* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: linear-gradient(135deg, #ffffff, #ffffff);
  font-family: Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.caja {
  background: #d699ff;
  padding: 25px;
  border-radius: 8px;
  width: 300px;
}

/* Pestañas */
.tabs {
  display: flex;
  margin-bottom: 18px;
  background: #ddd;
  border-radius: 10px;
  padding: 3px;
}
.tabs button {
  flex: 1;
  padding: 7px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  font-weight: bold;
  color: #666;
  border-radius: 10px;
}
.tabs button.activo {
  background: #8125eb;
  color: white;
}

/* Campos */
label {
  display: block;
  font-size: 13px;
  font-weight: bold;
  color: #333;
  margin-bottom: 4px;
}
input[type="text"],
input[type="password"],
input[type="email"] {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 13px;
  margin-bottom: 12px;
  background: white;
}

/* Captcha */
.fila-captcha {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}
.fila-captcha input {
  flex: 1;
  padding: 8px 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  font-size: 13px;
  background: white;
}
.codigo-captcha {
  background: #8125eb;
  color: white;
  padding: 8px 10px;
  border-radius: 4px;
  font-weight: bold;
  font-size: 14px;
  letter-spacing: 3px;
  cursor: pointer;
  user-select: none;
  text-decoration: line-through;
  font-family: 'Courier New', monospace;
}

/* Botón */
.btn {
  width: 100%;
  padding: 9px;
  background: #8125eb;
  color: white;
  border: none;
  border-radius: 4px;
  font-size: 14px;
  font-weight: bold;
  cursor: pointer;
}
.btn:hover {
  background: #8125eb;
}

/* Mensajes */
.mensaje {
  padding: 7px 10px;
  border-radius: 4px;
  font-size: 12px;
  font-weight: bold;
  margin-bottom: 10px;
}
.mensaje.error  { background: #fee2e2; color: #b91c1c; }
.mensaje.exito  { background: #dcfce7; color: #15803d; }