foi usado as tecnicas tradicionas de divs e no css o display flex

Nice well done, to place the card in the middle of the page add this to the body (see below)

• Make it a habit of using min-height: 100vh; on the body. This is important for the responsiveness of the page

body {
    background-color: hsl(30, 38%, 92%);
    overflow: hidden;
    min-height: 100vh; /* add these three lines */
    display: grid;
    place-items: center;
}