Assignment 13 Problem

Unable to get the cyan color for mobile screen resolution. Below is the code please help me in getting the output.
Thank you

<meta charset="UTF-8">

<meta http-equiv="X-UA-Compatible" content="IE=edge">

<meta name="viewport" content="width=device-width, initial-scale=1.0">

<title>Question1</title>

<style type="text/css">

    body{

        background-color: lightgreen;

    }

    h3{

        color:blue;

        font-size: 50px;

    }

    /* for mobiles */

    @media only screen and (max-width:320px){

        body{

            background-color:cyan

        }

    }

   

    /* for tablets */

    @media only screen and (max-width: 768px){

        body{

            background-color: rgb(255, 174, 0);

        }

    }

</style>
<div class="col-">

    <h3 >Rajat Harwadekar</h3>

</div>