Back in the day, pixels were a front end developer’s best friend when it came to setting dimensions in CSS. Then came em (and rem) units. For the past few years, vw and vh (viewport width and height) units have become increasingly popular. In this session, I will take participants on a journey into the wonderful world of these wondrous scalable units, and how we can use them with Sass to yield displays that are more consistent and legible at any browser size. I will also highlight cases where the use of viewport units might yield undesired results, and I will demonstrate how we can use Sass logic and math to overcome these obstacles.