html, body {
    margin: 0px;
    padding: 0px;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
    user-select: none;
}

.main {
    display: grid;
    grid-gap: 10px;
    width: 600px;
}

#video {
    border: 1px solid gray;
    width: 600px;
}

button, label, input {
    font-size: 2.3rem;
}

input[type='radio'] {
    min-width: 30px;
    min-height: 30px;
}

.twocolumns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.element {
    font-size: 2.3rem;
    padding: 20px;
    background-color: #e8e1e730;
    border: 1px solid;
    text-align: center;
}