All the customizations you make to the appearance and user interface (UI) of XenForo are encapsulated within styles. This allows you to maintain any number of different themes for your installation in order to suit your site visitors.
For example, you could offer a black text on white background version of your site together with a white text on black background version and allow your visitors to choose how they view the site.
If you offer multiple styles to your visitors, you can specify which style will be shown to those who have not expressed a preference.
The easiest way to do this is to select the radio button for the style you want to be the default on the Appearance > Styles list.
Your selection will be saved as soon as you click it.
You may prevent styles from being selected by users by editing the style and un-checking the Allow user selection option.
Administrators will still be able to select the style, but regular visitors will not. Any visitors who have already selected the style will have the default style delivered to them.
The XenForo style system operates on a principle of inheritance. Styles can be arranged in trees, where any customizations made to a parent style automatically cascade down into all child styles, unless the child styles themselves re-customize the style elements customized in the parent.
A simple way to think about the inheritance structure is to consider each of your styles to be a transparent plastic sheet, sitting on top of the XenForo master style (which is uneditable most of the time).
- With no customizations, the master style emerges through all of the custom styles stacked on top of it.
- If one element of the master style is customized in a style, any styles stacked above it will reflect that customization.
- If the same element is customized in a higher style, the original customization will not emerge at the higher levels, which will instead show the higher customization.
This system allows the creation of multiple custom styles with small variations, which all inherit from a parent style with significant changes.
If you lack the time, inclination or talent to create your own customized styles, you can find a wealth of pre-built styles available on both a free and a paid basis at the XenForo Style Forums.
These styles can then be easily applied to your own XenForo installation using the Import a Style tool from the Appearance section of the Admin Control Panel.