Ekran büyüklüğüne göre siteyi ayarlıcaz. Bunun için iki farklı yöntem var:

<link rel="stylesheet" href="css/videolar.css"  media="only screen and (min-width:1200px)">				XL

<link rel="stylesheet" href="css/videolar.css"  media="only screen and (min-width:992px) and (max-width:1199px)">	L

<link rel="stylesheet" href="css/videolar.css"  media="only screen and (min-width:768px) and (max-width:991px)">	M
		
<link rel="stylesheet" href="css/videolar.css"  media="only screen and (min-width:576px) and (max-width:767px)">	S

<link rel="stylesheet" href="css/videolar.css"  media="only screen and (max-width:575px)">				XS
/* zaten kendisi normal hali bizim ekranımız 1200den büyük */
@media only screen and (min-width:1200px)  {								        /*XL*/ 
	<div></div>
}
@media only screen and (min-width:991px) and (max-width:1199px) {		/*L*/
	<div></div>
}
@media only screen and (min-width:768px) and (max-width:991px) {		/*M*/
	<div></div>
}

@media only screen and (min-width:576px) and (max-width:767px) {		/*S*/
	<div></div>
}

@media only screen and  (max-width:575px) {							             /*XS*/
	<div></div>
}