h1 {
    text-align: center;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
}

.topnav {
    position: relative;
    overflow: hidden;
    background-color: #333;
    border: 2px solid white;
    border-radius: 15px;
}

.topnav a {
    float: left;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}

.topnav a:hover {
    background-color: #ddd;
    color: black;
}

.topnav a.active {
    background-color: #4CAF50;
    color: white;
}

.topnav-centered a {
    float: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

@media screen and (max-width: 600px) {
    .topnav a, .topnav-right {
        float: none;
        display: block;
    }

    .topnav-centered a {
        position: relative;
        top: 0;
        left: 0;
        transform: none;
    }
}

#pdf-canvas {
    border: 1px solid black;
    direction: ltr;
}

#pdf-div {
    align-content: center;
    text-align: center;
}