:root {
  --bg: #0d0e12;
  --panel: rgba(255, 255, 255, 0.05);
  --panel-fuerte: rgba(255, 255, 255, 0.08);
  --borde: rgba(255, 255, 255, 0.1);
  --texto: #f4f5f7;
  --suave: #a3a8b5;
  --acento: #8b7bff;
  --acento-2: #ff8a65;
  --error: #ff6b6b;
  --ok: #4ade80;
  --radio: 18px;
  --transicion: cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--texto);
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.fondo {
  position: fixed;
  inset: -10%;
  z-index: -1;
  background:
    radial-gradient(60% 50% at 20% 10%, rgba(139, 123, 255, 0.25), transparent 70%),
    radial-gradient(50% 40% at 85% 0%, rgba(255, 138, 101, 0.18), transparent 70%),
    radial-gradient(45% 40% at 50% 100%, rgba(139, 123, 255, 0.12), transparent 70%);
}

/* ===== Barra superior ===== */
.barra {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1100px;
  margin: 0 auto;
  padding: 18px 22px;
}

.marca {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--texto);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.1rem;
}
.marca img { filter: brightness(0) invert(1); }

.enlace-suave {
  color: var(--suave);
  text-decoration: none;
  font-size: 0.92rem;
  transition: color 0.2s ease;
}
.enlace-suave:hover { color: var(--texto); }

.barra-derecha {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--texto);
}

/* ===== Tarjeta ===== */
.contenedor {
  display: flex;
  justify-content: center;
  padding: 12px 18px 60px;
}

.tarjeta {
  width: 100%;
  max-width: 460px;
  padding: 34px 30px;
  border-radius: 24px;
  background: var(--panel);
  border: 1px solid var(--borde);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
  transition: max-width 0.4s var(--transicion);
}
.tarjeta.ancha { max-width: 640px; }

.vista { animation: aparecer 0.45s var(--transicion); }

@keyframes aparecer {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: none; }
}

.cabecera { text-align: center; margin-bottom: 24px; }
.cabecera h1 { margin: 0 0 8px; font-size: 1.65rem; letter-spacing: -0.02em; }
.sub { margin: 0; color: var(--suave); line-height: 1.5; }

/* ===== Pestañas ===== */
.pestanas {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 4px;
  margin-bottom: 22px;
  border-radius: 14px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--borde);
}

.pestana {
  position: relative;
  z-index: 1;
  padding: 10px;
  border: 0;
  background: none;
  color: var(--suave);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.25s ease;
}
.pestana[aria-selected="true"] { color: var(--texto); }

.pestana-indicador {
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: 4px;
  width: calc(50% - 4px);
  border-radius: 10px;
  background: var(--panel-fuerte);
  border: 1px solid var(--borde);
  transition: transform 0.35s var(--transicion);
}
.pestanas[data-modo="registro"] .pestana-indicador { transform: translateX(100%); }

/* ===== Formularios ===== */
.formulario { display: flex; flex-direction: column; gap: 14px; }

.campo { display: flex; flex-direction: column; gap: 6px; font-size: 0.9rem; color: var(--suave); }
.campo > span small { opacity: 0.75; }

.campo input,
.campo select {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--borde);
  background: rgba(0, 0, 0, 0.35);
  color: var(--texto);
  font: inherit;
  font-size: 1rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.campo input:focus,
.campo select:focus {
  outline: none;
  border-color: var(--acento);
  box-shadow: 0 0 0 3px rgba(139, 123, 255, 0.25);
}
.campo input.invalido,
.campo select.invalido { border-color: var(--error); }
.campo input:disabled { opacity: 0.6; }
.campo select option,
.campo select optgroup { background: #1b1d2e; color: var(--texto); }

.campo-clave { position: relative; }
.campo-clave input { padding-right: 64px; }
.ver-clave {
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  padding: 6px 10px;
  border: 0;
  border-radius: 8px;
  background: none;
  color: var(--suave);
  font: inherit;
  font-size: 0.82rem;
  cursor: pointer;
}
.ver-clave:hover { color: var(--texto); background: var(--panel); }

.fuerza { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin-top: 2px; }
.fuerza i { height: 4px; border-radius: 4px; background: var(--borde); transition: background 0.3s ease; }
.fuerza[data-nivel="1"] i:nth-child(-n+1) { background: var(--error); }
.fuerza[data-nivel="2"] i:nth-child(-n+2) { background: #fbbf24; }
.fuerza[data-nivel="3"] i:nth-child(-n+3) { background: #a3e635; }
.fuerza[data-nivel="4"] i { background: var(--ok); }

.ayuda { color: var(--suave); font-size: 0.8rem; }
.centrado { display: block; text-align: center; margin-left: auto; margin-right: auto; }

.fila { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* ===== Botones ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 13px 18px;
  border-radius: 12px;
  border: 1px solid transparent;
  font: inherit;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.2s var(--transicion), opacity 0.2s ease, background 0.2s ease;
}
.btn:hover:not(:disabled) { transform: translateY(-1px); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn.cargando { pointer-events: none; opacity: 0.75; }
.btn.cargando::after {
  content: "";
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid currentColor;
  border-right-color: transparent;
  animation: girar 0.7s linear infinite;
}
@keyframes girar { to { transform: rotate(360deg); } }

.btn-primario {
  background: linear-gradient(135deg, var(--acento), #6d5cf0);
  color: #fff;
  box-shadow: 0 10px 30px rgba(139, 123, 255, 0.3);
}
.btn-secundario { background: var(--panel); border-color: var(--borde); color: var(--texto); }
.btn-google { background: #fff; color: #1f1f1f; }

.vista > .btn + .btn { margin-top: 10px; }

.botones { display: grid; grid-template-columns: 1fr 2fr; gap: 10px; margin-top: 8px; }

.enlace {
  align-self: flex-end;
  padding: 2px 0;
  border: 0;
  background: none;
  color: var(--acento);
  font: inherit;
  font-size: 0.88rem;
  cursor: pointer;
}
.enlace:hover { text-decoration: underline; }
.vista > .enlace { margin-top: 16px; }

.separador {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  color: var(--suave);
  font-size: 0.82rem;
}
.separador::before, .separador::after { content: ""; flex: 1; height: 1px; background: var(--borde); }

.casillas-legales { display: grid; gap: 8px; margin: 4px 0 14px; font-size: 0.84rem; }
.casilla { display: flex; gap: 8px; align-items: flex-start; color: var(--texto); }
.casilla input { margin-top: 3px; }
.enlaces-legales { display: flex; flex-wrap: wrap; gap: 8px 14px; margin: 0; }
.enlaces-legales a { color: var(--acento); font-size: 0.8rem; }

.icono-grande {
  width: 72px;
  height: 72px;
  margin: 0 auto 16px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  font-size: 2rem;
  background: rgba(139, 123, 255, 0.15);
  border: 1px solid rgba(139, 123, 255, 0.35);
}

/* ===== Aviso flotante ===== */
.aviso {
  position: fixed;
  left: 50%;
  bottom: max(24px, env(safe-area-inset-bottom));
  transform: translateX(-50%);
  z-index: 50;
  max-width: min(92vw, 460px);
  padding: 13px 18px;
  border-radius: 14px;
  background: rgba(20, 21, 28, 0.92);
  border: 1px solid var(--borde);
  border-left: 4px solid var(--error);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  font-size: 0.92rem;
  line-height: 1.45;
  animation: aparecer 0.3s var(--transicion);
}
.aviso.ok { border-left-color: var(--ok); }

@media (max-width: 520px) {
  .barra { padding: 14px 16px; }
  .tarjeta { padding: 26px 20px; border-radius: 20px; }
  .cabecera h1 { font-size: 1.4rem; }
  .fila { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  .vista, .aviso { animation: none; }
}