How to Validate CSS on Internal Web Pages?

What are the best methods to validate CSS on internal web pages?

/* Example of using a CSS validator tool */
<link rel="stylesheet" type="text/css" href="style.css" />

Validating CSS is crucial for maintaining clean, error-free styles that comply with web standards. This guide covers various methods for validating CSS on internal web pages.

/* Example of a simple CSS validation setup using Stylelint */
"stylelint": {
  "rules": {
    "color-no-invalid-hex": true,
    "block-no-empty": true,
    "selector-max-id": 0
  }
}

Causes

• Non-compliant code leading to rendering issues.
• Browser compatibility problems due to outdated or incorrect CSS.
• Performance issues from large, unoptimized CSS files.

Solutions

• Use online CSS validation tools like the W3C CSS Validation Service.
• Incorporate CSS linting tools into your development workflow (e.g., Stylelint).
• Validate CSS within development environments using IDE plugins.

Mistake: Ignoring browser-specific prefixes for CSS rules.

Solution: Use a tool like Autoprefixer to automatically add necessary prefixes.

Mistake: Not validating CSS after modifications or additions.

Solution: Regularly validate CSS during the development process, especially after major changes.

Mistake: Using outdated CSS properties that are no longer recommended.

Solution: Refer to the CSS specifications for updates on deprecated properties.