I need to conditionally format a report template for Quotation:

....<tbody class="sale_tbody">

<t t-foreach="o.order_line" t-as=i">

<tr t-if="something">                     // <<< Have to set CSS depending on condition here

<td><span t-field="i.name" /></td>

</tr>

</tbody>

In the code snippet, I basically want to change the background colour of the row based on a value in the order_line table (like quantity less than 4 etc.)

I have been struggling to do it. I have tried to use t-if and t-att, but I can't understand how to change CSS format with the conditions.

Can anyone please help me out on this?