Bad value 30px for attribute [width] and [height] on element <img>

Significant HTML5 validation/parsing errors should be avoided. Check at http://validator.w3.org/
Expected a digit (30) for [width] and [height] attributes but saw pixels (30px) instead.

At the same time, the HTML source code should be reviewed to be compliant with front-end best practices and accessibility guidelines (WCAG 2.1).