@media only screen and (min-width: 320px) and (max-width: 480px) {
}

@media only screen and (min-width: 320px) and (max-width: 640px) {
}

<meta content="width=device-width, initial-scale=1, maximum-scale=1" name="viewport">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0' name='viewport' />

@media only screen and (min-width: 320px) and (max-width: 480px) {