       '@-webkit-keyframes empty{}',
       '@keyframes empty{}',
+      '@supports (display: grid){@media (min-width: 500px){.a::-webkit-input-placeholder{color:red;}}}',
+      '@supports (display: grid){@media (min-width: 500px){.a::-moz-placeholder{color:red;}}}',
+      '@supports (display: grid){@media (min-width: 500px){.a:-ms-input-placeholder{color:red;}}}',
+      '@supports (display: grid){@media (min-width: 500px){.a::placeholder{color:red;}}}',
+      '@media (min-width: 500px){a:-moz-read-only{color:red;}}',
+      '@media (min-width: 500px){a:read-only{color:red;}}',
     ])
   })
 
   test('namespace', () => {
-  	expect(serialize(compile(`.user{width:0; :global(p,a){width:1;} h1 {width:1; h2:last-child {width:2} h2 h3 {width:3}}}`), middleware([namespace, stringify]))).to.equal([
+    expect(serialize(compile(`.user{width:0; :global(p,a){width:1;} h1 {width:1; h2:last-child {width:2} h2 h3 {width:3}}}`), middleware([namespace, stringify]))).to.equal([
       `.user{width:0;}`, `p,a{width:1;}`, `h1.user.user{width:1;}`, `h1.user h2:last-child.user{width:2;}`, `h1.user h2 h3.user{width:3;}`
     ].join(''))
 
@@ -59,34 +79,42 @@ describe('Middleware', () => {
     ].join(''))
 
     expect(serialize(compile(`textarea::placeholder{font-size:14px;@media{font-size:16px;}}`), middleware([prefixer, stringify]))).to.equal([
-      `textarea::-webkit-input-placeholder{font-size:14px;}textarea::-moz-placeholder{font-size:14px;}textarea:-ms-input-placeholder{font-size:14px;}textarea::placeholder{font-size:14px;}`,
-      `@media{textarea::-webkit-input-placeholder{font-size:16px;}textarea::-moz-placeholder{font-size:16px;}textarea:-ms-input-placeholder{font-size:16px;}textarea::placeholder{font-size:16px;}}`
+      `textarea::-webkit-input-placeholder{font-size:14px;}`,
+      `textarea::-moz-placeholder{font-size:14px;}`,
+      `textarea:-ms-input-placeholder{font-size:14px;}`,
+      `textarea::placeholder{font-size:14px;}`,
+      `@media{textarea::-webkit-input-placeholder{font-size:16px;}}`,
+      `@media{textarea::-moz-placeholder{font-size:16px;}}`,
+      `@media{textarea:-ms-input-placeholder{font-size:16px;}}`,
+      `@media{textarea::placeholder{font-size:16px;}}`,
     ].join(''))
 
     expect(serialize(compile(`div:read-write{background-color:red;span{background-color:green;}}`), middleware([prefixer, stringify]))).to.equal([
       `div:-moz-read-write{background-color:red;}`,
       `div:read-write{background-color:red;}`,
       `div:-moz-read-write span{background-color:green;}`,
-      `div:read-write span{background-color:green;}`
+      `div:read-write span{background-color:green;}`,
     ].join(''))
 
     expect(serialize(compile(`div:read-write span{background-color:hotpink;}`), middleware([prefixer, stringify]))).to.equal([
       `div:-moz-read-write span{background-color:hotpink;}`,
-      `div:read-write span{background-color:hotpink;}`
+      `div:read-write span{background-color:hotpink;}`,
     ].join(''))
 
     expect(serialize(compile(`.read-write:read-write,.read-only:read-only,.placeholder::placeholder{background-color:hotpink;}`), middleware([prefixer, stringify]))).to.equal([
       `.read-write:-moz-read-write{background-color:hotpink;}`,
+      `.read-write:read-write{background-color:hotpink;}`,
       `.read-only:-moz-read-only{background-color:hotpink;}`,
+      `.read-only:read-only{background-color:hotpink;}`,
       `.placeholder::-webkit-input-placeholder{background-color:hotpink;}`,
       `.placeholder::-moz-placeholder{background-color:hotpink;}`,
       `.placeholder:-ms-input-placeholder{background-color:hotpink;}`,
-      `.read-write:read-write,.read-only:read-only,.placeholder::placeholder{background-color:hotpink;}`,
+      `.placeholder::placeholder{background-color:hotpink;}`,
     ].join(''))
 
     expect(serialize(compile(`:read-write{background-color:hotpink;}`), middleware([prefixer, stringify]))).to.equal([
       `:-moz-read-write{background-color:hotpink;}`,
-      `:read-write{background-color:hotpink;}`
+      `:read-write{background-color:hotpink;}`,
     ].join(''))
   })
 })
diff --git a/test/Tokenizer.js b/test/Tokenizer.js
index fedf45b..42695a8 100644
--- a/test/Tokenizer.js
+++ b/test/Tokenizer.js
@@ -2,9 +2,9 @@ import {tokenize} from "../index.js"
 
 describe('Tokenizer', () => {
   test('tokenize', () => {
-  	expect(tokenize(`h1 h2 (h1 h2) 1 / 3 * 2 + 1 [1 2] "1 2" a`)).to.deep.equal([
-  		'h1', ' ', 'h2', ' ', '(h1 h2)', ' ', '1', ' ', '/', ' ', '3', ' ', '*', ' ', '2', ' ', '+', ' ', '1', ' ', '[1 2]', ' ', '"1 2"', ' ', 'a'
-  	])
+    expect(tokenize(`h1 h2 (h1 h2) 1 / 3 * 2 + 1 [1 2] "1 2" a`)).to.deep.equal([
+      'h1', ' ', 'h2', ' ', '(h1 h2)', ' ', '1', ' ', '/', ' ', '3', ' ', '*', ' ', '2', ' ', '+', ' ', '1', ' ', '[1 2]', ' ', '"1 2"', ' ', 'a'
+    ])
 
     expect(tokenize(`:global([data-popper-placement^='top'])`)).to.deep.equal([
       `:`, `global`, `([data-popper-placement^='top'])`