* {
    margin: 0px;
    padding: 0px;
  }
  
  body {
      background-image: url("mur2.jpg");
    background-size: cover;
  
  }
  
  #instruction {
    width: 100%;
    height: 100%;
    position: fixed;
    background: pink;
    z-index: 2;
    display: block;
  }
  
  #well-done {
    width: 100%;
    height: 100%;
    position: fixed;
    background: #87CEFA;
    z-index: 2;
    display: none;
  }
  
  .what {
    margin: auto;
    width: 400px;
    height: 100%;
    text-align: center;
    padding-top: 5%;
  }
  
  button {
    background-color: blue;
    border: none;
    color: white;
    padding: 10px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    cursor: pointer;
  }
  
  h1 {
    padding: 4px;
  }
  
  p {
    width; 100%;
    margin: auto;
    padding: 9px;
    text-align: center;
  }
  
  .a {
    position: relative;
    width: 50px;
  }
  #free {
    padding-top: 10%;
    font-size: 22px;
  }
  .window {
    padding: 0px;
    padding-top: 50px;
    width: 700px;
    height: 350px;
    margin: 0 auto;
    background-image: url("fenetre.jpg");
    background-repeat: no-repeat;
    cursor: pointer;
    background-position: center center;
  }
  
  #mouche {
    width: 100%;
    height: auto;
  }