抽屉el-drawer 底层有遮罩问题

<el-drawer :title="sourceData.name1" :visible.sync="drawer" direction="ltr" :before-close="handleClose"
            :modal="false" :append-to-body="true" class="drawerC">

          
          

        </el-drawer>





data() {
        return {
            drawer: false,
}
}

:deep(.el-drawer__open .el-drawer.ltr) {
    padding: 0 15px !important;
}
:deep(.el-drawer) {
    width: 100% !important;
}
.drawerC {
    width: 763px;
    height: 533px;
    top: 20%;
}
:deep(.el-drawer__open .el-drawer.ltr) {
    background: url('../../assets/handOver/box-bg.png') center center no-repeat !important;
    background-size: 100% 100% !important;
}

:deep(.el-drawer__header) {
    padding: 5px 10px 0 !important;
    color: #fff !important;
    margin-bottom: 10px !important;
}