.chess-area .board-table .controls button .icon {
    display: block;
    width: 100%;
    height: 100%;
    background-size: 50%;
    background-position: center;
    background-repeat: no-repeat;
}

.chess-area .board-table .controls button {
    display: block;
    opacity: 0.7;
    width: 50px;
    height: 50px;
    margin: 3px 5px 0 8px;
    font-family: Arial;
    font-size: 12px;
    font-weight: bold;
    background-size: 50%;
    background-position: center;
    background-repeat: no-repeat;
    border-radius: 5px;
    border: 1px solid #bfbfbf;
    box-shadow: 1px 1px 3px -2px #888;
}

.chess-area .board-table .controls button:focus {
    outline: 0;
}

.chess-area .board-table .controls button:hover {
    cursor: pointer;
    opacity: 1.0;
    box-shadow: 3px 3px 4px -3px #444;
}

.chess-area .board-table .controls button.disabled {
    opacity: 0.4;
}

.chess-area .board-table .controls button.disabled:hover {
    cursor: initial;
    opacity: inital;
    box-shadow: 0px 0px 0px 0px #000;
}

/*** Bottom buttons ***/

#btn-flip-board {
    background-image: url('../img/icons/switch-enabled.svg');
}
#btn-flip-board.disabled {
    background-image: url('../img/icons/switch-disabled.svg');
}

#btn-switch-sides {
    background-image: url('../img/icons/switch-sides.svg');
}

/* Hint */
#btn-show-hint .icon {
    background-image: url('../img/icons/hint-enabled.svg');
}
#btn-show-hint.disabled .icon {
    background-image: url('../img/icons/hint-disabled.svg');
}
#btn-show-hint.loading .icon {
    background-image: url('../img/icons/loading.svg');
    animation: spin 5s linear infinite;
}

#btn-engine-disable .active {
    text-decoration: line-through;
}

#btn-back {
    background-image: url('../img/icons/previous.svg');
}

#btn-forward {
    background-image: url('../img/icons/next.svg');
}

/* Analyse */
#btn-analyze .icon {
    background-image: url('../img/icons/analyze.svg');
}
#btn-analyze.loading .icon {
    background-image: url('../img/icons/loading.svg');
    animation: spin 5s linear infinite;
}

/* Play */
#btn-play-game .icon {
    background-image: url('../img/icons/new-game.svg');
}
.btn-play-game:hover {
    opacity: 0.8;
    cursor: pointer;
    background: #c40c2b;
    animation: spin 5s linear infinite;
}

.btn-play-game .icon {
    background: #d41c3b;
}

.btn-play-game .icon:hover {
    background: #000000;
}