Opacity error please help html : Can anyone please help me ? opacity issue this is my whole code i need a opacity background and everything working fine but when i add opacity to the backgorund i cant use my bar like if u copy and paste the code u'll see everything with opacity but i cant use the bar buttons and i want only the background to be 0.5 opacity not the whole website can anyone please help ?

    <html>
    <style>
    #background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%
    height: 100%
    background-image: url('https://i.ytimg.com/vi/3KNQfA21QyQ/maxresdefault.jpg');
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: 100%;
    opacity: 0.5;
    filter:alpha(opacity=80);
    }
    ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color:#333;
    }
    
    li {
    float: left;
    }

    li a, dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    }

    li a:hover, .dropdown:hover .dropbtn {
    background-color: red;
    }
    
    li.dropdown {
    display: inline-block;
    }
    
    li.dropdown {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width:160px;
    box-shaodw: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
    }
    
    .dropdown-content a {
    color: black;
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
    }
    
    .dropdown-content a:hover {background-color: #f1f1f1}
    
    .dropdown:hover .dropdown-content {
    display: block;
    }
    </stlye>
    <body>
    <ul>
    <li class="dropdown">
    <a href="javascript:void(0)" class="dropbtn">dropdown</a>
    <div class="dropdown-content">
          <a href="#">Link 1</a>
          <a href="#">Link 1</a>
          <a href="#">Link 1</a>
    </div>
    </li>
    <body bgcolor="black">
    <body class="my-container">
    <div id="background"></div>
    </body>
    </html>

 

