cannot change table style

I am using the following code to try and change the font and table style but could not do it.
:host ::ng-deep {
ng2-smart-table table tr {
color: black !important;
page-break-inside: avoid;
font-weight: bolder;
}
ng2-smart-table tbody>tr>th {
color: #000000 !important;
text-decoration: none;
font-size: medium;
font-weight: bolder;
}
}

but it won't change my style no matter what. pleast help