A practical workshop designed to teach CSS preprocessors through- Integrate LESS compilation into development workflows
This lab takes a problem-first approach to learning CSS preprocessors. Instead of jumping straight into syntax, you'll first experience the real maintenance nightmares that make preprocessors essential in professional web development.
Duration: ~2 hours
Prerequisites: Basic knowledge of SCSS from previous lessons
By completing this lab, you'll understand:
- Why CSS preprocessors exist and when they become essential
- What problems variables, mixins, and partials actually solve in real projects
- How LESS syntax compares to SCSS you already know
- How preprocessors fit into professional web development workflows
- When to choose LESS over other preprocessors
The lab consists of three main exercises that build upon each other:
Experience the maintenance hell of changing colors across a stylesheet manually, then discover how LESS variables provide a single source of truth.
Problem: Client wants to change brand color from terracotta to teal across entire site
Learning: Variables aren't just convenient - they're essential for maintainable CSS
Feel the pain of repetitive CSS patterns when updating dozens of similar button components, then solve it with LESS mixins.
Problem: Update border-radius across 9+ nearly identical button classes
Learning: Mixins eliminate repetitive patterns and make scalable CSS possible
Navigate an unorganized stylesheet chaos to find specific components, then solve it with LESS partials and imports.
Problem: Hunt through a massive single-file stylesheet to find one component
Learning: Partials organize code into logical, maintainable files for team development
# Install dependencies (run from project root)
npm install
# Compile LESS to CSS and open demo
npm startNote: Some files contain intentional errors that you'll fix during the exercises.
From the project root directory:
npm run compile:ex1 # Compile exercise 1 only
npm run compile:ex2 # Compile exercise 2 only
npm run compile:ex3 # Compile exercise 3 only
npm run compile:all # Compile all exercises
npm run watch:less # Watch for changes and auto-compile
npm start # Compile all and prepare demoLESS remains popular in web development because:
- Simpler syntax - Closer to vanilla CSS with easier learning curve
- Client-side compilation - Can run in browser during development
- JavaScript integration - Written in JavaScript, easy to extend
- Bootstrap legacy - Many projects still use LESS from Bootstrap's legacy
- Flexible approach - Less opinionated than SCSS
After completing this lab, you'll be able to:
✅ Identify when CSS preprocessors become essential (file size, team size, repetition)
✅ Use LESS variables, mixins, and partials to solve real maintenance problems
✅ Organize stylesheets for professional team development
✅ Choose the right preprocessor for different project needs
✅ Integrate LESS compilation into development workflows
├── package.json # Build scripts and dependencies
├── .gitignore # Git ignore patterns
└── lab/
├── demo.html # Demo page to test your solutions
├── README.md # Detailed exercise instructions
├── exercises/ # LESS exercise files
│ ├── exercise1.less # Variables exercise
│ ├── exercise2.less # Mixins exercise
│ └── exercise3.less # Partials exercise
└── resources/ # Reference images
├── less_ex_1.png
├── less_ex_2.png
└── less_ex_3.png
Ready to start? Check the lab/README.md for detailed exercise instructions!