I've found a TON of posts and questions on mobile width/height. The top two answers are to use media queries, or to use vh/calc(). The other issue I've seen numerously is the mis-understanding of width/height(100%) vs width/height(auto) with the use of margins/padding/borders. What I've run into seems to be unique, but with the flood of mobile issues, I have a feeling somewhere out there is an answer to this already. If you've seen this, please point us to the correct question/answer.
I've created a black glass along with an element to use as an image previewer. The glass and image have width("100%") and height("100%") without any padding, margin, or border. On a computer, it looks perfect. On a mobile device, the dimensions can get thrown off and the background shows through.
If I remove the height("100%") on images that are taller than wide, it resizes to the entire element. If an image is wider than tall, removing the width("100%") causes it to grow appropriately again too. However, this doesn't solve my issue because without a width or height cap at 100%, larger images will overflow.
I first noticed this issue on my cellphone (android) and have had no issue repeating it on Chrome's emulator. I have uploaded a quick recording of what I am seeing to screencast.
It's been suggested that a css rule is leaking from a parent element. Chrome supports the style 'all: initial;' to reset the css. I also manually reset my css with this method. Resetting the styles did not change the issue.
Once again, thank you for taking the time to look at my issue!