Baback jan, first and foremost nice job
Security:
You are protecting against most common sql injections however, there's one that isn't protected, I don't want to list it here in case someone with malicious intent sees it before you do and have a chance to fix it, pm me if you'd like to know the command I used. Using that method, logged me into the site, as you.
Layout:
I like the layout for the most part it's very well done, however the first thing that caught my eye, was the right side of the screen... the table never seems to end, and the eye just wonders as to what's going on there. Not sure if that was by design or there are other reasons for it.
I also noticed that it took a couple of seconds to load the orange color on the left side, I didn't check the css to see if you're using an image or just a color, I would recommend using an orange bg color so the load is seamless.
Other than that, very well done
