This depends on you, if you are motivated and willing to work really hard to learn everything you need then I would say that you have a high change.
You have two options:
1. Don't quit your day job and work all your free time to learn HTML/CSS and then whatever path you want, in a few weeks/months you will know if this is something you will be good at or not.
Keep in mind that in this field you will have to learn new things for the rest of your life if you want to promote or sometimes even keep your job.
2. If you have some money set aside and you want to go all in, go all in. Spend every time you can (at least 40 hours per week) on learning and in a few months of work if you manage to understand the basics you will be able to find a Junior web developer job or start doing freelancing looking for opportunities.
Then depending on your learning style watch as many video courses or read as many books as you can.
Once you have a basic understanding (you are able to create websites from designs, PSD to HTML/CSS) you can move up to the next level.
If you want to have a better foundation for your knowledge but will be a lot more difficult to get started learn Ruby for a few weeks then move to Ruby on Rails (framework).
If you want an easier path but your understanding of things might be
If you only want to get by you could just learn HTML/CSS and some bits of Javascript and do small website projects (there is still a market for that, but the prices are low because it's a low entry point).
If you want to earn more and promote etc, you will have to learn to create and maintain complex web apps which is a lot of work and takes ears to get to a mid-senior level.
An IT career today might be hard (depending on what you want to do), but
the rewards in therms of motivation and money are very good.