h1 {
    text-align:center;
}

summary.header {
    font-weight: bolder;
    padding-bottom:0.5%;
    padding-top:0.5%;
    font-size:larger;
}

details > details > summary {
    font-style:italic;
    font-weight:bold;
    font-size:medium;
    padding-top:0.5%;
}

ul {
    padding-top:-5%;
}

div.certificate {
    font-size: 80%;
    right:1%;
    position:fixed;
    bottom:1%;
  }

ul.difficulty {
    list-style:none;
}

li.positive:before {
    content: "+";
    margin-right: 0.5%;
    margin-left: -1%;
}

li.negative:before {
    content: "-";
    margin-right: 0.5%;
    margin-left: -1%;
}