body {
    margin: 0;
    overflow: hidden;
    font-family: sans-serif;
}

#ui {
    position: absolute;
    top: 20px;
    left: 20px;
    z-index: 10;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

#ui button {
    padding: 10px 20px;
    font-size: 18px;
    border-radius: 6px;
    border: none;
    background: rgba(255,255,255,0.8);
    cursor: pointer;
}