スクロール方向で自動反応するトグルインジケータ

<div class="d08-13-05-stage">
          <div class="d08-13-05-panel">
            <span class="d08-13-05-label">AUTO DETECT</span>
            <span class="d08-13-05-toggle"><span class="d08-13-05-knob"></span></span>
            <span class="d08-13-05-state">OFF</span>
          </div>
          <div class="d08-13-05-scroll">
            <div class="d08-13-05-body">
              <p>↓ 下スクロールでON / ↑ 上スクロールでOFF</p>
              <div class="d08-13-05-block"></div>
              <div class="d08-13-05-block"></div>
              <div class="d08-13-05-block"></div>
            </div>
          </div>
        </div>

.prev.d08-13-05{padding:0;display:block}
        .d08-13-05-stage{position:relative;width:100%;height:100%;min-height:260px;overflow:hidden;background:#eff6ff}
        .d08-13-05-panel{
          position:absolute;top:0;left:0;right:0;z-index:2;height:56px;
          display:flex;align-items:center;justify-content:center;gap:10px;
          background:#fff;box-shadow:0 2px 8px rgba(0,0,0,.08);
        }
        .d08-13-05-label{font-size:11px;font-weight:700;color:#1d4ed8;letter-spacing:.06em}
        .d08-13-05-toggle{
          width:52px;height:26px;border-radius:13px;background:#dbeafe;position:relative;
          transition:background .3s ease;
        }
        .d08-13-05-knob{
          position:absolute;top:2px;left:2px;width:22px;height:22px;border-radius:50%;
          background:#fff;box-shadow:0 2px 5px rgba(0,0,0,.2);
          transition:transform .3s cubic-bezier(.4,0,.2,1);
        }
        .d08-13-05-stage.is-down .d08-13-05-toggle{background:#2563eb}
        .d08-13-05-stage.is-down .d08-13-05-knob{transform:translateX(26px)}
        .d08-13-05-state{font-size:11px;font-weight:700;color:#64748b;min-width:26px}
        .d08-13-05-scroll{position:absolute;inset:0;overflow-y:auto;padding-top:56px}
        .d08-13-05-body{padding:16px}
        .d08-13-05-body p{font-size:11.5px;color:#1d4ed8;margin:0 0 12px;text-align:center}
        .d08-13-05-block{height:80px;border-radius:8px;margin-bottom:12px;background:linear-gradient(135deg,#dbeafe,#93c5fd)}

(function(){
        var stage=document.querySelector('.d08-13-05-stage');
        if(!stage)return;
        var scroller=stage.querySelector('.d08-13-05-scroll');
        var state=stage.querySelector('.d08-13-05-state');
        var last=0;
        scroller.addEventListener('scroll',function(){
          var top=scroller.scrollTop;
          if(top>last+2){stage.classList.add('is-down');state.textContent='ON';}
          else if(top<last-2){stage.classList.remove('is-down');state.textContent='OFF';}
          last=top<=0?0:top;
        });
      })();