drupal/core/modules/openid/openid.css

input[name="openid_identifier"] {
  background-image: url("login-bg.png");
  background-position: left 50%; /* LTR */
  background-repeat: no-repeat;
  padding-left: 20px; /* LTR */
}
.js form.user-login-block.openid-login-form {
  display: none;
}
form.user-login-block a.openid-link,
form.user-login-block a.user-link {
  display: none;
}
.js form.user-login-block a.openid-link,
.js form.user-login-block a.user-link {
  display: block;
}
form.user-login-block a.openid-link {
  background-image: url("login-bg.png");
  background-position: left top; /* LTR */
  background-repeat: no-repeat;
  padding: 0 0 0 1.5em; /* LTR */
}