    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>화면에 나타내기</title>
      <style>
        span {
          display: inline-block;
          background-color: #feb;
          border: 1px solid #715;
          width: 180px;
          height: 60px;
          text-align: center;
          line-height: 60px;   /* 박스 높이와 같으면 박스의 위 아래 중간에 배치 */
        }
      </style>
    </head>
    <body style="font-size: 20px; font-weight: bold">
      <span style="visibility: visible">visibility: visible</span>
          보이기 <span>visibility: visible</span><br><br>
      <span style="visibility: hidden">visibility: hidden</span>
          숨기기 <span>visibility: hidden</span><br><br>
      <span style="display: none">display: none</span>
          없애기 <span>display: none</span>
    </body>
    </html>