Prism.languages.scss = Prism.languages.extend('css', {
	'comment': {
		pattern: /(^|[^\\])(?:\/\*[\s\S]*?\*\/|\/\/.*)/,
		lookbehind: true
	},
	'atrule': {
		pattern: /@[\w-]+(?:\([^()]+\)|[^(])*?(?=\s+[{;])/,
		inside: {
			'rule': /@[\w-]+/
			// See rest below
		}
	},
	// url, compassified
	'url': /(?:[-a-z]+-)*url(?=\()/i,
	// CSS selector regex is not appropriate for Sass
	// since there can be lot more things (var, @ directive, nesting..)
	// a selector must start at the end of a property or after a brace (end of other rules or nesting)
	// it can contain some characters that aren't used for defining rules or end of selector, & (parent selector), or interpolated variable
	// the end of a selector is found when there is no rules in it ( {} or {\s}) or if there is a property (because an interpolated var
	// can "pass" as a selector- e.g: proper#{$erty})
	// this one was hard to do, so please be careful if you edit this one :)
	'selector': {
		// Initial look-ahead is used to prevent matching of blank selectors
		pattern: /(?=\S)[^@;{}()]?(?:[^@;{}()]|#\{\$[-\w]+\})+(?=\s*\{(?:\}|\s|[^}]+[:{][^}]+))/m,
		inside: {
			'parent': {
				pattern: /&/,
				alias: 'important'
			},
			'placeholder': /%[-\w]+/,
			'variable': /\$[-\w]+|#\{\$[-\w]+\}/
		}
	},
	'property': {
		pattern: /(?:[\w-]|\$[-\w]+|#\{\$[-\w]+\})+(?=\s*:)/,
		inside: {
			'variable': /\$[-\w]+|#\{\$[-\w]+\}/
		}
	}
});

Prism.languages.insertBefore('scss', 'atrule', {
	'keyword': [
		/@(?:if|else(?: if)?|for|each|while|import|extend|debug|warn|mixin|include|function|return|content)/i,
		{
			pattern: /( +)(?:from|through)(?= )/,
			lookbehind: true
		}
	]
});

Prism.languages.insertBefore('scss', 'important', {
	// var and interpolated vars
	'variable': /\$[-\w]+|#\{\$[-\w]+\}/
});

Prism.languages.insertBefore('scss', 'function', {
	'placeholder': {
		pattern: /%[-\w]+/,
		alias: 'selector'
	},
	'statement': {
		pattern: /\B!(?:default|optional)\b/i,
		alias: 'keyword'
	},
	'boolean': /\b(?:true|false)\b/,
	'null': /\bnull\b/,
	'operator': {
		pattern: /(\s)(?:[-+*\/%]|[=!]=|<=?|>=?|and|or|not)(?=\s)/,
		lookbehind: true
	}
});

Prism.languages.scss['atrule'].inside.rest = Prism.languages.scss;
