#container {
    display: flex;              /* establish flex container */
    flex-direction: row;     /* stack flex items vertically */
    justify-content: center;    /* center items vertically, in this case */
    align-items: center;        /* center items horizontally, in this case */
    height: 600px;
    border: 1px solid black;
}

.box {
    width: 300px;
    margin: 5px;
    justify-content: center;
    align-items: center;
    text-align: center;
    border: 1px solid black;
}

.mathbox {
    width: 600px;
    margin: 5px;
    justify-content: center;
    align-items: center;
    text-align: center;
    border: 1px solid black;
}

.divisionBox {
    border-left: 4px solid black; 
    border-top: 4px solid black;
}

.onechar {
    width: 20px;
    
}

.twochar {
    width: 40px;
    
}

.onecharsmall {
    width: 10px;
}

.mathInputs {
    font-weight: bold;
    font-size: 2rem;
    font-family:Arial, Helvetica, sans-serif;
    margin-right: 1px;
    text-align: right;
}

.title {
    font-weight: bold;
    font-size: 3rem;
}

.subtitle {
    font-weight: bold;
    font-size: 1.5rem;
}

input { 
    text-align:right;
}

.mono {
    font-family: monospace;
}

.fake-button { 
    background-color: transparent;
    border-width: 0;
    font-family: inherit;
    font-size: inherit;
    font-style: inherit;
    font-weight: inherit;
    line-height: inherit;
    padding: 0;
}

.red {
    color: red;
}

.green {
    color: green;
    font-weight: bold;
}

.hider {
    visibility: hidden;
}

.unhider {
    visibility: visible;
}

.superscript {
    font-size: 0.83em; 
    vertical-align: super;
}

.strike {
    text-decoration: line-through;
}