Minimal Slide-in Menu with JavaScript and CSS3 Transitions

A minimal JavaScript side menu that uses CSS3 transitions to slide in a vertical menu when you click on the toggle icon.

How to use it:

Include the Font Awesome Icon Font for menu icons.

<link rel="stylesheet" href="font-awesome.min.css">

Create a side menu bar to toggle the side menu.

<div class="ms_menu_bar__wrapper">
  <ul class="ms_menu">
    <li class="ms_menu__trigger">
      <i class="fa fa-bars"></i>
    </li>
  </ul>
</div>

Create a list of items for the side menu.

<div class="ms_menu_body__wrapper hide-menu">
  <ul>
    <li class="ms_menu__item">
      <i class="ms_menu__item-icon fa fa-circle-thin"></i>
        Menu 1
    </li>
    <li class="ms_menu__item">
      <i class="ms_menu__item-icon fa fa-circle-thin"></i>
        Menu 2
    </li>
    <li class="ms_menu__item">
      <i class="ms_menu__item-icon fa fa-circle-thin"></i>
        Menu 3
    </li>
  </ul>
</div>

Basic CSS styles.

ul,
ol,
li {
  list-style: none;
  color: white;
  margin: 0;
  padding: 0;
}
.ms_menu_bar__wrapper {
  height: 100%;
  width: 60px;
  background: #2B1F34;
  padding: 15px 10px;
  float: left;
  position: relative;
  z-index: 10;
}
.ms_menu__trigger {
  font-size: 30px;
  text-align: center;
  cursor: pointer;
  transition: color 0.6s;
}
.ms_menu__trigger:hover { color: #2F879B; }
.ms_menu__item-icon { margin-right: 10px; }
.ms_menu_body__wrapper {
  float: left;
  background: rgba(24, 88, 109, 0.8);
  position: relative;
  left: -1px;
}
.ms_menu__item {
  border-bottom: 1px solid #37616A;
  padding: 15px 40px 15px 15px;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.6s;
}
.ms_menu__item:hover { background: rgba(0,0,0,0.4); }
.hide-menu {
  opacity: 0;
  transition: all 0.06s;
  position: relative;
  z-index: 0;
  left: -90px;
}
.show-menu {
  transition: all 0.1s;
  left: -1px;
}

Load the menu.js JavaScript library at the bottom of the document.

<script src="js/menu.js"></script>

Initialize the side menu.

var init = (function(window, undefined) {
    menuTrigger();
    return init;
})(window);