:root {
  /* Colores principales */
  --color-primary: #000000;
  --color-accent: #ff0000;
  --color-accent-secondary: #faac26;
  --color-background: #f4f7f6;
  --color-text: #333;
  --color-white: #ffffff;
  --color-footer: #333;
  
  /* Colores específicos para cajas de temas */
  --color-box1: #e8f4f8; /* Azul muy claro */
  --color-box2: #f4f8e8; /* Verde muy claro */
  --color-box3: #f8e8f4; /* Rosa muy claro */
  --color-box-border1: #3498db; /* Azul */
  --color-box-border2: #2ecc71; /* Verde */
  --color-box-border3: #9b59b6; /* Morado */
  
  /* Tipografía */
  --font-main: 'Helvetica Neue', Arial, sans-serif;
  --font-size-base: 16px;
  --line-height-base: 1.6;
  
  /* Diseño */
  --border-radius: 10px;
  --border-width: 4px;
  --max-width-content: 1200px;
  
  /* Efectos */
  --shadow-default: 0 4px 10px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 6px 15px rgba(0, 0, 0, 0.15);
  --transition-default: 0.3s ease;
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background-color: var(--color-background);
  color: var(--color-text);
  line-height: var(--line-height-base);
  margin: 0;
  padding: 0;
}

/* ==================
   Cabecera y navegación
   ================== */

/* Cabecera */
.cabecera {
  display: flex;
  justify-content: center;
  align-items: center;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  padding: 1rem 0;
  border: 4px solid #e0e0e0;
  margin-bottom: 1rem;
}

.cabecera img {
  width: 15%;
  max-width: 100px;
  min-width: 50px;
  height: auto;
}

/* Barra de navegación */
nav {
  background-color: var(--color-primary);
  padding: 0;
  border: 4px solid var(--color-white);
  border-radius: var(--border-radius);
  position: relative;
  margin-bottom: 2rem;
}

nav .nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 1rem;
}

nav ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0;
  padding: 0;
}

nav ul li {
  margin: 0;
  padding: 0;
}

nav ul li::before {
  content: none; /* Eliminar el marcador personalizado para los elementos de navegación */
}

nav ul li a {
  display: flex;
  align-items: center;
  color: var(--color-white);
  text-decoration: none;
  padding: 1rem 1.25rem;
  transition: background-color var(--transition-default);
  border-radius: var(--border-radius);
  font-weight: 500;
}

nav ul li a:hover,
nav ul li a:focus {
  background-color: var(--color-accent);
  color: var(--color-white);
  outline: none;
}

/* Botón de menú para móviles */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-white);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* Título principal de la página */
.main-title {
  text-align: center;
  margin: 2rem 0;
  font-size: 2.5rem;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 1px;
}

/* ==================
   Contenedores de temas
   ================== */

.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
  gap: 1.25rem;
  padding: 1.25rem;
  margin: 1.25rem auto;
  max-width: var(--max-width-content);
  border-radius: var(--border-radius);
  background: var(--color-white);
  box-shadow: var(--shadow-default);
}
a {
  text-decoration: none;
}
/* Cajas de temas */
.box {
  display: flex;
  flex-direction: column;
  flex: 1 1 calc(33.333% - 2.5rem);
  min-width: 250px;
  margin-bottom: 1.25rem;
  padding: 1.25rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-default);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-decoration: none;
}

/* Variantes de cajas por tema */
.box1 {
  background-color: var(--color-box1);
  border-top: 5px solid var(--color-box-border1);
}

.box2 {
  background-color: var(--color-box2);
  border-top: 5px solid var(--color-box-border2);
}

.box3 {
  background-color: var(--color-box3);
  border-top: 5px solid var(--color-box-border3);
}

/* Efecto hover para las cajas */
.box:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

/* Títulos de temas */
.box h2 {
  font-size: 1.4rem;
  margin-top: 0;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid rgba(0,0,0,0.1);
}

/* Enlaces de temas */
.box h2 a {
  color: var(--color-text);
  text-decoration: none;
  transition: color var(--transition-default);
  display: block;
}

.box h2 a:hover,
.box h2 a:focus {
  color: var(--color-accent);
  outline: none;
  background-color: transparent;
}

/* Listas de contenidos por tema */
.box ul {
  list-style-position: inside;
  padding-left: 0.5rem;
  margin-top: 0.5rem;
}

.box li {
  margin-bottom: 0.5rem;
  position: relative;
  padding-left: 0.5rem;
}




/* Párrafos */
.box p {
  margin-bottom: 1rem;
}

/* ==================
   Footer
   ================== */

footer {
  background-color: var(--color-footer);
  color: var(--color-white);
  padding: 2rem 1rem;
  margin-top: 2rem;
}

.pie {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  max-width: var(--max-width-content);
  margin: 0 auto;
}

.informacion, .recursos {
  flex: 1 1 300px;
}

.informacion h3, .recursos h3 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  position: relative;
}

.informacion p {
  margin-bottom: 1rem;
  text-align: left;
}

.recursos ul {
  list-style: none;
  padding: 0;
}

.recursos ul li {
  padding: 0;
  margin-bottom: 0.5rem;
}

.recursos ul li::before {
  content: none;
}

.recursos a {
  color: var(--color-white);
  transition: color var(--transition-default);
}

.recursos a:hover, .recursos a:focus {
  color: var(--color-accent);
  text-decoration:none;
  background-color: transparent;
}

/* ==================
   Media queries responsivos
   ================== */

@media screen and (max-width: 1200px) {
  .container {
    padding: 1rem;
    margin: 1rem auto;
  }
}

@media screen and (max-width: 992px) {
  .box {
    flex: 1 1 calc(50% - 1.5rem);
  }
  
  .box h2 {
    font-size: 1.3rem;
  }
  
  nav ul li a {
    padding: 0.75rem 1rem;
    font-size: 0.95rem;

  }
}

@media screen and (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .nav-container {
    flex-wrap: wrap;
  }
  
  nav ul {
    display: none;
    width: 100%;
    flex-direction: column;
    padding: 0.5rem 0;
  }
  
  nav ul.active {
    display: flex;
  }
  
  nav ul li {
    width: 100%;
  }
  
  nav ul li a {
    width: 100%;
    padding: 0.75rem 1rem;
    justify-content: flex-start;
  }
  
  .container {
    flex-direction: column;
    padding: 1rem;
  }
  
  .box {
    flex: 0 0 100%;
    margin-bottom: 1rem;
  }
  
  .box h2 {
    font-size: 1.2rem;
  }
  
  .cabecera {
    padding: 0.75rem 0;
  }
  
  .cabecera img {
    width: 25%;
  }
  
  .main-title {
    font-size: 2rem;
  }
}

@media screen and (max-width: 480px) {
  .container {
    padding: 0.75rem;
    margin: 0.75rem auto;
    border-radius: calc(var(--border-radius) / 2);
  }
  
  .box {
    padding: 1rem;
    border-radius: calc(var(--border-radius) / 2);
  }
  
  .box h2 {
    font-size: 1.1rem;
    margin-bottom: 0.75rem;
  }
  
  .box li {
    font-size: 0.95rem;
    margin-bottom: 0.4rem;
    text-decoration: none;
  }
  
  .cabecera img {
    width: 30%;
  }
  
  nav {
    border-width: 2px;
  }
  
  nav ul li a {
    padding: 0.6rem 0.75rem;
    font-size: 0.9rem;
  }
  
  .main-title {
    font-size: 1.75rem;
    margin: 1.5rem 0;
  }
}

/* ==================
   Accesibilidad
   ================== */

:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  
  .box,
  .box h2 a,
  nav ul li a {
    transition: none;
  }
  
  .box:hover {
    transform: none;
  }
}