:root {
  --green: #008C45;
  --red: #CD212A;
  --blue: #1D4F91;
  --white: #F4F5F0;
  --bg: #FAFAFA;
  --card: #FFFFFF;
  --text: #333333;
  --text-light: #666666;
  --border: #E0E0E0;
  --correct: #2E7D32;
  --incorrect: #C62828;
  --almost: #E65100;
  --masc: #1565C0;
  --fem: #AD1457;
  --radius: 12px;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

/* === NAV === */
.navbar {
  background: var(--blue);
  color: white;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}
.navbar .logo { font-size: 1.5rem; font-weight: 700; text-decoration: none; color: white; }
.navbar .flag { font-size: 1.2rem; }
.navbar nav { margin-left: auto; display: flex; gap: 1.5rem; }
.navbar nav a { color: rgba(255,255,255,0.85); text-decoration: none; font-weight: 500; }
.navbar nav a:hover, .navbar nav a.active { color: white; }

/* === DASHBOARD === */
.dashboard { max-width: 1000px; margin: 0 auto; padding: 2rem; }
.dashboard h1 { font-size: 2rem; margin-bottom: 0.5rem; }
.dashboard .subtitle { color: var(--text-light); margin-bottom: 2rem; }

.stats-bar {
  display: flex; gap: 1.5rem; margin-bottom: 2rem;
  padding: 1rem; background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.stat { text-align: center; flex: 1; }
.stat-value { font-size: 1.8rem; font-weight: 700; color: var(--blue); }
.stat-label { font-size: 0.85rem; color: var(--text-light); }

#lesson-grid { display: flex; flex-direction: column; gap: 1rem; }

.lesson-card {
  display: flex; align-items: center; gap: 1.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow); text-decoration: none; color: var(--text);
  border-left: 4px solid var(--blue);
  transition: transform 0.15s, box-shadow 0.15s;
}
.lesson-card:hover { transform: translateY(-2px); box-shadow: 0 4px 16px rgba(0,0,0,0.12); }
.lesson-card.completed { border-left-color: var(--green); }
.lesson-icon {
  width: 56px; height: 56px; border-radius: 50%;
  background: var(--blue); color: white;
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; font-size: 0.85rem; flex-shrink: 0;
}
.lesson-card.completed .lesson-icon { background: var(--green); }
.lesson-info { flex: 1; }
.lesson-info h3 { font-size: 1.1rem; margin-bottom: 0.25rem; }
.lesson-subtitle { color: var(--text-light); font-size: 0.9rem; }
.lesson-date { font-size: 0.8rem; color: var(--text-light); }
.lesson-topics { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 0.5rem; }
.topic-tag {
  font-size: 0.75rem; padding: 0.15rem 0.6rem;
  background: #E8EAF6; color: var(--blue);
  border-radius: 99px;
}
.lesson-check { font-size: 1.5rem; color: var(--green); font-weight: 700; }
.lesson-progress-bar { height: 4px; background: var(--border); border-radius: 2px; margin-bottom: 0.5rem; }
.progress-fill { height: 100%; background: var(--green); border-radius: 2px; transition: width 0.3s; }

/* === LESSON PAGE === */
.lesson-page { max-width: 800px; margin: 0 auto; padding: 2rem; }
.lesson-header { margin-bottom: 2rem; }
.lesson-header h1 { font-size: 1.8rem; color: var(--blue); }
.lesson-header .subtitle { color: var(--text-light); margin: 0.25rem 0; }
.lesson-nav { display: flex; justify-content: space-between; margin: 1rem 0; }
.lesson-nav a {
  padding: 0.5rem 1rem; background: var(--card); border-radius: var(--radius);
  text-decoration: none; color: var(--blue); font-weight: 500;
  box-shadow: var(--shadow);
}
.lesson-nav a.disabled { opacity: 0.3; pointer-events: none; }
.lesson-meta { font-size: 0.9rem; color: var(--text-light); margin-bottom: 0.5rem; }

.section { margin-bottom: 2.5rem; }
.section > h2 {
  font-size: 1.3rem; color: var(--blue);
  border-bottom: 2px solid var(--blue); padding-bottom: 0.5rem;
  margin-bottom: 1rem;
}

.pdf-links { display: flex; gap: 0.75rem; flex-wrap: wrap; margin-top: 0.5rem; }
.pdf-link {
  padding: 0.4rem 1rem; background: #E8EAF6; color: var(--blue);
  border-radius: var(--radius); text-decoration: none; font-size: 0.85rem; font-weight: 500;
}
.pdf-link:hover { background: #C5CAE9; }

/* Grammar */
.grammar-card {
  background: var(--card); border-radius: var(--radius); padding: 1.25rem;
  box-shadow: var(--shadow); margin-bottom: 1rem;
}
.grammar-card h3 { color: var(--green); margin-bottom: 0.75rem; font-size: 1.1rem; }
.grammar-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
.grammar-table th { background: var(--blue); color: white; padding: 0.6rem 0.8rem; text-align: left; }
.grammar-table td { padding: 0.6rem 0.8rem; border-bottom: 1px solid var(--border); }
.grammar-table tr:last-child td { border-bottom: none; }
.grammar-list { padding-left: 1.25rem; }
.grammar-list li { margin-bottom: 0.4rem; }

/* Vocabulary */
#vocabulary { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 0.75rem; }
.vocab-card {
  background: var(--card); border-radius: var(--radius); padding: 0.75rem 1rem;
  box-shadow: var(--shadow); border-left: 3px solid var(--border);
  display: flex; flex-direction: column; position: relative;
}
.vocab-card.masc { border-left-color: var(--masc); }
.vocab-card.fem { border-left-color: var(--fem); }
.vocab-it { font-weight: 600; font-size: 1rem; }
.vocab-pt { color: var(--text-light); font-size: 0.85rem; }
.vocab-note {
  position: absolute; top: 0.5rem; right: 0.5rem;
  font-size: 0.7rem; color: var(--text-light); font-style: italic;
}

/* Speak buttons */
.speak-btn {
  background: none; border: none; cursor: pointer;
  font-size: 1.1rem; padding: 0.15rem 0.3rem;
  border-radius: 4px; transition: all 0.2s;
  opacity: 0.5;
}
.speak-btn:hover { opacity: 1; background: #E8EAF6; }
.speak-btn.speaking { opacity: 1; transform: scale(1.2); }
.speak-btn.speak-small { font-size: 0.85rem; vertical-align: middle; margin-left: 0.25rem; }
.vocab-card .speak-btn { position: absolute; bottom: 0.5rem; right: 0.5rem; }

/* Audio tracks */
.audio-card {
  background: var(--card); border-radius: var(--radius); padding: 1.25rem;
  box-shadow: var(--shadow); margin-bottom: 1rem;
  border-left: 4px solid var(--green);
}
.audio-card h4 { color: var(--green); margin-bottom: 0.25rem; }
.audio-desc { color: var(--text-light); font-size: 0.9rem; margin-bottom: 0.75rem; }
.audio-card audio { width: 100%; border-radius: 8px; }
.audio-words { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.75rem; }
.audio-word {
  display: inline-flex; align-items: center; gap: 0.2rem;
  padding: 0.25rem 0.7rem; background: #F1F8E9; color: #33691E;
  border-radius: 99px; font-size: 0.85rem; font-weight: 500;
}
.audio-section-tag {
  display: inline-block; margin-top: 0.5rem;
  font-size: 0.75rem; padding: 0.15rem 0.6rem;
  background: #E8F5E9; color: var(--green);
  border-radius: 99px;
}

/* === EXERCISES === */
.exercise-block {
  background: var(--card); border-radius: var(--radius); padding: 1.5rem;
  box-shadow: var(--shadow); margin-bottom: 1.5rem;
}
.exercise-header { margin-bottom: 1rem; }
.exercise-header h3 { font-size: 1.05rem; }
.exercise-source { font-size: 0.8rem; color: var(--text-light); font-style: italic; }
.prev-score { font-size: 0.8rem; color: var(--green); margin-top: 0.25rem; }

.exercise-item { margin-bottom: 0.75rem; display: flex; align-items: flex-start; gap: 0.5rem; flex-wrap: wrap; }
.item-number { font-weight: 600; color: var(--blue); min-width: 2rem; }

/* Fill blanks */
.fill-text { flex: 1; }
.fill-input {
  border: none; border-bottom: 2px solid var(--border);
  padding: 0.25rem 0.5rem; font-size: inherit; font-family: inherit;
  width: 120px; outline: none; background: transparent;
  transition: border-color 0.2s;
}
.fill-input:focus { border-color: var(--blue); }
.fill-input.correct { border-color: var(--correct); color: var(--correct); }
.fill-input.incorrect { border-color: var(--incorrect); color: var(--incorrect); }
.fill-input.almost { border-color: var(--almost); color: var(--almost); }
.hint-btn {
  width: 24px; height: 24px; border-radius: 50%;
  background: #E8EAF6; color: var(--blue); border: none;
  cursor: pointer; font-size: 0.8rem; font-weight: 700;
}
.feedback { font-size: 0.8rem; color: var(--incorrect); margin-left: 0.25rem; }

/* Multiple choice */
.mc-prompt { flex: 1; font-weight: 500; }
.mc-options { display: flex; gap: 0.5rem; flex-wrap: wrap; width: 100%; padding-left: 2rem; }
.mc-option {
  padding: 0.5rem 1rem; border: 2px solid var(--border); border-radius: var(--radius);
  background: var(--card); cursor: pointer; font-size: 0.9rem;
  transition: all 0.2s;
}
.mc-option:hover { border-color: var(--blue); background: #E8EAF6; }
.mc-option.correct { border-color: var(--correct); background: #E8F5E9; color: var(--correct); font-weight: 600; }
.mc-option.incorrect { border-color: var(--incorrect); background: #FFEBEE; color: var(--incorrect); }

/* Matching */
.matching-container { display: flex; gap: 2rem; justify-content: center; }
.matching-col { display: flex; flex-direction: column; gap: 0.5rem; }
.matching-item {
  padding: 0.6rem 1.25rem; border: 2px solid var(--border); border-radius: var(--radius);
  cursor: pointer; text-align: center; min-width: 100px;
  transition: all 0.2s; user-select: none;
}
.matching-item:hover { border-color: var(--blue); }
.matching-item.selected { border-color: var(--blue); background: #E8EAF6; }
.matching-item.matched.correct { border-color: var(--correct); background: #E8F5E9; cursor: default; }
.matching-item.incorrect { border-color: var(--incorrect); background: #FFEBEE; }

/* True/False */
.tf-statement { flex: 1; }
.tf-buttons { display: flex; gap: 0.5rem; }
.tf-btn {
  padding: 0.4rem 1rem; border: 2px solid var(--border); border-radius: var(--radius);
  background: var(--card); cursor: pointer; font-weight: 600;
  transition: all 0.2s;
}
.tf-btn:hover { border-color: var(--blue); }
.tf-btn.correct { border-color: var(--correct); background: #E8F5E9; color: var(--correct); }
.tf-btn.incorrect { border-color: var(--incorrect); background: #FFEBEE; color: var(--incorrect); }

/* Conjugation */
.conjugation-block { margin-bottom: 1.5rem; }
.verb-infinitive { color: var(--blue); font-size: 1.2rem; margin-bottom: 0.75rem; }
.conjugation-grid { display: grid; gap: 0.5rem; }
.conj-row { display: flex; align-items: center; gap: 0.75rem; }
.conj-pronoun { font-weight: 600; min-width: 60px; color: var(--blue); }
.conj-input {
  border: none; border-bottom: 2px solid var(--border);
  padding: 0.25rem 0.5rem; font-size: inherit; font-family: inherit;
  width: 150px; outline: none; background: transparent;
}
.conj-input:focus { border-color: var(--blue); }
.conj-input.correct { border-color: var(--correct); color: var(--correct); }
.conj-input.incorrect { border-color: var(--incorrect); color: var(--incorrect); }
.conj-input.almost { border-color: var(--almost); color: var(--almost); }

/* Buttons & Score */
.btn { padding: 0.6rem 1.5rem; border: none; border-radius: var(--radius); cursor: pointer; font-weight: 600; font-size: 0.95rem; transition: all 0.2s; }
.btn-check { background: var(--blue); color: white; margin-top: 1rem; }
.btn-check:hover { background: #153d73; }
.btn-green { background: var(--green); color: white; }
.btn-green:hover { background: #006d35; }

.score-display {
  margin-top: 1rem; padding: 0.75rem; border-radius: var(--radius);
  text-align: center; font-weight: 700; font-size: 1.1rem;
}
.score-display.perfect { background: #E8F5E9; color: var(--correct); }
.score-display.good { background: #FFF3E0; color: var(--almost); }
.score-display.needs-work { background: #FFEBEE; color: var(--incorrect); }

/* Video section */
.video-link {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.75rem 1.25rem; background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow); text-decoration: none; color: var(--blue); font-weight: 500;
}
.video-link:hover { background: #E8EAF6; }

/* Responsive */
@media (max-width: 640px) {
  .navbar { padding: 0.75rem 1rem; }
  .dashboard, .lesson-page { padding: 1rem; }
  #vocabulary { grid-template-columns: 1fr 1fr; }
  .matching-container { flex-direction: column; gap: 1rem; }
  .stats-bar { flex-wrap: wrap; }
}