body.login { min-height: 100vh; display: grid; place-items: center; background: var(--bg-sub); padding: 16px; }
.tarjeta { width: min(360px, 100%); background: var(--bg); border: 1px solid var(--borde); border-radius: 14px; padding: 28px 26px 26px; box-shadow: var(--sombra); }
.tarjeta h1 { font-size: 20px; font-weight: 600; letter-spacing: -.015em; margin: 22px 0 18px; }
.tarjeta form { display: grid; gap: 14px; }
.tarjeta .btn { height: 38px; justify-content: center; margin-top: 4px; }
.tarjeta .error { margin: 0; color: var(--error); background: var(--error-suave); border-radius: 8px; padding: 8px 10px; font-size: 13px; }