* {
    margin: 0;
    box-sizing: border-box;
}

/* body {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
} */

header {
    text-align: center;
    padding: 1em 0;
    margin-bottom: 1em;
    border-bottom: 3px solid black;
}

table {
    margin: 1em auto;
    width: 39vh;
    height: 39vh;
    text-align: center;
    border-collapse: collapse;
    font-family: sans-serif;
    font-size: 2em;
    font-weight: bold;
    table-layout: fixed;
}

td {
    height: 13vh;
    width: 13vh;
    border: solid;
}

caption {
    font-size: 1em;
    color: green;
}

.hidden {
    display: none;
}

.block {
    display: block;
}

#reset {
    text-align: center;
    /* font-size: 2em; */
    padding: 1em;
    margin: 2em auto 2em auto;
}