.green {
    background-color: green;
    color: white;
    cursor: pointer;
    padding: 10px;
}

.center-text {
    text-align: center;
}

.draggable-circle {
    position: fixed;
    width: 100px;
    height: 100px;
    background-color: limegreen;
    -webkit-border-radius: 50%;
    -moz-border-radius: 50%;
    border-radius: 50%;
    z-index: 1000;
}

.fade-out {
    -moz-animation-name: fadeOut;
    animation-name: fadeOut;

    -moz-animation-duration: 2s;
    animation-duration: 2s;
}

@-moz-keyframes fadeOut {
    0% {
        opacity: 1;
        visibility: visible;
    }
    100% {
        opacity: 0;
        visibility: hidden;
    }
}

@keyframes fadeOut {
    0% {
        opacity: 1;
        visibility: visible;
    }
    100% {
        opacity: 0;
        visibility: hidden;
    }
}