How can I create this corner shadow (without images)?

Question

I want to reduce external dependencies, in particular, replacing images with CSS effects, where possible, for example, in this case:

HTML and CSS ( as this script shows ) is as follows.

HTML

<div id="one">
  <div></div>
</div>

CSS

#one{
  width: 940px;
  height: 350px;
  padding: 0 10px;
  margin: 10px 0;
  position: relative;
}

#one{
  background-image: url("http://webhost.ischool.uw.edu/~joatwood/portfolio/images/slider-shadow.png");
}

#one > div{
  background-color: purple;
  width: 100%;
  height: 100%;
}

I want to achieve these three things:

• Inclined shadow that breaks away from the element only on the left and right edges (cannot hide overflow otherwise, other pseudo-elements inside this element should go beyond its edges)
• The shadow should disappear from black to white, as it is farther from the middle vertically.
• The shadow should not use straight edges - it should be slightly blurry, like a shadow if you applied box-shadow: 5px 5px 5px

---

I have tried two methods so far, none of them have been completely successful:

• transform: skewX - # 1 # 2, , № 3.
• transform: rotate - # 3 №1 №2.

CSS3, (Firefox, Chrome), <div>, " re .

Answer 1

, , . , - , linear-gradient . CSS- ( :before/:after) , .

jsFiddle - .

. Chrome, FF .

HTML

<div id="two">
  <div></div>
</div>

CSS

#two {
    width: 940px;
    height: 350px;
    padding: 0;
    margin-left: 10px;
    position: relative;
    background: rgb(255,255,255);
    background: -moz-linear-gradient(top,  rgba(255,255,255,1) 2%, rgba(0,0,0,1) 40%, rgba(0,0,0,1) 60%, rgba(255,255,255,1) 98%);
    background: -webkit-linear-gradient(top,  rgba(255,255,255,1) 2%,rgba(0,0,0,1) 40%,rgba(0,0,0,1) 60%,rgba(255,255,255,1) 98%);
    background: linear-gradient(to bottom,  rgba(255,255,255,1) 2%,rgba(0,0,0,1) 40%,rgba(0,0,0,1) 60%,rgba(255,255,255,1) 98%);
}

#two > div {
    background-color: purple;
    width: 920px;
    height: 100%;
    margin: 0px auto;
}

#two:before, #two:after {
    content: "";
    width: 10px;
    height: 0px;
    border-top: 175px solid transparent;
    border-bottom: 175px solid transparent;
    position: absolute;
    top: 0;
}

#two:before {
    left: 0px;
    border-left: 10px solid white;
}

#two:after {
    right: 0px;
    border-right: 10px solid white;
}

, - , . , .

Answer 2

<style type="text/css">
#container {
    width: 350px;
    height: 250px;
    position: relative;
}
#box {
    height: 100%;
    width: 100%;
    background-color: #909;
    position: absolute;
}
.shadow {
    width: 10px;
    height: 50%;
    position: absolute;
    background: -moz-linear-gradient(top,  rgba(0,0,0,0) 0%, rgba(0,0,0,0.9) 100%); /* FF3.6+ */
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(0,0,0,0)), color-stop(100%,rgba(0,0,0,0.9))); /* Chrome,Safari4+ */
    background: -webkit-linear-gradient(top,  rgba(0,0,0,0) 0%,rgba(0,0,0,0.9) 100%); /* Chrome10+,Safari5.1+ */
    background: -o-linear-gradient(top,  rgba(0,0,0,0) 0%,rgba(0,0,0,0.9) 100%); /* Opera 11.10+ */
    background: -ms-linear-gradient(top,  rgba(0,0,0,0) 0%,rgba(0,0,0,0.9) 100%); /* IE10+ */
    background: linear-gradient(to bottom,  rgba(0,0,0,0) 0%,rgba(0,0,0,0.9) 100%); /* W3C */
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#00000000', endColorstr='#e6000000',GradientType=0 ); /* IE6-9 */
    z-index: -1;
}
#TL {
    transform:rotate(-2deg);
    -ms-transform:rotate(-2deg); /* IE 9 */
    -webkit-transform:rotate(-2deg); /* Safari and Chrome */
    left: -3px;
}
#TR {
    transform:rotate(2deg);
    -ms-transform:rotate(2deg); /* IE 9 */
    -webkit-transform:rotate(2deg); /* Safari and Chrome */
    right: -3px;
}
#BR {
    transform:rotate(178deg);
    -ms-transform:rotate(178deg); /* IE 9 */
    -webkit-transform:rotate(178deg); /* Safari and Chrome */
    right: -3px;
    bottom: 0px;
}
#BL {
    transform:rotate(182deg);
    -ms-transform:rotate(182deg); /* IE 9 */
    -webkit-transform:rotate(182deg); /* Safari and Chrome */
    left: -3px;
    bottom: 0px;
}
</style>

<div id="container">
    <div id="box"></div>
    <div class="shadow" id="TL"></div>
    <div class="shadow" id="TR"></div>
    <div class="shadow" id="BR"></div>
    <div class="shadow" id="BL"></div>
</div>