In UI Toolkit, you can use USS to customize the appearance of visual elements. The suggested workflow for USS is that you visually style an element in UI Builder, extract the style to a USS file, and then reference it in UXML.
If you style an element in UI Builder, the style is added as an inline style to the style
attribute of UXML elements:
<ui:UXML ...>
<ui:VisualElement style="width: 200px; height: 200px; background-color: red;" />
</ui:UXML>
To reference a stylesheet file, add the <Style>
element under the root element of a UXML file.
For example, if you have a USS file named styles.uss
with the following content:
# root {
width: 200px;
height: 200px;
background-color: red;
}
You can reference it like this:
<ui:UXML ...>
<Style src="<path-to-file>/styles.uss" />
<ui:VisualElement name="root" />
</ui:UXML>
You can use a relative or an absolute path:
Assets
folder and begin with a /
or project://database/
. For example, /Assets/myFolder/myFile.uss
or project://database/Assets/myFolder/myFile.uss
./
. For example, ../myFolder/myFile.uss
.Note: To reference a file from packages, use the absolute path of the package file that starts from the Packages
folder. For example, /Packages/com.unity.package.name/file-name.uss
or project://database/Packages/com.unity.package.name/file-name.uss
. you must use the format of com.unity.package.name
rather than package name
for the package name.