Select all tables with a given class and apply a class to the firt cell and another one to the second cell.

Hello,
I am working on a html document and I have the following tables


<table class="titles">
        <tr>
            <td class="cells">Nom de l'assuré</td>
            <td class="content">{{#childtable.place.rows}}{{fields.name}}{{/childtable.place.rows}}</td>
        </tr>
        <tr>
            <td class="cells">Lieu du sinistre</td>
            <td class="content">{{#childtable.address_view.rows}}{{fields.address}}&nbsp;-&nbsp;{{fields.second_address}}{{/childtable.address_view.rows}}</td>
        </tr>
        <tr>
            <td class="cells">Adresse de l'assuré</td>
            <td class="content">{{#childtable.address_view.rows}}{{fields.address}}&nbsp;-&nbsp;{{fields.second_address}}{{/childtable.address_view.rows}}</td>
        </tr>
        <tr>
            <td class="cells">N° de dossier</td>
            <td class="content">{{#childtable.request.rows}}{{fields.user_def16}}{{/childtable.request.rows}}</td>
        </tr>
    </table>
With the following CSS:
.titles{
            border-left: solid grey;
            border-width: thick;
            border-collapse: collapse;
        }

        .cells{
            font-weight: bold;
            background-color: lightgrey;
            padding-left: 3px;
            width: 25%;
        }
        .content{
            background-color: paleturquoise;
            width: 75%;
            padding-left: 3px;
            border: solid thin black;
            border-width: 0px 0px 1px 1px;
        }


Since I have a lot fof tables with taht layout, and I want to avoid to put the class .cells and the class .content to all the cells of the table, I would like a css code that can select all tables that have the class "titles" and apply them the class.

Thank you