index.css

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    height: 100vh;
    display: flex;
    justify-content: center;
    background-color: #C7C7C7;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1600 900'%3E%3Cpolygon fill='%23f0f2f0' points='957 450 539 900 1396 900'/%3E%3Cpolygon fill='%23eceeed' points='957 450 872.9 900 1396 900'/%3E%3Cpolygon fill='%2322736a' points='-60 900 398 662 816 900'/%3E%3Cpolygon fill='%237ac0cd' points='337 900 398 662 816 900'/%3E%3Cpolygon fill='%237fa8b0' points='1203 546 1552 900 876 900'/%3E%3Cpolygon fill='%23c5d2db' points='1203 546 1552 900 1162 900'/%3E%3Cpolygon fill='%2363a2be' points='641 695 886 900 367 900'/%3E%3Cpolygon fill='%237fa8dd' points='587 900 641 695 886 900'/%3E%3Cpolygon fill='%235d778f' points='1710 900 1401 632 1096 900'/%3E%3Cpolygon fill='%23a6a4d5' points='1710 900 1401 632 1365 900'/%3E%3Cpolygon fill='%23b0bbe2' points='1210 900 971 687 725 900'/%3E%3Cpolygon fill='%23eae3ea' points='943 900 1210 900 971 687'/%3E%3C/svg%3E");
    background-attachment: fixed;
    background-size: cover;
    position: relative;
}
.form {
    margin-top: 200px;
    width: 800px;
    height: 230px;
}
.alert-good {
    position: absolute;
    margin-top: 50px;
}
.active{
    visibility: hidden;
}