Hi All,
I am brand new to CSS, and need some help with my new blog, that I'm creating using Weebly. I've been doing all of my work on a mac. When I view my page on the mac, it looks perfect; however, when I veiw it on a PC, it is totally off center--the background, header, text and navigation. I've looked at it on three different PCs, and it looks different on each one (all off center). I'm not sure what I'm doing wrong.
Can anyone help? I'm pasting the CSS code below. I would be forever grateful if someone could help me figure out what's what!
Thanks in advance :)

*|* {
margin:auto;
padding:auto;
}
body {
background-image:url('background redo 19.jpg');
background-position: center-center;
background-attachment: fixed;
background-repeat: no-repeat;
margin: 0pt auto;
padding: auto;
min height: 100%;
min width: 1183pix;
max width: 1183pix;
}
p {
line-height:1.5;
}
h1, h2, h3{
line-height:1.5;
}
#wrapper {
width:100%;
margin:0pt auto;
}
#contents {
width:80%;
margin:0pt auto;
}
*html #contents {
width:1183px;
}
#header {
background-image:url('logo 100.png');
float:center-center;
width:900px;
height:289px;
text-align:center;
margin:0pt auto;
}
#sitename {
position:relative;
float:left;
padding-top:25px;
font-family:"times new roman",garamond, serif;
color:#333333;
font-size:2.5em;
text-align:center;
}
#navigation {
float:left;
background: transparent url(nav_background.jpg) no-repeat center top;
float:center;
width:960px;
height:40px;
margin:0 auto;
font-family:"lucida sans", arial, sans-serif;
font-size:1em;
}
#navigation ul {
float:left;
padding-left:20px;
padding-top:12px;
margin-left:0px;
width:940px;
height:28px;
}
*html #navigation ul {
margin-left:-12px;
}
#navigation li {
float:left;
display:inline;
font-size:1em;
padding:12px 20px 13px 20px;
margin-top:-12px;
height:15px;
}
*html #navigation li {
margin-right:4px;
}
#active {
float:center;
background: transparent url(activetab_background.jpg) no-repeat center top;
color:#fff;
text-align:center;
}
#navigation a:link {
color:#fff;
text-decoration:none;
}
#navigation a:hover {
color:#fff;
text-decoration:none;
}
#navigation a:visited {
color:#fff;
text-decoration:none;
}
#active a:link {
color:#fff;
text-decoration:none;
}
#active a:hover {
color:#fff;
text-decoration:none;
}
#active a:visited {
color:#fff;
text-decoration:none;
}
a:link, a:hover, a:visited {
color:#198bef;
font-weight:normal;
text-decoration:underline;
}
#main {
clear:both;
width:920px;
min-height:400px;
height:auto !important;
height:400px;
padding:30px 20px 30px 20px;
}
img.image-left {
margin-right:15px;
float:left;
}
img.image-right {
margin-left:15px;
float:right;
}
#footer {
float:left;
width:960px;
border-top:1px solid #000000;
margin:0px 0 30px 0;
}
#footer-contents {
float:left;
color:#000000;
font-family:"lucida grande", "lucida sans", arial, sans-serif;
padding:15px 0 0 20px;
width:940px;
height:28px;
}
*html #footer-contents {
margin-top:-5px;
}
input {
background-color:#fff;
border:1px solid #999;
font-size:12px;
}
textarea {
background-color:#fff;
border:1px solid #999;
font-size:12px;
}