A CodePen by dodozhang21. Responsive search bar - A great technique of styling a search bar.

index.slim

form.search
  input.searchTerm placeholder="Enter your search term ..."
  input.searchButton type="submit"
  span.searchIcon

script.js

$('.searchButton').on('click',function(){
  alert('You clicked search button');
});

style.css

.search {
  position: relative;
  width: 100%;
}
.searchTerm {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  -webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
  -moz-box-sizing: border-box;    /* Firefox, other Gecko */
  box-sizing: border-box; 
  height: 40px;
  border: 5px solid #8FC357;
  border-radius: 5px;
  outline: none;
  padding: 5px 45px 5px 5px;
}
.searchButton,
.searchIcon {
  display: block;
  position: absolute;
  top: 0;
  right: 0;
  width: 40px;
  height: 40px;
  line-height: 40px;
  font-family: 'FontAwesome';
  background: #8FC357;
  text-align: center;
  color: #fff;
  border-radius: 5px;
  -webkit-font-smoothing: subpixel-antialiased;
  font-smooth: always;
  cursor: pointer;
}
.searchButton {
  opacity: 0;
  z-index: 1;
}
.searchIcon:before {
  content: '\f002';
}