반응형 웹(Responsive Web)
디바이스 해상도에 따라 웹페이지의 크기가 자동으로 변경되는 것을 말한다.

CSS 2.1부터 미디어타입으로 단말기 종류에따라 각각 다른 스타일을 적용이 가능해졌다.

디바이스별 해상도 크기는 다음거 같다.

@media (max-width:1199px) { 
	/* Style  */
}


@media (min-width: 992px) and (max-width: 1199px) {
	/* Style - laptop*/
}

@media (max-width:991px) {

}

@media (min-width: 768px) and (max-width: 991px) {
	/* Style - Tablet*/
}

@media (max-width:767px) {
	
}

@media (min-width: 480px) and (max-width: 767px) {
	/* Style - handheld*/
}

@media (max-width: 479px) {
	/* Style - smallest*/
}


/* ----------------------------------------------------------------
	Retina CSS
-----------------------------------------------------------------*/


@media
only screen and (-webkit-min-device-pixel-ratio: 2),
only screen and (   min--moz-device-pixel-ratio: 2),
only screen and (     -o-min-device-pixel-ratio: 2/1),
only screen and (        min-device-pixel-ratio: 2),
only screen and (                min-resolution: 192dpi),
only screen and (                min-resolution: 2dppx) {
	/* Style*/
}


@media
only screen and (-webkit-min-device-pixel-ratio: 2) and (max-width: 991px),
only screen and (   min--moz-device-pixel-ratio: 2) and (max-width: 991px),
only screen and (     -o-min-device-pixel-ratio: 2/1) and (max-width: 991px),
only screen and (        min-device-pixel-ratio: 2) and (max-width: 991px),
only screen and (                min-resolution: 192dpi) and (max-width: 991px),
only screen and (                min-resolution: 2dppx) and (max-width: 991px) {
	/* Style*/
}