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

/* Fuente base */
html {
  font-size: 16px;
}

body {
  background-color: #000;
  color: #FFF;
  font-family: Arial, Verdana, sans-serif;
  font-size: 1rem;
  line-height: 1.6;
}

/* HEADER Y FOOTERS */
header, footer {
  background-color: #000;
  color: #FFD700;
  padding: 1rem;
  text-align: center;
}

footer {
  padding: 0rem;
}

header img {
  max-height: 10rem;
  vertical-align: middle;
  margin-right: 0.625rem;
}

/* Barra A-Z */
nav ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  list-style: none;
  padding: 0.625rem;
  background-color: #111;
  margin-bottom: 1.25rem;
}

nav ul li {
  margin: 0.3125rem;
}

nav ul li a {
  display: inline-block;
  padding: 0.5rem 0.75rem;
  background-color: #FFD700;
  color: #000;
  font-weight: bold;
  text-decoration: none;
  border-radius: 0.3125rem;
  border: 2px solid #FFF;
}

nav ul li a:hover {
  background-color: #FFF;
  color: #000;
}

.letras {
  width: 90%;
  margin: 0 auto;
  background-color: #222;
  border-radius: 6px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

/* MAIN */
main {
  background-color: #000;
  padding: 1.25rem;
  border-radius: 0.5rem;
  box-shadow: 0 0 5px rgba(255, 255, 255, 0.2);
  margin-bottom: 1.875rem;
}

h1, h2, h3 {
  color: #FFD700;
  margin-bottom: 0.9375rem;
}

h2 {
  font-size: 2rem;
}

p {
  margin-bottom: 0.9375rem;
}

/* Artículos destacados */
article {
  background-color: #111;
  border: 2px solid #FFF;
  border-radius: 8px;
  border-left: 6px solid #FFD700;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 6px rgba(255, 255, 255, 0.1);
}

article h2,
article h3 {
  color: #FFD700;
  margin-top: 0;
}

article p {
  margin-bottom: 1rem;
  line-height: 1.6;
}

/* Menú principal */
.menu_principal {
  background-color: #111;
  border-top: 2px solid #FFD700;
  border-bottom: 2px solid #FFD700;
  margin-bottom: 0.5rem;
}

.menu_principal ul {
  display: flex;
  justify-content: space-between;
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu_principal li {
  flex: 1;
  text-align: center;
}

.menu_principal li a {
  display: inline-block;
  width: 100%;
  text-decoration: none;
  color: #FFD700;
  font-weight: bold;
  padding: 0.5rem 1rem;
  background-color: #222;
  border: 1px solid #FFD700;
  border-radius: 5px;
  transition: all 0.3s ease;
}

/* Imágenes en general */
img {
  max-width: 100%;
  margin: 0.625rem 0;
}

/* Tablas */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 1em;
  background-color: #111;
  color: #FFF;
  border: 2px solid #FFD700;
}

caption {
  font-weight: bold;
  font-size: 1.2em;
  padding: 12px;
  background-color: #000;
  color: #FFD700;
}

th, td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid #FFD700;
}

th {
  background-color: #000;
  color: #FFD700;
  font-weight: bold;
}

tr:nth-child(even) td {
  background-color: #222;
}

tr:hover td {
  background-color: #333;
}

/* Formularios */
form {
  max-width: 90%;
  max-width: 50rem;
  margin: 2.5rem auto;
  padding: 2rem;
  background-color: #111;
  border: 1px solid #FFF;
  border-radius: 0.625rem;
}

form label {
  display: block;
  margin-top: 1.25rem;
  font-weight: bold;
}

form input, form select, form textarea {
  width: 100%;
  padding: 0.625rem;
  margin-top: 0.375rem;
  background-color: #000;
  color: #FFF;
  border: 1px solid #FFD700;
  border-radius: 0.3125rem;
}

form input[type="submit"] {
  margin-top: 1.5rem;
  background-color: #FFD700;
  color: #000;
  border: none;
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  font-weight: bold;
}

form input[type="submit"]:hover {
  background-color: #FFF;
}

/* Campo "color" del formulario IMC */
form input[type="color"] {
  width: 3.75rem;
  height: 2.5rem;
  padding: 0;
  border: none;
  margin-top: 0.625rem;
  background: none;
  cursor: pointer;
}

.form-fila {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.form-fila .form-elem {
  flex: 1;
  min-width: 18.75rem;
}

.titulo-form {
  text-align: center;
  margin-bottom: 1.5rem;
}

fieldset {
  border: none;
  padding: 0;
  margin: 1.5rem 0;
  display: flex;
  align-items: center;
  gap: 2rem;
  flex-wrap: wrap;
}

fieldset legend {
  font-weight: bold;
  margin-right: 1rem;
  color: #FFD700;
}

fieldset label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: normal;
}

/* Enlaces */
a {
  color: #FFD700;
  text-decoration: underline;
}

a:visited {
  color: #FFD700;
}

/* Migas de pan */
.migas_de_pan {
  background-color: #111;
  border: 2px solid #FFD700;
  border-radius: 4px;
  padding: 0.3rem 1rem;
  font-size: 1.3rem;
  color: #FFF;
}

.migas_de_pan a {
  color: #FFD700;
}

/* Acerca de */
.acerca_de {
  display: flex;
  justify-content: center;
  gap: 8rem;
  padding: 1rem;
  margin: 1rem auto;
  max-width: fit-content;
  border-radius: 8px;
  color: #FFD700;
}

/* Intro */
.intro_contenedor {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px;
  background-color: #111;
  width: 80%;
  margin: 0 auto;
  border-radius: 6px;
  margin-bottom: 2rem;
}

.intro_texto {
  flex: 1;
  min-width: 300px;
  max-width: 600px;
  font-size: 1.1em;
  text-align: left;
  color: #FFF;
}

/* Tabla de contenidos */
.tabla_contenidos {
  background-color: #111;
  border: 2px solid #FFD700;
  padding: 20px;
  border-radius: 8px;
  max-width: 400px;
  margin-bottom: 30px;
  color: #FFF;
}

.tabla_contenidos a {
  color: #FFD700;
}

h3 {
  font-size: 1.4em;
  margin-bottom: 10px;
  margin-top: 30px;
}

/* Mapa textual */
.mapa_textual {
  background-color: #111;
  padding: 20px;
  margin: 30px 0 30px 5%;
  width: fit-content;
  max-width: 800px;
  border-radius: 10px;
  text-align: left;
  color: #FFF;
}

.mapa_textual a {
  color: #FFD700;
}

/* Error */
.error_contenedor {
  display: flex;
  align-items: center;
  background-color: #111;
  border-radius: 10px;
  padding: 30px 40px;
  max-width: 900px;
  margin: 50px auto;
  gap: 30px;
  color: #FFF;
}

.error_texto h2 {
  color: #FF0000;
}

.error_texto p {
  color: #FFF;
}


.videos-en-fila {
  margin-top: 2rem;
  padding: 2rem;
  background-color: #fafafa;
  border: 1px solid #ccc;
  border-radius: 10px;
  text-align: center;
}

.contenedor-videos {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 1.5rem;
  margin-top: 1rem;
}

.video-item {
  flex: 1 1 30%;
  max-width: 320px;
}

.video-item p {
  color: #004080;
  font-weight: bold;
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}