Bootstrap 3 Form sign-in in SASS (http://getbootstrap.com/examples/signin/)

_form_signin.scss

.form-signin {
  max-width: 330px;
  padding: 15px;
  margin: 0 auto;
  .form-signin-heading, .checkbox {
    margin-bottom: 10px;
  }
  .checkbox {
    font-weight: normal;
  }
  .form-control {
    position: relative;
    font-size: 16px;
    height: auto;
    padding: 10px;
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
    &:focus {
      z-index: 2;
    }
  }
  input[type="text"] {
    margin-bottom: -1px;
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
  }
  input[type="password"] {
    margin-bottom: 10px;
    border-top-left-radius: 0;
    border-top-right-radius: 0;
  }
}