src/elm_src/Gui/Gui.css

.gui {
    position: absolute;
    /* top: 0; */
    /* left: 0; */
    bottom: 160px;
    width: 100%;
    /* height: 60%; */
    margin: 0 auto;
    pointer-events: none;
}

.grid {
    width: 60%;
    margin: 0 auto;
    pointer-events: none;
}

.gui:focus {
    outline: none;
}

.cells {
    display: flex;
    flex-direction: column;
}

.row {
    display: flex;
    flex-direction: row;
}

.cell {
    display: block;
    width: 70px;
    height: 70px;
    min-width: 70px;
    min-height: 70px;
    /* background:
        linear-gradient(0deg, rgba(0,0,0,0.2) 0%, rgba(0,0,0,0.4) 75%, rgba(0,0,0,0.2) 100%); */
    background-color: rgba(0,0,0,0.2);
    border: 1px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    margin: 5px;
    color: white;
    transition: background-color 0.3s ease-in, opacity 0.3s ease-in;
    pointer-events: all;
}

.cell.hole, .cell.ghost {
    pointer-events: none;
}

.gui-arrow {
    transition: transform 0.3s ease-in;
}

.gui-toggle circle {
    transition: stroke 0.3s ease-in;
}

.selected {
    background-color: rgba(0,200,200,0.2);
}

.focused {
    background-color: rgba(200,0,200,0.2);
}

.focused.selected {
    background-color: rgba(0,200,0,0.2);
}

.focused--0 {
    /* TODO */
    background-color: rgba(200,0,200,0.5);
    /* color: rgba(0, 255, 255, 1); */
}

.focused--1 {
    background-color: rgba(200,0,200,0.4);
    /* color: rgba(0, 255, 255, .8); */
}

.focused--2 {
    background-color: rgba(200,0,200,0.3);
    /* color: rgba(0, 255, 255, .6); */
}

.focused--3 {
    background-color: rgba(200,0,200,0.2);
    /* color: rgba(0, 255, 255, .4); */
}

.focused--4 {
    background-color: rgba(200,0,200,0.1);
    /* color: rgba(0, 255, 255, .2); */
}

.focused--5 {
    background-color: rgba(200,0,200,0);
    /* color: rgba(0, 255, 255, 0); */
}

.level--0 {
    opacity: 1;
}

.level--1 {
    opacity: 0.8;
}

.level--2 {
    opacity: 0.5;
}

.level--3 {
    opacity: 0.3;
}

.level--4 {
    opacity: 0.2;
}

.level--5, .level--6, .level--7 {
    opacity: 0;
}

.gui-ghost {
    background-color: rgba(0,0,0,0.1);
}

.hole {
    /* border-color: #333;
    background-color: rgba(0, 0, 0, 0.3); */
    border-color: transparent;
    background: none;
}

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