:root {
  --bg-color: #fdfbf7;
  --text-color: #4a4a4a;
  --primary-pastel: #a0c4ff;
  --secondary-pastel: #ffadad;
  --accent-pastel: #fdffb6;
  --soft-green: #caffbf;
  --soft-purple: #bdb2ff;
  --white: #ffffff;
  --shadow: 0 8px 24px rgba(149, 157, 165, 0.15);
  --btn-radius: 16px;
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Nunito', sans-serif; }

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
.site-header {
  display: flex;
  align-items: center;
  padding: 1rem 1.5rem;
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-left { flex: 0 0 auto; }
.header-inner { flex: 1; text-align: center; }
.header-right { flex: 0 0 auto; }

.theme-btn { background: transparent; border: none; font-size: 1.5rem; cursor: pointer; transition: transform 0.2s; }
.theme-btn:hover { transform: scale(1.1); }

h1 { font-size: 1.2rem; color: #333; margin-bottom: 4px; }
.teacher { font-size: 0.9rem; color: #888; font-weight: 500; }

.nav-btn {
  background: transparent;
  border: none;
  cursor: pointer;
  transition: transform 0.2s;
  color: var(--text-color);
  display: flex;
  align-items: center;
}
.nav-btn:hover { transform: scale(1.1); }

/* Container */
.container {
  max-width: 600px;
  margin: 0 auto;
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hidden { display: none !important; }

/* Home & Lang Cards */
.home h2 { text-align: center; margin-bottom: 20px; color: #555; }
.home { flex: 1; display: flex; flex-direction: column; }

.lang-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  flex: 1;
  min-height: 50vh;
}

.lang-card {
  border: none;
  border-radius: 20px;
  background-size: cover;
  background-position: center;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
}
.lang-card:hover { transform: translateY(-5px); box-shadow: 0 12px 30px rgba(0,0,0,0.2); }

/* Menu Options */
.menu-grid {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.menu-card {
  background: var(--white);
  border: 2px solid var(--soft-purple);
  padding: 24px;
  border-radius: var(--btn-radius);
  font-size: 1.1rem;
  font-weight: 600;
  color: #555;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: var(--shadow);
}
.menu-card:hover { background: var(--soft-purple); color: white; }

/* Back Button (High Contrast) */
.back-btn {
  background-color: #e63946; /* Solid high contrast red */
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 12px;
  font-weight: bold;
  cursor: pointer;
  margin-top: 10px;
  display: inline-block;
}
.back-btn:hover { opacity: 0.9; }

/* Grades Grid */
.grades-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 20px;
}

.grade-btn {
  padding: 20px;
  border: none;
  border-radius: 16px;
  background: var(--white);
  font-size: 1rem;
  font-weight: 700;
  box-shadow: var(--shadow);
  cursor: pointer;
  transition: 0.2s;
}
.grade-btn:hover { transform: translateY(-3px); }

/* Lang specific theming for grades */
.grades.lang-it .grade-btn { color: #2a9d8f; border-bottom: 4px solid #2a9d8f; }
.grades.lang-en .grade-btn { color: #3a86ff; border-bottom: 4px solid #3a86ff; }

/* Practice Section */
.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}
.section-head h2 { font-size: 1.1rem; }

.exercise {
  background: var(--white);
  padding: 24px;
  border-radius: 24px;
  box-shadow: var(--shadow);
  text-align: center;
}

.phrase {
  font-size: 1.5rem;
  margin-bottom: 30px;
  color: #333;
  font-weight: 600;
}

.options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.opt {
  padding: 16px;
  border: 2px solid #eee;
  border-radius: 16px;
  background: white;
  font-size: 1.1rem;
  cursor: pointer;
  transition: all 0.2s;
}
.opt:hover:not(:disabled) { background: #f9f9f9; border-color: #ddd; }
.opt.selected { border-color: var(--primary-pastel); background: #eef4ff; }
.opt.correct { background: var(--soft-green); border-color: #b7e4c7; color: #1b4332; }
.opt.incorrect { background: var(--secondary-pastel); border-color: #ff9999; color: #590d0d; }

.controls { margin-top: 24px; min-height: 60px; }

.check-btn {
  width: 100%;
  padding: 16px;
  border-radius: 16px;
  border: none;
  font-size: 1rem;
  font-weight: 800;
  text-transform: uppercase;
  cursor: pointer;
  background: var(--soft-green);
  color: #1b4332;
  box-shadow: 0 4px 0 #b7e4c7;
  transition: transform 0.1s;
}
.check-btn:active { transform: translateY(4px); box-shadow: none; }
.check-btn:disabled { background: #eee; color: #aaa; box-shadow: none; cursor: not-allowed; }

.feedback { margin-top: 16px; font-weight: bold; font-size: 1.1rem; }
.feedback.good { color: #2a9d8f; }
.feedback.bad { color: #e63946; }

.progress { text-align: center; margin-top: 20px; color: #aaa; font-size: 0.9rem; }

/* Mobile */
@media (max-width: 480px) {
  .lang-grid { height: 200px; }
  .phrase { font-size: 1.2rem; }
}

/* Dark Mode */
body.dark-mode {
  --bg-color: #121212;
  --text-color: #e0e0e0;
  --white: #1e1e1e;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
}
body.dark-mode h1,
body.dark-mode .teacher,
body.dark-mode .home h2,
body.dark-mode .menu-card,
body.dark-mode .phrase {
  color: var(--text-color);
}
body.dark-mode .opt {
  background-color: #2d2d2d;
  border-color: #444;
  color: var(--text-color);
}
body.dark-mode .opt:hover:not(:disabled) {
  background: #3d3d3d;
  border-color: #666;
}
body.dark-mode .opt.selected {
  background-color: #283747;
  border-color: #5dade2;
}
body.dark-mode .opt.correct {
  background-color: #145a32;
  border-color: #2ecc71;
  color: #ffffff;
}
body.dark-mode .opt.incorrect {
  background-color: #78281f;
  border-color: #e74c3c;
  color: #ffffff;
}

/* Tooltip Evaluaciones */
.eval-wrapper {
  position: relative;
  width: 100%;
  display: flex;
  align-items: center;
  gap: 12px;
}
.eval-wrapper .menu-card { flex: 1; }

.info-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 2px solid var(--soft-purple);
  background: transparent;
  color: var(--soft-purple);
  font-weight: 800;
  font-size: 1.4rem;
  font-family: 'Times New Roman', serif;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s, background 0.2s, color 0.2s;
  flex-shrink: 0;
}
.info-btn:hover { background: var(--soft-purple); color: white; transform: scale(1.1); }

.tooltip {
  visibility: hidden;
  background-color: #333;
  color: #fff;
  text-align: left;
  border-radius: 12px;
  padding: 15px;
  position: absolute;
  z-index: 20;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  margin-top: 12px;
  width: 90%;
  max-width: 300px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.2);
  opacity: 0;
  transition: opacity 0.3s, transform 0.3s;
  font-size: 0.95rem;
  line-height: 1.5;
}
.tooltip.visible { visibility: visible; opacity: 1; transform: translateX(-50%) translateY(0); }

/* Tooltip Dark Mode */
body.dark-mode .tooltip { background-color: #444; border: 1px solid #555; }

/* --- UI Evaluación #1 (Inglés 6to) --- */
.eval-ui { margin-bottom: 20px; }
.eval-top-bar { display: flex; align-items: center; gap: 15px; justify-content: space-between; }

.eval-counter { font-weight: 800; color: var(--soft-purple); font-size: 1.1rem; min-width: 45px; }

.eval-progress {
  flex: 1;
  display: flex;
  gap: 4px;
  height: 12px;
}
.progress-segment {
  flex: 1;
  background: #e0e0e0;
  border-radius: 4px;
  transition: background 0.3s;
}
.progress-segment.filled { background: var(--primary-pastel); }

.eval-scores { display: flex; gap: 10px; }
.score-pill {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 12px;
  border-radius: 20px;
  font-weight: bold;
  font-size: 0.9rem;
  background: var(--white);
  box-shadow: var(--shadow);
}
.score-pill.correct { color: #2a9d8f; }
.score-pill.incorrect { color: #e63946; }

/* Hint Section */
.hint-box { margin: 20px 0; text-align: center; }
.hint-btn {
  background: none; border: 2px dashed var(--soft-purple);
  color: var(--soft-purple); padding: 8px 16px;
  border-radius: 12px; cursor: pointer; font-weight: bold;
  transition: all 0.2s;
}
.hint-btn:hover { background: var(--soft-purple); color: white; }
.hint-content {
  margin-top: 10px; padding: 12px;
  background: #fff3cd; color: #856404;
  border-radius: 8px; font-size: 0.95rem;
  animation: fadeIn 0.3s ease;
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(-5px); } to { opacity: 1; transform: translateY(0); } }

/* Dark Mode Adjustments for Eval UI */
body.dark-mode .progress-segment { background: #333; }
body.dark-mode .progress-segment.filled { background: var(--primary-pastel); }
body.dark-mode .score-pill { background: #2d2d2d; }
body.dark-mode .hint-content { background: #4a3b00; color: #ffeb3b; }

/* Footer */
.site-footer {
  text-align: center;
  padding: 20px;
  font-size: 0.8rem;
  color: #999;
  margin-top: auto;
}
body.dark-mode .site-footer { color: #666; }

/* Popup Styles */
.popup-overlay {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(5px);
  z-index: 1000;
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.popup-overlay.active { opacity: 1; pointer-events: auto; }

.popup-content {
  background: var(--white);
  padding: 2.5rem 2rem;
  border-radius: 24px;
  width: 90%;
  max-width: 420px;
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
  position: relative;
  text-align: center;
  transform: translateY(20px);
  transition: transform 0.3s ease;
}
.popup-overlay.active .popup-content { transform: translateY(0); }

.close-popup-btn {
  position: absolute;
  top: 15px;
  right: 20px;
  background: none;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  color: #aaa;
  line-height: 1;
}
.close-popup-btn:hover { color: var(--text-color); }

.popup-content h3 { margin-bottom: 12px; color: var(--text-color); }
.popup-content p { font-size: 0.95rem; color: #666; margin-bottom: 24px; line-height: 1.5; }

.popup-form { display: flex; flex-direction: column; gap: 12px; }
.popup-form input, .popup-form textarea {
  width: 100%; padding: 12px 16px; border: 1px solid #ddd; border-radius: 12px;
  font-family: inherit; font-size: 0.95rem; background: #f9f9f9; color: #333;
}
.popup-form textarea { resize: vertical; min-height: 80px; }
.popup-submit-btn {
  background: var(--soft-purple); color: white; border: none; padding: 14px;
  border-radius: 12px; font-weight: bold; cursor: pointer; transition: opacity 0.2s; font-size: 1rem;
}
.popup-submit-btn:hover { opacity: 0.9; }

/* Dark Mode Popup */
body.dark-mode .popup-content { background: #1e1e1e; }
body.dark-mode .popup-content p { color: #aaa; }
body.dark-mode .popup-form input, body.dark-mode .popup-form textarea { background: #2d2d2d; border-color: #444; color: #eee; }

#evalPopupBody { color: #666; }
body.dark-mode #evalPopupBody { color: #e0e0e0; }