Zooming on PDF viewer

[tim-macphail]

On mobile, one should definitely be able to zoom in on the pdf viewer. I have 20/20 vision and can hardly read the words on the pdf.

Also, on my 14 inch laptop, the font size of text in CPSC457.pdf for example is 7.2 px, which is far too small for accessibility purposes. We could add zooming in the viewer with [+ / -] buttons, or have the viewer take up more horizontal screen space. Another thought is having the border between the assessment section and document section movable by the user to make the viewer bigger. See how much unused horizontal space is being used by the assessments section: