Custom Carousel

HTML

<custom-carousel id="num3">

            <div id="mass">1</div>

            <div id="mass" style="background-color:orange">2</div>

            <img src="https://images.pexels.com/photos/1343537/pexels-photo-1343537.jpeg?auto=compress&cs=tinysrgb&dpr=1&w=500">

            <div id="mass" style="background-color:green">4</div>

            <img src="https://images.pexels.com/photos/2539177/pexels-photo-2539177.jpeg?auto=compress&cs=tinysrgb&dpr=1&w=500">

</custom-carousel>

CSS

#num3{

   display:block;

   --container-size: 95vw;

  --button-size: 20vw;

 --button-color: green;

}