如何从CSS排除元素？

Question

Note: I've looked around at other threads, but I can't seem to get the answers there to work.

I've been trying to exclude "#menu" from the margin property in "body{}" so that it doesn't overlap the text.

My code:

body {
    text-align: center;
    background: black;
    background: url("http://tuxlink.files.wordpress.com/2010/04/snow-leopard-server-wallpaper.jpg");
    font-family: Helvetica;
    background-size: 100%;
    background-position: center center;
    background-repeat: no-repeat;
    color: black;
    background-attachment: fixed;
    background-size: cover;
    font-size: 20px;
    margin: 15%;
}

#menu{
    position: absolute;
    color: white;
    position: fixed;
    background-attachment: fixed;
    border: 5px;
    background-color: grey;
    background-size: contain;
    border-style: ridge;
    border-color: grey;
    width: 150px;
    text-align: left;
    float: left;
}

Answer 1

Override the CSS from the body with the CSS for the menu:

#menu { border: none; border-width: 5px; }

Add anything else you might need in there.

Answer 2

If you are trying to make the margin on #menu be reset to the default value, you can add margin: none; to your CSS, so that it looks something like this:

body {
    text-align: center;
    background: black;
    background: url("http://tuxlink.files.wordpress.com/2010/04/snow-leopard-server-wallpaper.jpg");
    font-family: Helvetica;
    background-size: 100%;
    background-position: center center;
    background-repeat: no-repeat;
    color: black;
    background-attachment: fixed;
    background-size: cover;
    font-size: 20px;
    margin: 15%;
}

#menu{
    position: absolute;
    color: white;
    position: fixed;
    background-attachment: fixed;
    border: 5px;
    background-color: grey;
    background-size: contain;
    border-style: ridge;
    border-color: grey;
    width: 150px;
    text-align: left;
    float: left;
    margin: none;
}

That should do the trick!

Answer 3

probably it was what inside your #menu

#menu{
position:absolute;  <-- this are interfering with your margins
color:white;        
position:fixed;     <-- this are interfering with your margins
float:left;         <-- this are interfering with your margins
margin: none;       <-- remove that and try set the margin here (eg: margin: 10px;)
}