https://french-stream.net/js/fss-mobile-dock-u1.js?v=23

1(function(){
2  if(!window.matchMedia) return;
3  var mq=window.matchMedia('(max-width:430px)');
4  var de=document.documentElement, vv=window.visualViewport||null;
5  var TH=90,ticking=false,active=false,docked=false,offset=0,lastY=0,ignore=0,savedPad=0;
6  function H(){return document.getElementById('header');}
7  function fs(){return document.fullscreenElement||document.webkitFullscreenElement;}
8  function vb(){return window.innerHeight||(vv&&vv.height)||de.clientHeight;}
9  function paint(h){h.style.setProperty('background-color','#222','important');h.style.setProperty('z-index','99999','important');}
10  function put(h,y,anim){h.style.setProperty('transition',anim?'transform .55s cubic-bezier(.22,.61,.36,1)':'none','important');h.style.setProperty('transform','translateY('+y+'px)','important');}
11  function flush(h){if(!docked)return;var r=h.getBoundingClientRect();var diff=vb()-r.bottom;if(Math.abs(diff)>0.5){offset+=diff;put(h,offset,false);}}
12  function zeroPad(){document.body.style.setProperty('padding-top','0px','important');}
13  function cleanup(h){if(docked)return;de.classList.remove('fss-dockdown');h.style.removeProperty('background-color');h.style.removeProperty('z-index');h.style.removeProperty('transform');h.style.removeProperty('transition');}
14  function dock(h){
15    if(docked)return;docked=true;de.classList.add('fss-dockdown');
16    paint(h);
17    savedPad=parseFloat(getComputedStyle(document.body).paddingTop)||0;
18    zeroPad();
19    if(savedPad>0.5){ignore=4;try{window.scrollTo(0,Math.max(0,(window.pageYOffset||0)-savedPad));}catch(e){}lastY=window.pageYOffset||0;}
20    put(h,vb()+30,false);void h.offsetHeight;
21    requestAnimationFrame(function(){if(!docked)return;var hh=h.offsetHeight||52;offset=Math.max(0,vb()-hh);put(h,offset,true);setTimeout(function(){flush(h);},520);setTimeout(function(){flush(h);},980);});
22  }
23  function undock(h){
24    if(!docked)return;docked=false;
25    document.body.style.removeProperty('padding-top');
26    if(savedPad>0.5){ignore=4;try{window.scrollTo(0,(window.pageYOffset||0)+savedPad);}catch(e){}lastY=window.pageYOffset||0;}
27    put(h,0,true);setTimeout(function(){cleanup(h);},520);
28  }
29  function reflow(){if(!active||!docked)return;var h=H();if(h)flush(h);}
30  function tick(){
31    ticking=false;if(!active)return;
32    var h=H();if(!h)return;
33    var y=window.pageYOffset||de.scrollTop||0;
34    if(ignore>0){ignore--;lastY=y;if(docked){zeroPad();paint(h);}return;}
35    if(fs()){undock(h);lastY=y;return;}
36    var d=y-lastY;lastY=y;
37    if(y<=TH){undock(h);}
38    else if(d>8){dock(h);}
39    else if(d<-2){undock(h);}
40    if(docked){zeroPad();paint(h);}
41  }
42  function onScroll(){if(ticking||!active)return;ticking=true;requestAnimationFrame(tick);}
43  function enable(){if(active)return;active=true;lastY=window.pageYOffset||0;window.addEventListener('scroll',onScroll,{passive:true});tick();}
44  function disable(){active=false;window.removeEventListener('scroll',onScroll);document.body.style.removeProperty('padding-top');var h=H();if(h){docked=false;cleanup(h);}}
45  function apply(){if(mq.matches)enable();else disable();}
46  apply();
47  if(mq.addEventListener)mq.addEventListener('change',apply);else if(mq.addListener)mq.addListener(apply);
48  window.addEventListener('resize',reflow);
49  window.addEventListener('orientationchange',function(){setTimeout(reflow,300);});
50  if(vv)vv.addEventListener('resize',reflow);
51  document.addEventListener('fullscreenchange',onScroll);
52})();