.main-div {
    width: 100%;
    display: flex;
    flex-direction: column;
    text-align: center;
    padding: 10px;
    padding-top: 100px;
    margin-bottom: 50px;
}

.navigation {
    margin-bottom: 50px;
}

.main-container {
    width: 100%;
    display: flex;
    flex-direction: row;
}

.navbar-brand {
    font-size: 2rem;
}

.board {
    width: 100%;
    margin: 2px;
}

.input-box {
    width: 100%;
    padding: 5%;
   /* // background-color: #005566; */
}

button {
    width: 100%;
    margin: 0;
    border: 2px solid #000000;
    height: 50px;
    background-color: #fff;
}

.input-box th {
    font-size: xx-large;
    padding: 0;
    background-color: #220055;
}

tr {
    padding: 0;
}

th {
    padding: 0;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    cursor: pointer;
}

button:hover {
    color: #fff;
    background-color: greenyellow;
    transition: 0.2s;
}

button:active {
    color: #fff;
    background-color: red;
    transition: 0.3s;
}

.board table,
th {
    border: 3px solid #000;
}

.board table,
th {
    border: 3px solid #000;
}

.navbar-brand {
    color: #fff;
}

.navbar-brand:hover {
    color: grey;
}

.fixed-digit {
    background-color: #212121;
    color: #fff;
}

.float-digit {
    background-color: greenyellow;
    color: #000;
}

.float-digit:hover {
    background-color: #220055;
    color: #fff;
}

.float-digit:focus {
    color: #fff;
    background-color: red;
}

h4 {
    cursor: pointer;
    transition: 1s;
}

h4:hover {
    cursor: pointer;
    color: red;
    text-decoration: underline;
    transition: 1s;
}

footer {
    position: fixed;
    left: 0;
    bottom: 0;
    width: 100%;
    background-color: red;
    color: white;
    text-align: center;
    background-color: gray;
}

.timer {
    color: white;
    font-weight: bold;
    font-size: 1.5rem;
}

.timer-clock {
    color: white;
    font-weight: bold;
    font-size: 1.5rem;
}


@media (max-width: 1080px) {

    .main-container {
        flex-direction: column;
        text-align: center;
        margin-bottom: 100px;
    }

    .board table,
    th {
        border: 3px solid #000;
    }

    .board table,
    th {
        border: 3px solid #000;
    }

    .navigation {
        margin-bottom: 0px;
    }
}

@media (max-width: 720px) {

    .main-container {
        flex-direction: column;
        text-align: center;
    }

    .board table,
    th {
        border: 2px solid #000;
    }

    .board table,
    th {
        border: 2px solid #000;
    }

    .navigation {
        margin-bottom: 0px;
    }
}