@media only screen and (max-width: 768px) {
    #content {
        margin: 0 10%;
    }

    #sidebar {
        display: none;
    }
}

@media only screen and (min-width: 768px) {
    #content {
        margin-left: 25%;
        margin-right: 10%;
    }
}

h1, h2, h3, h4 {
    font-weight: bold;
    margin-top: 5%;
    white-space: pre-wrap;
}

section p {
    text-indent: 2em;
    text-align: justify;
}

div.img > img {
    display: block;
    margin: 30px auto 5px auto;
    text-align: center;
    max-width: 90%;
}

div.img > .caption {
    text-indent: 0;
    text-align: center;
    margin-bottom: 30px;
}

#ref-table {
    text-align: justify;
}

#ref-table * {
    border: none;
}

#ref-table tr td:first-child {
    vertical-align: top; /* Adjust the numbers of ref. */
}