The difference between the Test environment and the web. I am interested in your experience.

I just completed my first "production" version of my personal website. What a shock. I was using my best understanding of a flexbox approach ( that may not be perfect ). I have been using a mobile first approach with two min-size breaks (media queries) @ 801px and 1201px. I use Sublime Text 3 and its "View in Browser" option for editing and testing. I have been compressing and expanding my browser window through my break points. The flexbox has been working like a dream in my testing environment. I have been using hex notation for my colors instead of keywords, thinking it to be more precise and fully functioned. I stay away from measuring with pixels, preferring to use % and rem in all places where it makes sense. In general, trying to use the best practices taught in the Front-End Development Tutorials. Though I had a couple of minor "undocumented features" I felt I could publish

www.dhawkinson.com (it is live)

and feel good enough to work on the annoyances. However, it renders like a bad remake of a beloved original movie on the web. The colors are significantly different from the test environment. What is defined as flex-direction: row; and woks perfectly in the test environment, renders like flex-direction: column; on the web. On the portfolio page I have a background image that renders behind the menu in the test environment. It doesn't render at all on the web. I could go on. My question is this: What is your experience? Is this normal? Am I going to have to rework every thing on the web with my hosting site? How can I rely on knowing if anything is truly working correctly in my test environment? Am I using a faulty IDE (its not really a full IDE). I would really like to hear from some folks with more experience than I, including some of the instructors.

Thanks for listening to (reading) my rant. Please feel free to visit my website (see above) but understand I know it is not looking too good. I have work to do. I really need some guidance on what direction to take. I am expecting to use the site as a introduction/portfolio/resume to find work. Time is of the essence.

Thanks.

Doug