.round-button {
    display:inline-block;
    min-width:12vmin;
    line-height:5vmin;
    border-radius: 2.5vmin;
    border: 0.25vmin solid rgba(255,255,255,1.0);
    text-align:center;
    text-decoration:none;
    box-shadow: 0px 0px 0.5vmin grey;
    font-size:2.5vmin;
    font-weight:bold;
    font-family:Arial,sans-serif;
    cursor: pointer;
}

.round-button.green-button, .round-button.green-button:visited {
    color:rgba(255,255,255,1.0);
    background:#408040;
}
.round-button.red-button, .round-button.red-button:visited {
    color:rgba(255,255,255,1.0);
    background:#eb0000;
}
.round-button.grey-button, .round-button.grey-button:visited {
    color:rgba(255,255,255,1.0);
    background:#A0A0A0;
}
.pane-ok {
    position:absolute; bottom:2vh; text-align:center; width:100%;
}
.round-button:hover {
    color:#ebebeb;
}
.round-button.green-button:hover {
    background: #008000;
}
.round-button.red-button:hover {
    background: #FF0000;
}
.round-button.grey-button:hover {
    background: #808080;
}
.round-button:visited {
    color:rgba(255,255,255,0.5);
}