```coffeescript
fs = require 'fs-utils'
Theme = require 'theme'
CSON = require 'cson'

module.exports =
class AtomTheme extends Theme

  loadStylesheet: (stylesheetPath)->
    @stylesheets[stylesheetPath] = window.loadStylesheet(stylesheetPath)

  load: ->
    if fs.extension(@path) in ['.css', '.less']
      @loadStylesheet(@path)
    else
      metadataPath = fs.resolveExtension(fs.join(@path, 'package'), ['cson', 'json'])
      if fs.isFile(metadataPath)
        stylesheetNames = CSON.readObject(metadataPath)?.stylesheets
        if stylesheetNames
          @loadStylesheet(fs.join(@path, name)) for name in stylesheetNames
      else
        @loadStylesheet(stylesheetPath) for stylesheetPath in fs.list(@path, ['.css', '.less'])

    super
```

Allow theme's package.cson to leave off stylesheet extension
user
```coffeescript
fs = require 'fs-utils'
Theme = require 'theme'
CSON = require 'cson'

module.exports =
class AtomTheme extends Theme

  loadStylesheet: (stylesheetPath)->
    @stylesheets[stylesheetPath] = window.loadStylesheet(stylesheetPath)

  load: ->
    if fs.extension(@path) in ['.css', '.less']
      @loadStylesheet(@path)
    else
      metadataPath = fs.resolveExtension(fs.join(@path, 'package'), ['cson', 'json'])
      if fs.isFile(metadataPath)
        stylesheetNames = CSON.readObject(metadataPath)?.stylesheets
        if stylesheetNames
          for name in stylesheetNames
            filename = fs.resolveExtension(fs.join(@path, name), ['.css', '.less', ''])
            @loadStylesheet(filename)
      else
        @loadStylesheet(stylesheetPath) for stylesheetPath in fs.list(@path, ['.css', '.less'])

    super
```
assistant