How to do margin-top only in Firefox browser - css

Question

I have menu bar which need to be margin-top: 150px;
But visually in Firefox looking different as on Chrome.
Header code: https://codepen.io/bugerman21/pen/rNxvyOv
Chrome:
Correct display
Firefox:
Incorrect display
HTML:
<nav>
<ul class="nav">
<li class="category"><span>Category <i class="fas fa-sort-down"></i></span>
<ul>
<li>Qwerty 1</li>
<li>Qwerty 2</li>
<li>Qwerty 3</li>
<li>Qwerty 4</li>
</ul>
</li>
<li>Cuntact us</li>
<li>FAQ</li>
</ul>
CSS:
* {
margin: 0;
pading: 0;
}
.nav li ul {
position: absolute;
margin-top: 150px;
min-width: 150px;
list-style-type: none;
display: none;
}
How to do margin-top only for the Firefox browser?
Unsuccessful attempt:
#-moz-document url-prefix() {
.nav li ul {
margin-top: 150px;
}
}

Answer 1

Here ya go buddy, sorry I left for the day yesterday but see the changes made and I left outlines on the elements to give a better visual reference. As it is now it will display as expected on all browsers even old internet explorer. Although you could accomplish the same thing cleaner overall, this at least gets you back on track. Cheers and welcome to StackOverflow! :)
PS : since the nav menu items don't have a fixed height you might want to consider making that something static so you can change the top: 56px to a value that places the drop down consistently no matter the width of the screen. If you make the example full screen you'll see what I mean.
header {
display: flex;
margin: 0;
padding: 0 20px;
justify-content: space-between;
align-items: center;
background-color: silver;
}
.header {
grid-area: header;
background-color: #1f1f1f;
}
nav {
display: flex;
justify-content: space-between;
align-items: center;
}
/*---------- Logo ----------*/
.logo {
font-family: 'Gentium Book Basic', serif;
font-size: 2.5em;
color: #808080;
}
/*---------- Nav menu ----------*/
.nav {
list-style-type: none;
display: flex;
justify-content: flex-start;
margin: 0;
}
.nav > li {
text-decoration: none;
font-family: 'Roboto', sans-serif;
color: #ffffff;
transition: background-color .25s ease;
}
.nav a {
display: block;
padding: 20px;
color: #ffffff;
font-size: 1em;
}
.category {
padding: 0 20px;
display: flex;
align-items: center;
position: relative;
overflow: visible;
border: red 1px solid;
}
/*---------- Sub menu ----------*/
.nav li ul {
position: absolute;
top: 56px;
left: 0;
min-width: 150px;
margin: 0;
padding: 0;
list-style-type: none;
display: none;
border: green 1px solid;
}
.nav li > ul li {
border-bottom: 1px solid #ffffff;
background-color: #1f1f1f;
}
.nav li > ul li a {
text-transform: none;
}
.nav li:hover > ul {
display: block;
}
.nav > li:hover {
background-color: #404040;
/* box-shadow: -5px 5px #1f1f1f; */
}
.nav li ul > li:hover {
background-color: #404040;
}
/*---------- Search & Profile----------*/
.search_and_profile {
display: flex;
align-items: center;
}
.search_and_profile > p {
margin: 0;
color: #ffffff;
}
.search-container button {
float: right;
padding: 6px 10px;
background: #e0e0e0;
font-size: 17px;
border: none;
cursor: pointer;
}
.search-container input[type=text] {
padding: 6px;
font-size: 17px;
border: none;
}
<header class="header">
<span class="logo">Qwerty</span>
<nav>
<ul class="nav">
<li class="category"><span>Category <i class="fas fa-sort-down"></i></span>
<ul>
<li><a href=#>Qwerty 1</a></li>
<li>Qwerty 2</li>
<li>Qwerty 3</li>
<li>Qwerty 4</li>
</ul>
</li>
<li>Cuntact us</li>
<li>FAQ</li>
</ul>
</nav><!-- .nav -->
<div class="search_and_profile">
<div class="search-container">
<form action="#">
<input type="text" placeholder="Search.." name="search">
<button type="submit"><i class="fa fa-search"></i></button>
</form>
</div><!-- .search-container -->
</div><!-- .search_and_profile -->
</header>

Answer 2

It will work for me, additionally i included color too to make sure.
Also you try this option too
#media screen and (-moz-images-in-menus:0) {
/* your style */
}
* {
margin: 0;
pading: 0;
}
.nav li ul {
position: absolute;
margin-top: 150px;
min-width: 150px;
list-style-type: none;
display: none;
}
/* Added */
#-moz-document url-prefix('') {
.nav li ul {
margin-top: 150px;
color: orange;
}
}
<div class="nav">
<ul>
<li>Home</li>
<li>About
<ul>
<li>Some text</li>
<li>Some more text</li>
</ul>
</li>
<li>Contact</li>
</ul>
</div>