html, body {
    margin: 0;
}

h1 {
    text-align: center;
    font-size: 40px;
}

h2 {
    text-align: center;
    font-size: 30px;
}

h3 {
    text-align: center;
    font-size: 25px;
    border: 1px solid black;
}

p {
    text-align: center;
    font-size: 20px;
}

button {
    display: block;
    text-align: center;
    border: 1px solid black;
    border-radius: 7px;
    text-align: center;
    margin: 5px auto;
    font-size: 15px;
    background-color: #498363;
}