html,
body {
    width: 100%;
    height: 100%;
    margin: 0px;
    overflow: hidden;

    &:hover {
        span {
            display: none;
        }
    }
}

.container {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
    flex-direction: row;
}

iframe {
    flex: 1;
    width: 50%;
    height: 50%;
    pointer-events: none;
}

#iframe2 {
    filter: invert(0.9);
}

canvas#canvas {
    cursor: crosshair;
    position: absolute;
    z-index: 1;
}

span {
    font-family: 'SimSun', cursive;
    font-size: 40px;
    position: fixed;
    top: 50%;
    left: 50%;
    color: #000;
    margin-top: -40px;
    margin-left: -200px;
}