.cardd {
    width: 400px;
    height: 600px;
    border-radius: 50px;
    box-shadow: var(--gradient-shadow) 0px 0px 20px 20px;
    background: white;
    top: 15px;
    left: 15px;
    z-index: 1;
    position: relative;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
    background: #fff;
}

.back {
    width: calc(400px + 30px);
    height: calc(600px + 30px);
    position: absolute;
    transform: translate(-50%,-50%);
    top: 50%;
    left: 50%;
    border-radius: 60px;
    overflow: hidden;
}

    .back::before {
        content: '';
        height: 200%;
        width: 200%;
        position: absolute;
        background: conic-gradient( #ff0000, #ff6a00, #ffd800, #b6ff00,#4cff00,#00ff21,#00ff90,#00ffff,#0094ff,#0026ff,#4800ff,#b200ff,#ff00dc,#ff006e,#ff006e,#ff0000);
        left: -50%;
        top: -50%;
        animation: spin 3s infinite linear;
        z-index: 0;
        filter: blur(125px);
    }

input {
    border: 0 !important;
    outline: unset !important;
    box-shadow: unset !important;
}

    input:focus,
    input:hover {
        transition: 0.5s ease-in-out all;
        border-bottom: 2px solid black !important;
    }

@keyframes spin {
    100% {
        transform: rotate(-360deg);
    }
}