The one-word answer is No.

Let's look at their definitions for a better understanding:

HTML (HyperText Markup Language) is the standard markup language for documents designed to be displayed in a web browser. It was modeled on SGML (Standard Generalized Markup Language), which is a declarative standard for describing document structure and attributes.

CSS (Cascading Style Sheet) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML.

And now, let's look at the definition of a programming language:

A programming language is a set of commands, instructions, and other syntax use to create a software program.

Ahhhhh that was too much Wikipedia. Let's understand it in simpler terms. HTML and CSS can't be used to write algorithms (a set of rules/instructions that step-by-step define how a task is to be performed) that can help us solve problems that languages like Java, C/C++, Python, etc. help us in solving. HTML is used to just create web pages and CSS is used for styling web pages, neither of them has the ability to solve problems and help a programmer in writing algorithms.

Hence, they aren't programming languages.

That's it folks, hope it cleared your doubt!
Keep Learning.