#id_ext_url {
background-position-x: calc(100% - 8px);
background-position-y: 50%;
background-clip: padding-box;
background-size: 24px;
background-repeat: no-repeat;
}
#id_ext_url.valid {
background-image: url('data:image/svg+xml;utf8,') !important;
}
#id_ext_url.invalid {
background-image: url('data:image/svg+xml;utf8,');
}