.page-name {
    margin: 0.5em 2.5em;
    color: #ff2525;
    font-size: 2.5em;
}

#text-box {
    position:fixed;
    top: 50%;
    left: 50%;
    width:30em;
    height:18em;
    font-family: math;
    margin-top: -9em; /*set to a negative number 1/2 of your height*/
    margin-left: -15em; /*set to a negative number 1/2 of your width*/
}

.btn-primary {
    color: #fff;
    background-color: #ff2525;
    border-color: #ff2525;
}

.btn-primary:hover {
    color: #fff;
    background-color: #ff252585;
    border-color: #ff252585;
}

.form-control {
    display: block;
    width: 100%;
    padding: .5rem .75rem;
    font-size: 1rem;
    line-height: 1.25;
    color: #495057;
    background-color: #fff;
    background-image: none;
    background-clip: padding-box;
    border: 1px solid rgb(255 0 0 / 15%);
    border-radius: .25rem;
    transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
}