Not sure what you mean with warp, but the reason for the missing highlight is, that you are in “Inline-Math-Mode” which is usualy only used inside of a text line. It should still work for the preview i think.
However normaly when you whant to write something in LaTeX (or MathJax) you would use the Math-mode (wrap your LaTeX-Code in double-dollar-signs like $$a+b=c$$ For multiple lines you would also need an \begin and \end.
For example:
$$\begin{align}
a+b=c\
c^2=d
\end{align}$$
