(function(){ var cv=document.getElementById('dust'),cx=cv.getContext('2d'),W,H; function size(){W=cv.width=innerWidth;H=cv.height=innerHeight}size();addEventListener('resize',size); var P=[];var GOLD=[255,217,138],PERI=[159,176,255],WHITE=[240,243,255]; function spawn(x,y,opt){opt=opt||{};var c=[GOLD,PERI,WHITE][Math.random()*3|0]; P.push({x:x,y:y,vx:(Math.random()-.5)*(opt.sp||1.2),vy:(Math.random()-.5)*1.2,life:1,decay:.012+Math.random()*.02,s:opt.s||(1+Math.random()*2.2),c:c,tw:Math.random()*6.28});} addEventListener('mousemove',function(e){for(var i=0;i<3;i++)spawn(e.clientX+(Math.random()-.5)*10,e.clientY+(Math.random()-.5)*10,{sp:.9});}); setInterval(function(){spawn(Math.random()*W,Math.random()*H*.6,{sp:.3,s:1});},300); function loop(){cx.clearRect(0,0,W,H);cx.globalCompositeOperation='lighter'; for(var i=P.length-1;i>=0;i--){var p=P[i];p.x+=p.vx;p.y+=p.vy;p.life-=p.decay;p.tw+=.25; if(p.life<=0){P.splice(i,1);continue} var a=p.life*(.55+.45*Math.sin(p.tw)); var g=cx.createRadialGradient(p.x,p.y,0,p.x,p.y,p.s*3.2); g.addColorStop(0,'rgba('+p.c[0]+','+p.c[1]+','+p.c[2]+','+a+')');g.addColorStop(1,'rgba('+p.c[0]+','+p.c[1]+','+p.c[2]+',0)'); cx.fillStyle=g;cx.beginPath();cx.arc(p.x,p.y,p.s*3.2,0,6.28);cx.fill();} requestAnimationFrame(loop);}loop(); var io=new IntersectionObserver(function(es){es.forEach(function(e){if(e.isIntersecting)e.target.classList.add('awake');});},{threshold:.15}); document.querySelectorAll('.awaken').forEach(function(el){io.observe(el)}); })();
人体工学枕，在工作时
专为颈部设计