* {
    margin: 0;
    padding: 0;
}

body {
    background-color: lightgray;
    width: 100%;
    height: 100vh;
}

iframe {
    width: 100%;
    height: 100%;
}

.start{
    margin-top: 10vh;
    display: flex;
    flex-direction: column;
}

.start button{
    background-color: cornflowerblue;
    border: none;
    border-radius: .3rem;
    padding: 1rem;
    font-size: 1.5rem;
    margin: auto;
    max-width: 30%;
    min-width: 150px;
    cursor: pointer;
}

.start img{
    width: 50%;
    height: auto;
    margin: auto;
}

.none{
    display: none;
}