Why marker disappearing from form input in HTML

Question

Hi everybody. I try to create HTML form in my web page. I created and style it with CSS. But when I put marker to wright something (name, surname, email, textarea message) my marker disappears from input area and I can not enter anything :(
I tried to copy same form to empty document without any other content. It is works good.
But other content in my webpage just header, footer and two empty div's. What the problem could be?

Answer 1

In your line 38 you forgot to close button tag, that was making this problems
https://code.sololearn.com/W8OhXOEj7sCb/?ref=app

Answer 2

Can you post your code

Answer 3

@Sanja Panic
I am very appreciate. THANKS SO MUCH ;)
I already changed :
<a class="btn" href="contact.html"><button>Contact</button></a>
to
<li><a href="contact.html">Contact</a></li>
and solved problem as well. But you fixed my original code. Thanks again

Answer 4

@Sanja Panic
https://code.sololearn.com/W9vKYd9thwPI/#
There is my code. But on playground when i try to put marker inside a input field, form is disappearing at all.