/* ============================================================
   Fislab — shared lesson-page template styles
   Brand tokens reused from the homepage (primary green / secondary red)
   ============================================================ */
:root {
  --brand-primary: #00573f;
  --brand-primary-dark: #012116;
  --brand-primary-light: #8dd5b6;
  --brand-primary-lighter: #a9f2d1;
  --brand-secondary: #bb001e;
  --brand-secondary-dark: #7a0013;
  --brand-secondary-light: #ffb3ae;
  --brand-surface: #fcf9f8;
  --brand-surface-alt: #f6f3f2;
  --brand-ink: #1c1b1b;
  --brand-ink-soft: #3f4944;
}

body.lesson-body {
  background: var(--brand-surface);
  color: var(--brand-ink);
  font-family: "Inter", "Tahoma", sans-serif;
}

/* Tailwind's preflight resets every <svg> to display:block, which breaks
   MathJax's inline equations (each one jumps to its own line mid-sentence). */
mjx-container, mjx-container svg {
  display: inline-block !important;
}

.lesson-container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 16px 60px;
}

/* ===== شريط عنوان الدرس ===== */
.lesson-hero {
  background: linear-gradient(180deg, #0a1a13 0%, #050b08 100%);
  color: #fff;
  padding: 130px 16px 50px;
  margin-bottom: 30px;
}
.lesson-hero .crumbs {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 14px;
}
.lesson-hero .crumbs a { color: rgba(255, 255, 255, 0.8); text-decoration: none; }
.lesson-hero .crumbs a:hover { color: var(--brand-primary-lighter); }
.lesson-hero h1 {
  font-family: "Montserrat", sans-serif;
  font-size: clamp(24px, 4vw, 38px);
  font-weight: 700;
  margin-bottom: 6px;
}
.lesson-hero .en-subtitle {
  color: rgba(255, 255, 255, 0.55);
  font-size: 16px;
  margin-bottom: 20px;
}
.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}
.lesson-meta span {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  padding: 6px 16px;
  font-size: 13px;
  color: #fff;
}

/* ===== أزرار التبديل بين اللغتين ===== */
.lang-switch {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 22px;
  flex-wrap: wrap;
}
body.lang-ar .lang-switch { justify-content: flex-start; }
body.lang-ar .lang-switch { flex-direction: row-reverse; }

.lang-btn {
  padding: 10px 24px;
  border: none;
  border-radius: 10px;
  font-size: 15px;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.25s ease;
}
.lang-btn-ar { background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-dark)); color: #fff; }
.lang-btn-ar:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(0, 87, 63, 0.4); }
.lang-btn-en { background: linear-gradient(135deg, var(--brand-secondary), var(--brand-secondary-dark)); color: #fff; }
.lang-btn-en:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(187, 0, 30, 0.4); }
.lang-btn.active { outline: 3px solid var(--brand-primary-lighter); outline-offset: 2px; }

/* ===== النصوص الثنائية اللغة ===== */
.arabic-text { display: none; }
.english-text { display: block; }
body.lang-ar .arabic-text { display: block; }
body.lang-ar .english-text { display: none; }
body.lang-en .arabic-text { display: none; }
body.lang-en .english-text { display: block; }

/* ===== صناديق الأسئلة ===== */
.qntxtbox {
  background: #fff;
  border-radius: 14px;
  margin: 20px 0;
  padding: 20px 25px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
  border: 1px solid #e3ede8;
  transition: box-shadow 0.3s ease;
}
.qntxtbox:hover { box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1); }

.question-number { display: flex; align-items: center; margin-bottom: 15px; }
.question-number span { color: var(--brand-primary); font-weight: bold; font-size: 24px; margin-inline-end: 10px; }

.question-text {
  font-size: 18px;
  font-weight: bold;
  color: var(--brand-primary);
  margin: 15px 0;
  padding: 15px;
  background: var(--brand-surface-alt);
  border-radius: 8px;
  border-inline-start: 5px solid var(--brand-primary);
  text-align: center;
}

/* ===== خيارات الاختيار ===== */
.quiz-container { margin: 20px 0; }
.option {
  display: flex;
  align-items: center;
  padding: 14px 18px;
  margin: 10px 0;
  border: 2px solid #e0e0e0;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.25s ease;
  background-color: #fafafa;
}
body.lang-ar .option { flex-direction: row-reverse; }
.option:hover { background-color: #eef7f2; transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); }

.option-letter {
  font-weight: bold;
  font-size: 18px;
  min-width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background-color: #e8ecf1;
  transition: all 0.25s ease;
  margin-inline-end: 15px;
}
.option-text { font-size: 16px; flex-grow: 1; line-height: 1.6; }

.option.selected.correct,
.option.correct-answer { border-color: var(--brand-primary); background-color: #e8f3ee; }
.option.selected.incorrect { border-color: var(--brand-secondary); background-color: #fbe9ea; }
.option.selected { transform: scale(1.02); box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12); }

@keyframes pulse { 0% { transform: scale(1); } 50% { transform: scale(1.03); } 100% { transform: scale(1); } }

/* ===== الحل ===== */
.solution-link {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 20px;
  padding: 10px;
  background-color: #f5f5f5;
  border-radius: 8px;
  color: #333;
  transition: all 0.3s;
  cursor: pointer;
  border: none;
  font-size: 16px;
  font-weight: bold;
  width: 100%;
}
.solution-link:hover { background-color: #e8ecf1; transform: translateY(-2px); }
.solution-link img { margin-inline-end: 10px; }

.solution-content {
  display: none;
  background: linear-gradient(135deg, #eef7f2, #e1efe6);
  padding: 25px 30px;
  border-radius: 14px;
  margin-top: 18px;
  border-inline-start: 6px solid var(--brand-secondary);
  box-shadow: inset 0 2px 10px rgba(0, 0, 0, 0.04);
  animation: fadeSlide 0.4s ease;
}
.solution-content.show { display: block; }
@keyframes fadeSlide { from { opacity: 0; transform: translateY(-12px); } to { opacity: 1; transform: translateY(0); } }

.solution-steps { background: #fff; border-radius: 10px; padding: 20px 25px; border-inline-start: 4px solid var(--brand-primary); }
.solution-steps .step { margin: 12px 0; padding: 12px 16px; background: var(--brand-surface-alt); border-radius: 8px; border-inline-start: 3px solid var(--brand-primary); }
.solution-steps .step-number {
  display: inline-block;
  background: var(--brand-primary);
  color: white;
  border-radius: 50%;
  width: 28px;
  height: 28px;
  text-align: center;
  line-height: 28px;
  font-size: 14px;
  font-weight: bold;
  margin-inline-end: 12px;
}
.solution-steps .formula-box { background: #eef6f1; padding: 12px 18px; border-radius: 8px; margin: 10px 0; text-align: center; font-size: 20px; border: 1px solid #d7e7de; }
.solution-steps .result-box { background: #e8f5e9; padding: 14px 20px; border-radius: 8px; margin: 14px 0; border-inline-start: 4px solid var(--brand-primary); text-align: center; font-weight: bold; font-size: 19px; }
.solution-steps .concept-box { background: #fff3e0; padding: 12px 16px; border-radius: 8px; margin: 10px 0; border-inline-start: 4px solid #ff9800; }
.solution-steps .tip-box { background: #fdecec; padding: 12px 16px; border-radius: 8px; margin: 10px 0; border-inline-start: 4px solid var(--brand-secondary); }

/* ===== عناصر إضافية ===== */
center, .center { text-align: center; }
hr { border: none; border-top: 2px solid #e8ecf1; margin: 18px 0; }
img { max-width: 100%; height: auto; border-radius: 8px; }
table { width: 100%; border-collapse: collapse; margin: 15px 0; }
table td, table th { padding: 10px; text-align: center; border: 1px solid #e0e0e0; }
.caption { font-size: 22px; font-weight: bold; color: var(--brand-primary); text-align: center; margin-bottom: 15px; }

/* ===== قسم العالِم المميّز ===== */
.helmholtz-section {
  background: linear-gradient(135deg, #eaf6f0, #d7ede1);
  border-radius: 16px;
  padding: 30px 35px;
  margin: 25px 0;
  border: 2px solid var(--brand-primary);
  box-shadow: 0 6px 20px rgba(0, 87, 63, 0.18);
}
.helmholtz-header { display: flex; align-items: center; justify-content: center; gap: 25px; flex-wrap: wrap; margin-bottom: 25px; }
.helmholtz-header .portrait { width: 130px; height: auto; border-radius: 50%; border: 4px solid var(--brand-primary); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15); }
.helmholtz-header .title { font-size: 32px; font-weight: bold; color: var(--brand-primary-dark); text-align: center; }
.helmholtz-header .subtitle { font-size: 16px; color: var(--brand-primary); text-align: center; font-style: italic; }

.helmholtz-content { display: flex; flex-wrap: wrap; gap: 30px; align-items: flex-start; }
.helmholtz-content .text { flex: 2; min-width: 280px; font-size: 15pt; line-height: 2.2; color: var(--brand-ink); }
.helmholtz-content .text .highlight { color: var(--brand-primary-dark); font-weight: bold; background: rgba(0, 87, 63, 0.12); padding: 2px 8px; border-radius: 4px; }

.helmholtz-points { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 25px; }
.helmholtz-point { background: #fff; padding: 18px 22px; border-radius: 12px; border-inline-start: 5px solid var(--brand-primary); box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06); transition: transform 0.2s; }
.helmholtz-point:hover { transform: translateY(-3px); box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1); }
.helmholtz-point .point-icon { font-size: 28px; margin-inline-end: 12px; display: inline-block; }
.helmholtz-point .point-title { font-size: 18px; font-weight: bold; color: var(--brand-primary-dark); }
.helmholtz-point .point-desc { font-size: 14pt; color: #333; margin-top: 8px; line-height: 1.6; }

.helmholtz-footer {
  margin-top: 25px;
  padding: 18px 22px;
  background: #fff;
  border-radius: 12px;
  text-align: center;
  font-size: 16pt;
  font-weight: bold;
  color: var(--brand-primary-dark);
  border: 2px dashed var(--brand-primary);
}

/* ===== المحاكاة التفاعلية ===== */
.simulation-wrapper {
  background: linear-gradient(135deg, #0a1a13, #04120c);
  border-radius: 16px;
  padding: 20px;
  margin: 25px 0;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}
.simulation-wrapper .sim-header {
  color: white;
  text-align: center;
  font-size: 20px;
  font-weight: bold;
  margin-bottom: 15px;
  padding: 10px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 10px;
}
.simulation-container { background: rgba(255, 255, 255, 0.97); border-radius: 16px; padding: 20px; box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2); }

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  background: #f3f8f5;
  padding: 15px 20px;
  border-radius: 12px;
  border: 1px solid #dcece3;
  margin-bottom: 15px;
  align-items: center;
  justify-content: center;
}
.controls .control-group { display: flex; align-items: center; gap: 10px; }
.controls label { font-weight: 600; color: var(--brand-ink-soft); font-size: 0.9rem; }
.controls select { padding: 6px 14px; border: 2px solid var(--brand-primary); border-radius: 8px; background: white; font-size: 0.9rem; font-weight: 600; cursor: pointer; outline: none; transition: all 0.25s; }
.controls select:hover { border-color: var(--brand-primary-dark); }
.controls input[type="range"] {
  -webkit-appearance: none;
  width: 140px;
  height: 6px;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--brand-primary), var(--brand-secondary));
  outline: none;
  cursor: pointer;
}
.controls input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: white;
  cursor: pointer;
  border: 3px solid var(--brand-primary);
  box-shadow: 0 2px 10px rgba(0, 87, 63, 0.4);
}
.controls .value-badge {
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-secondary));
  color: white;
  padding: 2px 14px;
  border-radius: 30px;
  font-weight: 700;
  font-size: 0.85rem;
  min-width: 45px;
  text-align: center;
}

.canvas-wrapper { position: relative; width: 100%; display: flex; justify-content: center; }
.canvas-wrapper canvas { border-radius: 12px; border: 2px solid #dcece3; background: #fafbff; max-width: 100%; height: auto; cursor: crosshair; }

.info-panel { display: flex; flex-wrap: wrap; gap: 20px; background: #f3f8f5; border-radius: 12px; padding: 15px 20px; border: 1px solid #dcece3; margin-top: 15px; }
.info-panel .info-item { display: flex; align-items: center; gap: 8px; flex: 1; min-width: 120px; }
.info-panel .label { color: var(--brand-ink-soft); font-weight: 500; font-size: 0.85rem; }
.info-panel .value { color: var(--brand-ink); font-weight: 700; font-size: 0.95rem; }
.info-panel .value.highlight { color: var(--brand-primary); font-size: 1.1rem; }

.legend { display: flex; flex-wrap: wrap; gap: 15px; justify-content: center; padding: 10px 0; }
.legend-item { display: flex; align-items: center; gap: 6px; font-size: 0.8rem; color: var(--brand-ink-soft); }
.legend-color { width: 20px; height: 3px; border-radius: 2px; display: inline-block; }
.legend-color.dashed { height: 0; border-top: 3px dashed #1565c0; width: 20px; }

.instructions {
  background: linear-gradient(135deg, rgba(0,87,63,0.08), rgba(187,0,30,0.06));
  padding: 12px 18px;
  border-radius: 10px;
  border-inline-start: 4px solid var(--brand-primary);
  font-size: 0.85rem;
  color: var(--brand-ink-soft);
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 12px;
}
.instructions .emoji { font-size: 1.2rem; }

/* ===== قسم الاختبار ===== */
.hidden { display: none !important; }

.lang-tabs { display: flex; gap: 10px; margin-bottom: 20px; justify-content: center; flex-wrap: wrap; }
.lang-tab {
  padding: 10px 30px;
  border: 2px solid var(--brand-primary);
  border-radius: 10px;
  background: white;
  cursor: pointer;
  font-weight: 700;
  font-size: 16px;
  transition: 0.25s;
  color: var(--brand-primary);
}
.lang-tab.active { background: var(--brand-primary); color: white; }
.lang-tab:hover:not(.active) { background: #eef7f2; }

.quiz-title { text-align: center; color: var(--brand-primary-dark); margin-bottom: 5px; font-size: 28px; font-family: "Montserrat", sans-serif; }
.subtitle { text-align: center; color: var(--brand-ink-soft); margin-bottom: 25px; font-size: 16px; }

.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-weight: 600; color: var(--brand-ink-soft); margin-bottom: 5px; }
.form-group input { width: 100%; padding: 12px 15px; border: 2px solid #e2e8f0; border-radius: 10px; font-size: 16px; transition: 0.25s; }
.form-group input:focus { outline: none; border-color: var(--brand-primary); box-shadow: 0 0 0 3px rgba(0, 87, 63, 0.15); }

.btn-start {
  width: 100%;
  padding: 15px;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-dark));
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 18px;
  font-weight: 600;
  cursor: pointer;
  transition: 0.25s;
}
.btn-start:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(0, 87, 63, 0.35); }

.quiz-header { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; border-bottom: 2px solid #e2e8f0; margin-bottom: 18px; flex-wrap: wrap; }
.timer { font-size: 24px; font-weight: 700; color: var(--brand-ink); background: #f7fafc; padding: 6px 18px; border-radius: 10px; }
.timer.warning { color: var(--brand-secondary); animation: blink 1s infinite; }
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }

.progress-container { width: 100%; background: #e2e8f0; border-radius: 10px; height: 10px; margin: 12px 0; overflow: hidden; }
.progress-bar { height: 100%; background: linear-gradient(90deg, var(--brand-primary), var(--brand-secondary)); border-radius: 10px; transition: width 0.5s ease; width: 0%; }
.progress-info { display: flex; justify-content: space-between; font-size: 14px; color: var(--brand-ink-soft); margin-bottom: 12px; }

.question-list { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.question-btn { width: 38px; height: 38px; border-radius: 50%; border: 2px solid #e2e8f0; background: white; cursor: pointer; font-weight: 600; transition: 0.25s; display: flex; align-items: center; justify-content: center; font-size: 14px; }
.question-btn:hover { border-color: var(--brand-primary); transform: scale(1.05); }
.question-btn.current { border-color: var(--brand-primary); background: var(--brand-primary); color: white; }
.question-btn.answered { border-color: var(--brand-primary-light); background: var(--brand-primary-light); color: var(--brand-primary-dark); }

.quiz-container-local { background: var(--brand-surface-alt); border-radius: 15px; padding: 22px; }
.question-header { display: flex; gap: 15px; margin-bottom: 18px; align-items: flex-start; }
.question-number-local { background: var(--brand-primary); color: white; width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; flex-shrink: 0; font-size: 16px; }
.question-text-local { font-size: 18px; font-weight: 500; color: var(--brand-ink); line-height: 1.7; }

.options-container { display: flex; flex-direction: column; gap: 10px; margin: 18px 0; }
.option-local { display: flex; align-items: center; gap: 15px; padding: 14px 20px; background: white; border-radius: 10px; cursor: pointer; transition: 0.25s; border: 2px solid transparent; }
.option-local:hover { border-color: var(--brand-primary); transform: translateX(5px); }
body.lang-en .option-local:hover { transform: translateX(-5px); }
.option-local.selected { border-color: var(--brand-primary); background: #eaf6f0; }
.option-letter-local { width: 32px; height: 32px; border-radius: 50%; background: #e2e8f0; display: flex; align-items: center; justify-content: center; font-weight: 700; color: var(--brand-ink-soft); flex-shrink: 0; font-size: 14px; }
.option-local.selected .option-letter-local { background: var(--brand-primary); color: white; }
.option-text-local { font-size: 16px; color: var(--brand-ink); }

.show-solution-btn { display: inline-block; padding: 10px 22px; background: #eef7f2; border: 2px solid var(--brand-primary); border-radius: 8px; color: var(--brand-primary); font-weight: 600; cursor: pointer; transition: 0.25s; margin: 10px 0; }
.show-solution-btn:hover { background: var(--brand-primary); color: white; }

.solution-area-local { display: none; background: white; padding: 22px; border-radius: 12px; margin: 15px 0; border-inline-start: 4px solid var(--brand-primary); box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); }
.solution-area-local h4 { color: var(--brand-primary-dark); margin-bottom: 12px; font-size: 18px; }
.solution-content-local { color: var(--brand-ink); line-height: 2; font-size: 16px; white-space: pre-wrap; }
.solution-content-local .math-box { display: block; text-align: center; margin: 12px 0; padding: 14px; background: var(--brand-surface-alt); border-radius: 8px; border: 1px solid #e2e8f0; font-size: 18px; }

.navigation { display: flex; justify-content: space-between; margin-top: 18px; gap: 10px; }
.nav-btn { padding: 10px 25px; border: 2px solid var(--brand-primary); background: white; border-radius: 8px; color: var(--brand-primary); font-weight: 600; cursor: pointer; transition: 0.25s; }
.nav-btn:hover:not(:disabled) { background: var(--brand-primary); color: white; }
.nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }

.btn-submit { width: 100%; padding: 15px; background: var(--brand-primary); color: white; border: none; border-radius: 10px; font-size: 18px; font-weight: 600; cursor: pointer; transition: 0.25s; margin-top: 18px; }
.btn-submit:hover { background: var(--brand-primary-dark); transform: translateY(-2px); }

.results-container { text-align: center; padding: 30px 20px; }
.results-container .score-circle {
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-primary), var(--brand-primary-dark));
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 20px auto;
  color: white;
  font-size: 40px;
  font-weight: 700;
}
.results-container .result-details { margin: 20px 0; padding: 15px; background: var(--brand-surface-alt); border-radius: 10px; }
.results-container .result-details p { margin: 8px 0; color: var(--brand-ink-soft); }
.results-container .result-message { font-size: 20px; font-weight: 600; margin: 20px 0; }

.btn-restart { padding: 12px 35px; background: var(--brand-primary); color: white; border: none; border-radius: 10px; font-size: 16px; font-weight: 600; cursor: pointer; transition: 0.25s; }
.btn-restart:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(0, 87, 63, 0.35); }

.lang-en { direction: ltr !important; }
.lang-en .question-header { flex-direction: row; }

/* ===== تذييل الدرس (مصدر + تعليق) ===== */
.lesson-footnote {
  margin-top: 30px;
  padding: 18px 22px;
  background: var(--brand-surface-alt);
  border-radius: 12px;
  text-align: center;
  color: var(--brand-ink-soft);
  font-size: 14px;
  line-height: 2;
}
.lesson-footnote a { color: var(--brand-primary); font-weight: 600; }
.lesson-footnote strong { color: var(--brand-primary-dark); }

/* ===== Responsive ===== */
@media (max-width: 850px) {
  .helmholtz-points { grid-template-columns: 1fr; }
  .helmholtz-content { flex-direction: column; }
  .helmholtz-header { flex-direction: column; text-align: center; }
  .helmholtz-header .title { font-size: 24px; }
  .helmholtz-content .text { font-size: 14pt; }
  .controls { flex-direction: column; align-items: stretch; }
  .controls .control-group { justify-content: center; flex-wrap: wrap; }
}

@media (max-width: 768px) {
  .lesson-container { padding: 0 12px 40px; }
  .qntxtbox { padding: 15px; }
  .option { padding: 10px 12px; font-size: 14px; }
  .option-text { font-size: 14px; }
  .solution-steps { padding: 15px; }
  .lang-btn { padding: 10px 18px; font-size: 14px; }
  .question-text { font-size: 16px; padding: 10px; }
  .info-panel { flex-direction: column; gap: 10px; }
  .helmholtz-section { padding: 20px; }
  .helmholtz-footer { font-size: 14pt; padding: 14px 16px; }
  .simulation-wrapper { padding: 10px; }
  .simulation-container { padding: 10px; }
  .lang-tabs { flex-direction: column; align-items: center; }
  .lang-tab { width: 100%; text-align: center; }
  .question-text-local { font-size: 16px; }
  .option-local { padding: 10px 15px; }
  .quiz-header { flex-direction: column; gap: 10px; }
}

@media (max-width: 480px) {
  .helmholtz-header .title { font-size: 20px; }
  .helmholtz-header .portrait { width: 100px; }
  .helmholtz-content .text { font-size: 13pt; }
  .helmholtz-point .point-desc { font-size: 12pt; }
  .helmholtz-footer { font-size: 12pt; }
  .controls input[type="range"] { width: 100px; }
  .info-panel .info-item { min-width: 80px; font-size: 0.8rem; }
}