<body>
<div class="box">
<span class="number">5</span>초 후에 세일 마감!
</div>
<script>
var num = 5
var timer = setInterval(()=>{
num -= 1
document.querySelector('.number').innerHTML=num;
},1000);
if(num >= 0){
setInterval(timer,1000);
} else {
clearTimeout(timer);
document.querySelector('.box').style.display='none';
}
</script>
</body>
왜 안될까요????
