:root {
    /* :root is a clever way of saying "the outer-most element" */
    --box-color: lightgreen; /* the default */
    --button-color: lightgrey
}

.box {
    float: none;
    height: 200px;
    width: 200px;
    margin-bottom: 15px;
    border: 1px solid black;
    clear: both;
    background-color: var(--box-color)

}

.investmentButtons {
    float: bottom;
    height: 40px;
    width: 175px;
    margin-bottom: 15px;
    border: 1px solid black;
    clear: both;
    background-color: var(--button-color);
}