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As you can see, if all you want to change in a module's front - office appearance while keeping its organzation, you only have to edit its CSS file and leave its template file alone. For instance, to change the styling of the Layered Navigation module, you should put your customized version in this folder: /themes/YOUR_THEME/css/modules/blocklayered/blocklayered.css. Just make sure to use the same file path as the original module files.
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