<form method="post" action="" class="myform">
      <div>
        <label for="fldSearch">Keywords</label>
        <input type="search" id="fldSearch" name="keywords">
        <input type="submit" name="btnSubmit" value="Search"></div>
    </form>

      body {
        background-color: #fff;
        color: #333;
        font: 1.2em / 1.5 Helvetica Neue, Helvetica, Arial, sans-serif;
        padding: 1em;
        margin: 0;
      }

      .preview .myform input {
        display: inline;
        margin: 0;
      }

      .myform {
        border: 2px solid #000;
        padding: 5px;
      }

      /* inherit the patents */
      .myform,input {
         font-family:inherit;
        font-size: 100%; 
      }

      input[type="submit"] {
        background-color: purple;
        color:white;
        border: none;
        border-radius: 5px;
      }