What is code quality in HTML and CSS?

Code quality in HTML and CSS is a set of characteristics that make the code understandable, maintainable, and efficient. The main aspects of code quality:

• Readability: the code should be structured, use understandable class and selector names, and have indentation and comments when necessary.
• Maintainability: the code should be easy to modify and extend without risking breaking existing functionality.
• Semantics: in HTML, use the correct tags for their intended purpose (e.g., <header>, <nav>, <article>), which improves accessibility and SEO.
• Optimization: minimize redundancy in CSS, use reusable styles, and avoid duplication.
• Cross-browser and responsiveness: the code should work correctly across different browsers and devices.

An example of good practice in CSS:

/* Use semantic classes and nesting */
.nav {
  background-color: #333;
}
.nav__item {
  display: inline-block;
  padding: 10px;
  color: white;
}
.nav__item--active {
  font-weight: bold;
}

This approach facilitates understanding and maintaining the code.