how to add css in javafx code example

Example 1: add css to javafx fxml

.root {
    -fx-background-color:lightgray;
}

Example 2: add css to javafx fxml

<StackPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="app.fxml.SettingsController" stylesheets="@app/cssfilepath.css">

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</StackPane>