body {
    background: #3399ff;
}


.circle {
    position: absolute;
    border-radius: 50%;
    background: skyblue;
    animation: ripple 15s infinite;
    box-shadow: 0px 0px 1px 0px #508fb9;
}

.small {
    width: 100px;
    height: 100px;
    left: -100px;
    bottom: -100px;
}

.medium {
    width: 300px;
    height: 300px;
    left: -200px;
    bottom: -200px;
}

.large {
    width: 500px;
    height: 500px;
    left: -300px;
    bottom: -300px;
}

.xlarge {
    width: 600px;
    height: 600px;
    left: -400px;
    bottom: -400px;
}

.xxlarge {
    width: 800px;
    height: 800px;
    left: -500px;
    bottom: -500px;
}

.shade1 {
    opacity: 0.2;
}

.shade2 {
    opacity: 0.3;
}

.shade3 {
    opacity: 0.7;
}

.shade4 {
    opacity: 0.8;
}

.shade5 {
    opacity: 0.9;
}

@keyframes ripple {
    0% {
        transform: scale(0.8);
    }

    50% {
        transform: scale(1.2);
    }

    100% {
        transform: scale(0.8);
    }
}