add_pink_scrollbar_to_right_side.js

(function addRS(){
 if(document.getElementById('rs')) return;
 const s=document.createElement('div'), t=document.createElement('div');
 s.id='rs'; Object.assign(s.style,{position:'fixed',top:0,right:0,width:'12px',height:'100%',background:'rgba(255,192,203,0.2)',zIndex:999999,cursor:'pointer'});
 t.id='rst'; Object.assign(t.style,{width:'100%',height:'60px',background:'deeppink',borderRadius:'6px',position:'absolute',top:0});
 s.appendChild(t); document.body.appendChild(s);
 let dragging=false, startY=0, startScroll=0;
 const update=()=>{
  const sh=document.body.scrollHeight-window.innerHeight, bh=s.offsetHeight-t.offsetHeight;
  t.style.top = (sh && bh ? (window.scrollY/sh)*bh : 0) + 'px';
 };
 t.onmousedown=e=>{ dragging=true; startY=e.clientY; startScroll=window.scrollY; document.body.style.userSelect='none'; };
 document.onmouseup=()=>{ dragging=false; document.body.style.userSelect=''; };
 document.onmousemove=e=>{ if(!dragging) return; const sh=document.body.scrollHeight-window.innerHeight, bh=s.offsetHeight-t.offsetHeight||1, dy=e.clientY-startY; window.scrollTo(0, Math.max(0, Math.min(sh, startScroll + (dy/bh)*sh))); update(); };
 window.addEventListener('scroll', update);
 update();
})();