+/* We want our board to be the largest square that can
+ * fit. Unfortunately, it requires a bit of CSS magic to make that
+ * happen. We can set a width easily enough, but what we can't easily
+ * do is to set the height to be exactly the same as the width.
+ *
+ * So here's the magic to get that to happen. On the board container
+ * we set the height to 0 and the bottom padding to 100% (which just
+ * happens to be defined as relative to the _width_). So, now we have
+ * a square element. Hurrah!
+ *
+ * The problem is that this element has a nominal height of 0, so if
+ * any child sas "height: 100%" that will result in a 0-height child
+ * and won't be what we want.
+ *
+ * So the last piece of the magic is to use absolute placement of the
+ * board (which requires position:relative on its parent) and set all
+ * of its edges (top, left, bottom, right) to the extents of the
+ * container.
+ *
+ * Ta-da! Now our board element is square and does not have any
+ * dimensions of 0 so child elements can compute their sizes
+ * naturally.
+ */
+.board-container {
+ position: relative;
+ width: 100%;
+ height: 0;
+ padding-bottom: 100%;