html {
    height: 100%;
    font-size: 16px;
}

body {
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #fcfc62;
}

.container {
    border: 5px solid black;
    border-radius: 5px;
    width: 600px;
    background: #feffea;
}

.title {
    text-align: center;
    margin-top: 20px;
}

.number {
    text-align: center;
    font-size: 10rem;
    margin: -20px 0;
}

.center {
    text-align: center;
}

.btn {
    border: 1px solid #a9a9a9;
    border-radius: 5px;
    text-align: center;
    font-size: 1rem;
    padding: 5px 10px;
    margin: 0 10px 20px;
}

.btn:hover {
    background: #808080;
    color: #ffffff;
}

.btn:active {
    outline: 3px solid #a9a9a9;
}