style.css

.pane 
{
-fx-skin: "com.sun.javafx.scene.control.skin.TitledPaneSkin";    
-fx-text-fill: -fx-text-base-color;
}
.pane:focused 
{
-fx-text-fill: white;
}
.pane > .title 
{
-fx-background-color: -fx-box-border, -fx-inner-border, -fx-body-color;
-fx-background-insets: 0, 1, 2;
-fx-background-radius: 5 5 0 0, 4 4 0 0, 3 3 0 0;
-fx-padding: 0.166667em 0.833333em 0.25em 0.833333em; /* 2 10 3 10 */
}

.pane:focused > .title 
{
-fx-color: -fx-focus-color;
}

.pane > .title > .arrow-button 
{
-fx-background-color: null;
-fx-background-insets: 0;
-fx-background-radius: 0;
-fx-padding: 0.0em 0.25em 0.0em 0.0em; /* 0 3 0 0 */
}

.pane > .title > .arrow-button .arrow 
{
-fx-background-color: -fx-mark-highlight-color, -fx-mark-color;
-fx-background-insets: 1 0 -1 0, 0;
-fx-padding: 0.25em 0.3125em 0.25em 0.3125em; /* 3 3.75 3 3.75 */
-fx-shape: "M 0 0 h 7 l -3.5 4 z";
}

.pane:collapsed > .title > .arrow-button .arrow 
{
-fx-rotate: -90;
}

.pane > *.content 
{
-fx-background-color:
-fx-box-border,
linear-gradient(to bottom, derive(-fx-color,-02%), derive(-fx-color,65%) 12%,      derive(-fx-color,23%) 88%, derive(-fx-color,50%) 99%, -fx-box-border);
-fx-background-insets: 0, 0 1 1 1;
-fx-padding: 0.167em;
 }

.pane:focused > .title > .arrow-button .arrow 
{
-fx-background-color: white;
}