#outerbox {
    width:calc(100% - 32px);
    height:300px;
    margin:24px auto 16px auto;
}

#innerbox {
    width:520px;
    height:220px;
    margin:40px 40px 40px 40px;
    background:#eee;
    display:table-cell;
    vertical-align:middle;
    border:#000 1px solid;
    text-align:center;
    padding-bottom:40px;
}       

.button {
    background-color:#ccc;
    font-family:"IBM Plex Sans",sans-serif;
    border-radius: 5px;
    border:#000 1px solid;
    color: black;
    padding: .5em;
    text-decoration: none;
    display:inline;
    margin:0 8px 0 8px;
}

.button:hover, .button:focus {
    background-color: FireBrick;
    color: White;
}

#p0 {
    max-width:100%;
    height:auto;
    width:auto;
}