Navbar overflows when emulating from phone

Mobile menu should not be visible and it should not overflow when used from phone. When I just decrease the browser on the computer it works as intended. Here is my code. HTML:

document.addEventListener('DOMContentLoaded', function () {
    const toggleButton = document.querySelector('.navbar .mobile-menu-toggle');
    const mobileMenu = document.querySelector('.navbar .mobile-menu-items');

    toggleButton.addEventListener('click', function () {
        mobileMenu.classList.toggle('active');
    })
})

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Poppins', sans-serif;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: #333;
}

li {
  list-style: none;
}

img {
  max-width: 100%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.navbar {
  background-color: lightblue;
  padding: 1rem 2rem;
  height: 80px;
}

.navbar .logo {
  width: 50px;
}

.navbar-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar .main-menu-list {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.navbar a:hover {
  color: blue;
}

/* Mobile Menu */

.navbar .mobile-menu-items {
  position: absolute;
  top: 80px;
  bottom: 0;
  left: 0;
  width: 100%;
  background: rgba(154, 192, 204, 0.5);
  text-align: center;
  transition: transform 0.3s ease;
  transform: translateX(100%);
}

.navbar .mobile-menu-list {
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 100%;
  padding-top: 300px;
  gap: 2rem;
  font-size: 1.2rem;
}

.navbar .mobile-menu-toggle {
  cursor: pointer;
}

.navbar .mobile-menu-items.active {
  transform: translateX(0);
}

.navbar .mobile-menu {
  display: none;
}

@media (max-width: 768px) {
  .navbar .main-menu {
    display: none;
  }

  .navbar .mobile-menu {


    display: block;
  }
}

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="preconnect" href="https://fonts.googleapis.com" />
    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
    <link
      href="https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&display=swap"
      rel="stylesheet" />
    <link
      rel="stylesheet"
      href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css"
      integrity="sha512-DTOQO9RWCH3ppGqcWaEA1BIZOC6xxalwEsw9c2QQeAIftl+Vegovlnee1c9QX4TctnWMn13TZye+giMm8e2LwA=="
      crossorigin="anonymous"
      referrerpolicy="no-referrer" />
    <link rel="stylesheet" href="styles.css" />
    <title>HTML & CSS Sandbox</title>
  </head>
  <body>
    <nav class="navbar">
      <div class="container navbar-flex">
        <img src="./logo.png" alt="Traversy Media" class="logo" />
        <div class="main-menu">
          <ul class="main-menu-list">
            <li>
              <a href="#">Home</a>
            </li>
            <li>
              <a href="#">About</a>
            </li>
            <li>
              <a href="#">Services</a>
            </li>
            <li>
              <a href="#">Blog</a>
            </li>
            <li>
              <a href="#">Contact</a>
            </li>
          </ul>
        </div>
        <!-- Mobile Menu -->
        <div class="mobile-menu">
          <div class="mobile-menu-toggle">
            <i class="fas fa-bars fa-2x"></i>
          </div>
          <div class="mobile-menu-items">
            <ul class="mobile-menu-list">
              <li>
                <a href="#">Home</a>
              </li>
              <li>
                <a href="#">About</a>
              </li>
              <li>
                <a href="#">Services</a>
              </li>
              <li>
                <a href="#">Blog</a>
              </li>
              <li>
                <a href="#">Contact</a>
              </li>
            </ul>
          </div>
        </div>
      </div>
    </nav>
    <script src="./script.js"></script>
  </body>
</html>

When I open inspect element in browser(I tried it in Chrome and Firefox as well as with browserstack app) it overflows and I can see mobile menu when I should not.

Solution

You forgot to add position: relative to the .navbar element. Without it, the absolute positioned menu items can overflow outside the navbar, causing layout issues.

Also, don’t forget to add overflow-x: hidden to the html tag, to prevent horizontal scrolling caused by off-screen elements.

Here’s how you can fix it:

/* add this new props */
html {
    overflow-x: hidden; 
}

.navbar {
    background-color: lightblue;
    padding: 1rem 2rem;
    height: 80px;
    
    /* and add code below */
    position: relative;
}

Update Solution

base on your issue on comment, that code above will totally remove the mobile menu. so the solution is to remove

html{
    overflow-x: hidden
}

and use this instead

.navbar {
    background-color: lightblue;
    padding: 1rem 2rem;
    height: 80px;
    /* add these 2 code below */
    position: relative;
    overflow-x: clip;
}

I also make your navbar more clean and beauty by adjust some padding and height. so you could use this full code instead (don't worry, I add comment to make sure you know what changes I made)

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: #333;
}

li {
    list-style: none;
}

img {
    max-width: 100%;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.navbar {
    background-color: lightblue;
    padding: 1rem 2rem;
    height: 80px;
    /* add these 2 code below */
    position: relative;
    overflow-x: clip;
}

.navbar .logo {
    width: 50px;
}

.navbar-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar .main-menu-list {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.navbar a:hover {
    color: blue;
}

/* Mobile Menu */

.navbar .mobile-menu-items {
    position: absolute;
    top: 80px;
    bottom: 0;
    left: 0;
    width: 100%;
    background: rgba(154, 192, 204, 0.5);
    text-align: center;
    transition: transform 0.3s ease;
    transform: translateX(100%);
    /* add these 2 props bellow */
    height: fit-content;
    padding-block: 25px;
}

.navbar .mobile-menu-list {
    display: flex;
    flex-direction: column;
    align-items: center;
    height: 100%;
    /* padding-top: 300px; comment this code */
    gap: 2rem;
    font-size: 1.2rem;
}

.navbar .mobile-menu-toggle {
    cursor: pointer;
}

.navbar .mobile-menu-items.active {
    transform: translateX(0);
}

.navbar .mobile-menu {
    display: none;
}

@media (max-width: 768px) {
    .navbar .main-menu {
        display: none;
    }

    .navbar .mobile-menu {


        display: block;
    }
}