vue父组件修改子组件的样式

<template>
    <div class='Contact'>
        <popup :show.sync="isShowContact"
               has-close-footer-btn="true"
               :footerBtnText="'取消'"
               @close="close">
                <div class="row-item border-top-light"
                     @click="onCall">
                    电话
                </div>
            </div>
        </popup>
    </div>
</template>

.Contact {
    /deep/ .btn,
    /deep/ .btn:link,
    /deep/ .btn:hover,
    /deep/ .btn:active {
        background-color: white;
    }
}