问题
I need to create a box-shadow on some block element, but only (for example) on its right side. The way I do it is to wrap the inner element with box-shadow into an outer one with padding-right and overflow:hidden; so the three other sides of the shadow are not visible.
Is there some better way to achieve this? Like box-shadow-right?
EDIT: My intentions are to create only the vertical part of the shadow. Exactly the same as what repeat-y of the rule background:url(shadow.png) 100% 0% repeat-y would do.
回答1:
Yes, you can use the shadow spread property of the box-shadow rule:
.myDiv
{
border: 1px solid #333;
width: 100px;
height: 100px;
box-shadow: 10px 0 5px -2px #888;
}<div class="myDiv"></div>The fourth property there -2px is the shadow spread, you can use it to change the spread of the shadow, making it appear that the shadow is on one side only.
This also uses the shadow positioning rules 10px sends it to the right (horizontal offset) and 0px keeps it under the element (vertical offset.)
5px is the blur radius :)
Example for you here.
回答2:
My self-made solution which is easy to edit:
HTML:
<div id="anti-shadow-div">
<div id="shadow-div"></div>
</div>
css:
#shadow-div{
margin-right:20px; /* Set to 0 if you don't want shadow at the right side */
margin-left:0px; /* Set to 20px if you want shadow at the left side */
margin-top:0px; /* Set to 20px if you want shadow at the top side */
margin-bottom:0px; /* Set to 20px if you want shadow at the bottom side */
box-shadow: 0px 0px 20px black;
height:100px;
width:100px;
background: red;
}
#anti-shadow-div{
margin:20px;
display:table;
overflow:hidden;
}
Demo:
http://jsfiddle.net/jDyQt/103
回答3:
To get the clipped effect on up to two sides you can use pseudo elements with background gradients.
header::before, main::before, footer::before, header::after, main::after, footer::after {
display: block;
content: '';
position: absolute;
width: 8px;
height: 100%;
top: 0px;
}
header::before, main::before, footer::before {
left: -8px;
background: linear-gradient(to left, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0));
}
header::after, main::after, footer::after {
right: -8px;
background: linear-gradient(to right, rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0));
}
will add a nice shadow-like effect to the left and right of the elements that normally make up a document.
回答4:
Just use ::after or ::before pseudo element to add the shadow. Make it 1px and position it on whatever side you want. Below is example of top.
footer {
margin-top: 50px;
color: #fff;
background-color: #009eff;
text-align: center;
line-height: 90px;
position: relative;
}
footer::after {
content: '';
position: absolute;
width: 100%;
height: 1px;
top: 0;
left: 0;
z-index: -1;
box-shadow: 0px 0px 10px 1px rgba(0, 0, 0, 0.75);
}<footer>top only box shadow</footer>回答5:
Here's a little hack that I did.
<div id="element"><!--element that I want an one-sided inset shadow from the bottom--></div>
<div class="one_side_shadow"></div>
1. Create a <div class="one_side_shadow"></div> right below the element that I want to create the one-side box shadow (in this case I want a one-sided inset shadow for id="element" coming from the bottom)
2. Then I created a regular box-shadow using a negative vertical offset to push the shadow upwards to one-side.
`box-shadow: 0 -8px 20px 2px #DEDEE3;`
回答6:
This could be a simple way
border-right : 1px solid #ddd;
height:85px;
box-shadow : 10px 0px 5px 1px #eaeaea;
Assign this to any div
回答7:
Here is my example:
.box{
width: 400px;
height: 80px;
background-color: #C9C;
text-align: center;
font: 20px normal Arial, Helvetica, sans-serif;
color: #fff;
padding: 100px 0 0 0;
-webkit-box-shadow: 0 8px 6px -6px black;
-moz-box-shadow: 0 8px 6px -6px black;
box-shadow: 0 8px 6px -6px black;
}<div class="box">
</div>回答8:
This site helped me: https://gist.github.com/ocean90/1268328 (Note that on that site the left and right are reversed as of the date of this post... but they work as expected). They are corrected in the code below.
<!DOCTYPE html>
<html>
<head>
<title>Box Shadow</title>
<style>
.box {
height: 150px;
width: 300px;
margin: 20px;
border: 1px solid #ccc;
}
.top {
box-shadow: 0 -5px 5px -5px #333;
}
.right {
box-shadow: 5px 0 5px -5px #333;
}
.bottom {
box-shadow: 0 5px 5px -5px #333;
}
.left {
box-shadow: -5px 0 5px -5px #333;
}
.all {
box-shadow: 0 0 5px #333;
}
</style>
</head>
<body>
<div class="box top"></div>
<div class="box right"></div>
<div class="box bottom"></div>
<div class="box left"></div>
<div class="box all"></div>
</body>
</html>
回答9:
div {
border: 1px solid #666;
width: 50px;
height: 50px;
-webkit-box-shadow: inset 10px 0px 5px -1px #888 ;
}
回答10:
What I do is create a vertical block for the shadow, and place it next to where my block element should be. The two blocks are then wrapped into another block:
<div id="wrapper">
<div id="shadow"></div>
<div id="content">CONTENT</div>
</div>
<style>
div#wrapper {
width:200px;
height:258px;
}
div#wrapper > div#shadow {
display:inline-block;
width:1px;
height:100%;
box-shadow: -3px 0px 5px 0px rgba(0,0,0,0.8)
}
div#wrapper > div#content {
display:inline-block;
height:100%;
vertical-align:top;
}
</style>
jsFiddle example here.
回答11:
Ok, here is one try more. Using pseudo elements and aplying the shadow-box porperty over them.
html:
<div class="no-relevant-box">
<div class="div-to-shadow-1"></div>
<div class="div-to-shadow-2"></div>
</div>
sass:
.div-to-shadow-1, .div-to-shadow-2
height: 150px
width: 150px
overflow: hidden
transition: all 0.3s ease-in-out
&::after
display: block
content: ''
position: relative
top: 0
left: 100%
height: 100%
width: 10px
border: 1px solid mediumeagreen
box-shadow: 0px 7px 12px rgba(0,0,0,0.3)
&:hover
border: 1px solid dodgerblue
overflow: visible
https://codepen.io/alex3o0/pen/PrMyNQ
来源：https://stackoverflow.com/questions/5115427/how-can-i-add-a-box-shadow-on-one-side-of-an-element