Yii2 Bootstrap modal slide

index.php

<?php
Modal::begin(
    [
        'size' => Modal::SIZE_LARGE,
        'options' => ['class'=>'slide'],
    ]
);

echo $this->render('view', ['model' => $model]);

Modal::end();

site.css

.modal-lg {
    width: 80%;
    margin: 0 0 0 20%;
    border-radius: 0;
}

.modal-lg .modal-content {
    border-radius: 0;
}

.modal.slide .modal-dialog {
    -webkit-transition: -webkit-transform .3s ease-out;
    -o-transition:      -o-transform .3s ease-out;
    transition:         transform .3s ease-out;
    -webkit-transform: translate3d(100%, 0, 0);
    transform: translate3d(100%, 0, 0);
}

.modal.in .modal-dialog {
    -webkit-transform: translate3d(0, 0, 0);
    transform: translate3d(0, 0, 0);
}

location file ?