body {
    padding-top: 50px;
    padding-bottom: 50px;
}

a:link,
a:visited,
a:hover,
a:active {
    text-decoration: none;
}

ul.letters li:nth-child(1)::before {
    content: "a) ";
}

ul.letters li:nth-child(2)::before {
    content: "b) ";
}

ul.letters li:nth-child(3)::before {
    content: "c) ";
}

ul.letters li:nth-child(4)::before {
    content: "d) ";
}

ul.letters li:nth-child(5)::before {
    content: "e) ";
}

ul.letters li:nth-child(6)::before {
    content: "f) ";
}

ul.letters li:nth-child(7)::before {
    content: "g) ";
}

section {
    text-align: justify;
}

section.fact {
    background-color: rgb(255, 186, 186);
    padding: 10px 10px 10px 10px;
    text-align: justify;
}

section.definition {
    background-color: rgb(201, 233, 201);
    padding: 10px 10px 10px 10px;
    text-align: justify;
}

section.statement {
    background-color: rgb(167, 253, 253);
    padding: 10px 10px 10px 10px;
    text-align: justify;
}

section.proof {
    background-color: rgb(222, 252, 252);
    padding: 10px 10px 10px 10px;
    text-align: justify;
}

section.example {
    background-color: rgb(247, 252, 229);
    padding: 10px 10px 10px 10px;
    text-align: justify;
}

table.reference td{
    padding: 10px 10px 10px 10px;
}