* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    line-height: inherit;
    color: inherit;
    font: inherit;
}

html, body {
    height: 100%;
    overflow-y: hidden;
}

.rectangle-rouge {
    background-color: red;
    color: white;
    text-align: center;
    padding: 10px;
    font-size: 20px;
}

iframe {
    height: 96%;
    width: 100%;
    border: none;
}