Update HTML, CSS, and video file

- Updated index.html with latest changes
- Updated vr180player/vr180-player.css with styling improvements
- Updated sbs-video.mp4 with new video content

vr180player/vr180-player.css

@@ -4,6 +4,12 @@
 	width: 100%;
 }
 
+video {
+	width: 100%;
+	height: auto;
+    aspect-ratio: 16/9;
+}
+
 #playBtn {
 	position: absolute;
 	top: 50%;