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1. Select the desired element.
2. In the Properties view, find the property styleClass.
3. When clicking in the field, a drop down list will appear with all the available style classes for the element.  This list is contextual for the element (meaning you will only see label style classes if the element is a label, field classes if the element is a field, and so on.)
4. Select the desired class from the list.
5. If you want to go back to the default style definition, select DEFAULT.

Solution StyleSheet

The stylesheet can be specified at solution level. It has to be stored in the solution's media node; for usage of images from media library inside the .css/.less please use relative URL's.

In the Solution Explorer Tree you can just create a new file (xxxx.css or yyyy.less) in your media folder of your solution, which can then be assigned to the stylesheet property of the solution node.

Working With a Style

To open an existing style sheet:

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