CSS Box Shadow - Top and Bottom Only [duplicate]_问答_开发者

This questi开发者_StackOverflow社区on already has answers here: How to create a drop shadow only on one side of an element? (18 answers) Closed 2 years ago.

I cannot find any examples of how to do this, but how can I add a box shadow only to the top and bottom of an element?

As Kristian has pointed out, good control over z-values will often solve your problems.

If that does not work you can take a look at CSS Box Shadow Bottom Only on using overflow hidden to hide excess shadow.

I would also have in mind that the box-shadow property can accept a comma-separated list of shadows like this:

box-shadow: 0px 10px 5px #888, 0px -10px 5px #888;

This will give you some control over the "amount" of shadow in each direction.

Have a look at http://www.css3.info/preview/box-shadow/ for more information about box-shadow.

Hope this was what you were looking for!

After some experimentation I found that a fourth value in the line controls the spread (at least in FF 10). I opposed the vertical offsets and gave them a negative spread.

Here's the working pen: http://codepen.io/gillytech/pen/dlbsx

<html>
<head>
<style type="text/css">

#test {
    width: 500px;
    border: 1px  #CCC solid;
    height: 200px;

    box-shadow: 
        inset 0px 11px 8px -10px #CCC,
        inset 0px -11px 8px -10px #CCC; 
}
</style>
</head>
<body>
    <div id="test"></div>
</body>
</html>

This works perfectly for me!

So this is my first answer here, and because I needed something similar I did with pseudo elements for 2 inner shadows, and an extra DIV for an upper outer shadow. Don't know if this is the best solutions but maybe it will help someone.

HTML

<div class="shadow-block">
    <div class="shadow"></div>
    <div class="overlay">
        <div class="overlay-inner">
            content here
        </div>
    </div>
</div>

CSS

.overlay {
    background: #f7f7f4;
    height: 185px;
    overflow: hidden;
    position: relative;
    width: 100%; 
}

.overlay:before {
    border-radius: 50% 50% 50% 50%;
    box-shadow: 0 0 50px 2px rgba(1, 1, 1, 0.6);
    content: " ";
    display: block;
    margin: 0 auto;
    width: 80%;
}

.overlay:after {
    border-radius: 50% 50% 50% 50%;
    box-shadow: 0 0 70px 5px rgba(1, 1, 1, 0.5);
    content: "-";
    display: block;
    margin: 0 auto;
    position: absolute;
    bottom: -65px;
    left: -50%;
    right: -50%;
    width: 80%;
}

.shadow {
    position: relative;
    width:100%;
    height:8px;
    margin: 0 0 -22px 0;
    -webkit-box-shadow: 0px 0px 50px 3px rgba(1, 1, 1, 0.6);
    box-shadow: 0px 0px 50px 3px rgba(1, 1, 1, 0.6);
    border-radius: 50%;
}

I've played around with it and I think I have a solution. The following example shows how to set Box-Shadow so that it will only show a shadow for the inset top and bottom of an element.

Legend: insetOption leftPosition topPosition blurStrength spreadStrength color

Description
The key to accomplishing this is to set the blur value to <= the negative of the spread value (ex. inset 0px 5px -?px 5px #000; the blur value should be -5 and lower) and to also keep the blur value > 0 when subtracted from the primary positioning value (ex. using the example from above, the blur value should be -9 and up, thus giving us an optimal value for the the blur to be between -5 and -9).

Solution

.styleName {   
/* for IE 8 and lower */
background-color:#888; filter: progid:DXImageTransform.Microsoft.dropShadow(color=#FFFFCC, offX=0, offY=0, positive=true);  

/* for IE 9 */ 
box-shadow: inset 0px 2px -2px 2px rgba(255,255,204,0.7), inset 0px -2px -2px 2px rgba(255,255,204,0.7); 

/* for webkit browsers */ 
-webkit-box-shadow: inset 0px 2px -2px 2px rgba(255,255,204,0.7), inset 0px -2px -2px 2px rgba(255,255,204,0.7); 

/* for firefox 3.6+ */
-moz-box-shadow: inset 0px 2px -2px 2px rgba(255,255,204,0.7), inset 0px -2px -2px 2px rgba(255,255,204,0.7);   
}

essentially the shadow is the box shape just offset behind the actual box. in order to hide portions of the shadow, you need to create additional divs and set their z-index above the shadowed box so that the shadow is not visible.

If you'd like to have extremely specific control over your shadows, build them as images and created container divs with the right amount of padding and margins.. then use the png fix to make sure the shadows render properly in all browsers