CSS Mastery

What it covers

Squarespace CSS Mastery is a coding course, not a web design course. The old listing here described it as a class on building Squarespace sites from scratch, which is wrong: it teaches CSS from the ground up using Squarespace as the example platform. Roman, Applet Studio's co-founder and a full stack developer, is the instructor.

The curriculum starts with how HTML and CSS fit together, then goes deep on CSS: the cascade, selectors, responsive techniques and recorded coding sessions applying styles to real elements. A Squarespace-specific section covers where custom CSS lives and how the platform's blocks behave, followed by practical work with the Chrome inspector. The stated outcomes are the things that actually come up in client work: custom typography, fonts, colours and gradients, small animations on standard blocks, and fixing tablet and mobile layouts in Fluid Engine. You also get a library of Squarespace CSS snippets with explanations. A 2025 update added a lecture and hands-on session on using ChatGPT to write, edit and debug CSS, with the emphasis on how to phrase the prompt so the code actually works when pasted in.

Who it is for

Designers who copy snippets from the internet and feel lost when they fail, and anyone who wants full control over how a Squarespace site looks. Applet Studio says it is not for people who already write CSS comfortably, or for people who only want ready-made snippets without learning.

Format and access

Over eight hours of pre-recorded video on Teachable, in lessons of roughly eight to twenty minutes, with all CSS examples included. Access is immediate and self-paced; Applet Studio expects most people to take a couple of months working through it weekly. The first lecture is free to watch before you buy. Sales are final, with no refunds. Optional one to one tutoring with Roman (five sessions over two months) is sold separately.

Where it falls short

Eight hours is a real commitment, and Applet Studio is honest that watching videos will not make you a front end developer: you learn CSS by fixing your own sites. The course is priced modestly, which the vendor explains as a deliberate choice, but it means no community and no live support unless you pay for tutoring. I would pair it with a free CSS refresher and a live client project to practise on.

Related guide: browse every course we list in the Squarespace courses collection, and read my practical guide on how to use custom CSS in Squarespace before you start. I also rank it in our best Squarespace courses in 2026 roundup as the course for learning CSS properly.