Media query

iPad – 768px x 1024px
iPhone – 320px x 480px

For IE 8-

@media screen and (max-width: 1000px) {
#container{
width : 95%;
}
}
@media screen and (max-width: 760px) {
/* style */
}
@media screen and (max-width: 480px) {…}
@media screen and (max-width: 320px) {…}

@media only screen and (min-device-width: 760px)
and (max-device-width: 1000px){
/* style */
}

or import

css round corner what is -moz-, -webkit-

[html]
.box {
  -moz-border-radius: 15px;
  -webkit-border-radius: 15px;
  border-radius: 15px;
 
  -moz-box-shadow: 10px 10px 20px #000;
  -webkit-box-shadow: 10px 10px 20px #000;
  box-shadow: 10px 10px 20px #000;
}
[/html]

-moz- –> firefox 1.0
-webkit- –> safari 0.2 and chrome 3.0
border-radius –> opera 10.5, IE9, Firefox, Chrome

more detail in developer.mozilla