bootstrap 的轮询图片中，去掉两侧的阴影。

<style>
.carousel-control.left {
    background-image:none;
    background-repeat: repeat-x;
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#80000000', endColorstr='#00000000', GradientType=1)
}
 
.carousel-control.right {
    left: auto; right: 0;
    background-image:none;
    background-repeat: repeat-x;
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#00000000', endColorstr='#80000000', GradientType=1)
}

</style>