/* ========== Base ========= */
/* RESET & FUENTE BASE */
html, body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', sans-serif;
  height: 100%;
  box-sizing: border-box;
}

/* FONDO GENERAL */
body.acceso-estudiantes {
  background: linear-gradient(135deg, #003366, #005a99);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

/* CONTENEDOR FORMULARIO */
.formulario {
  background-color: #ffffffee;
  border-radius: 10px;
  box-shadow: 0 0 20px rgba(0,0,0,0.3);
  padding: 30px;
  max-width: 380px;
  width: 100%;
  color: #003366;
  text-align: center;
}

/* IMAGEN SUPERIOR */
.imagen-estudiantes {
  width: 160px;
  height: auto;
  margin-bottom: 12px;
  border-radius: 8px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* LOGO INSTITUCIONAL OPCIONAL */
.logo-iutam {
  width: 60px;
  height: auto;
  margin-bottom: 12px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* CAMPOS CON ICONO */
.campo-icono {
  display: flex;
  align-items: center;
  background-color: #f9f9f9;
  border: 1px solid #ccc;
  border-radius: 6px;
  padding: 10px 12px;
  margin-bottom: 16px;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
}

.icono-input {
  width: 18px;
  height: 18px;
  margin-right: 10px;
  object-fit: scale-down;
  vertical-align: middle;
  display: inline-block;
}

.campo-icono input {
  border: none;
  outline: none;
  width: 100%;
  font-size: 16px;
  background-color: transparent;
  color: #333;
}

/* ÍCONO DE VISIBILIDAD DE CLAVE */
.toggle-visibility {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 18px;
  color: #555;
  cursor: pointer;
  visibility: hidden;
  transition: opacity 0.3s ease;
}

/* CONTENEDOR RELATIVO PARA CLAVE */
.input-contenedor {
  position: relative;
}

/* GRUPO DE BOTONES */
.grupo-botones {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 10px;
}

.boton-icono {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: bold;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s ease;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.icono-boton {
  width: 18px;
  height: 18px;
  margin-right: 6px;
  object-fit: contain;
}

/* ESTILOS BOTÓN INDIVIDUAL */
.boton-icono.ingresar {
  background-color: #004080;
}

.boton-icono.ingresar:hover {
  background-color: #0072c6;
}

.boton-icono.salir {
  background-color: #555;
}

.boton-icono.salir:hover {
  background-color: #888;
}

/* MENSAJE DE VALIDACIÓN */
#mensaje {
  margin-top: 15px;
  font-size: 0.9em;
  color: #d80000;
  text-align: center;
  background-color: #ffe6e6;
  border: 1px solid #d80000;
  padding: 8px;
  border-radius: 6px;
}

/* RESPONSIVE */
@media screen and (max-width: 480px) {
  .formulario {
    padding: 16px;
  }

  .campo-icono {
    flex-direction: column;
    align-items: stretch;
    padding: 8px 10px;
  }

  .icono-input {
    margin-bottom: 6px;
  }

  .boton-icono {
    font-size: 12px;
    padding: 6px 10px;
    width: 100%;
  }

  .icono-boton {
    width: 16px;
    height: 16px;
    margin-right: 4px;
  }

  .imagen-estudiantes {
    width: 120px;
    margin-bottom: 6px;
  }
}