style.css

#c2d {
    height: 100vh;
    aspect-ratio: 160 / 144;
    position: absolute;
    image-rendering: pixelated; /* You definitely want this if you are doing pixel art */
    background-color: black;
}

/* Get rid of any margins, set background black, use flexbox to center */
html, body {
    margin: 0;
    background-color: #111;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
    user-select: none;
}

@media (max-width: 900px) {
    body {
        background: #f7cebd;
    }
    #gamepad {
        position: fixed;
        top: 0;
        left: 0;
        height: 100vh;
        width: 100vw;
    }

    b {
        position: absolute;
        display: inline-flex;
        border: 2px solid;
        border-radius: 7vmax;
        height: 7vmax;
        width: 7vmax;
        font-size: 3vmax;
        color: #b85930;  
        justify-content: center;
        align-items: center;
        font-family: monospace;  
        transition: all 50ms ease-in-out;
    }

    b:active {
        color: #f7cebd;
        transform: scale(1.2);
    }

    #up, #down {
        left: 8vmax;
        bottom: 20vmax;
    }

    #down {
        bottom: 7vmax;
    }

    #left, #right {
        left: 1.5vmax;
        bottom: 13.5vmax;
    }

    #right {
        left: 14.5vmax;
    }

    #ok {
        right: 8vmax;
        bottom: 13.5vmax;
    }
}


@media (orientation: portrait) {
    body {
        align-items: flex-start;
        padding-top: 20vh;
    }

    #gamepad {
        top: -10vw;
        left: 4vw;
    }

    #c2d {
        height: auto;
        width: 100vw;
    }

    #ok {
        right: 7vmax;
    }
}