You can get away with PageMod , which will bring the desired stylesheet and can also add JavaScript.
Something like this might work:
var pm = require("sdk/page-mod").PageMod({ include: tabs.activeTab.url, attachTo: ["existing", "top"], contentScriptFile: [ self.data.url('jquery/jquery.min.js'), self.data.url('jquery/jquery-ui.js'), self.data.url('recuperation.js'), self.data.url('dialog.js') ], contentStyleFile: self.data.url('jquery/jquery-ui.css') });
Then later, you will want to destroy this PageMod when you are done with it so that they do not just hang over the pages attached to the old ones.
pm.destroy();
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