<div id="app-cover">
  <div id="app">
    <form method="get" action="">
      <div id="f-element">
        <div id="inp-cover"><input type="text" name="query" placeholder="Type something to search ..." autocomplete="off"></div>
      </div>
      <button type="submit" class="shadow"><i class="fas fa-search"></i></button>
    </form>
  </div>
  <div id="layer" title="Click the blue area to hide the form"></div>
  <div id="init"></div>
</div>
*
{
    outline: none;
}

html, body
{
    height: 100%;
    min-height: 100%;
}

body
{
    margin: 0;
}

body, input
{
    cursor: url(http://k003.kiwi6.com/hotlink/vp054ir5gt/c1.png) 32 32, auto;
    cursor: -webkit-image-set(url(http://k003.kiwi6.com/hotlink/vp054ir5gt/c1.png) 1x,url(http://k003.kiwi6.com/hotlink/z6fy599487/c2.png) 2x) 32 32, auto;
}

body:active, input:active
{
    cursor: url(http://k003.kiwi6.com/hotlink/3p6w4icbzt/c1a.png) 32 32, auto;
    cursor: -webkit-image-set( url(http://k003.kiwi6.com/hotlink/3p6w4icbzt/c1a.png) 1x, url(http://k003.kiwi6.com/hotlink/6ma7828al1/c2a.png) 2x ) 32 32, auto;
}

#app-cover
{
    position: absolute;
    top: 50%;
    right: 0;
    left: 0;
    width: 434px;
    margin: -41px auto 0 auto;
}

#app
{
    position: relative;
    width: 82px;
    height: 82px;
    border-radius: 120px;
    margin: 0 auto;
    transition: 0.15s ease width;
    z-index: 2;
}

form
{
    position: relative;
    height: 82px;
    cursor: auto;
    border-radius: 120px;
}

#f-element
{
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    overflow: hidden;
    border-radius: 120px;
}

#inp-cover
{
    position: absolute;
    top: 0;
    right: 41px;
    bottom: 0;
    left: 0;
    padding: 0 35px;
    background-color: #fff;
}

input
{
    display: block;
    width: 100%;
    font-size: 19px;
    font-family: Arial, Helvetica, sans-serif;
    color: #00688a;
    border: 0;
    padding: 30px 0;
    margin: 0;
    margin-top: 52px;
    line-height: 1;
    background-color: transparent;
    transition: 0.15s ease margin-top;
    cursor: auto;
}

button
{
    position: absolute;
    top: 0;
    right: 0;
    width: 82px;
    height: 82px;
    color: #fff;
    font-size: 30px;
    line-height: 1;
    padding: 26px;
    margin: 0;
    border: 0;
    background-color: #1eaddc;
    transition: 0.2s ease background-color;
    border-radius: 50%;
}

button.shadow
{
    box-shadow: 0 10px 30px #d0d0d0;
}

button i.fas
{
    display: block;
    line-height: 1;
}

#layer
{
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background-color: #1eaddc;
    transition: 0.9s ease all;
    z-index: 1;
}

#layer.sl
{
    transition: 0.3s ease all;
}

#layer, #init
{
    position: fixed;
    top: 50%;
    margin: -40px auto 0 auto;
}

#layer
{
    right: -100px;
    left: -100px;
}

#init
{
    right: 0;
    left: 0;
    width: 82px;
    height: 82px;
    cursor: pointer;
    z-index: 2;
}

#app.opened
{
    width: 434px;
    box-shadow: 0 10px 30px #0190bf;
}

.opened input.move-up
{
    margin-top: 0;
}

.opened button
{
    color: #1eaddc;
    background-color: #fff;
    box-shadow: none;
    cursor: pointer;
}

#app.opened + #layer
{
    width: 4000px;
    height: 4000px;
    margin-top: -2000px;
    opacity: 1;
    z-index: 0;
}

#app.opened ~ #init
{
    z-index: -1;
}
$(function()
{
    var app = $('#app'), init = $('#init'), layer = $('#layer'), input = $('#inp-cover input'), button = $('button');

    function toggleApp()
    {
        app.toggleClass('opened');

        if( button.hasClass('shadow') )
            button.toggleClass('shadow');
        else
            setTimeout(function(){ button.toggleClass('shadow'); },300);

        if( app.hasClass('opened') )
        {
            setTimeout(function(){ input.toggleClass('move-up'); },200);
            setTimeout(function(){ input.focus(); },500);
        }
        else
            setTimeout(function(){ input.toggleClass('move-up').val(''); },200);

        if( ! layer.hasClass('sl') )
        {
            setTimeout(function()
            {  
                layer.addClass('sl');
            },800);
        }
        else
            setTimeout(function(){ layer.removeClass('sl'); },300);
    }

    layer.on('click',toggleApp);
    init.on('click',toggleApp);
});
Run Pen

External CSS

  1. https://use.fontawesome.com/releases/v5.3.1/css/all.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js