<script type="text/javascript">
        $(function() {
            $('button.expand').click(function() {
                $('#test').width(0).show().animate({width: 180}, 500);
            });
            $('html').click(function() {
            $('#test').width(180).show().animate({width: 0}, 500);
        });
        });
    </script>

<nav id="menu">
        <ul>

            <li><a href="Home.html">Home</a></li>
            <li><a href="About.html">About</a></li>


            <li>
                  <div id="search-container">
        <span id="search" >
             <form  name="form1" >
                <input id="test" type="search" placeholder="Search..." required="required" onfocus="if(this.placeholder == 'Search...') {this.placeholder=''}" onblur="if(this.placeholder == ''){this.placeholder ='Search...'}" />
                <button class="expand" type="submit"><i class="fa fa-search"></i></button>
             </form>
        </span>
    </div>
            </li>
           </ul>
    </nav>

.form-container input {display:none;}

$(function() {
    $('button.expand').click(function() {
        $('#test').width(0).show().animate({width: 180}, 500);
        $('#test').addClass("visible");
    });
    $('html').click(function() {
        if($('#test').hasClass("visible")){
            $('#test').width(180).show().animate({width: 0}, 500).removeClass("visible");
        }
    });
});