    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>시간 조절하기</title>
      <link rel="stylesheet" href="style_js.css">
    </head>
    <body style="text-align: center">
      <button onclick="showImage()">1초 후 이미지 보기</button>
      <div id="cont" style="display: none"><img src="../media/photo1.jpg"></div>
      <script>
        function showImage() {
           window.setTimeout(function() {
             document.getElementById("cont").style.display = "block";
          }, 1000);
        }
      </script>
    </body>
    </html>