Navigation bar messing with other elments in CSS

问题

Hi there i had a nav bar which was working perfectly. Then i added a lightbox effect. Both work perfectly however in my css they are messing up. When i added some css to lightbox effects to the div it messes up my navigation bar. I think its something to do with the a tag. My code is below

Html:

<div id="nav">
            <ul>
                <li><a href="#home">Home</a></li>
                <li><a href="#news">Regsiter</a></li>
                <li><a href="#contact">Rules</a></li>
                <li><a href="#about">Photo's</a></li>
                <li><a href="#about">Contact Us</a></li>
            </ul> 
</div>


<div class = "lightbox">
     <a href="images/image1.jpg" rel="lightbox[group]"><img src="images/image1t.jpg" /></a>
     <a href="images/image2.jpg" rel="lightbox[group]"><img src="images/image2t.jpg" /></a>
     <a href="images/image3.jpg" rel="lightbox[group]"><img src="images/image3t.jpg" /></a>
     <a href="images/image4.jpg" rel="lightbox[group]"><img src="images/image4t.jpg" /></a>
     <a href="images/image5.jpg" rel="lightbox[group]"><img src="images/image5t.jpg" /></a>
     <a href="images/image6.jpg" rel="lightbox[group]"><img src="images/image6t.jpg" /></a>
</div>

CSS:

#nav ul
{
    list-style-type:none;
    margin:0;
    padding:0;
    overflow:hidden;
}

#nav ul li
{
    float:left;
}

#nav a:link,a:visited
{
    display:block;
    width:163.2px;
    height: 35px;
    font-weight:bold;
    color:#FFFFFF;
    background-color:#181818;
    text-align:center;
    text-decoration:none;
    text-transform:uppercase;
    line-height: 35px;
}

#nav ul li a:hover
{
    background-color:#989898;
}

//Below is the lightbox CSS

a
{
    border:3px solid #ccc;
    display:block;
    float:left;
    margin:10px;
}

a img
{
    margin:3px;
}

a:hover
{
    border:3px solid #666;
}
img
{
        display:block;
}

Like i said. If i delete the light box CSS the nav bar works fine. When i add it, the border on the nav bar and everything changes. I think it something to do with them both having the a tag but not sure. Thanks for the help.

回答1:

Apply the lightbox CSS only to elements inside the lightbox:

.lightbox a{
  border:3px solid #ccc;
  display:block;
  float:left;
  margin:10px;
}

.lightbox a img{
  margin:3px;
}

.lightbox a:hover{
  border:3px solid #666;
}
.lightbox img{
  display:block;
}

Demo: http://jsfiddle.net/42BjW/ (I don't have the lightbox JS, so obviously the lightbox itself is not working)

回答2:

just add .lightbox in front of your later classes , the lightbox css

来源：https://stackoverflow.com/questions/15800054/navigation-bar-messing-with-other-elments-in-css