CSS Print StyleSheet Not Working on Webforms

Question

Can someone help me how to use correctly the css for media print? I'm very novice when it comes to html and css, hence, all the styles that I use is inline. I tried to follow what I found on google on how to use the media print but no luck. Below is a snippet of my css media print where it doesn't work.

<style>
        @media print {
            .imageLogo {
                margin-top: 5px;
            }

            .fontfamily {
                font-family: 'Phetsarath OT';
                text-align: center;
                font-weight: bold;
            }

            .regularfont {
                text-align: center;
                font-weight: bold;
            }

            .sched {
                text-align: center;
                font-weight: bolder;
                font-family: 'Phetsarath OT','Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
                font-size: 35px;
            }

            .leftSide {
                width: 200px;
            }

            .next-to-left {
                width: 300px;
            }

            .grid {
                margin-left: 200px;
            }

            .gridview td {
                width: 300px;
                text-align: center;
            }
        }
    </style>

 Thanks in advance for any help.