You could use calc():
#footer {
width: calc(100% - 12px);
border: 1px solid #000000;
position:fixed;
margin:0 5px;
}
body {
margin:0;
padding:0;
}
The 12px in the calc comes from the 5px of each margin, plus the 1px for the left and right border.
Or option #2 (no width
or calc()
needed). Simply set the left and right to 5px and the footer will stretch the full width, minus those amounts:
#footer {
border: 1px solid #000000;
position:fixed;
left:5px;
right:5px;
}
body {
margin:0;
padding:0;
}