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

body {
    display: flex;
    flex-direction: column;
}

.fallback {
    padding: 8px 12px;
    background: #222;
    color: #eee;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.fallback a {
    color: #4ea8ff;
}

.frame {
    flex: 1;
}

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