leaflet-reveal-unzoom.js

L.Map.addInitHook(function() {
    var slides = document.querySelector('.slides'),
        zoom = Number(slides.style.zoom);

    // Reveal.js sometimes use the zoom CSS property, but sometimes a scale
    // transform instead. We handle both.
    if (zoom) {
        this._container.style.zoom = 1/zoom;
    } else {
        zoom = Number(slides.style.transform.replace(/.*scale\(([0-9\.]+)\).*/, '$1'));
        this._container.style.transform = 'scale(' + (1 / zoom) + ')';
    }

    this.invalidateSize();
});