如何修改BootStrap popover的默认样式？（代码）

.popover {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 1060;
    display: none;
    max-width: 276px;
    padding: 1px;
    font-size: 14px;
    font-weight: 400;
    line-height: 1.42857143;
    text-align: left;
    white-space: normal;
    background-color: #fff;
    -webkit-background-clip: padding-box;
    background-clip: padding-box;
    border: 1px solid #ccc;
    border: 1px solid rgba(0,0,0,.2);
    border-radius: 6px;
    -webkit-box-shadow: 0 5px 10px rgba(0,0,0,.2);
    box-shadow: 0 5px 10px rgba(0,0,0,.2);
}

1 .popover{
2     padding:6px;
3     background-color:#000;
4     color:#fff;
5 }