/*Ipad ngang(1024 x 768)*/
@media screen and (max-width: 1024px){
    #wrapper{ width: 100%;}
    #header { height: 70px; text-align: center;}
}
/*Ipad dọc(768 x 1024)*/
@media screen and (max-width: 768px){
    #content{ width: 100%; float: none;}
    #header { height: 60px; text-align: center;}
}
/*Tablet nhỏ(480 x 640)*/
@media screen and (max-width: 480px){
    #content{ width: 100%; float: none;}
    #header { height: 50px; text-align: center;}
}
/*Iphone(480 x 640)*/
@media screen and (max-width: 320px){
    #content{ width: 100%; float: none;}
    #header { height: 40px; text-align: center;}
}
/*Smart phone nhỏ*/
@media screen and (max-width: 240px)
{
    #content{ width: 100%; float: none;}
    #header { height: 30px; text-align: center;}
    
}