.search-h1 #leo_search_block_top form {
    border-radius: 8px;
}

@media (min-width: 992px) {
    .search-h1 #leo_search_block_top .title_block {
        display: none;
    }
    .search-h1 #leo_search_block_top form {
        position: relative;
        opacity: 1;
        visibility: visible;
        top: 0;
        left: 0;
        transform: none;
        border-radius: 8px;
        /* le background reste appliqué automatiquement */
    }
}