I'm creating a test scenario for new project and I'm wondering if it is a good idea to write TC such as "Access to xxxxxxx/xxxxxx-xxxxxx and verify CSS & HTML properties" has even sense. Approach would be that the tester should open the documentation and compare whether all properties of the elements have properly values or not. Also the tester should verify if elements such as textbox are "number", "tel" etc. indeed.

I'm not a web developer but I understand a structure of HTML & CSS code so - in theory - I'm able do it. Question: Is it a good/widely-known practice or not?