To achieve responsive design, utilize media rules with the following viewport meta tag:
<meta name="viewport" content="width=device-width">
/* Smartphones (portrait and landscape) ----------- */
@media only screen
and (min-device-width : 320px)
and (max-device-width : 480px) {
}
/* Smartphones (portrait) ----------- */
@media only screen
and (min-width: 320px) {
#align,.pau,.slides,.slide img,#header,#footer,#content img,#content h1,.subtext,.text,#nav,.nav-dots,#responsive{width:320px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:40px;padding:2}
#header h1 img{width:30;}
#align{margin-top:320px;}
#nav{margin-top:40px}
#nav li{display:block;}
#sidecontent{position:center;float:left;}
#sidecontent3{margin-top:100px;float:left;}
}
/* Smartphones (landscape) ----------- */
@media only screen
and (min-width: 480px){
#align,.pau,.slides,.slide img,#header,#footer,#content img,#content h1,.subtext,.text,#nav,.nav-dots,#responsive{width:480px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:40px;padding:20px;}
#header h1 img{width:50;}
#align{margin-top:320px;}
#nav{margin-top:40px}
#nav li{display:block;}
#sidecontent{margin-top:440px;position:center;float:left;}
#sidecontent3{margin-top:440px;float:left;}
}
/* iPads (portrait and landscape) ----------- */
@media only screen
and (min-device-width : 768px)
and (max-device-width : 1024px) {
/* Styles */
}
/* iPads (portrait) ----------- */
@media only screen
and (min-width : 768px){
#align,.slides,.slide img,#header,#footer, h1,#nav,.nav-dots,#responsive{width:768px;}
.pau,.subtext,.text,#content img,#content{width:500px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:40px;padding:10px;}
#header h1 img{width:30;}
#align{margin-top:160px;}
#nav{margin-top:1px}
#nav li{display:inline;}
#sidecontent{margin-top:500px;position:center;float:right;font-size:16px;padding:5px;}
#sidecontent3{margin-top:600px;float:right;font-size:16px;padding:5px;}
}
/* iPads (landscape) ----------- */
@media only screen
and (min-width : 1024px){
#align,.slides,.slide img,#header,#footer, h1,#nav,.nav-dots,#responsive{width:1024px;}
.pau,.subtext,.text,#content img,#content,#content h1{width:800px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:40px;padding:20px;}
#header h1 img{width:50;}
#align{margin-top:160px;}
#nav{margin-top:1px}
#nav li{display:inline;}
#sidecontent{margin-top:500px;position:center;float:right;font-size:16px;padding:5px;}
#sidecontent3{margin-top:600px;float:right;font-size:16px;padding:5px;}
}
/* Desktops and laptops ----------- */
@media only screen
and (min-width : 1224px){
#align,.slides,.slide img,#header,#footer, h1,#nav,.nav-dots,#responsive{width:1100px;}
.pau,.subtext,.text,#content img,#content,#content h1{width:800px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:40px;padding:20px;}
#header h1 img{width:50;}
#align{margin-top:160px;}
#nav{margin-top:1px}
#nav li{display:inline;}
#sidecontent{margin-top:500px;position:center;float:right;font-size:16px;padding:5px;}
#sidecontent3{margin-top:600px;float:right;font-size:16px;padding:5px;}
}
/* Large screens ----------- */
@media only screen
and (min-width : 1824px){
#align,.slides,.slide img,#header,#footer, h1,#nav,.nav-dots,#responsive{width:1600px;}
.subtext,.text{width:800px;}
.pau,#content img,#content,#content h1{width:1300px;}
#align,#header,#nav,#footer{overflow-x:hidden;}
#header{margin-top:10px;}
#header h1{font-size:50px;padding-right:10px;margin-right:30px;}
#header h1 img{width:50;}
#align{margin-top:160px;}
#nav{margin-top:1px}
#nav li{display:inline;}
#sidecontent{margin-top:500px;position:center;float:right;font-size:20px;padding:10px;}
#sidecontent3{margin-top:600px;float:right;font-size:20px;padding:10px;}
}