Cannot figure out the difference. Need a hand.

Hello guys. I have a big problem, especially with coding.

I cannot change the font size of my articles. Sometimes I can sometimes I cannot.

If I figure out the difference between these 2 codes, I will fix this problem.

my question is. How can 2 different codes can be created even after making same progress…?

<h2 style="text-align: center;"><span style="color: #ff3333; font-size: 16px;"><a title="Hotspot shield" href="http://websitelinkasdasda.com/"><span style="color: #ff3333;">Hotspot Shield</span></a></span></h2>

<h2 style="text-align: center;"><span style="color: #ff0033;"><a href="http://websitelinkasdasda.com/"><span style="font-size: 16px; color: #ff0033;">Hotspot shield</span></a></span></h2>

[Please remember to wrap your code in backticks]