The Sandbox.UI.PseudoClass.Active field represents the :active pseudo-class in CSS, which is used to style a button or element that is currently being pressed down by the user. This pseudo-class is part of the PseudoClass enumeration, which is a collection of CSS pseudo-classes used within the Sandbox UI styling system.
Use the Active pseudo-class to apply specific styles to elements when they are in the active state, such as when a button is being clicked. This can be useful for providing visual feedback to users when they interact with UI elements.
// Example of using the Active pseudo-class in a CSS style block
.my-button:active {
background-color: #005f5f;
color: white;
transform: scale(0.98);
}