* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: sans-serif;
    scroll-behavior: smooth;
  }

#topBtn {
  display: none;
  color: #fff;
  font-size: 3em;
  background-color: #000;
  width: 50px;
  height: 50px;
  text-align: center;
  border-radius: 4px;
  position: fixed;
  bottom: 30px;
  right: 30px;
  transition: background-color 0.3s, opacity 0.5s, visibility 0.5s;
}

#topBtn:hover {
  cursor: pointer;
  background-color: gray;
}

nav {
    background-color: #333;
    overflow: hidden;
}
  
nav .btNav {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
    background: #333;
  }

button {
  cursor:pointer;
}

article {
  text-align: center;
}

#bilde {
  max-width: 450px;
  display: inline-block;
}


#b1, #b2, #b3 {
  display: none;
}

.svar {
  text-align: center;
}