<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Animated Search Bar With Glowing Effect</title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
    <div class="container">
    <input type="text" placeholder="Search...">
    <div class="search"></div>
    </div>
    </body>
</html>
 *
{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html,body
{
    width: 100%;
    height: 100%;
}
body
{
    background: #111;
}
.container
{
    position: absolute;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    margin: auto;
    width: 300px;
    height: 100px;
}
.search
{
    position: absolute;
    margin: auto;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    width: 80px;
    height: 80px;
    background: #35d0ba;
    border-radius: 50%;
    z-index: 4;
    box-shadow: 0 0 25px 0 rgba(0,0,0,0.4);
    transition: all 1s;
}
.search:hover
{
    cursor: pointer;
}
.search:before
{
    content: '';
    position: absolute;
    margin: auto;
    top: 30px;
    right: 0;
    bottom: 0;
    left: 24px;
    width: 20px;
    height: 2px;
    background: #fff;
    transform: rotate(45deg);
    transition: all 0.5s;
}
.search:after
{
    content: '';
    position: absolute;
    margin: auto;
    top: -5px;
    width: 25px;
    height: 25px;
    left: -5px;
    right: 0;
    bottom: 0;
    border: 4px solid #fff;
    border-radius: 50%;
    transition: all .5s;
}
input
{
    font-family: monospace;
    position: absolute;
    margin: auto;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    width: 50px;
    height: 50px;
    outline: none;
    border: none;
    background: #35d0ba;
    color: #fff;
    padding: 0 80px 0 20px;
    text-shadow: 0 0 10px #35d0ba;
    border-radius: 30px;
    box-shadow:  0 0 25px 0  #35d0ba, 0 20px 25px 0 rgba(0,0,0,.2);
    z-index: 5;
    font-weight: bold;
    letter-spacing: 0.1em;
    opacity: 0;
    transition: all 1s;
}
input:hover
{
    cursor: pointer;
}
input:focus
{
    width: 300px;
    opacity: 1;
    cursor: text;
}
input:focus ~ .search
{
    right: -250px;
    background: #fff;
    z-index: 8;
}
input:focus ~ .search:before
{
    background: #111;
}
input:focus ~ .search:after
{
    border: 4px solid #111;
}
input::placeholder 
{
    color: #fff;
    font-weight: bold;
    opacity: 0.5;
}

External CSS

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External JavaScript

This Pen doesn't use any external JavaScript resources.