#game_div table tr td{
    padding: 5%;
    background-repeat: no-repeat; 
    background-size: 100%;
    margin:0%;
    border: solid 2px green;
}

#game_div table{
    opacity: 0.9;
    position: relative;
    margin:0%;
    padding:0%;
    width: 100%;
    border: solid 2px green;
    border-collapse: separate;
    border-spacing: 1px;
}

#gameHud{
    position: absolute;
    display:flex;
    flex-direction: column; /* 👈 This makes it vertical */
    justify-content: space-between; /* THIS evenly distributes content vertically */
    overflow: hidden;
    margin: 0%;
    padding:0%;
    width: 100%;
    height: 100%;
    border: none 2px white;
    
    /*The following will ensure that the width of the element will not grow with the added border-size.
    So the border will be within the defined element width.
    */
    -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
    -moz-box-sizing: border-box;    /* Firefox, other Gecko */
    box-sizing: border-box;         /* Opera/IE 8+ */
}

#gameHud h6{ 
    padding: 2%;
    margin: auto;
    width:90%;
}

#score{
    position: relative;
    display: block;
    width:20%;
    border-style:white;
    border-width:2px;
    border-color:darkred;
    padding:0%;
    background-color: rgba(255,255,255,0.1);
    color:white;
    font-family: Georgia;
    font-weight: normal;
    font-size:1.3vw;
    line-height: 1.2; /*the line height is proportional to the font*/
    opacity: 0.9;
}

@keyframes tdPulsePink {
    0%   { background-color: white; }
    50%  { background-color: pink; }
    100% { background-color: white; }
}

/* class that activates the animation */
.td_pulse_pink {
    animation: tdPulsePink 1s infinite;
}

@keyframes tdPulseRed {
    0%   { background-color: black; }
    50%  { background-color: red; }
    100% { background-color: black; }
}

/* class that activates the animation */
.td_pulse_red {
    animation: tdPulseRed 1s infinite;
}

#result{
    position: relative;
    width:100%;
    border: none 2px darkred;
    padding:1%;
    /*background-color: rgba(255,255,255,0.9);*/
    background-color: transparent;
    font-family: Georgia;
    font-weight: normal;
    font-size: 17px; /* font-size 1% of the viewport size.*/
    height: auto;
    text-align: center;
    opacity: 0.9;
    color: lightgreen;
    line-height: 1.2rem; /*the line height is proportional to the font*/
}

#button_div
{
    width: auto;
    margin: auto;
    display: inline-block;

    border: none 2px red;
}

#button_div input{
    margin: 0px 5px;
    padding: 2px 4px;
    font: Calibri;
    font-size: 13px;
    border: groove 1px transparent;
}

#button_div input:hover{
    transition: opacity 0.2s ease;
    opacity: 0.7;
}

#game_content_first_column{
    width: 60%; /* the width of game_content_first_column influences the width of game_div*/
}

#game_div
{
    width: 100%; /* the width of game_div influences the width of game_content*/
    height:auto;
    left: 0%;
}

#fullscreen_button{
    margin-left: 5%;
}

#page_block #game_content
{
    position:relative;
    float: left;
    table-layout: fixed;
    width:60%; /* the width of game_content is also influenced by width of game_div*/
    margin: 0%;
    margin-right: 20px;
    margin-bottom: 10px;
    padding: 0%;
    height:auto;
    background-image: url(knight_background.jpg);
    background-repeat: no-repeat;
    background-size: cover;
    position:relative;
    border: ridge 2px rgba(255,255,255, 0.1);
    border-radius: 1vw;
    /*The following will ensure that the width of the element will not grow with the added border-size.
    So the border will be within the defined element width.
    */
    -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
    -moz-box-sizing: border-box;    /* Firefox, other Gecko */
    box-sizing: border-box;         /* Opera/IE 8+ */
}

#page_block #game_content tr td{
    vertical-align: top;
    position: relative; 
    /*by having columns with position: relative will ensure that no element 
    with absolute position is gonna drift outside the table*/
}

#gameHud #author
{
    position: relative;
    border-style: none;
    color: black;
    text-align: center;
    font-family: Georgia;
    font-size: 1vw;
    font-weight: bold;
    background-color: rgba(255,255,255,0.5);
    margin-top: 5%;
    line-height: 1.2; /*the line height is proportional to the font*/
}