.signup-form{container:signup-fields / inline-size}.signup-subdomain{display:grid;grid-template-columns:minmax(0,1fr) auto}@container signup-fields (max-width: 16rem){.signup-subdomain{grid-template-columns:minmax(0,1fr);gap:.5rem}.signup-subdomain input,.signup-subdomain span{border-radius:.5rem}.signup-subdomain span{border-inline-start-width:1px}}