style.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    /* background: #181c1f; */
    background: #0AA1DD;
}

.container {
    position: relative;
    height: 400px;
    border-bottom: 2px solid #fff;
}

.cloud {
    position: relative;
    top: 50px;
    width: 320px;
    height: 100px;
    background: #fff;
    border-radius: 100px;
}

.cloud::before {
    content: '';
    position: absolute;
    top: -50px;
    left: 40px;
    width: 110px;
    height: 110px;
    background: #fff;
    border-radius: 50%;
    box-shadow: 90px 0 0 30px #fff;
}

.rain {
    position: relative;
    display: flex;
    z-index: 1;
    padding: 0 20px;
}

.rain span {
    position: relative;
    bottom: 10px;
    width: 10px;
    height: 10px;
    background: #fff;
    margin: 0 2px;
    border-radius: 50%;    
    animation: animate 5s linear infinite;
    animation-duration: calc(15s / var(--i));
    transform-origin: bottom;
}

@keyframes animate {
    0% {
        transform: translateY(0) scale(1);
    }
    70% {
        transform: translateY(298px) scale(1);
    }
    100% {
        transform: translateY(298px) scale(0);
    }
}