body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: white;
    margin: 0 auto;
    width: 360px;
    border: 3px solid blue;
    padding: 0 2em 1em;
}
h1 {
    color: blue;
    margin-bottom: .25em;
}
table {
    border-collapse: collapse;
    border: 1px solid black;
}
td {
    width: 3em;
    height: 3em;
    vertical-align: top;
    padding: 0.25em;
    border: 1px solid black;
}
.today {
    background-color: aliceblue;
}