* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

.big {
    display: flex;
    justify-content: center;
    align-items: center;


}

.welcome {
    margin-top: 50px;
    padding: 25px;
    box-shadow: 0 0 10px black;
    width: 500px;
    height: 400;
    border-radius: 10px;
    background-color: aqua;
}