grey line on top of my visual studio website - css

Question

I'm currently working on a website.. I've check the css but I can't seem to figure out why this grey line keeps on showing on top of my Visual Studio website website... I'm using the default Site.css present when creating a asp.net website... please help....
my css:
/* DEFAULTS
----------------------------------------------------------*/
body
{
background: #b6b7bc;
font-size: .80em;
font-family: "Helvetica Neue", "Lucida Grande", "Segoe UI", Arial, Helvetica, Verdana, sans-serif;
margin: 0px;
padding: 0px;
color: #696969;
}
a:link, a:visited
{
color: #034af3;
}
a:hover
{
color: #1d60ff;
text-decoration: none;
}
a:active
{
color: #034af3;
}
p
{
margin-bottom: 10px;
line-height: 1.6em;
}
/* HEADINGS
----------------------------------------------------------*/
h1, h2, h3, h4, h5, h6
{
font-size: 1.5em;
color: #666666;
font-variant: small-caps;
text-transform: none;
font-weight: 200;
margin-bottom: 0px;
}
h1
{
font-size: 1.6em;
padding-bottom: 0px;
margin-bottom: 0px;
}
h2
{
font-size: 1.5em;
font-weight: 600;
}
h3
{
font-size: 1.2em;
}
h4
{
font-size: 1.1em;
}
h5, h6
{
font-size: 1em;
}
/* this rule styles <h1> and <h2> tags that are the
first child of the left and right table columns */
.rightColumn > h1, .rightColumn > h2, .leftColumn > h1, .leftColumn > h2
{
margin-top: 0px;
}
/* PRIMARY LAYOUT ELEMENTS
----------------------------------------------------------*/
.page
{
width: 960px;
background-color: #fff;
margin: 20px auto 0px auto;
border: 1px solid #496077;
}
.header
{
position: relative;
margin: 0px;
padding: 0px;
background: #4b6c9e;
width: 100%;
}
.header h1
{
font-weight: 700;
margin: 0px;
padding: 0px 0px 0px 20px;
color: #f9f9f9;
border: none;
line-height: 2em;
font-size: 2em;
}
.main
{
padding: 0px 12px;
margin: 12px 8px 8px 8px;
min-height: 420px;
}
.leftCol
{
padding: 6px 0px;
margin: 12px 8px 8px 8px;
width: 200px;
min-height: 200px;
}
.footer
{
color: #4e5766;
padding: 8px 0px 0px 0px;
margin: 0px auto;
text-align: center;
line-height: normal;
}
/* TAB MENU
----------------------------------------------------------*/
div.hideSkiplink
{
background-color:#3a4f63;
width:100%;
}
div.menu
{
padding: 4px 0px 4px 8px;
}
div.menu ul
{
list-style: none;
margin: 0px;
padding: 0px;
width: auto;
}
div.menu ul li a, div.menu ul li a:visited
{
background-color: #465c71;
border: 1px #4e667d solid;
color: #dde4ec;
display: block;
line-height: 1.35em;
padding: 4px 20px;
text-decoration: none;
white-space: nowrap;
}
div.menu ul li a:hover
{
background-color: #bfcbd6;
color: #465c71;
text-decoration: none;
}
div.menu ul li a:active
{
background-color: #465c71;
color: #cfdbe6;
text-decoration: none;
}
/* FORM ELEMENTS
----------------------------------------------------------*/
fieldset
{
margin: 1em 0px;
padding: 1em;
border: 1px solid #ccc;
}
fieldset p
{
margin: 2px 12px 10px 10px;
}
fieldset.login label, fieldset.register label, fieldset.changePassword label
{
display: block;
}
fieldset label.inline
{
display: inline;
}
legend
{
font-size: 1.1em;
font-weight: 600;
padding: 2px 4px 8px 4px;
}
input.textEntry
{
width: 320px;
border: 1px solid #ccc;
}
input.passwordEntry
{
width: 320px;
border: 1px solid #ccc;
}
div.accountInfo
{
width: 42%;
}
/* MISC
----------------------------------------------------------*/
.clear
{
clear: both;
}
.title
{
display: block;
float: left;
text-align: left;
width: auto;
}
.loginDisplay
{
font-size: 1.1em;
display: block;
text-align: right;
padding: 10px;
color: White;
}
.loginDisplay a:link
{
color: white;
}
.loginDisplay a:visited
{
color: white;
}
.loginDisplay a:hover
{
color: white;
}
.failureNotification
{
font-size: 1.2em;
color: Red;
}
.bold
{
font-weight: bold;
}
.submitButton
{
text-align: right;
padding-right: 10px;
}

Answer 1

(This is based on Blender's answer, I will delete this if Blender will post his answer)
In order to be formal and to have an answer to this question, as what Blender suggested change
margin: 20px auto 0px auto;
to
margin: 0px auto 0px auto;
This solved the issue according to the one who asked the question.