HTML Guide for px

css
px
width

The value px for a width property is incorrect, it should include both the value and the units, like 10px, or just 0 if it’s zero width. Using only the units without the value is incorrect.

Example of Incorrect CSS

<style>
  .example {
    width: 300; /* This is missing the unit */
  }
  .example2 {
    width: px; /* This is missing the value */
  }
</style>

Corrected Example of CSS

Make sure to include the unit (like px, em, %, etc.) when specifying the width:

<style>
  .example {
    width: 300px; /* Correctly includes 'px' unit */
  }
</style>

Conclusion

Always ensure to provide proper units when specifying dimensions in CSS. Common units are:

px (pixels)
em (relative to the font size of the element)
% (percentage of the parent element’s width)