:root{--app-bg: #f5f5f5}body{margin:0;background:var(--app-bg)}.pantalla-centrada{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px 16px;box-sizing:border-box}.espacio-carga{width:160px;height:80px}.tarjeta-acceso{width:100%;max-width:440px}.formulario-angosto{max-width:420px}.clave-temporal{flex:1;display:flex;align-items:center;padding:4px 8px;font-size:16px;letter-spacing:1px;-webkit-user-select:all;user-select:all}