.video__iframe:not([src]) {
    display: none;
}

.video__iframe[src]+.video__notice {
    display: none;
}

.video {
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    margin-top: 1em;
    margin-bottom: 1em;
}

.video > form {
    margin: 0;
}

.video::before {
    display: block;
    content: '';
    width: 0;
    height: 0;
}

.video__notice {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background-position: center center;
    background-size: cover;    
}

.video__notice > div {
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    opacity: 0.9;
    padding: 1.5rem;
    display: flex;
    width: 100%;
}

.video__notice > div > * {
    max-width: 38rem;
    margin: auto;
}