// Leaflet JS - note the *className* attribute
// [...]
L.tileLayer('https://{s}.tile.openstreetmap.fr/hot/{z}/{x}/{y}.png', {
attribution: '© <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
className: 'map-tiles'
}).addTo(map);
// [...]