SOURCE

<div class="mysearch"><input type="text" /><button>搜 索</button></div>

.mysearch{
  width:80%;
  height:60px;
  margin:30px auto;
  border:1px solid #eee;
  background:#fff;
  border-radius:6px;
  overflow:hidden;
}
.mysearch>input{
  height:calc(100% - 2px);
  border:none;
  width:calc(100% - 150px);
  padding:0 15px;
  font-size:16px;
  outline:none;
}
.mysearch>button{
  height:100%;
  width:120px;
  background:#00b374;
  border:none;
  color:#fff;
  font-size:16px;
}