CODE EXAMPLE FOR CSS

css waves background

section {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 400px;
    padding-top: 100px;
    background: #3c31dd;
}

.curve {
    position: absolute;
    height: 250px;
    width: 100%;
    bottom: 0;
    text-align: center;
}

.curve::before {
    content: '';
    display: block;
    position: absolute;
    border-radius: 100% 50%;
    width: 55%;
    height: 100%;
    transform: translate(85%, 60%);
    background-color: hsl(216, 21%, 16%);
}

.curve::after {
    content: '';
    display: block;
    position: absolute;
    border-radius: 100% 50%;
    width: 55%;
    height: 100%;
    background-color: #3c31dd;
    transform: translate(-4%, 40%);
    z-index: -1;
}