html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;

  -webkit-touch-callout: none; /* iOS Safari */
  -webkit-user-select: none; /* Safari */
     -khtml-user-select: none; /* Konqueror HTML */
       -moz-user-select: none; /* Old versions of Firefox */
        -ms-user-select: none; /* Internet Explorer/Edge */
            user-select: none; /* Non-prefixed version, currently
                                  supported by Chrome, Edge, Opera and Firefox */
}

#board {
  background-image: url('bg.png');
  background-size: contain;
  width: 100%;
  height: 100%;
  display: block;
}


.touchButton {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 50%;
  background: transparent;
  z-index: 10;
}

#leftButton {
  left: 0;
}

#rightButton {
  right: 0;
}

.instructions {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(255, 255, 255, 0.8);
  padding: 20px;
  border-radius: 10px;
  text-align: center;
  z-index: 20;
  font-size: 18px;
  color: #000;
}