/* ====== CONTENEDOR PRINCIPAL ====== */
.container {
  width: 1080px;
  max-width: 100%;
  margin: 0 auto;
  padding: 0 15px;
  font-family: "Arial", Georgia, Serif;
  font-size: 15px;
  box-sizing: border-box;
}

/* ====== ENCABEZADO ====== */
header {
  text-align: center;
  border: 1px solid #666;
  background: #ccc;
}

.titulo1 {
  background-color: green;
  padding: 10px;
}

/* ====== ENLACES GENERALES ====== */
a {
  color: #333;
  text-decoration: none;
}

/* ====== SECCIÓN Y ASIDE ====== */
section,
aside {
  margin-top: 5px;
  padding: 10px;
  border-radius: 3px;
}

section {
  float: left;
  width: 70%;
  background: #fafafa;
  border: 1px solid #ccc;
}

aside {
  float: right;
  width: 25%;
  background: #ccc;
  color: #333;
}

/* ====== NAVEGACIÓN ====== */
nav {
  padding: 0.2%;
  background: #f06156;
  margin-top: 0.5%;
}

nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  width: 100%;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  text-align: center;
}

nav ul li {
  display: inline-block;
  margin: 2px;
}

nav ul li a {
  display: inline-block;
  padding: 6px 15px;
  background: #fafafa;
  color: #75302a;
  font-weight: bold;
  border-radius: 3px;
  transition: all 0.3s ease;
}

nav ul li a:hover {
  background-color: #ccc;
  color: blueviolet;
  text-decoration: underline;
}

/* ====== PIE DE PÁGINA ====== */
footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 10px 0;
  background-color: #333;
  text-align: center;
}

footer a {
  color: #fff;
}

/* ====== TEXTOS ====== */
h2 {
  color: #f06156;
}

h3 {
  font-size: 14px;
  padding: 5px;
  color: #333;
  background-color: pink;
  text-align: center;
}

.fecha {
  font-size: 0.9em;
  color: #777;
  margin-bottom: 10px;
}

/* ====== FORMULARIOS ====== */
input,
select,
textarea {
  width: 300px;
  margin-left: 10px;
  margin-bottom: 5px;
  padding: 10px;
  display: block;
  border: 3px solid green;
  box-sizing: border-box;
}

/* ====== COMPONENTES ====== */
.info_clases {
  display: inline-block;
  background-color: beige;
  width: 200px;
  padding: 10px;
  margin-left: 35px;
  margin-bottom: 5px;
  overflow: hidden;
  box-sizing: border-box;
}

/* ====== ARTICLE GENERAL ====== */
article {
  background-color: #fafafa;
  border: 1px solid #ccc;
  padding: 20px;
  margin-bottom: 20px;
  border-radius: 6px;
  box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.05);
  scroll-margin-top: 80px;
}

article h2 {
  margin-top: 0;
}

/* ====== ARTICLES INDIVIDUALES CON ID ====== */
#articulo1 {
  border-left: 5px solid #f06156;
}

#articulo2 {
  border-left: 5px solid #3498db;
}

#articulo3 {
  border-left: 5px solid #27ae60;
}

/* ====== ENLACES DE LECTURA ====== */
.enlace {
  display: inline-block;
  margin-top: 10px;
  color: #3498db;
  text-decoration: none;
  font-weight: bold;
  transition: all 0.3s ease;
}

.enlace:hover {
  color: blueviolet;
  text-decoration: underline;
}

/* ====== MEDIA QUERIES ====== */

/* 💻 Hasta 980px (tablets y pantallas medianas) */
@media screen and (max-width: 980px) {
  .container {
    width: 98%;
  }

  section {
    width: 68%;
  }
}

/* 📱 Hasta 700px (pantallas pequeñas) */
@media screen and (max-width: 700px) {
  section,
  aside {
    float: none;
    width: 96%;
    font-size: 1.2em;
  }

  nav,
  section {
    font-size: 1.2em;
  }

  aside {
    margin-top: 5px;
    background: #333;
    color: #fff;
  }

  nav ul {
    flex-direction: column;
    align-items: center;
  }

  nav ul li {
    width: 100%;
  }
}

/* 📱 Hasta 480px (móviles) */
@media screen and (max-width: 480px) {
  .container {
    padding: 10px;
  }

  section {
    width: 94%;
    font-size: 1.5em;
  }

  aside {
    display: block;
    background: #333;
    color: #fff;
    font-size: 1.5em;
  }

  article {
    padding: 15px;
  }

  .enlace {
    font-size: 1.1em;
  }

  nav ul {
    display: block;
    text-align: center;
  }

  nav ul li {
    float: none;
    width: 100%;
  }
}
#img_centro {
  width: 300px;
  height: 200px;
  background-image: url('imagen/libros.jpg');
  background-size: cover;
  background-position: center;
  margin: 0 auto; /* Centra horizontalmente */
  display: block;
}
#mkt,#prog, #dis{
  display: none;
}
#mkt img {
  width: 100%;
  height: 100%;

}
#formulario {
  background-color: green;
}
#formu {
  display: none;
}
.rojo {
  color:greenyellow;
  font-weight: bold;
  font-size: 15px;
}
.error {
    border: 9px solid red;
    background-color: blueviolet;
}
/*#myElement { //ejemplo 2
  background: silver;
  height: 300px;
  text-align: center;
  font: 30px/300px Helvetica, Arial, sans-serif;
}*/
#caja{
  width: 300xp;
  height: 300px;
}
.seleccionado{
  background-color: pink;
  padding: 5px;
  margin-bottom: 5px;
}