/* ============================================
   LESSON ENGINE — Estilos de lecciones
   ============================================ */

/* ── Layout de lección ── */
.lesson-layout {
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.lesson-topbar {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: .875rem var(--container-pad);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-back {
  display: flex;
  align-items: center;
  gap: .4rem;
  font-size: .875rem;
  color: var(--color-text-muted);
  font-weight: var(--weight-medium);
  transition: color var(--transition);
  flex-shrink: 0;
}
.topbar-back:hover { color: var(--color-primary); }

.topbar-progress {
  flex: 1;
  display: flex;
  align-items: center;
  gap: .75rem;
}
.topbar-bar {
  flex: 1;
  height: 8px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.topbar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}
.topbar-steps {
  font-size: .8125rem;
  font-weight: var(--weight-semi);
  color: var(--color-text-muted);
  flex-shrink: 0;
  min-width: 4rem;
  text-align: right;
}

.topbar-level {
  padding: .3rem .75rem;
  border-radius: var(--radius-full);
  font-size: .75rem;
  font-weight: var(--weight-bold);
  letter-spacing: .06em;
  background: var(--color-primary-lt);
  color: var(--color-primary);
  flex-shrink: 0;
}

/* ── Área de contenido ── */
.lesson-main {
  padding: 2.5rem var(--container-pad);
  max-width: 720px;
  margin: 0 auto;
  width: 100%;
}

/* ── Pantallas de la lección ── */
.lesson-screen {
  display: none;
  animation: fadeSlide .3s ease forwards;
}
.lesson-screen.active { display: block; }

@keyframes fadeSlide {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Pantalla: Bienvenida/Intro ── */
.screen-intro {
  text-align: center;
  padding: 2rem 0;
}
.intro-icon {
  font-size: 4rem;
  margin-bottom: 1.25rem;
  line-height: 1;
}
.intro-tag {
  display: inline-block;
  font-size: .8rem;
  font-weight: var(--weight-semi);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-lt);
  padding: .3rem .9rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}
.intro-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  margin-bottom: 1rem;
}
.intro-desc {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  max-width: 520px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}
.intro-objectives {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  margin: 0 auto 2.5rem;
  max-width: 460px;
  text-align: left;
}
.intro-objectives h4 {
  font-size: .875rem;
  font-weight: var(--weight-semi);
  color: var(--color-text-muted);
  letter-spacing: .06em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}
.intro-objectives ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: .6rem;
}
.intro-objectives li {
  display: flex;
  align-items: flex-start;
  gap: .6rem;
  font-size: .9375rem;
  color: var(--color-text);
}
.intro-objectives li::before {
  content: '✓';
  color: var(--color-accent);
  font-weight: var(--weight-bold);
  flex-shrink: 0;
  margin-top: .05rem;
}

/* ── Pantalla: Vocabulario ── */
.vocab-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2.5rem;
}
.vocab-card {
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.vocab-card:hover, .vocab-card.revealed {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
.vocab-card.revealed .vocab-translation {
  opacity: 1;
  transform: translateY(0);
}
.vocab-emoji   { font-size: 2.25rem; margin-bottom: .75rem; }
.vocab-english {
  font-size: 1.125rem;
  font-weight: var(--weight-semi);
  color: var(--color-text);
  margin-bottom: .35rem;
}
.vocab-phonetic {
  font-size: .8125rem;
  color: var(--color-text-light);
  font-style: italic;
  margin-bottom: .5rem;
}
.vocab-translation {
  font-size: .9rem;
  color: var(--color-text-muted);
  opacity: 0;
  transform: translateY(4px);
  transition: all var(--transition);
}
.vocab-hint {
  font-size: .75rem;
  color: var(--color-text-light);
  margin-top: .4rem;
}

.screen-label {
  font-size: .8125rem;
  font-weight: var(--weight-semi);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.screen-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

/* ── Pantalla: Diálogo/Patrón ── */
.dialogue-block {
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin-bottom: 2rem;
  border: 1px solid var(--color-border);
}
.dialogue-title {
  font-size: .8125rem;
  font-weight: var(--weight-semi);
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
}
.dialogue-line {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .75rem 1rem;
  align-items: start;
  padding: .75rem 0;
  border-bottom: 1px solid var(--color-border);
}
.dialogue-line:last-child { border-bottom: none; }

.dialogue-speaker {
  font-size: .75rem;
  font-weight: var(--weight-bold);
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--color-primary);
  padding-top: .1rem;
  min-width: 4rem;
}
.dialogue-content {}
.dialogue-en {
  font-size: 1.0625rem;
  font-weight: var(--weight-medium);
  color: var(--color-text);
  margin-bottom: .25rem;
}
.dialogue-es {
  font-size: .875rem;
  color: var(--color-text-muted);
}

.pattern-note {
  background: var(--color-primary-lt);
  border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 1rem 1.25rem;
  margin-bottom: 2rem;
  font-size: .9375rem;
}
.pattern-note strong { color: var(--color-primary); }

/* ── Pantalla: Ejercicios ── */
.exercise-block {
  margin-bottom: 2rem;
}
.exercise-question {
  font-size: 1.125rem;
  font-weight: var(--weight-medium);
  color: var(--color-text);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}
.exercise-hint {
  font-size: .875rem;
  color: var(--color-text-muted);
  margin-bottom: 1.25rem;
}

/* Opción múltiple */
.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .75rem;
}
.option-btn {
  padding: .9rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  font-size: .9375rem;
  font-weight: var(--weight-medium);
  color: var(--color-text);
  cursor: pointer;
  transition: all var(--transition);
  text-align: left;
  font-family: var(--font-sans);
}
.option-btn:hover:not(:disabled) {
  border-color: var(--color-primary);
  background: var(--color-primary-lt);
  color: var(--color-primary);
}
.option-btn.selected {
  border-color: var(--color-primary);
  background: var(--color-primary-lt);
  color: var(--color-primary);
  font-weight: var(--weight-semi);
  box-shadow: 0 0 0 3px rgba(26, 86, 219, .15);
}
.option-btn.correct {
  border-color: var(--color-accent);
  background: var(--color-accent-lt);
  color: var(--color-accent);
}
.option-btn.incorrect {
  border-color: var(--color-danger);
  background: #fee2e2;
  color: var(--color-danger);
}
.option-btn:disabled { cursor: default; }

/* Frase con espacio en blanco */
.fill-blank-sentence {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-wrap: wrap;
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  margin-bottom: 1rem;
  font-size: 1.25rem;
  font-weight: var(--weight-semi);
  color: var(--color-text);
}
.fbs-blank {
  color: var(--color-primary);
  border-bottom: 2.5px solid var(--color-primary);
  min-width: 90px;
  text-align: center;
  letter-spacing: .1em;
}

/* Input de texto */
.exercise-input {
  width: 100%;
  padding: .9rem 1rem;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-surface);
  transition: border-color var(--transition);
  outline: none;
}
.exercise-input:focus { border-color: var(--color-primary); }
.exercise-input.correct { border-color: var(--color-accent); background: var(--color-accent-lt); }
.exercise-input.incorrect { border-color: var(--color-danger); background: #fee2e2; }

/* Feedback */
.exercise-feedback {
  display: none;
  align-items: flex-start;
  gap: .75rem;
  padding: 1rem 1.25rem;
  border-radius: var(--radius-md);
  margin-top: 1rem;
  font-size: .9375rem;
}
.exercise-feedback.show { display: flex; }
.exercise-feedback.feedback-correct {
  background: var(--color-accent-lt);
  color: #065f46;
  border: 1px solid #a7f3d0;
}
.exercise-feedback.feedback-incorrect {
  background: #fee2e2;
  color: #991b1b;
  border: 1px solid #fecaca;
}
.feedback-icon { font-size: 1.1rem; flex-shrink: 0; margin-top: .05rem; }
.feedback-text {}
.feedback-text strong { display: block; margin-bottom: .2rem; }

/* ── Barra inferior de navegación ── */
.lesson-nav {
  position: sticky;
  bottom: 0;
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: 1rem var(--container-pad);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  z-index: 50;
}
.lesson-nav-left { display: flex; align-items: center; gap: .75rem; }
.xp-badge {
  display: flex;
  align-items: center;
  gap: .3rem;
  font-size: .8125rem;
  font-weight: var(--weight-semi);
  color: var(--color-warning);
  background: #fef3c7;
  padding: .3rem .7rem;
  border-radius: var(--radius-full);
}

/* ── Pantalla: Completado ── */
.screen-complete {
  text-align: center;
  padding: 2rem 0;
}
.complete-icon { font-size: 5rem; margin-bottom: 1.25rem; }
.complete-title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  margin-bottom: .75rem;
}
.complete-subtitle {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  max-width: 440px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}
.complete-stats {
  display: flex;
  justify-content: center;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}
.cs-item { display: flex; flex-direction: column; align-items: center; }
.cs-num {
  font-size: 2rem;
  font-weight: var(--weight-bold);
  color: var(--color-primary);
  line-height: 1;
}
.cs-label {
  font-size: .8125rem;
  color: var(--color-text-muted);
  margin-top: .3rem;
}
.complete-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Responsive ── */
@media (max-width: 600px) {
  .options-grid { grid-template-columns: 1fr; }
  .vocab-grid   { grid-template-columns: 1fr 1fr; }
  .complete-stats { gap: 1.5rem; }
}