body {
    text-align: center;
}

.hide {
    display: none;
}

h1 {
    color:#fff;
    font-family: Coda, sans-serif;
    font-size: 3rem;
    text-align: center;
}

.modal_bg {
    text-align: center;
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.5);
}

.modal_bg::before {
    content: '';
    display: inline-block;
    height: 100%;
    vertical-align: -webkit-baseline-middle;
}

.modal_body {
    width: 550px;
    border-radius: 6px;
    display: inline-block;
    vertical-align: -webkit-baseline-middle;
    position: fixed; 
    background: linear-gradient(160deg, blue 0%, green 100%);
    transform: translate(-150px, 40%);
}

.modal_button {
    border-radius: 4px;
    background-color: blue;
    color: #fff;
    padding: 0.5rem;
    margin: 1rem;
}