in frontend/janus.js [89:100]
recalculate = function() {
const lowestVisiblePixel = win.scrollY + win.innerHeight,
footerPosition = footer.getBoundingClientRect().top + win.scrollY;
if (lowestVisiblePixel > footerPosition) {
controlContainer.style.position = "relative";
footer.style.marginTop = 0;
} else {
controlContainer.style.position = "fixed";
footer.style.marginTop = controlContainer.offsetHeight + "px";
}
};