body {
    background-color: #333333;
    font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

.container {
    display: block;
    margin: 100px auto;

    width: 370px;
    height: 700px;

    background-color: black;

    border-radius: 70px;
    border: 5px white solid;
}

.header {
    color: white;
    text-align: center;
    margin-bottom: 110px;
}

#display {
    color: white;
    text-align: right;

    max-height: 60px;

    font-size: 50px;
    overflow: hidden;
    text-overflow:ellipsis;
    display: block;

    margin-right: 47px;
    margin-left: 47px;
    margin-bottom: 30px;
}

.btn-table {
    display: flex;
    margin: 10px auto;
    justify-content: center;

    max-width: 400px;
    max-height: 500px;

    border-spacing: 10px;
}

button {
    border-radius: 50%;
    height: 70px;
    width: 70px;
}

button:hover {
    opacity: 50%;
}

.dark-grey-btn, .zero-btn, .orange-btn {
    border: none;

    color: white;
    font-size: 25px;
    font-weight: normal;
}

.dark-grey-btn, .zero-btn {
    background-color: #313131;
}

.orange-btn {
    background-color: #f59906;
    border: none;
}

.grey-btn {
    background-color: #9d9d9d;
    border: none;
    font-size: 25px;
    font-weight: normal;
}

.zero-btn {
    width: 150px;
    border-radius: 50px;
}