XJKpRV

index.html

 <form action="#" class="search-form">
  <label class="search" for="search-term">
    <input type="text" id="search-term" name="q" placeholder="Search...">
    <img src="http://s11.postimg.org/6o8p91g1b/search.png?noCache=1418841941" class="search-icon" alt="Search">
  </label>
</form>

style.css

.search:before {
  content: '';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
}
.search {
  display: inline-block;
  background: #333;
  min-width: 60px;
  height: 60px;
  border-radius: 30px;
  text-align: center;
  cursor: pointer;
}

#search-term {
  width: 0;
  padding: 0;
  border-width: 0;
  background: none;
  color: white;
  margin: 0 20px 0 0;
  font-size: 16px;
  vertical-align: center;
  outline: none;
  transition: all 0.1s ease-out;
}
#search-term:focus {
  padding: 0 20px;
  width: 250px;
  transition: all 0.1s ease-out;
}
.search-icon {
  vertical-align: middle;
  position: relative;
  left: -15px;
}

XJKpRV.markdown

XJKpRV

A Pen by Captain Anonymous on CodePen.

License.