ぷるんと震えるゼリードラッグ

<div class="d08-15-08-jelly" id="d08-15-08-jelly">Drag</div>

.d08-15-08{width:100%;display:flex;align-items:center;justify-content:center}
        .d08-15-08-jelly{width:92px;height:92px;border-radius:50%;background:linear-gradient(135deg,#22c55e,#4ade80);color:#fff;font-size:12px;font-weight:800;display:flex;align-items:center;justify-content:center;box-shadow:0 8px 18px rgba(34,197,94,.35);cursor:grab;touch-action:none}
        .d08-15-08-jelly.is-drag{cursor:grabbing}
        .d08-15-08-jelly.is-wobble{animation:d08-15-08-wobble .6s cubic-bezier(.34,1.56,.64,1)}
        @keyframes d08-15-08-wobble{
          0%{border-radius:50%}
          20%{border-radius:60% 40% 55% 45%/45% 55% 40% 60%}
          40%{border-radius:40% 60% 45% 55%/55% 45% 60% 40%}
          60%{border-radius:55% 45% 50% 50%/50% 50% 55% 45%}
          80%{border-radius:48% 52% 50% 50%/50% 50% 48% 52%}
          100%{border-radius:50%}
        }

(function(){
        var root=document.getElementById('item-08-15-08');if(!root)return;
        var jelly=root.querySelector('#d08-15-08-jelly');if(!jelly)return;
        var dragging=false,sx=0,sy=0,px=0,py=0,lastX=0,lastY=0,raf=null;
        function apply(x,y,sxr,syr){jelly.style.transform='translate('+x+'px,'+y+'px) scale('+sxr+','+syr+')';}
        jelly.addEventListener('pointerdown',function(e){
          dragging=true;jelly.classList.remove('is-wobble');jelly.classList.add('is-drag');
          if(raf)cancelAnimationFrame(raf);
          sx=e.clientX-px;sy=e.clientY-py;lastX=e.clientX;lastY=e.clientY;
          try{jelly.setPointerCapture(e.pointerId);}catch(err){}
        });
        jelly.addEventListener('pointermove',function(e){
          if(!dragging)return;
          px=e.clientX-sx;py=e.clientY-sy;
          var vx=e.clientX-lastX,vy=e.clientY-lastY;
          lastX=e.clientX;lastY=e.clientY;
          var stretch=Math.max(-.18,Math.min(.18,vx*.03));
          apply(px,py,1+stretch,1-stretch);
        });
        function end(){
          if(!dragging)return;
          dragging=false;jelly.classList.remove('is-drag');
          var x=px,y=py,vx=0,vy=0,stiff=.16,damp=.72;
          function step(){
            var fx=(0-x)*stiff,fy=(0-y)*stiff;
            vx=(vx+fx)*damp;vy=(vy+fy)*damp;
            x+=vx;y+=vy;apply(x,y,1,1);
            if(Math.abs(x)>.5||Math.abs(y)>.5||Math.abs(vx)>.5||Math.abs(vy)>.5){
              raf=requestAnimationFrame(step);
            }else{
              px=0;py=0;apply(0,0,1,1);
              jelly.classList.add('is-wobble');
              setTimeout(function(){jelly.classList.remove('is-wobble');},650);
            }
          }
          raf=requestAnimationFrame(step);
        }
        jelly.addEventListener('pointerup',end);
        jelly.addEventListener('pointercancel',end);
      })();