Allow browsers to determine video or slideshow dimensions based on the width of their containing block by creating an intrinsic ratio that will properly scale on any device.
-Rules are directly apply to <iframe>, <embed> and <object> elements, optionally use of an explicit descendant class .embed-responsive-item when you want to match the styling for other attributes.
Rules are directly applied to <iframe>, <embed>, and <object> elements; optionally use an explicit descendant class .embed-responsive-item when you want to match the styling for other attributes.
Pro-Tip! You don't need to include frameborder="0" in your <iframe>s as we override that for you.