My Bloggers Code: Mobile Dropdown Sidenev for Bloggers

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style>

body {
font-family: "Lato", sans-serif;
transition: background-color .5s;
}

.sidenav {
height: 100%;
width: 0;
position: fixed;
z-index: 1;
top: 0;
left: 0;
background-color: #111;
overflow-x: hidden;
transition: 0.5s;
padding-top: 60px;
}

/* Style the sidenav links and the dropdown button */
.sidenav a, .dropdown-btn {
padding: 6px 8px 6px 16px;
text-decoration: none;
font-family: 'Oswald', sans-serif;
font-size: 15px;
color: #818181;
display: block;
border-bottom: 1px solid;
border-color:#332C2B;
background: none;
width: 100%;
text-align: left;
cursor: pointer;
outline: 1px;

}
.sidenav a {
transition: 0.3s;

}

/* On mouse-over */
.sidenav a:hover, .dropdown-btn:hover {
color: #f1f1f1;
}

.sidenav a:hover {
color: #f1f1f1;
}

.sidenav .closebtn {
position: absolute;
top: 0;
right: 50px;
left:190px;
font-size:70px;
border-bottom: none;
margin-top:-30px;

}

/* Add an active class to the active dropdown button */
.active {
background-color: green;
color: white;
}

/* Dropdown container (hidden by default). Optional: add a lighter background color and some left padding to change the design of the dropdown content */
.dropdown-container {
display: none;
background-color: #1C1B0B;
padding-left: 48px;
border: none;
}
}

/* Optional: Style the caret down icon */
.fa-caret-down {
float: right;
padding-right: 8px;
}

/* Some media queries for responsiveness */
@media screen and (max-height: 450px) {
.sidenav {padding-top: 15px;}
.sidenav a {font-size: 18px;}
}

}
</style>
</head>
<body>

<div id="mySidenav" class="sidenav">
<a href="javascript:void(0)" class="closebtn" onclick="closeNav()">×</a>

<a class="list-group-item" href="#"><i class="fa fa-home fa-fw" aria-hidden="true"></i>  Home</a>
<a class="list-group-item" href="#"><i class="fa fa-book fa-fw" aria-hidden="true"></i>  About us</a>
<a class="list-group-item" href="#"><i class="fa fa-pencil fa-fw" aria-hidden="true"></i>  Applications</a>
<a class="list-group-item" href="#"><i class="fa fa-cog fa-fw" aria-hidden="true"></i>  Settings</a>

<button class="dropdown-btn"><i class="fa fa-cog fa-fw" aria-hidden="true"></i>Services <i class="fa fa-caret-down"></i>
</button>

<div class="dropdown-container">
<a href="#">Hotel Promotion</a>
<a href="#">Restaurant promotion</a>
<a href="#">Waterpark Promotion</a>
<a href="#">Spa-Parlour Promotion</a>
</div>

<button class="dropdown-btn"><i class="fa fa-cog fa-fw" aria-hidden="true"></i>Dropdown <i class="fa fa-caret-down"></i>
</button>

<div class="dropdown-container">
<a href="#">Link 1</a>
<a href="#">Link 2</a>
<a href="#">Link 3</a>
</div>

<a class="list-group-item" href="#"><i class="fa fa-home fa-fw" aria-hidden="true"></i>  Contact us</a>
</div>

<div id="main">

<span style="font-size:30px;cursor:pointer" onclick="openNav()">☰ open</span>
</div>

<script>
function openNav() {
document.getElementById("mySidenav").style.width = "250px";
document.body.style.backgroundColor = "rgba(0,0,0,0.4)";
}

function closeNav() {
document.getElementById("mySidenav").style.width = "0";
document.body.style.backgroundColor = "white";
}

var dropdown = document.getElementsByClassName("dropdown-btn");
var i;

for (i = 0; i < dropdown.length; i++) {
dropdown[i].addEventListener("click", function() {
this.classList.toggle("active");
var dropdownContent = this.nextElementSibling;
if (dropdownContent.style.display === "block") {
dropdownContent.style.display = "none";
} else {
dropdownContent.style.display = "block";
}
});
}
</script>

</body>
</html>