Develop Reference

I can't fix my bottom menu in any way on Chrome (while on FIrefox works perfectly)

I'm new to HTML/CSS3, so in order to strengthen the skills I've learned during an online course I'm trying to clone homepages of famous websites.
Now, I've almost completed the homepage of flickr.com but I've made a stupid mistake: I tested it only on Firefox (where it works smoothly on smartphone, tablet and desktop 1920*1080p view). Then I tried it on Chrome and...it was a disaster. My footer section was not working:
in tablet and desktop view, there's a gap between the footer and the bottom of the page I can't fix;
but although I can't fix the problem on my own, I managed to identify the problem: it's the little arrow near the word 'English' inside the footer (I need it cause when I click on it the language menu will pop up as in the original website). And I'm almost sure that this has to do with the 'position:absolute' propriety I assigned to that arrow in my style.css file (but I can't remove that property, otherwise it'll look ugly) ;
I tried working on padding and margin in any way I could think about, but I can't solve the problem and I can't tell if it's just bad styling or if the problem is connected to bad framing in my index.html file.
I don't know if someone is willing to give a look to my work. Any help will be really appreciated.
Thank you.
index.html:
<div class="header-container">
<header>
<a class="logo" href="#">
<img class="flickr" src="images/flickr-logo-2435.svg" alt="#">
<p>flickr</p>
</a>
<nav>
<div class="search-box">
<input class="search-txt" type="text" name="search" id="searchbar"
placeholder="Photos, people or groups">
<a class="search-icon" href="#">
<i class="fa-solid fa-magnifying-glass"></i>
</a>
</div>
<div class="nav-button-A">
Log In
</div>
<div class="nav-button-B">
Sign Up
</div>
</nav>
</header>
</div>
<main>
<div class="wrapper">
<h1>Find your inspiration.</h1>
<h2>Join the Flickr community, home to tens of billions of photos and 2 million groups.</h2>
<div class="start-button">
Start for free
</div>
</div>
</main>
<footer>
<div class="footer-nav1">
<div class="footer-button">About</div>
<div class="footer-button">Jobs</div>
<div class="footer-button">Blog</div>
<div class="footer-button">Developers</div>
<div class="footer-button">Guidelines</div>
<div class="footer-button">Help</div>
<div class="footer-button">Help forum</div>
<div class="footer-button">English
<img class="arrow" src="/images/pngegg.png" alt="line down">
<div class="language-nav" style="display: none;">
<a class="language" href="#">Italiano</a>
<a class="language" href="#">French</a>
<a class="language" href="#">Espanol</a>
<a class="language" href="#">Deutsch</a>
<a class="language" href="#">日本語</a>
<a class="language" href="#">Portugues</a>
<a class="language" href="#">한국어</a>
</div>
</div>
</div>
<div class="footer-nav2">
<div class="footer-button">Privacy</div>
<div class="footer-button">Terms</div>
<div class="footer-button">Cookies</div>
<div class="footer-button">
<p>SmugMug+Flickr.</p>
<p>Connecting people through photography.</p>
</div>
<div class="social-nav">
<a class="social-button">
<i class="fa-brands fa-square-facebook"></i>
</a>
<a class="social-button">
<i class="fa-brands fa-twitter"></i>
</a>
<a class="social-button">
<i class="fa-brands fa-instagram"></i>
</a>
</div>
</div>
</footer>
</body>
</html>
style.css:
html {
position: absolute;
left: 0;
top: 0;
width: 100%;
height: 100vh;
animation: animate 20s ease-in-out infinite;
background-size: cover;
background-position: center center;
margin: 0;
padding: 0;
}
#keyframes animate {
0%,
100% {
background-image: url(images/0.jpg);
}
25% {
background-image: url(images/1.jpg);
}
50% {
background-image: url(images/4.jpg);
}
75% {
background-image: url(images/3.jpg);
}
}
/* GLOBAL MOBILE */
body {
font-family: 'Roboto', sans-serif;
margin: 0;
padding: 0;
}
.header-container {
position: fixed;
width: 100%;
}
header {
background-color: rgba(53, 57, 57, 0.376);
height: 65px;
display: flex;
align-items: center;
justify-content: space-between;
padding: 0px 20px 0 15px;
}
.logo {
display: flex;
text-decoration: none;
}
.flickr {
width: 25px;
height: 25px;
align-items: center;
padding-bottom: 5px;
box-sizing: border-box;
}
.logo p {
font-size: 1.6rem;
font-weight: 700;
margin-left: 5px;
color: white;
}
.search-box {
display: flex;
justify-content: flex-end;
align-items: center;
background: #2f364000;
height: 34px;
border-radius: 3px;
padding: 0px 0px;
}
.search-txt {
border-radius: 3px 0px 0px 3px;
border: none;
padding: 0;
background: #ffffffbd;
outline: none;
color: #4e5052;
font-size: 12px;
transition: 0.1s;
line-height: 34px;
width: 0px;
}
.search-icon {
color: #ffffff;
font-size: 1.2rem;
font-weight: 700;
width: 34px;
height: 34px;
border-radius: 0px 3px 3px 0px;
background: #2f364000;
display: flex;
justify-content: center;
align-items: center;
transition: 0.1s;
text-decoration: none;
}
.search-box:hover>.search-txt {
display: inline-block;
width: 130px;
padding: 0 0 0 3px;
}
.search-box:hover>.search-icon {
font-size: 1rem;
color: #4e5052;
background: #ffffffbd;
}
nav {
display: flex;
}
a {
color: white;
text-decoration: none;
}
.nav-button-A,
.nav-button-B {
font-size: 1rem;
font-weight: 500;
}
.nav-button-A {
border: 2px solid white;
margin-left: 10px;
padding: 7px 10px;
}
.nav-button-B {
/*show only in TABLET and DESKTOP mode*/
display: none;
margin-right: 15px;
border: 1.5px solid white;
background-color: white;
border-radius: 3px;
margin-left: 10px;
padding: 7px 10px;
}
.nav-button-B a {
color: #000000;
}
.nav-button-B a:hover {
color: #8b8c8d;
}
main {
height: 100vh;
width: 100%;
margin: 0 auto;
display: flex;
justify-content: center;
align-items: center;
}
.wrapper {
display: block;
text-align: center;
color: white;
padding: 0 30px;
}
.wrapper h1 {
font-size: 3.5rem;
font-weight: 500;
margin-bottom: 18px;
box-sizing: border-box;
}
/*to reactivate in TABLET and DESKTOP mode*/
.wrapper h2 {
display: none;
font-size: 1.56rem;
font-weight: 500;
margin: 30px 40px 50px 40px;
line-height: 1.9rem;
box-sizing: border-box;
}
.wrapper a {
font-size: 1.45rem !important;
color: black;
font-weight: 700;
background-color: white;
padding: 17px 23px;
border-radius: 3px;
box-sizing: border-box;
}
.start-button {
margin-top: 40px;
}
.start-button a:hover {
color: #8b8c8d;
}
footer {
background-color: #000000;
color: white;
font-weight: 300;
width: 100%;
margin: 0 auto;
padding: 0 auto;
}
.footer-nav1 {
display: block;
padding: 0px 10px 0px 10px;
}
.footer-nav2 {
display: block;
padding: 0px 10px 15px 10px;
}
.footer-button {
font-size: 0.8rem;
color: rgba(255, 255, 255, 0.734);
text-align: left;
padding: 20px 20px;
font-weight: 300;
border-bottom: 1px solid rgba(255, 255, 255, 0.257);
}
.footer-button p {
padding: 3px 0px;
text-align: center;
}
.footer-button:hover {
color: white;
font-weight: 700;
}
.language-nav {
position: absolute;
margin-top: -240px;
margin-left: -5px;
margin-bottom: 100px;
}
.language {
display: block;
margin-left: 10px;
padding: 10px 20px;
color: #000000;
background-color: white;
}
.language:first-child {
border-radius: 4px 4px 0 0;
}
.language:last-child {
border-radius: 0 0 4px 4px;
}
.language:hover {
background-color: #e6eaec;
}
.arrow {
position: absolute;
width: 15px;
padding-left: 5px;
color: white;
display: inline-block;
}
.arrow:hover>.language-nav {
display: block;
}
.social-nav {
text-align: center;
padding-top: 10px;
padding-bottom: 10px;
}
.social-button {
color: #808080;
display: inline-block;
padding: 10px 20px;
box-sizing: border-box
}
.social-button:hover {
color: white;
font-weight: 700;
}
/* TABLET */
#media (min-width: 444px) {
.logo {
font-size: 2rem;
}
.search-box:hover>.search-txt {
width: 420px;
padding-left: 10px;
}
.nav-button-B {
display: inline-block;
padding: 7px 20px;
}
.nav-button-A {
border: none;
padding: 7px 15px 7px 5px;
}
main {
height: calc(100vh - 110px);
width: 100%;
margin: 0 auto;
display: flex;
justify-content: center;
align-items: center;
}
.wrapper {
padding: 0 40px;
box-sizing: border-box;
}
.wrapper h2 {
display: block;
}
.start-button {
margin-top: 70px;
}
.wrapper a {
font-size: 1.35rem;
font-weight: 700;
background-color: white;
padding: 18px 30px;
border-radius: 3px;
}
.footer {
margin: 0 auto;
padding: 0 auto;
}
.footer-nav1 {
display: flex;
justify-content: space-between;
border-bottom: 1px solid rgba(255, 255, 255, 0.257);
}
.footer-nav2 {
display: flex;
justify-content: space-between;
flex-wrap: wrap;
padding: 0px 10px 0px 10px;
}
.footer-button {
font-size: 0.85rem;
border-bottom: none;
}
.footer-nav2>.footer-button {
border-bottom: none;
padding: 20px 15px;
}
.footer-button p {
display: inline;
}
.language-nav {
position: absolute;
display: inline;
margin-top: -265px;
margin-left: -45px;
margin-bottom: 100px;
}
}
/* DESKTOP 1920x1080p */
#media (min-width: 1080px) {
nav {
width: 95%;
}
.search-box {
justify-content: center;
width: 85%;
margin-right: auto;
margin-left: auto;
}
.search-txt {
border-radius: 3px 0px 0px 3px;
border: none;
padding-left: 15px;
background: #ffffffbd;
outline: none;
color: #4e5052;
font-size: 12px;
transition: 0.1s;
line-height: 34px;
width: 1400px;
}
.search-icon {
display: none;
}
.search-box:hover>.search-txt {
display: inline-block;
width: 1400px;
padding-left: 15px;
}
main {
/* background-color: beige; */
height: calc(100vh - 60px);
width: 100%;
margin: 0 auto;
}
.wrapper {
padding: 0 600px;
box-sizing: border-box;
}
.wrapper h2 {
line-height: 2.1rem;
}
footer {
display: flex;
align-items: center;
justify-content: space-between;
min-height: 60px;
margin: 0 auto;
padding: 0 auto;
}
.footer-nav1 {
display: flex;
justify-content: space-between;
flex-grow: 2;
border-bottom: none;
}
.footer-nav2 {
display: flex;
justify-content: space-between;
flex-grow: 1;
align-items: center;
padding: 0 auto;
margin-left: 25px;
box-sizing: border-box;
}
.footer-nav2>.footer-button p:last-of-type {
display: none;
}
.footer-button {
padding: 5px 10px;
box-sizing: border-box;
}
.social-nav {
display: flex;
justify-content: space-between;
flex-grow: 1;
padding-left: 10px;
padding-right: 10px;
box-sizing: border-box;
}
.social-button {
font-size: 1.5rem;
color: #808080;
padding: 0 auto;
box-sizing: border-box;
}
.footer-nav2>.footer-button {
border-bottom: none;
padding: 20px 37px;
box-sizing: border-box;
}
.social-nav {
text-align: center;
max-width: 300px;
padding-top: 10px;
padding-bottom: 10px;
box-sizing: border-box;
}
.social-button {
color: #808080;
display: inline-block;
padding: 10px 20px;
box-sizing: border-box;
}
}
jquery-nav.js:
$(document).ready(function(){
$('.arrow').on('click', function(){
$('.language-nav').toggle();
})
});

You were exactly right! It was that English word causing problems... well not really the English word, it was the div surrounding it.
You have to close that div, from this:
<div class="footer-button">English
To this:
<div class="footer-button">English</div>

list has 8 items but the the last 4 items moves out from the blue background in testimonials-section

As i am running the html and css code the list of testimonials are 8 but , when i increased the size of the screen to 950px the list of 8 items start coming out of the background, so please can anyone give me the hint that where the code is wrong
const mobileBtn = document.getElementById('mobile-cta');
nav = document.querySelector('nav');
mobileBtnExit = document.getElementById('mobile-sta');
mobileBtn.addEventListener('click' , () => {
nav.classList.add('mobile-menu');
})
mobileBtnExit.addEventListener('click' , () => {
nav.classList.remove('mobile-menu');
})
:root {
--primary-color: #007af3;
}
body{
background: #F2F2F2;
margin: 0 ;
font-family: 'Poppins';
}
.navbar {
background: white;
padding: 1em;
.logo{
text-decoration: none;
font-weight: bold;
color: black ;
font-size: 1.2em;
span {
color: var(--primary-color);
}
}
nav{
display: none;
}
.container{
display: flex;
place-content: space-between;
}
.mobile-menu{
cursor: pointer;
}
}
a{
color: #444444;
}
ul {
list-style-type: none;
margin: 0;
padding: 0;
}
section{
padding: 5em 2em;
}
.hero{
text-align: center;
}
.left-col{
.subhead{
text-transform: uppercase;
font-weight: bold;
color: gray;
letter-spacing: .3em;
}
h1{
font-size: 2.5em;
line-height: 1.3em;
margin-top: .2em;
}
.primary-cta{
background: var(--primary-color);
color: white;
text-decoration: none;
padding: .6em 1.3em;
font-size: 1.4em;
border-radius: 5em;
font-weight: bold;
display: inline-block;
}
.watch-video-cta{
display: block;
margin-top: 1em;
img {
margin-right: .5em;
}
}
}
.hero-img{
width: 70% ;
margin-top: 3em;
}
section.features-section{
background: #20272e;
color: white;
}
ul.feature-list{
margin: 0;
padding-left: .1em;
display: grid;
grid-template-columns: repeat(auto-fit , minmax(19rem, 1fr));
li{
font-size: 1.1em;
margin-bottom: 1em;
margin-left: 2em;
position: relative;
&:before{
content: '';
left: -2em;
position: absolute;
width: 20px;
height: 20px;
background-image: url('../2021frontend/images/bullet.svg');
background-size: contain;
margin-right: .5em;
}
}
}
.features-section img{
display: none;
}
.testimonials-section{
background: var(--primary-color);
color: white;
li{
width: #006bd6;
text-align: center;
padding: 2em 1em;
width: 75%;
margin: 0 auto 5em auto;
border-radius: 1em;
img{
width: 5em;
height: 5em;
border: 5px solid #006bd6;
border-radius: 50%;
margin-top: -4.5em;
}
}
}
h2{
font-size: 2em;
}
label{
display: block;
font-size: 1.2em;
margin-bottom: .5em;
}
input, textarea{
width: 100%;
padding: .8em;
margin-bottom: 1em;
border-radius: .3em;
border: 1px solid gray;
box-sizing: border-box;
}
input[type="submit"]{
background-color: var(--primary-color);
color: white;
font-weight: bold;
font-size: 1.3em;
border: none;
margin-bottom: 5em;
border-radius: 5em;
display: inline-block;
padding: .8em 6.7em;
width: unset;
cursor: pointer;
}
iframe{
width: 100%;
height: 300px;
}
nav.mobile-menu{
display: block;
}
nav{
position: fixed;
z-index: 999;
width: 66%;
right: 0;
top: 0;
background: #20272e;
height: 100vh;
padding: 1em;
ul.primary-nav{
margin-top: 5em;
}
li{
a{
color:white;
text-decoration: none;
display: block;
padding: .5em;
font-size: 1.3em;
text-align: right;
&:hover{
font-weight: bold;
}
}
}
}
.mobile-mobile-closed {
float: right;
margin: .5em;
cursor: pointer;
}
//now here we desinging the pc version of the website
#media only screen and (min-width: 768px){
.mobile-menu, .mobile-menu-closed{
display: none;
}
.navbar .container{
display: grid;
grid-template-columns: 180px auto;
justify-content: unset;
}
.navbar nav{
display: flex;
justify-content: space-between;
background: none;
position: unset;
height: auto;
width: 100%;
padding: 0;
ul{
display: flex;
}
a{
color: black;
font-size: 1em;
padding: .1em 1em;
}
ul.primary-nav{
margin: 0;
}
li.current a{
font-weight: bold;
}
li.go-premium-cta a{
color: var(--primary-color);
border: 3px solid var(--primary-color);
font-weight: bold;
border-radius: 5em;
margin-top: -.2em;
&:hover{
background: var(--primary-color);
color: white;
}
}
}
}
#media only screen and (min-width: 950px) {
.container{
width: 950px;
margin: 0 auto;
}
section{
padding: 10em 4em;
}
.hero .container{
display: flex;
justify-content: space-between;
text-align: left;
.left-col{
margin: 3em 3em 0 5em;
h1 {
font-size: 3em;
width: 90%;
}
}
}
.hero-img{
width: 30%;
margin-right: 8em;
}
.hero-cta{
display: flex;
}
.primary-cta{
margin-right: 1em;
}
ul.features-list{
display: block;
margin-left: 5em;
li{
font-size: 1.4em;
&:before{
width: 30px;
height: 30px;
}
}
}
.features-section{
position: relative;
}
.features-section img{
display:block;
position: absolute;
right: 0;
width: 325px;
bottom: -6em;
height: 250px;
}
.testimonials-section ul{
display: flex;
li {
margin: 0 1em;
flex-basis: 33.333333%;
}
}
.contact-section{
position: relative;
display: flex;
}
.contact-right{
position: absolute;
right: 0;
top: 0;
width: 45%;
height: 100%;
iframe{
height: 100%;
}
}
}
//here we done the styling of 1220px and after
#media only screen and (min-width: 1220px){
.features-section{
&:before{
content: '';
position: absolute;
width: 10%;
height: 20em;
background: var(--primary-color);
left: 0;
top: -4em;
}
&:after{
content: '';
position: absolute;
width: 200px;
height: 18em;
background: url('../2021frontend/images/dots.svg') no-repeat;
top: -1em;
left: auto;
}
}
}
<div class="navbar"> <!-- here class is the name given to the div block so that the css identify it for styling it-->
<div class="container">
<a class="logo" href="#">Let's<span>Code</span></a>
<img id="mobile-cta" class="mobile-menu" src="2021frontend/images/menu.svg" alt="Open navigation">
<nav>
<img id="mobile-sta" class="mobile-menu-closed" src="2021frontend/images/exit.svg" alt="Closed navigation">
<ul class="primary-nav">
<li class="home">Home</li>
<li>Events</li>
<li>Registration</li>
</ul>
<ul class="secondary-nav">
<li>GrowYourMoney</li>
<li>Projects</li>
</ul>
</nav>
</div>
</div>
<section class="hero">
<div class="container">
<div class="left-col">
<p class="subhead">Share with the World & Grow with the World</p>
<h1>We are here to make the Future</h1>
<div class="hero-cta">
Click Here
<a href="#" class="watch-video-cta">
<img src="2021frontend/images/watch.svg" alt="Watch a video">Watch a Video
</a>
</div>
</div>
<img src="2021frontend/images/illustration.svg" class="hero-img" alt="illustration-images">
</div>
</section>
<section class="features-section">
<div class="container">
<ul class="feature-list">
<li>Full Stack Web Development</li>
<li>Full Stack Mobile App Development</li>
<li>Cloud tech</li>
<li>Devops</li>
<li>Web3 Development</li>
<li>Stock Market</li>
</ul>
<img src="2021frontend/images/holding-phone.jpg" alt="Man holding phone">
</div>
</section>
<section class="testimonials-section">
<div class="container">
<ul>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"has a strong hold in full stack web Development, leader of team antidote in sih prefinal round"</blockquote>
<cite>- saksham bansal</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"starting my journey as a full stack developer and interested in web3 domain"</blockquote>
<cite>- sayan halder</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"currently doing frontend development with bootstrap and loves playing football and cricket"</blockquote>
<cite>- varun sharma</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"currently learning web Development and see myself in future as a android developer "</blockquote>
<cite>- parth barara</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"iam the tomper of the class and likes chemistry very much"</blockquote>
<cite>- sakshi gupta</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"i dont know what i am doing but my boyfriend loves me very much"</blockquote>
<cite>- nandini gulati</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"same as nandini"</blockquote>
<cite>- kushi suri</cite>
</li>
<li>
<img src="2021frontend/images/person.jpg" alt="person">
<blockquote>"iam the don of kv, dont even try to fight with me in palam"</blockquote>
<cite>- sribash paul</cite>
</li>
</ul>
</div>
</section>
<br>
<section class="contact-section">
<div class="contact-left">
<h2>Contact</h2>
<form action="">
<label for="name">Name</label>
<input type="text" id="name" name="name" placeholder="Your Name"> <br>
<br>
<label for="email">Email</label>
<input type="email" id="email" name="email" placeholder="#email.com"> <br>
<br>
<label for="message">Message</label> <br>
<textarea name="message" id="message" cols="30" rows="10"></textarea> <br>
<br>
<input type="submit" class="send-message-cta" value="Send Message">
</form>
</div>
<div>
<div class="contact-right">
<iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d28026.467037845872!2d77.08443149999997!3d28.59052415000001!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x390d1b3f9902dce7%3A0xdf51d27e693abbea!2sPalam%2C%20New%20Delhi%2C%20Delhi!5e0!3m2!1sen!2sin!4v1649777392215!5m2!1sen!2sin" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
</div>
</div>
<img src="2021frontend/images/" alt="">
</section>

By default display: flex; will try and put everything onto one row. Where you have .testimonials-section ul { in your 950px breakpoint add flex-wrap: wrap;
One thing to note, and I may be mistaken here, is that flex-basis doesn't take margins into consideration, so you will find that your testimonials will be 2 per row instead of 3 because of the horizontal margins you've set. You can fix this by change flex-basis: 33.3333% to flex-basis: calc(33.3333% - 2em);

Moving a button in the navbar, best Practices?

I have shifted my CTA "subscribe" button in the navbar to the far right using margin. But I am wondering if there is a better way to write this code-wise?
Prior to using the margin, I couldn't get the button to move at all, it was originally located beside the other navbar link items.
I have attached the code I am using below.
* {
text-decoration: none;
}
body {
background-color: #f3f3f3;
}
header {
background-color: #fff;
width: 100%;
height: 100%;
display: block
}
.header-logo img {
height:150px;
margin-top: 10px;
float: left;
margin-right: 5px;
}
header nav ul {
display: block;
margin: 0 auto;
width: fit-content;
padding-top: 50px;
}
header nav ul li {
display: inline-flex;
float: left;
list-style: none;
padding: 0px 15px;
}
header nav ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-transform: uppercase;
}
.sub {
margin: 0px 1300px;
float: right;
height: auto;
position: relative;
z-index: 1000;
}
ul li a:hover {
color: firebrick;
}
#media only screen and (min-width: 1000px){
header .header-logo {
float: left;
padding: 15px 15px;
height: 0px;
max-width: 220px;
display: table;
}
header nav ul {
margin: 20px 0px 0px 20px;
float: left;
}
header nav ul li a {
line-height: 50px;
}
header .sub {
display: block;
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-transform: uppercase;
line-height: 40px;
border: 2px solid #111;
float: right;
margin-right: 40px;
margin-top: 5px;
padding: 0 20px;
}
}
/*INDEX*/
.index-banner {
margin: 0 auto;
width: 100%;
height:calc(100vh - 100px);
background-image: url('img/road_trip.jpg');
background-repeat: no-repeat;
background-position: center;
background-size: cover;
display: table;
}
.index-banner h1 {
font-family:'Karma', serif;
font-size: 60px;
font-weight: 100;
line-height: 70px;
color: #fff;
text-align: center;
text-shadow: 2px 2px 8px #111;
}
.verticial-center {
margin: 0 auto;
display: table-cell;
vertical-align: middle;
}
.footer {
font-family:'Sorts Mill Goudy', serif;
font-size: 16px;
color: #111;
margin: 0px 330px;
padding: 15px;;
}
.hero-section {
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
}
.hero-section {
font-family:'Karma', serif;
font-size: 40px;
color: #111;
text-align: center;
padding: 25px;
}
.hero-paragraph {
margin: 0 auto;
width: 1895px;
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-align: center;
padding: 25px;
}
#media only screen and (min-width: 1000px){
.wrapper {
width: 2000px;
margin:0 auto;
}
.index-banner {
height:500px;
}
.hero-paragraph {
width: 2000px;
margin:0 auto;
}
.hero-section {
width: 2000px;
margin:0 auto;
}
}
/* FOOTER*/
footer {
width: calc(100% - 80px);
padding: 40px 40px;
margin-top: 20px;
background-color: #111;
overflow: hidden;
}
footer ul {
width: fit-content;
float: left;
padding-left: 20px;
}
footer ul li {
display: block;
list-style: none;
}
footer ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 18px;
color: #fff;
line-height: 40px;
}
.footer-sm {
width: 50px;
float: right;
}
.footer-sm img {
width: 100%;
margin-bottom: 10px;
display: block;
}
#media only screen and (min-width: 1000px){
footer ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 18px;
color: #fff;
line-height: 40px;
}
}
</head>
<body>
<header>
<div class="header-logo">
<img src="img/Milestonehackers.jpg" alt="Milestonehackers logo">
</div>
<nav>
<ul>
<li>Home</li>
<li>Podcast</li>
<li>Newsletter</li>
<li>Blog</li>
<li>Contact</li>
<div class="sub">
<li>Subscribe</li>
</div>
</ul>
</nav>
</header>
<main>
<section class="index-banner">
<div class="verticial-center">
<h1>Milestonehackers Podcast & Newsletter</h1>
</div>
</section>
<div class="wrapper">
<section class="hero-section">
<h2>What Can you Expect From our Podcast</h2>
<p class="hero-paragraph">A host (meee, Paolo) interviewing various types of entrepreneurs or founders both technical and non-technical. Each entrepreneur has their own unique story that resulted in learning or experiencing something that can benefit our audience who may want to go down the entrepreneurial path!</p>
</section>
</div>
</main>
<div class="wrapper">
<footer>
<ul>
<li>Home</li>
<li>Podcast</li>
<li>Newsletter</li>
<li>Blog</li>
<li>Contact</li>
</ul>
<div class="footer-sm">
<a href="https://twitter.com/Milestonehacker">
<img src="img/twitter.png" alt="twiiter icon">
<a href="https://open.spotify.com/show/2ZiIxv5Mr83seTtNsg3LD9">
<img src="img/spotify.png" alt="spotify icon">
<img src="img/rss.png" alt="rss icon">
</a>
</div>
<p class="footer">Copyright © 2019; All Rights Reserved</p>
</footer>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-analytics.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-database.js"></script>
<script src="app.js"></script>
</div>
</body>
</html>

You can achieve that by removing float from ul element and add display flex. Also, remove float and margin from .sub element. Then by adding margin-left: auto to .sub the element will move to the far right.
One more note: your hero-section and some other elements have a width of 2000px which is not ideal for many screens. You can add max-width: 100% so it fits the screen if it is bigger than the screen.
See this code:
* {
text-decoration: none;
}
body {
background-color: #f3f3f3;
}
header {
background-color: #fff;
width: 100%;
height: 100%;
display: block
}
.header-logo img {
height:150px;
margin-top: 10px;
float: left;
margin-right: 5px;
}
header nav ul {
display: block;
margin: 0 auto;
width: 100%;
padding-top: 50px;
padding: 0;
}
header nav ul li {
display: inline-flex;
float: left;
list-style: none;
padding: 0px 15px;
}
header nav ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-transform: uppercase;
}
.sub {
/* Add margin-left: auto */
margin-left: auto;
/* float: right;*/
height: auto;
position: relative;
z-index: 1000;
}
ul li a:hover {
color: firebrick;
}
#media only screen and (min-width: 1000px){
header .header-logo {
float: left;
padding: 15px 15px;
height: 0px;
max-width: 220px;
display: table;
}
header nav ul {
margin: 20px 0px 0px 20px;
float: left;
}
header nav ul li a {
line-height: 50px;
}
header .sub {
display: block;
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-transform: uppercase;
line-height: 40px;
border: 2px solid #111;
float: right;
margin-right: 40px;
margin-top: 5px;
padding: 0 20px;
}
}
/*INDEX*/
.index-banner {
margin: 0 auto;
width: 100%;
height:calc(100vh - 100px);
background-image: url('img/road_trip.jpg');
background-repeat: no-repeat;
background-position: center;
background-size: cover;
display: table;
}
.index-banner h1 {
font-family:'Karma', serif;
font-size: 60px;
font-weight: 100;
line-height: 70px;
color: #fff;
text-align: center;
text-shadow: 2px 2px 8px #111;
}
.verticial-center {
margin: 0 auto;
display: table-cell;
vertical-align: middle;
}
.footer {
font-family:'Sorts Mill Goudy', serif;
font-size: 16px;
color: #111;
margin: 0px 330px;
padding: 15px;;
}
.hero-section {
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
}
.hero-section {
font-family:'Karma', serif;
font-size: 40px;
color: #111;
text-align: center;
padding: 25px;
}
.hero-paragraph {
margin: 0 auto;
width: 1895px;
font-family:'Sorts Mill Goudy', serif;
font-size: 24px;
color: #111;
text-align: center;
padding: 25px;
}
#media only screen and (min-width: 1000px){
.wrapper {
width: 2000px;
margin:0 auto;
}
.index-banner {
height:500px;
}
.hero-paragraph {
width: 2000px;
margin:0 auto;
}
.hero-section {
width: 2000px;
margin:0 auto;
}
}
/* FOOTER*/
footer {
width: calc(100% - 80px);
padding: 40px 40px;
margin-top: 20px;
background-color: #111;
overflow: hidden;
}
footer ul {
width: fit-content;
float: left;
padding-left: 20px;
}
footer ul li {
display: block;
list-style: none;
}
footer ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 18px;
color: #fff;
line-height: 40px;
}
.footer-sm {
width: 50px;
float: right;
}
.footer-sm img {
width: 100%;
margin-bottom: 10px;
display: block;
}
#media only screen and (min-width: 1000px){
footer ul li a {
font-family:'Sorts Mill Goudy', serif;
font-size: 18px;
color: #fff;
line-height: 40px;
}
}
<body>
<header>
<div class="header-logo">
<img src="img/Milestonehackers.jpg" alt="Milestonehackers logo">
</div>
<nav>
<ul>
<li>Home</li>
<li>Podcast</li>
<li>Newsletter</li>
<li>Blog</li>
<li>Contact</li>
<div class="sub">
<li>Subscribe</li>
</div>
</ul>
</nav>
</header>
<main>
<section class="index-banner">
<div class="verticial-center">
<h1>Milestonehackers Podcast & Newsletter</h1>
</div>
</section>
<div class="wrapper">
<section class="hero-section">
<h2>What Can you Expect From our Podcast</h2>
<p class="hero-paragraph">A host (meee, Paolo) interviewing various types of entrepreneurs or founders both technical and non-technical. Each entrepreneur has their own unique story that resulted in learning or experiencing something that can benefit our audience who may want to go down the entrepreneurial path!</p>
</section>
</div>
</main>
<div class="wrapper">
<footer>
<ul>
<li>Home</li>
<li>Podcast</li>
<li>Newsletter</li>
<li>Blog</li>
<li>Contact</li>
</ul>
<div class="footer-sm">
<a href="https://twitter.com/Milestonehacker">
<img src="img/twitter.png" alt="twiiter icon">
<a href="https://open.spotify.com/show/2ZiIxv5Mr83seTtNsg3LD9">
<img src="img/spotify.png" alt="spotify icon">
<img src="img/rss.png" alt="rss icon">
</a>
</div>
<p class="footer">Copyright © 2019; All Rights Reserved</p>
</footer>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-analytics.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.2.1/firebase-database.js"></script>
<script src="app.js"></script>
</div>

Why Does My slideToggle Have A Strange Jump Glitch?

I created a slideToggle menu that for some reason seems to jump around when it slides up and down. The border bottom of the sliding header just flies around and glitches when the menu slides up and down, but otherwise the slideToggle works fine.
I've tried setting the position of the .headermenu to relative as well as hiding the overflow, but neither of these seemed to have fixed the issue. Does slide toggle just not work properly with a border bottom or is the issue in my code?
The glitch is difficult to explain, but the glitch shows in my code snippet, so I suggest you view it to get an understanding of what's happening. Basically the border bottom is bouncing around when the menu slides down.
In order to activate the drop down header you have to click the little broken image in the corner, which will activate the menu (so you can see the glitch in action.)
Is it related to some sort of start height for the animation? Do I need the animation to start at a specific point in the page or is it something else entirely?
$(document).ready(function(){
$("button").click(function(){
$(".headermenu").slideToggle();
$(".headermenu").height('150')
});
});
* {
box-sizing: border-box;
}
#font-face {
font-family: 'monaco';
src: url('monaco-webfont.woff2') format('woff2'),
url('monaco-webfont.woff') format('woff');
font-weight: normal;
font-style: normal;
}
a {
font-family: 'monaco';
font-size: 16px;
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
a:visited {
color: blue;
}
body {
margin: 0px;
}
button {
background: none;
border: none;
float: right;
margin-right: 40px;
margin-top: 15px;
padding: 0px;
}
#hamburger {
padding-top: 2px;
width: 27px;
}
header {
background-color: blue;
border-bottom: solid white 1px;
color: white;
float: left;
height: 60px;
padding-top: 4px;
position: fixed;
width: 100%;
z-index: 150px;
}
.headermenu {
background-color: blue;
border-bottom: solid white 1px;
color: white;
display: none;
font-family: 'monaco';
height: 200px;
overflow: hidden;
padding-top: 40px;
position: relative;
width: 100%;
/*-webkit-transition: all .5s;
transition: all .5s;
height: 0;*/
}
.headermenu a {
color: white;
float: right;
padding-right: 40px;
text-decoration: none;
}
.headermenu a:hover {
text-decoration: underline;
}
.headermenu a:visited {
color: white;
}
#headermenuleft {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuleft ul {
list-style-type: none;
}
#headermenuright {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuright ul {
list-style-type: none;
}
<!DOCTYPE HTML>
<html>
<head>
<link href="css/main.css" rel="stylesheet"/>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script>
<script src="js/main.js"></script>
<title>Why Have There Been No Great Women Artists?</title>
</head>
<body>
<header>
<button><img id="hamburger" src="images/Menu,_Web_Fundamentals_(White).svg.png"></button>
<a id="home" href="index.html">Why Have There Been No Great Women Artists?</a>
<div class="headermenu">
<div id="headermenuleft">
<ul>
<li>Georgia O'Keeffe</li>
<li>Frida Kahlo</li>
<li>Artemisia Gentileschi</li>
</ul>
</div>
<div id="headermenuright">
<ul>
<li>The Essay</li>
<li>Judy Chicago</li>
<li>Kara Walker</li>
<li>Ana Mendieta</li>
</ul>
</div>
</div>
</header>
</body>
</html>

$(document).ready(function () {
$("button").click(function () {
$(".headermenu").slideToggle('slow', function () {
$(this).height('150');
});
});
});
* {
box-sizing: border-box;
}
#font-face {
font-family: 'monaco';
src: url('monaco-webfont.woff2') format('woff2'),
url('monaco-webfont.woff') format('woff');
font-weight: normal;
font-style: normal;
}
a {
font-family: 'monaco';
font-size: 16px;
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
a:visited {
color: blue;
}
body {
margin: 0px;
}
button {
background: none;
border: none;
float: right;
margin-right: 40px;
margin-top: 15px;
padding: 0px;
}
#essay {
background-color: white;
height: 400px;
padding-top: 60px;
width: 100%;
}
#essaytext {
width: 830px;
margin: auto;
padding-top: 30px;
}
#gallery {
background-color: blue;
height: 1000px;
width: 100%;
}
#gallery a{
color: white;
}
#gallery h2 {
color: white;
font-size: 28px;
}
#gallerytext {
margin: auto;
padding-bottom: 50px;
padding-top: 50px;
width: 830px;
}
#grid {
margin: auto;
padding-top: 30px;
width: 830px;
}
#gridone {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridtwo {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridthree {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridfour {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridfive {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridsix {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#hamburger {
padding-top: 2px;
width: 27px;
}
header {
background-color: blue;
border-bottom: solid white 1px;
color: white;
float: left;
padding-top: 4px;
position: fixed;
width: 100%;
z-index: 150;
}
header > div:first-child
{
height: 60px;
}
.headermenu {
background-color: blue;
border-bottom: solid white 1px;
color: white;
display: none;
font-family: 'monaco';
height: 200px;
overflow: hidden;
padding-top: 40px;
position: relative;
width: 100%;
/*-webkit-transition: all .5s;
transition: all .5s;
height: 0;*/
}
.headermenu a {
color: white;
float: right;
padding-right: 40px;
text-decoration: none;
}
.headermenu a:hover {
text-decoration: underline;
}
.headermenu a:visited {
color: white;
}
#headermenuleft {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuleft ul {
list-style-type: none;
}
#headermenuright {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuright ul {
list-style-type: none;
}
#home {
color: white;
display: block;
font-family: 'monaco';
font-size: 16px;
padding-left: 40px;
padding-right: 0px;
padding-top: 17px;
margin: auto;
}
h2 {
color: blue;
font-family: 'monaco';
font-size: 28px;
font-weight: normal;
}
nav#mobile-nav {
display: none;
z-index: 100;
width: 100%;
}
p {
font-family: 'monaco';
font-size: 16px;
line-height: 21px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
<div>
<button><img id="hamburger" src="https://upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Menu,_Web_Fundamentals.svg/2000px-Menu,_Web_Fundamentals.svg.png"></button>
<a id="home" href="index.html">Why Have There Been No Great Women Artists?</a>
</div>
<div class="headermenu">
<div id="headermenuleft">
<ul>
<li>Georgia O'Keeffe</li>
<li>Frida Kahlo</li>
<li>Artemisia Gentileschi</li>
</ul>
</div>
<div id="headermenuright">
<ul>
<li>The Essay</li>
<li>Judy Chicago</li>
<li>Kara Walker</li>
<li>Ana Mendieta</li>
</ul>
</div>
</div>
</header>
<div id="essay">
<div id="essaytext">
<h2>The Essay</h2>
<p>“Why Have There Been No Great Women Artists?” is an essay by Linda Nochlin that details how centuries of oppression and misogyny has led to a male dominated art world. Nochlin explains through her essay how sexism has prevented women from fully being recognized as historically significant artists.</p>
Read The Essay →
</div>
</div>
<div id="gallery">
<div id="gallerytext">
<h2>The Gallery</h2>
<p>This website is intended to shed a light on the many incredible women in art who have been overshadowed due to their gender. By viewing the gallery you can see the incredible works of women artists whose significant contributions to the art world have been cast aside because of their womanhood.</p>
<div id="grid">
<a href="./judy.html">
<div id="gridone">
"The Dinner Party"<br>
Judy Chicago
</div>
</a>
<a href="./kara.html">
<div id="gridtwo">
"A Subtlety"<br>
Kara Walker
</div>
</a>
<a href="./mendieta.html">
<div id="gridthree">
"Alma Silueta en Fuego"<br>
Ana Mendieta
</div>
</a>
<a href="./georgia.html">
<div id="gridfour">
"Black Iris"<br>
Georgia O'Keeffe
</div>
</a>
<a href="./frida.html">
<div id="gridfive">
"The Two Fridas"<br>
Frida Kahlo
</div>
</a>
<a href="./artemesia.html">
<div id="gridsix">
"Judith Slaying Holofernes"<br>
Artemisia Gentileschi
</div>
</a>
</div>
</div>
</div>

The problem is you have a white bottom border in .headermenu. If you remove that that fixes the problem.
There are other issues however, you are using pixels in the z-index, when that parameter only accepts a number.
Also, it doesn't look to me like you need $(".headermenu").height('150');. If you do, then it should be $(".headermenu").height(150); - without the quote around the number of pixels.
EDIT
It appears you need to add top: 6px; to .headermenu (at least to look correct to me in Firefox). I can't tell you why exactly, but it appears to be to do with the hamburger button being floated and not taking up enough vertical height (padding/margin).
$(document).ready(function(){
$("button").click(function(){
$(".headermenu").slideToggle();
});
});
* {
box-sizing: border-box;
}
#font-face {
font-family: 'monaco';
src: url('monaco-webfont.woff2') format('woff2'),
url('monaco-webfont.woff') format('woff');
font-weight: normal;
font-style: normal;
}
a {
font-family: 'monaco';
font-size: 16px;
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
a:visited {
color: blue;
}
body {
margin: 0px;
}
button {
background: none;
border: none;
float: right;
margin-right: 40px;
margin-top: 15px;
padding: 0px;
}
#essay {
background-color: white;
height: 400px;
padding-top: 60px;
width: 100%;
}
#essaytext {
width: 830px;
margin: auto;
padding-top: 30px;
}
#gallery {
background-color: blue;
height: 1000px;
width: 100%;
}
#gallery a{
color: white;
}
#gallery h2 {
color: white;
font-size: 28px;
}
#gallerytext {
margin: auto;
padding-bottom: 50px;
padding-top: 50px;
width: 830px;
}
#grid {
margin: auto;
padding-top: 30px;
width: 830px;
}
#gridone {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridtwo {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridthree {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridfour {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridfive {
background-color: white;
color: blue;
display: block;
float: right;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#gridsix {
background-color: white;
color: blue;
display: block;
float: left;
height: 200px;
margin-top: 30px;
padding-top: 20px;
padding-left: 25px;
width: 400px;
}
#hamburger {
padding-top: 2px;
width: 27px;
}
header {
background-color: blue;
border-bottom: solid red 1px;
color: white;
float: left;
height: 60px;
padding-top: 4px;
position: fixed;
width: 100%;
z-index: 150;
}
.headermenu {
background-color: green;
border-bottom: solid red 1px;
color: white;
display: none;
font-family: 'monaco';
height: 200px;
overflow: hidden;
padding-top: 60px;
position: relative;
width: 100%;
top: 6px;
/*-webkit-transition: all .5s;
transition: all .5s;
height: 0;*/
z-index: 200;
}
.headermenu a {
color: white;
float: right;
padding-right: 40px;
text-decoration: none;
}
.headermenu a:hover {
text-decoration: underline;
}
.headermenu a:visited {
color: white;
}
#headermenuleft {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuleft ul {
list-style-type: none;
}
#headermenuright {
float: right;
line-height: 25px;
text-align: left;
}
#headermenuright ul {
list-style-type: none;
}
#home {
color: white;
display: block;
font-family: 'monaco';
font-size: 16px;
padding-left: 40px;
padding-right: 0px;
padding-top: 17px;
margin: auto;
}
h2 {
color: blue;
font-family: 'monaco';
font-size: 28px;
font-weight: normal;
}
nav#mobile-nav {
display: none;
z-index: 100;
width: 100%;
}
p {
font-family: 'monaco';
font-size: 16px;
line-height: 21px;
}
<!DOCTYPE HTML>
<html>
<head>
<link href="css/main.css" rel="stylesheet"/>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script>
<script src="js/main.js"></script>
<title>Why Have There Been No Great Women Artists?</title>
</head>
<body>
<header>
<button><img id="hamburger" src="images/Menu,_Web_Fundamentals_(White).svg.png"></button>
<a id="home" href="index.html">Why Have There Been No Great Women Artists?</a>
<div class="headermenu">
<div id="headermenuleft">
<ul>
<li>Georgia O'Keeffe</li>
<li>Frida Kahlo</li>
<li>Artemisia Gentileschi</li>
</ul>
</div>
<div id="headermenuright">
<ul>
<li>The Essay</li>
<li>Judy Chicago</li>
<li>Kara Walker</li>
<li>Ana Mendieta</li>
</ul>
</div>
</div>
</header>
</body>
</html>

HTML/CSS Jquery hover not showing up

I am new to Jquery and
I am trying to make a dropdown on my navigation using simple Jquery hover effect, and I think I am using wrong selector on Jquery.
I would like to see the dropdown and be able to navigate when i hover over 'What's New'
Any help would be awesome. Thanks,
See ATTACHED IMG
$(document).ready(function () {
$("li .nav-level-1").hover(
function () {
$('.nav-level-2').slideDown('200');
},
function () {
$('.nav-level-2').slideUp('200');
}
);
});
.main-nav {
background: #000;
height: 30px;
position: relative;
overflow: visible;
z-index: 2;
width: 100%;
left: 0;
cursor: default;
}
.main-nav .inner{
height: 100%;
}
.main-nav>.inner{
text-align: justify;
}
.nav-links-container {
position: static;
/* background: red; */
height: 100%;
}
.nav-links{
padding: 0 0 0 3px;
display: inline;
margin-bottom: 20px;
overflow: hidden;
/*background-color: green; */
}
li {
vertical-align: top;
padding: 5px;
display: inline-block;
/* background: blue; */
}
li>a {
color: #FFF;
font-size: 12px;
letter-spacing: 1px;
text-transform: uppercase;
padding: 10px 9px 9px;
margin: 0 -3px;
}
li>a:hover {
background-color: white;
color:#000;
}
.nav-level-2 {
visibility: hidden;
position: absolute;
top: 30px;
left: 0;
width: 100%;
height: auto;
border-bottom: 5px solid #000;
background: red;
text-align: left;
}
.nav-level-2-container {
padding-top: 40px;
padding-bottom: 40px;
-ms-flex: 0px 1px auto;
-webkit-box-flex: 0;
-webkit-flex: 0px 1px auto;
flex: 0px 1px auto;
}
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
<nav class="main-nav">
<div class="inner max-girdle-width">
<div class="nav-links-container">
<ul class="nav-links">
<li class="nav-whats-new"> <a class="nav-level-1" href="#">What's New</a>
<div class="nav-level-2">
<div class="nav-level-2-container row max-girdle-width">
<div>Submenu </div>
</div>
</div>
</li>
</ul>
</div>
</div>
</nav>

You should use a nested ul for your dropdown menu. You don't need jQuery at all for this. It can all be done with CSS. Take a look at this simple hover effect under the Products tab.
Codepen
HTML
<header class="navbar">
<div class="container">
<ul class="menu">
<li>Home</li>
<li>About</li>
<li>
Products
<ul>
<li>Cars
<ul>
<li>Ford</li>
<li>Chevy</li>
<li>Toyota</li>
</ul>
</li>
<li>Trucks</li>
<li>Vans</li>
<li>SUVs</li>
</ul>
</li>
<li>Services</li>
<li>Contact</li>
</ul>
</div>
</header>
CSS
header {
width: 100%;
height: 50px;
margin: 0;
padding: 0;
background-color: #2EBAE8;
}
.container {
width: 100%;
max-width: 1040px;
margin: 0 auto;
}
ul {
float: left;
list-style-type: none;
margin: 0;
padding: 0;
}
ul ul {
width: 200px;
background-color: #046382;
display: none;
position: absolute;
top: 100%;
left: 0;
float: none;
}
ul ul ul {
top: 0;
left: 100%;
}
ul ul li {
float: none;
}
ul li {
float: left;
padding: 0 10px;
position: relative;
}
ul li:hover > ul {
display: block;
}
ul a {
display: block;
text-decoration: none;
color: white;
line-height: 50px;
transition: color 0.5s;
}
ul a:hover {
color: #E82E82;
}

Your submenu is hidden with visibility: hidden style.
I also separated the handled so that the menu doesn't hide while you're hovering it, and added finish() so that we're not queueing animations.
But yeah, like ncox85 said you should do this with css.
$(document).ready(function () {
$('.nav-level-2').hide();
$("li .nav-level-1").mouseenter(
function () {
$('.nav-level-2').finish().slideDown('200');
}
);
$("li .nav-level-2").mouseleave(
function () {
$('.nav-level-2').finish().slideUp('200');
});
});
.main-nav {
background: #000;
height: 30px;
position: relative;
overflow: visible;
z-index: 2;
width: 100%;
left: 0;
cursor: default;
}
.main-nav .inner{
height: 100%;
}
.main-nav>.inner{
text-align: justify;
}
.nav-links-container {
position: static;
/* background: red; */
height: 100%;
}
.nav-links{
padding: 0 0 0 3px;
display: inline;
margin-bottom: 20px;
overflow: hidden;
/*background-color: green; */
}
li {
vertical-align: top;
padding: 5px;
display: inline-block;
/* background: blue; */
}
li>a {
color: #FFF;
font-size: 12px;
letter-spacing: 1px;
text-transform: uppercase;
padding: 10px 9px 9px;
margin: 0 -3px;
}
li>a:hover {
background-color: white;
color:#000;
}
.nav-level-2 {
position: absolute;
top: 30px;
left: 0;
width: 100%;
height: auto;
border-bottom: 5px solid #000;
background: red;
text-align: left;
}
.nav-level-2-container {
padding-top: 40px;
padding-bottom: 40px;
-ms-flex: 0px 1px auto;
-webkit-box-flex: 0;
-webkit-flex: 0px 1px auto;
flex: 0px 1px auto;
}
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.1/jquery.min.js"></script>
<nav class="main-nav">
<div class="inner max-girdle-width">
<div class="nav-links-container">
<ul class="nav-links">
<li class="nav-whats-new"> <a class="nav-level-1" href="#">What's New</a>
<div class="nav-level-2">
<div class="nav-level-2-container row max-girdle-width">
<div>Submenu </div>
</div>
</div>
</li>
</ul>
</div>
</div>
</nav>

Just use display:none instead of visibility:hidden on class .nav-level-2

If any of you are wondering, I got a good result from just using html/css, got rid of jquery.
Maybe I will use jquery another time. fun lesson for myself and those of you out there. Thanks guys
.main-nav {
background: #000;
height: 30px;
position: relative;
overflow: visible;
z-index: 2;
width: 100%;
left: 0;
cursor: default;
}
.main-nav .inner{
height: 100%;
}
.main-nav>.inner{
text-align: justify;
}
.nav-links-container {
position: static;
/* background: red; */
height: 100%;
}
.nav-links{
padding: 0 0 0 3px;
display: inline;
margin-bottom: 20px;
overflow: hidden;
/*background-color: green; */
}
li {
vertical-align: top;
padding: 5px;
display: inline-block;
/* background: blue; */
}
li>a {
color: #FFF;
font-size: 12px;
letter-spacing: 1px;
text-transform: uppercase;
padding: 10px 9px 9px;
margin: 0 -3px;
}
li>a:hover {
background-color: white;
color:#000;
}
.nav-level-2 {
display: none;
position: absolute;
top: 30px;
left: 0;
width: 100%;
height: auto;
border-bottom: 5px solid #000;
background: red;
text-align: left;
}
.nav-level-2-container {
padding-top: 40px;
padding-bottom: 40px;
-ms-flex: 0px 1px auto;
-webkit-box-flex: 0;
-webkit-flex: 0px 1px auto;
flex: 0px 1px auto;
}
li>a:hover + .nav-level-2{
display: block;
}
.nav-level-2:hover {
display: block;
}
<nav class="main-nav">
<div class="inner max-girdle-width">
<div class="nav-links-container">
<ul class="nav-links">
<li class="nav-whats-new"> <a class="nav-level-1" href="#">What's New</a>
<div class="nav-level-2">
<div class="nav-level-2-container row max-girdle-width">
<div>Submenu </div>
</div>
</div>
</li>
</ul>
</div>
</div>
</nav>