:root {
  --primary-color: #082743;
  --bg-color: #fdfbe7;
  --text-color: #333;
  --card-bg: #fff;
  --radius: 8px;
}

/* Reset y base */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
body {
  font-family: Arial, sans-serif;
  background: var(--bg-color);
  color: var(--text-color);
}
img {
  max-width: 100%;
  display: block;
}
a {
  text-decoration: none;
  color: inherit;
}

/* Header y navegación */
header {
  background: var(--primary-color);
  padding: 1rem;
  border-radius: 0 0 var(--radius) var(--radius);
}
.nav-container {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  color: #fff;
  font-size: 1.25rem;
}
.nav-links {
  list-style: none;
  display: flex;
  gap: 1rem;
}
.nav-links li {
  position: relative;
}
.nav-links a {
  color: #fff;
  padding: 0.5rem;
  border-radius: var(--radius);
  transition: background 0.2s;
}
.nav-links a:hover,
.nav-links a.active {
  background: rgba(255,255,255,0.2);
}
.dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: var(--card-bg);
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  border-radius: var(--radius);
  overflow: hidden;
  z-index: 10;
}
.dropdown:hover .dropdown-menu {
  display: block;
}
.dropdown-menu li a {
  display: block;
  color: var(--text-color);
  padding: 0.5rem 1rem;
  white-space: nowrap;
}
.dropdown-menu li a:hover {
  background: var(--bg-color);
}

/* Main */
main {
  max-width: 960px;
  margin: 2rem auto;
}

/* Card */
.card {
  background: var(--card-bg);
  padding: 1.5rem;
  border-radius: var(--radius);
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
  margin-bottom: 2rem;
}
h2 {
  margin-bottom: 1rem;
}

/* Audio */
#audio {
  margin-bottom: 1.5rem;
}

/* Flex: texto e imagen */
.flex-two {
  display: flex;
  gap: 1.5rem;
}
.text-block {
  flex: 1;
  line-height: 1.6;
}
/* Imagen dentro de text-block (p.ej vocabulario) */
.text-block img {
  margin: 1rem 0;
}

.image-block img {
  width: 350px;
  height: auto;
  border-radius: 4px;
}

/* Tabla de vocabulario */
.vocab-table {
  flex: 1.2;
  background: #d0e1f2;
  border-radius: var(--radius);
  overflow: hidden;
}
.vocab-table table {
  width: 100%;
  border-collapse: collapse;
}
.vocab-table thead {
  background: #000;
  color: #fff;
}
.vocab-table th,
.vocab-table td {
  padding: 0.75rem;
  vertical-align: top;
}
.vocab-table td {
  width: 33%;
}
.vocab-table ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.vocab-table li {
  margin-bottom: 0.5rem;
}

/* Grid de dos columnas */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Gramática y ejercicio */
.grammar,
.exercise {
  background: var(--card-bg);
  padding: 1rem;
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

/* Layout for vocabulary exercises */
.exercise-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem 1rem;
}

.exercise-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.exercise-item .term {
  flex: 0 0 40%;
  text-align: right;
  font-weight: bold;
}

.exercise-item .answer {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.exercise-item .feedback-icon {
  width: 1.25rem;
  text-align: center;
}

.is-valid {
  border-color: #198754;
}

.is-invalid {
  border-color: #dc3545;
}

@media (max-width: 600px) {
  .exercise-grid {
    grid-template-columns: 1fr;
  }
  .exercise-item .term {
    text-align: left;
  }
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main {
  flex: 1;
}

.footer {
  background: var(--primary-color);
  padding: 0.5rem 0;
  color: #fff;
  border-radius: var(--radius) var(--radius) 0 0;
  margin-top: auto;
  box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.1);
  font-size: 0.9rem;
}

.footer-container {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
}

.footer-link {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: opacity 0.2s ease;
}

.footer-link:hover {
  opacity: 0.8;
}

.footer .icon {
  font-size: 1.5rem;
}


.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: #fff;
  font-weight: bold;
  font-size: 1.2rem;
}

.logo {
  height: 40px;
  width: auto;
}

.brand-text {
  display: inline-block;
  color: #fff;
}

/* Tooltips para vocabulario */
.tooltip {
  position: relative;
  border-bottom: 1px dotted #555;
  cursor: help;
}

.tooltiptext {
  visibility: hidden;
  background-color: #f9f9f9;
  color: #000;
  text-align: center;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 2px 6px;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  white-space: nowrap;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
}

@media (max-width: 600px) {
  .tooltiptext {
    bottom: auto;
    top: 125%;
  }
}

/* Botón para desplegar tabla de vocabulario */
.vocab-toggle {
  display: inline-block;
  margin: 1rem 0;
  padding: 0.6rem 1.5rem;
  font-size: 1.1rem;
  background: var(--primary-color);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
}

.vocab-toggle:hover {
  background: #0a3a63;
}

/* Quiz */
.quiz-card {
  max-width: 500px;
  margin: 0 auto 2rem;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 1rem;
}

.quiz-option {
  display: block;
  width: 100%;
  padding: 0.6rem 1.5rem;
  font-size: 1.1rem;
  background: var(--primary-color);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.2s;
}

.quiz-option:hover {
  background: #0a3a63;
}

.quiz-option.correct {
  background: #198754;
}

.quiz-option.incorrect {
  background: #dc3545;
}
@media (max-width: 600px) {
  .flex-two {
    flex-direction: column;
  }
  .image-block img {
    width: 100%;
  }
  .nav-container {
    flex-direction: column;
    align-items: flex-start;
  }
  .nav-links {
    flex-direction: column;
    width: 100%;
    gap: 0.5rem;
  }
  .dropdown-menu {
    position: static;
  }
}

/* --- Curso buttons grid --- */
.curso-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1rem;
  text-align: center;
  margin: 2rem 0;
}

@media (max-width: 900px) {
  .curso-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.curso-btn {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: var(--primary-color);
  color: #fff;
  border-radius: 50%;
  aspect-ratio: 1 / 1;
  padding: 1rem;
  font-size: 0.9rem;
  gap: 0.25rem;
}

.curso-btn i {
  font-size: 1.5rem;
}

@media (max-width: 600px) {
  .curso-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 400px) {
  .curso-grid {
    grid-template-columns: 1fr;
  }
}