Hello

Thank you for your query.

Please add the following css rule in custom css section:

.view-article article.item {
    float: none;
}

Kindly do let me know if that works.

it is not wide

Have you tried adding that in custom css section?

You can add the following css rule in custom css section instead. It will provide the same result.

.view-article article.item {
    width: 100%;
}