Move from sass to scss for stylesheets

src/ui/player/player.scss

@@ -0,0 +1,34 @@
+body {
+  background-color: #131313;
+}
+
+html, body, video {
+  width: 100%;
+  height: 100%;
+  margin: 0;
+}
+
+video {
+  position: absolute;
+  top: 0;
+  left: 0;
+}
+
+#message-container {
+  visibility: hidden;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  flex-direction: column;
+  color: white;
+  text-align: center;
+  height: 100%;
+
+  & * {
+    visibility: inherit;
+  }
+
+  & a, & a:visited {
+    color: red
+  }
+}