设置el-card、el-table背景色为透明

el-card：

<el-card class="transparent-card">
    ...
</el-card>

.transparent-card {
  background-color: transparent !important;
  border: none !important;
}

el-table：

:deep .el-table,
.el-table__expanded-cell {
  background-color: transparent;
}

:deep .el-table tr {
  background-color: transparent !important;
}