今天发现个事

        <el-dialogv-model="bindDialogVisible":title="bindDialogTitle"append-to-bodyclose-on-press-escapedraggablemodal-class="bindNdevice-dialog"width="500px"></el-dialog>

这个样式这样写生效

<style lang="scss">.bindNdevice-dialog .el-dialog {background: black;
}</style>

但是这样写却不生效

<style lang="scss">.el-dialog .bindNdevice-dialog {background: black;
}</style>