Menu isn´t responsive

October 28, 2022

I want to make my menu responsive and I found some info on w3school, but I probably made an error. Can you help me with that please? Thanks very much! I am a begginer codes.
If I tried to make the navigation responsive I edited the CSS code and it made the navigation not hidden and the responsive button is showing.

function myFunction() {
  var x = document.getElementById("myTopnav");
  if (x.className === "topnav") {
    x.className += " responsive";
  } else {
    x.className = "topnav";
  }
}

.dropdown .dropbtn {
  font-size: 16px;
  border: none;
  outline: none;
  color: white;
  padding: 14px 16px;
  background-color: inherit;
  font-family: inherit;
  margin: 0;
}

.header {
  overflow: hidden;
  background-color: orange;
  padding: 20px 10px;
}

.header a {
  float: left;
  color: white;
  text-align: center;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  line-height: 25px;
  border-radius: 4px;
}

.header a.logo {
  font-size: 25px;
  font-weight: bold;
}

.header a:hover {
  background-color: #ddd;
  color: black;
}

.header a.active {
  background-color: red;
  color: white;
}

.header-right {
  float: right;
}

@media screen and (max-width: 500px) {
  .header a {
    float: none;
    display: block;
    text-align: left;
  }
  .header-right {
    float: none;
  }
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  z-index: 1;
  top: 65px;
}

.dropdown-content a {
  float: none;
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {
  background-color: #ddd;
}

.dropdown {
  float: left;
  overflow: hidden;
}

.dropdown:hover .dropdown-content {
  display: block;
}

.dropdown-content:hover {
  display: block
}

.dropbtn:hover~.dropdown-content {
  display: block;
}

.hidden {
  display: none;
}

@media screen and (max-width: 600px) {
  .header-right a:not(:first-child) {
    display: none;
  }
  .header-right a.icon {
    float: right;
    display: block;
  }
}

@media screen and (max-width: 600px) {
  .header-right.responsive {
    position: relative;
  }
  .topnav.responsive .icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .header-right.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}

<div class="header">
  <a id="txt" hidden></a>
  <img src="https://i.ibb.co/6Nkbdb3/dlhemenu-1-1-1.png" class="logo" title="logo webstránky MENU - www.menu-web.eu" alt="MENU logo" width="150" height="50" onClick="window.location.reload();"> &nbsp
  <a class="dropbtn"><i class="fa fa-user">&nbsp</i>test<?php echo $_SESSION['meno']; ?> 
      <i class="fa fa-caret-down"></i>
    </a>
  <div class="dropdown-content">

    <a href="ucet.php">Môj účet</a>
    <a href="logout.php">Odhlásiť sa</a>

  </div>



  <div class="header-right" id="myTopnav">
    <a class="active" href="/welcome.php">Úvodné menu</a>
    <a href="/online.php">Online hodiny</a>
    <a href="/du.php">Domáce úlohy</a>
    <a href="webcentrum/znamky">Známky</a>
    <a href="/rozvrh.php">Rozvrh hodín</a>
    <a href="/ospravedlnenky.php">Ospravedlnenky</a>
    <a href="/ucenie.php">Učebný materiál</a>
    <a href="javascript:void(0);" class="icon" onclick="myFunction()">
      <i class="fa fa-bars"></i>
    </a>

  </div>
</div>

>Solution :

I read the mistake details carefully.
Please, Try the code following.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .dropdown .dropbtn {
  font-size: 16px;
  border: none;
  outline: none;
  color: white;
  padding: 14px 16px;
  background-color: inherit;
  font-family: inherit;
  margin: 0;
}

.header {
  overflow: hidden;
  background-color: orange;
  padding: 20px 10px;
}

.header a {
  float: left;
  color: white;
  text-align: center;
  padding: 12px;
  text-decoration: none;
  font-size: 18px;
  line-height: 25px;
  border-radius: 4px;
}

.header a.logo {
  font-size: 25px;
  font-weight: bold;
}

.header a:hover {
  background-color: #ddd;
  color: black;
}

.header a.active {
  background-color: red;
  color: white;
}

.header-right {
  float: right;
}

@media screen and (max-width: 500px) {
  .header a {
    float: none;
    display: block;
    text-align: left;
  }
  .header-right {
    float: none;
  }
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #f9f9f9;
  min-width: 160px;
  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
  z-index: 1;
  top: 65px;
}

.dropdown-content a {
  float: none;
  color: black;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
  text-align: left;
}

.dropdown-content a:hover {
  background-color: #ddd;
}

.dropdown {
  float: left;
  overflow: hidden;
}

.dropdown:hover .dropdown-content {
  display: block;
}

.dropdown-content:hover {
  display: block
}

.dropbtn:hover~.dropdown-content {
  display: block;
}

.hidden {
  display: none;
}

@media screen and (max-width: 600px) {
  .header-right a:not(:first-child) {
    display: none;
  }
  .header-right a.icon {
    float: right;
    display: block;
  }
}

@media screen and (max-width: 600px) {
  .header-right.responsive {
    position: relative;
  }
  .topnav.responsive .icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .header-right.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}
</style>
<body>
    <div class="header">
        <a id="txt" class="hidden"></a>
        <img src="https://i.ibb.co/6Nkbdb3/dlhemenu-1-1-1.png" class="logo" title="logo webstránky MENU - www.menu-web.eu" alt="MENU logo" width="150" height="50" onClick="window.location.reload();"> &nbsp
        <a class="dropbtn"><i class="fa fa-user">&nbsp</i>test
        <i class="fa fa-caret-down"></i>
        </a>
        <div class="dropdown-content">
        
            <a href="ucet.php">Môj účet</a>
            <a href="logout.php">Odhlásiť sa</a>
        
        </div>
        <div class="header-right" id="myTopnav">
            <a class="active" href="/welcome.php">Úvodné menu</a>
            <a href="/online.php">Online hodiny</a>
            <a href="/du.php">Domáce úlohy</a>
            <a href="webcentrum/znamky">Známky</a>
            <a href="/rozvrh.php">Rozvrh hodín</a>
            <a href="/ospravedlnenky.php">Ospravedlnenky</a>
            <a href="/ucenie.php">Učebný materiál</a>
            <a href="javascript:void(0);" class="icon" onclick="myFunction()">
              <i class="fa fa-bars"></i>
            </a>
        
          </div>
    </div>
</body>
<script>
    function myFunction() {
        var x = document.getElementById("myTopnav");
        if (x.classList.contains("topnav")) {
            x.classList.remove('topnav');
            x.classList.add('responsive');
        } else {
            x.classList.add('topnav');
            x.classList.remove('responsive');
        }
    }
</script>
</html>

Hope it helps little by little.

Thanks.