Add countdown CSS

src/static/css/style.css

@@ -3,6 +3,36 @@
     margin-right: 20%;
 } */
 
+html, body {
+    height: 100%;
+    width: 100%;
+}
+
+.fullscreen-countdown {
+    position: fixed;
+        top: 0;
+        left: 0;
+        right: 0;
+        bottom: 0;
+    z-index: 100;
+    height: 100%;
+    width: 100%;
+    /* backdrop-filter: blur(10px); */
+    color: black;
+    box-sizing: initial;
+
+}
+
+#countdown-number {
+    font-weight: bolder;
+    font-size: 10em;
+    text-shadow:   0px 0px 3em white, 1px 1px 1px rgba(255, 255, 255, 1);
+    position: fixed;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+}
+
 /*// Small devices (landscape phones, 576px and up)*/
 @media (min-width: 576px) {