html,
body {
  height: 100%;
  margin: 0;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  cursor: pointer;
}

.container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100%;
}

#score {
  position: absolute;
  top: 30px;
  right: 30px;
  font-size: 2em;
  font-weight: 900;
}

#introduction {
  width: 200px;
  height: 150px;
  position: absolute;
  font-weight: 600;
  font-size: 0.8em;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  text-align: center;
  transition: opacity 2s;
}

#restart {
  width: 120px;
  height: 120px;
  position: absolute;
  border-radius: 50%;
  color: white;
  background-color: red;
  border: none;
  font-weight: 700;
  font-size: 1.2em;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  display: none;
  cursor: pointer;
}

#perfect {
  position: absolute;
  opacity: 0;
  transition: opacity 2s;
}
  .page-footer {
    position: fixed;
    right: 0px;
    bottom: 0px;
    display: flex;
    align-items: center;
    padding: 5px;
    color: black;
    background: rgba(255, 255, 255, 0.65);
  }
  .page-left {
    position: fixed;
    left: 0px;
    bottom: 0px;
    display: flex;
    align-items: center;
    padding: 5px;
    color: black;
    background: rgba(255, 255, 255, 0.65);
  }
  
  .page-footer a {
    display: flex;
    margin-left: 4px;
  }
  .touxiang{
  	bottom: 0px;
  	width:30px;
  	height:30px;
  }