body{
    font-family: Arial, Helvetica, sans-serif;
    display: flex;
    justify-content: center;
    padding-top: 50px;
    background-color: #ffffff;
}

.number-box{
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #e0e0e0;
    width: 450px;
    height: 120px;
    border-radius: 4px;
    overflow: hidden;
}

.num-item{
    flex: 1;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
    color: #555555;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.num-item.active{
    font-size: 65px;
    font-weight: bold;
    color: #000000;
    background-color: radial-gradient(circle, #ffffff 0%, #b8b8b8 100%);
    box-shadow: inset 0 0 10px rgba(0,0,0,0.15);
}

.num-item.small{
    font-size: 24px;
    color: #777777;
}