
Make It Disappear
<style type="text/css">
.members_viewing { display: none; }
</style>

Borders
To give the members_viewing text a border:
<style type="text/css">
.members_viewing {
display: block;
border: 1px solid red;
}
</style>
[ More Border Styles ]

Background
To set a background color:
<style type="text/css">
.members_viewing {
display: block;
background: red;
}
</style>
Or a background image:
<style type="text/css">
.members_viewing {
display: block;
background: url('http://www.PATH TO YOUR IMAGE.gif');
}
</style>
More on
[ Backgrounds ]

Styling Text
The members viewing div contains both plain text and a link. You can style the text, link, and even link in
it's hover state all separately:
<style type="text/css">
.members_viewing {
color: red;
font-family: "Times New Roman", Times, serif;
}
.members_viewing a:link, .members_viewing a:visited {
color: orange;
font-size: 8pt;
text-decoration: none;
}
.members_viewing a:hover {
color: green;
background: yellow;
font-size: 8pt;
text-decoration: underline overline;
}
</style>
More
[ Text Styles ]

Positioning
To create a bit more space above and/or below this line, you could give it a margin:
<style type="text/css">
.members_viewing {
margin-top: 20px;
margin-bottom: 20px;
}
</style>