.center{text-align: center;}
 .addyoutube {width: 860px; height: 480px; text-align: center;}
 .addyoutube1080 {width: 480px; height: 480px; text-align: center;}
 .square {width: 860px; height: 480px; text-align: center;}

@media screen and (max-width:780px) {
	.addyoutube {width: 90%; height: 280px; margin: auto;}
	.addyoutube1080 {width: 100%; height: 220px}
	.square {width: 480px; height: 480px; text-align: center;}
    }