Aspect ratio to get consistently responsive images and iframes. Coupled with Image style. And to fix layout reflow, excessive height issues, whitespace below images, collapsed container, no-js users, etc. <a href="@dimensions" target="_blank">Image styles and video dimensions</a> must <a href="@follow" target="_blank">follow the aspect ratio</a>. If not, images will be distorted. <a href="@link" target="_blank">Learn more</a>. <ul><li><b>Fixed ratio:</b> all images use the same aspect ratio mobile up. Use it to avoid JS works, or if it fails Responsive image. </li><li><b>Fluid:</b> aka dynamic, dimensions are calculated and JS works are attempted to fix it.</li><li><b>Leave empty:</b> to DIY (such as using CSS mediaquery), or when working with multi-image-style plugin like GridStack.</li></ul>