Use follwoing style , put listgrid class to gridview and remove all default style sheet applied to gridview.
and then you can play with widh of the header ,row etc
<style>
.listgrid
{
border-collapse: collapse;
width: 100%;
border-top: 1px solid #DDDDDD;
border-left: 1px solid #DDDDDD;
margin-bottom: 20px;
}
.listgrid td
{
border-right: 1px solid #DDDDDD;
border-bottom: 1px solid #DDDDDD;
}
.listgrid th
{
border-right: 1px solid #DDDDDD;
border-bottom: 1px solid #DDDDDD;
}
.listgrid thead th
{
background-color: #EFEFEF;
padding: 7px;
}
.listgrid thead th a, .listgrid thead th
{
text-decoration: none;
color: #222222;
font-weight: bold;
}
.listgrid tbody td a
{
text-decoration: underline;
}
.listgrid tbody td
{
vertical-align: middle;
padding: 0px 5px;
background: #FFFFFF;
text-align: left;
padding: 7px;
}
</style>