Using the .less files of Bootstrap directly =========================================== If you want to include the [Bootstrap css directly in your less files](http://getbootstrap.com/getting-started/#customizing) you may need to disable the original bootstrap css files to be loaded. You can do this by setting the css property of the [[yii\bootstrap\BootstrapAsset|BootstrapAsset]] to be empty. For this you need to configure the `assetManager` [application component](https://github.com/yiisoft/yii2/blob/master/docs/guide/structure-application-components.md) as follows: ```php 'assetManager' => [ 'bundles' => [ 'yii\bootstrap\BootstrapAsset' => [ 'css' => [], ] ] ] ```