如何删除默认的 Bootstrap 3 轮播控件背景渐变？

我很确定这是我需要修改的代码，但由于某种原因我无法让渐变在 IE 中消失。我要他们彻底消失！

.carousel-control {
text-shadow: none;
opacity: 1;
filter: alpha(opacity=100)
}
.carousel-control.left {
background-image: -webkit-gradient(linear, 0 top, 100% top, from(rgba(0,0,0,0.5)), to(rgba(0,0,0,0.0001)));
background-image: -webkit-linear-gradient(left, color-stop(rgba(0,0,0,0.5) 0), color-stop(rgba(0,0,0,0.0001) 100%));
background-image: -moz-linear-gradient(left, rgba(0,0,0,0.5) 0, rgba(0,0,0,0.0001) 100%);
background-image: linear-gradient(to right, rgba(0,0,0,0.5) 0, rgba(0,0,0,0.0001) 100%);
background-repeat: repeat-x;
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#80000000', endColorstr='#00000000', GradientType=1)
}
.carousel-control.right {
background-image: -webkit-gradient(linear, 0 top, 100% top, from(rgba(0,0,0,0.0001)), to(rgba(0,0,0,0.5)));
background-image: -webkit-linear-gradient(left, color-stop(rgba(0,0,0,0.0001) 0), color-stop(rgba(0,0,0,0.5) 100%));
background-image: -moz-linear-gradient(left, rgba(0,0,0,0.0001) 0, rgba(0,0,0,0.5) 100%);
background-image: linear-gradient(to right, rgba(0,0,0,0.0001) 0, rgba(0,0,0,0.5) 100%);
background-repeat: repeat-x;
filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#00000000', endColorstr='#80000000', GradientType=1)
}
.carousel-control:hover, .carousel-control:focus {
opacity: 1;
filter: alpha(opacity=100)
}

.carousel-control.left, .carousel-control.right {
    background-image: none
}