html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}

.terzosito{background: #4182d1;
background: linear-gradient(180deg, rgba(65, 130, 209, 0.83) 0%, rgba(88, 176, 252, 0.84) 35%, rgba(199, 237, 255, 0.61) 100%);}