style.css

body {
    background-image: url("assets/images/background.jpg");
    background-size: cover;
	background-repeat: no-repeat;
	background-position: center;
    background-attachment: fixed;
}

div#resultsContainer {
    display: flex;
    flex-direction: column;
    flex-wrap: nowrap;
    margin-left: auto;
    margin-right: auto;
    padding-bottom: 10px;
    margin-bottom: 10px;
    border-bottom: 1px outset;
}

div#totalShotsFiredRow {
    order: 1;
}

div#shotsInsidePondRow {
    order: 2;
}

div#calculationOfPiRow {
    order: 3;
}

div.resultsRow {
    display: flex;
    flex-direction: column;
    flex-wrap: nowrap;
}

div.resultsRow span {
    text-align: center;
}

div.resultsRow span:first-child {
    font-weight: bold;
}

div#explanation {
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-bottom: 15%;
}

div#explanation p {
    text-align: justify;
    text-justify: inter-word;
}

div#pleaseRotateDevice {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: lightgray;
}

div#pleaseRotateDeviceMessage {
    border: 1px outset;
    border-radius: 25px;
    display: block;
    width: 50%;
    padding: 10px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

img.illo {
    width: 20%;
}

/* DESKTOP */

@media only screen and (orientation: landscape) and (min-width: 1201px) {
    canvas {
        width: 40%;
        margin-left: 30%;
        margin-right: 30%;
    }

    div#resultsContainer {
        width: 50%;
    }

    div#explanation {
        width: 66%;
    }

    div#pleaseRotateDevice {
        visibility: collapse;
        height: 0px;
        width: 0px;
    }
    img.illo {
        width: 50%;
    }
}

/* MOBILE, PORTRAIT */

@media only screen and (orientation: portrait) {
    p {
        font-size: 130%;
    }
    canvas {
        width: 100%;
    }

    div#resultsContainer {
        width: 85%;
    }

    div#explanation {
        width: 96%;
    }

    div#pleaseRotateDevice {
        visibility: collapse;
        height: 0px;
        width: 0px;
    }
    img.illo {
        width: 100%;
    }
}

/* MOBILE, LANDSCAPE */

@media only screen and (orientation: landscape) and (max-width: 1200px) {
    div#pleaseRotateDevice {
        visibility: visible;
    }
}