Technology & Coding

Building Your First Website with HTML and CSS

Write, style, and publish a real multi-section web page from a blank folder in seven days.

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What you will learn about Building Your First Website with HTML and CSS

The 7-day sprint
  1. A Page Is Just a File. A website starts as a plain text file named index.html that a browser opens and draws.
  2. Elements, Attributes, and Content. HTML marks up content by wrapping it in elements, and attributes add extra information to an element.
  3. Structure That Means Something. Wrap regions of the page in semantic elements and keep headings in order, so the structure makes sense to browsers, search engines, and screen readers.
  4. CSS Rules and Which One Wins. CSS is a list of rules that match elements by selector and set property values, and when two rules collide the cascade decides the winner.
  5. Every Element Is a Box. CSS draws each element as a box made of content, padding, border, and margin, and box-sizing decides what width measures.
  6. Laying Out With Flexbox. Flexbox arranges a container's children along one axis, which is how you build navigation bars, card rows, and side by side sections.
  7. Responsive, Valid, and Online. Make the page work at any screen width, check the markup with a validator, then publish the folder so it has a public address.
The 80/20: the 7 concepts that matter most
  • Markup describes meaning, not appearance
  • The document skeleton and the two file split
  • Selectors, the cascade, and inheritance
  • The box model
  • Normal flow and flexbox
  • Responsive by default
  • Semantics, accessibility, and validation
The core idea, explained like you are 5

HTML labels what each piece of your content is, and CSS says how the labeled pieces should look, because the browser turns those labels into nested boxes it draws on the screen.

Then the quiz and the ladder

10 questions that correct you when you are wrong, and beginner, intermediate, advanced levels, each with a practical exercise.

Created Sep 12, 2026. No mistakes have been reported by learners.

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