First working model.

assets/base.css

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+/*
+ * Chessground base css properties, for clarity.
+ *
+ * You can then include either desktop.css or mobile.css.
+ *
+ * And you need to include the css files in themes folder in order to have the
+ * board and pieces displayed!
+ */
+
+.cg-board-wrap {
+  width: 100%;
+  height: 100%;
+}
+.cg-board {
+  -webkit-user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
+  user-select: none;
+  line-height: 0;
+  background-size: cover;
+  position: relative;
+  width: 100%;
+  height: 100%;
+}
+square {
+  position: absolute;
+  width: 12.5%;
+  height: 12.5%;
+}
+square[data-coord-x]::after {
+  position: absolute;
+  left: 1px;
+  bottom: 1px;
+  font-size: 10px;
+  line-height: 10px;
+  content: attr(data-coord-x);
+  color: #fff;
+  opacity: 0.5;
+}
+square[data-coord-y]::before {
+  position: absolute;
+  right: 1px;
+  top: 1px;
+  font-size: 10px;
+  line-height: 10px;
+  content: attr(data-coord-y);
+  color: #fff;
+  opacity: 0.5;
+}
+square.move-dest {
+  background: radial-gradient(rgba(20, 85, 30, 0.5) 22%, #208530 0, rgba(0, 0, 0, 0.3) 0, rgba(0, 0, 0, 0) 0);
+}
+square.premove-dest {
+  background: radial-gradient(rgba(20, 30, 85, 0.5) 22%, #203085 0, rgba(0, 0, 0, 0.3) 0, rgba(0, 0, 0, 0) 0);
+}
+square.last-move {
+  background-color: rgba(155, 199, 0, 0.41);
+}
+square.selected {
+  background-color: rgba(20, 85, 30, 0.5);
+}
+square.check {
+  background: radial-gradient(ellipse at center, rgba(255, 0, 0, 1) 0%, rgba(231, 0, 0, 1) 25%, rgba(169, 0, 0, 0) 89%, rgba(158, 0, 0, 0) 100%);
+}
+square.current-premove {
+  background-color: rgba(20, 30, 85, 0.5);
+}
+piece {
+  position: absolute;
+  bottom: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  background-size: cover;
+  z-index: 2;
+  will-change: transform;
+}
+piece.dragging {
+  z-index: 9;
+}
+piece.ghost {
+  opacity: 0.3;
+}
+.minimal-dom piece {
+  position: absolute;
+  width: 12.5%;
+  height: 12.5%;
+}

assets/desktop.css

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+.cg-board {
+  cursor: pointer;
+}
+.cg-board .cg-square.move-dest.drag-over,
+.cg-board .cg-square.premove-dest.drag-over {
+  box-shadow: inset 0 0 10px 2px rgba(216, 85, 0, 0.9);
+}
+piece.dragging {
+  cursor: move;
+}