add flipcard feature into ox-reveal

scripts/flipcard/flipcard.css

@@ -0,0 +1,93 @@
+.reveal .slides section > section {
+  height: 95%;
+}
+
+.reveal li { margin: 0; padding: 0.1em}
+
+.reveal h2 { display: none; }
+
+/* THE MAINCONTAINER HOLDS EVERYTHING */
+
+.fc-maincontainer {
+  position: absolute;
+  width: 350px;
+  height: 460px;
+  background: none;
+  top: 50%;
+  left: 50%;
+  transform: translate(-50%, -50%);
+}
+
+/* THE CARD HOLDS THE FRONT AND BACK FACES */
+.fc-thecard{
+  position: relative;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  border-radius: 20px;
+  transform-style: preserve-3d;
+  transition: all 0.8s ease;
+}
+
+.fc-header p {
+    font-size: 2.0em !important;
+    margin: 0 0 20px 0;
+    color: #fff;
+    font-family: "Source Sans Pro", Helvetica, sans-serif;
+    font-weight: 600;
+    line-height: 1.2;
+    letter-spacing: normal;
+    text-transform: uppercase;
+    text-shadow: none;
+    word-wrap: break-word;
+}
+
+.fc-flip {
+  background-color: #4d7d43;
+  color: #7bdb96;
+  font-style: italic;
+  position: absolute;
+  bottom: 0;
+  left: 0;
+  width: 100%;
+  padding: 0.25em 0;
+}
+
+/* THE PSUEDO CLASS CONTROLS THE FLIP ON MOUSEOVER AND MOUSEOUT */
+/* .fc-thecard:hover{ */
+/*   /\* transform: rotateY(180deg); *\/ */
+/* } */
+
+/* THE FRONT FACE OF THE CARD, WHICH SHOWS BY DEFAULT */
+ .fc-thefront{
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  border-radius: 20px;
+  backface-visibility: hidden;
+  overflow: hidden;
+  /* background: #ffc728; */
+  background: #7bdb96;
+  color: #000;
+  padding: 30px;
+}
+
+/* THE BACK FACE OF THE CARD, WHICH SHOWS ON MOUSEOVER */
+.fc-theback{
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  border-radius: 20px;
+  backface-visibility: hidden;
+  overflow: hidden;
+  background: #dba57b;
+  color: #333;
+  text-align: center;
+  transform: rotateY(180deg);
+  padding: 30px;
+}

scripts/flipcard/flipcard.js

@@ -0,0 +1,31 @@
+function flipcard_main() {
+  var cardFront = document.getElementsByClassName("fc-thefront");
+  var i;
+  var flip;
+  for (i = 0; i < cardFront.length; i++) {
+    flip = document.createElement("div");
+    flip.appendChild(document.createTextNode("flip"));
+    flip.className = "fc-flip";
+    flip.addEventListener("mouseover", event => {
+      var flip = event.target;
+      var front = flip.parentElement;
+      var card = front.parentElement;
+      card.style.transform = "rotateY(180deg)";
+    });
+    cardFront[i].appendChild(flip);
+  };
+
+  var cardBack = document.getElementsByClassName("fc-theback");
+  var i;
+  for (i = 0; i < cardBack.length; i++) {
+    cardBack[i].addEventListener("mouseleave", flipcard_mouseLeave, true);
+  }
+};
+function flipcard_mouseLeave(event) {
+  if (event.target.className == "fc-theback") {
+    var back = event.target;
+    var card = back.parentElement;
+    card.style.transform = "rotateY(0deg)";
+  }
+};
+flipcard_main();