:root {
  --background-color: #121212; /* Very Dark Gray/Black */
  --surface-color: #1e1e1e; /* Dark Gray */
  --primary-color: #bb86fc; /* Purple */
  --secondary-color: #03dac6; /* Teal */
  --completed-color: #4caf50; /* Green */
  --fail-color: #cf6679; /* Red/Pink */
  --text-primary: #e0e0e0; /* Light Gray */
  --text-secondary: #aaaaaa; /* Gray */
  --font-family: 'Poppins', sans-serif;
  --border-radius: 12px;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--background-color);
  color: var(--text-primary);
  line-height: 1.6;
}

#root {
  display: flex;
  justify-content: center;
  padding: 2rem;
}

.app-container {
  width: 100%;
  max-width: 1200px;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

/* Header */
header {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  width: 100%;
  gap: 0.5rem;
}

.school-logo {
  width: 150px;
  height: auto;
  margin-bottom: 1rem;
}

.logo {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
}

.developer-info {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.developer-info p {
  margin: 0;
  line-height: 1.4;
}

/* Main Content */
main {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  color: #000000;
  border: none;
  border-radius: var(--border-radius);
  font-family: var(--font-family);
  font-weight: 500;
  font-size: 0.9rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn:hover:not(:disabled) {
  box-shadow: 0 4px 15px rgba(3, 218, 198, 0.3);
  transform: translateY(-2px);
}

.btn:disabled {
  background: rgba(255, 255, 255, 0.12);
  color: rgba(255, 255, 255, 0.3);
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

/* Welcome Section */
.welcome-section {
  display: flex;
  gap: 2rem;
  align-items: center;
  background-color: var(--surface-color);
  padding: 2.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
}

.welcome-content {
  flex: 1;
  text-align: left;
}

.welcome-image-container {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.welcome-image {
  max-width: 80%;
  height: auto;
  border-radius: var(--border-radius);
}


.welcome-section h2 {
  font-size: 2rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
  text-align: left;
}

.welcome-section .subtitle {
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--secondary-color);
  margin-bottom: 2rem;
  text-align: left;
}

.welcome-section p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.7;
}

.welcome-section .greeting {
  font-weight: 600;
  color: var(--text-primary);
}

.welcome-section .call-to-action,
.welcome-section .tagline {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text-primary);
  text-align: center;
  margin-top: 1.5rem;
}

.start-course-container {
  margin-top: 1rem;
  text-align: center;
}

.start-course-container .btn {
  background: linear-gradient(90deg, var(--completed-color), #81c784);
}

.start-course-container .btn:hover:not(:disabled) {
  box-shadow: 0 4px 15px rgba(76, 175, 80, 0.5);
}

/* Course List Section */
.course-list-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.course-list-header h2 {
  font-size: 2rem;
}

.course-list-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn-secondary {
  background: var(--surface-color);
  border: 1px solid var(--primary-color);
  color: var(--primary-color);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--primary-color);
  color: #000000;
  box-shadow: 0 4px 15px rgba(187, 134, 252, 0.4);
  transform: translateY(-2px);
}

.btn-danger {
  background: var(--fail-color);
  color: #000000;
  border: 1px solid var(--fail-color);
}

.btn-danger:hover:not(:disabled) {
  background: #d32f2f;
  box-shadow: 0 4px 15px rgba(207, 102, 121, 0.5);
}

.confirmation-message {
    text-align: center;
    width: 100%;
    margin-bottom: 1rem;
    padding: 0.75rem;
    background-color: rgba(76, 175, 80, 0.2);
    color: var(--completed-color);
    border-radius: calc(var(--border-radius) / 2);
    border: 1px solid var(--completed-color);
    animation: fadeIn 0.3s ease-in-out;
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.empty-state-message {
  grid-column: 1 / -1; /* Span all columns */
  text-align: center;
  padding: 4rem 2rem;
  background-color: var(--surface-color);
  border-radius: var(--border-radius);
  color: var(--text-secondary);
  border: 1px dashed rgba(255, 255, 255, 0.2);
}
.empty-state-message p {
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.course-card {
  background-color: #1B263B; /* Dark Blue */
  border-radius: var(--border-radius);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease, opacity 0.3s ease;
  border-left: 4px solid #4A90E2; /* Bright Blue Accent */
}

.course-card.unlocked:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.6);
}

.course-card-content {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.course-card h3 {
  font-size: 1.2rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.5rem;
}

.lock-icon {
  font-size: 1.2rem;
  color: var(--text-secondary);
  line-height: 1;
}

.course-card-description {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.4;
  margin-bottom: 1rem;
  flex-grow: 1;
}

.course-card .course-card-actions {
  margin-top: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.course-card .btn {
  width: 100%; /* Make button full-width */
}

/* Course Status Styles */
.course-card.locked {
  opacity: 0.85;
  border-left-color: #616161;
  background-color: #2a2a2a;
}

.course-card.locked .btn {
  cursor: not-allowed;
}

.course-card.locked:hover {
  transform: none;
  box-shadow: var(--shadow);
}

.course-card.completed {
  border-left-color: #81D4FA; /* Lighter Blue for completed */
}

.course-card.completed .btn {
  background: linear-gradient(90deg, #4A90E2, #81D4FA);
}

/* Progress Bar */
.progress-bar-container {
  width: 100%;
  height: 24px;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 25px;
  position: relative;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--secondary-color), var(--primary-color));
  border-radius: 25px;
  transition: width 0.4s ease-in-out;
}

.course-card.completed .progress-bar-fill {
    background: linear-gradient(90deg, #4A90E2, #81D4FA);
}

.progress-text {
  position: absolute;
  width: 100%;
  top: 50%;
  left: 0;
  transform: translateY(-50%);
  text-align: center;
  color: #000000;
  font-weight: 600;
  font-size: 0.8rem;
  text-shadow: none;
}

/* Course Detail View */
.course-detail-view {
  background-color: var(--surface-color);
  padding: 2.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow);
  animation: fadeIn 0.5s ease-in-out;
}

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

.course-detail-header {
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  padding-bottom: 1rem;
  margin-bottom: 2rem;
}

.course-detail-header h2 {
  font-size: 2.2rem;
  color: var(--text-primary);
}

.course-detail-content {
  min-height: 300px;
}

.course-discussion-content h3 {
  font-size: 1.8rem;
  color: var(--primary-color);
  margin: 1rem 0 1.5rem 0;
  border-bottom: 2px solid var(--primary-color);
  padding-bottom: 0.5rem;
}

.course-discussion-content h4 {
  font-size: 1.5rem;
  color: var(--text-primary);
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-weight: 600;
}

.course-discussion-content h5 {
    font-size: 1.2rem;
    color: var(--text-primary);
    margin-top: 1.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.course-discussion-content p, 
.course-discussion-content li {
  color: var(--text-secondary);
  line-height: 1.8;
  font-size: 1rem;
}

.course-discussion-content p {
  margin-bottom: 1rem;
}

.course-discussion-content strong {
  color: var(--text-primary);
  font-weight: 600;
}

.course-discussion-content ul, 
.course-discussion-content ol {
  padding-left: 2rem;
  margin-bottom: 1.5rem;
}

.course-discussion-content ol li {
    margin-bottom: 1rem;
}

.content-divider {
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    margin: 2rem 0;
}

.course-detail-content a {
  color: var(--secondary-color);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
  word-break: break-all;
}

.course-detail-content a:hover {
  color: var(--primary-color);
  text-decoration: underline;
}

.course-discussion-content li {
  margin-bottom: 0.75rem;
}

.course-discussion-content.part-2,
.course-discussion-content.part-3 {
    margin-top: 2.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    padding-top: 1.5rem;
}

.course-completion-container {
    text-align: center;
    margin-top: 2.5rem;
}

.course-completion-container .btn {
    font-size: 1.1rem;
    padding: 0.8rem 2rem;
}

.course-completion-container .btn.btn-assessment {
    background: linear-gradient(90deg, var(--completed-color), #81c784);
}

.btn-assessment:hover:not(:disabled) {
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.5);
}

.course-detail-footer {
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.course-detail-footer-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Quiz Styles */
.quiz-container {
    animation: fadeIn 0.5s ease-in-out;
    margin-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    padding-top: 2rem;
}

.start-quiz-container {
    text-align: center;
    padding: 2rem;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius);
    border-top: none;
    margin-top: 2rem;
}

.quiz-container h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    text-align: center;
}
.quiz-instruction {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-style: italic;
}
.quiz-question-container {
    background-color: rgba(255, 255, 255, 0.05);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--primary-color);
}
.quiz-question-text {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}
.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.quiz-options label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background-color: var(--surface-color);
    padding: 0.75rem 1rem;
    border-radius: calc(var(--border-radius) / 1.5);
    cursor: pointer;
    transition: background-color 0.2s ease-in-out, border-color 0.2s ease-in-out;
    border: 1px solid rgba(255, 255, 255, 0.12);
}
.quiz-options label:hover {
    background-color: rgba(255, 255, 255, 0.05);
}
.quiz-options input[type="radio"] {
    appearance: none;
    width: 20px;
    height: 20px;
    border: 2px solid var(--secondary-color);
    border-radius: 50%;
    transition: all 0.2s ease-in-out;
    flex-shrink: 0;
}
.quiz-options input[type="radio"]:checked {
    background-color: var(--secondary-color);
    border-color: var(--primary-color);
}
.quiz-options span {
    color: var(--text-secondary);
    font-size: 1rem;
    transition: color 0.2s ease-in-out;
}
.quiz-options label:hover span,
.quiz-options input[type="radio"]:checked + span {
    color: var(--text-primary);
}

.quiz-container .btn {
    display: block;
    width: 100%;
    margin-top: 2rem;
    font-size: 1.1rem;
}

/* Quiz Result Styles */
.quiz-result-container {
    text-align: center;
    padding: 3rem 2rem;
    border-radius: var(--border-radius);
    animation: fadeIn 0.5s ease-in-out;
    margin-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
}
.quiz-result-container.pass {
    background: linear-gradient(135deg, rgba(76, 175, 80, 0.1), rgba(76, 175, 80, 0.15));
    border: 1px solid var(--completed-color);
}
.quiz-result-container.fail {
    background: linear-gradient(135deg, rgba(207, 102, 121, 0.1), rgba(207, 102, 121, 0.15));
    border: 1px solid var(--fail-color);
}
.quiz-result-container.pass h3 {
    color: var(--completed-color);
}
.quiz-result-container.fail h3 {
    color: var(--fail-color);
}
.quiz-result-container h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
}
.quiz-score {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}
.quiz-result-container.pass .quiz-score {
    color: var(--completed-color);
}
.quiz-result-container.fail .quiz-score {
    color: var(--fail-color);
}
.quiz-result-message {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}
.quiz-result-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}
.completed-icon {
    color: var(--completed-color);
    margin-left: 0.5rem;
}

/* Styled Tables */
.styled-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    font-size: 0.95rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.3);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.styled-table caption {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
    text-align: left;
}

.styled-table th, .styled-table td {
    padding: 0.85rem 1rem;
    text-align: left;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.styled-table th {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    font-weight: 600;
}

.styled-table td {
    color: var(--text-secondary);
}
.styled-table td strong { color: var(--text-primary); }


.styled-table tbody tr:last-child td {
    border-bottom: none;
}

.styled-table tbody tr:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.example-box {
    padding: 1rem 1.5rem;
    margin: 1rem 0;
    border-radius: calc(var(--border-radius) / 1.5);
    border-left: 4px solid var(--secondary-color);
    background-color: rgba(3, 218, 198, 0.1);
}
.example-box p, .example-box li {
    color: var(--text-secondary);
}

.example-box strong {
    color: var(--secondary-color);
}

/* Locked Content Styles */
.part-content-wrapper {
    transition: filter 0.3s ease-in-out, opacity 0.3s ease-in-out;
}

.part-content-wrapper.content-locked {
    filter: blur(5px);
    opacity: 0.6;
    pointer-events: none;
    user-select: none;
}

/* Course Topic Button Styles */
.course-topic-buttons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 2rem;
    margin-bottom: 2rem;
}

.btn.btn-topic {
    width: 100%;
    text-align: left;
    background: var(--surface-color);
    border: 1px solid var(--secondary-color);
    color: var(--secondary-color);
    justify-content: space-between;
    display: flex;
    align-items: center;
    padding: 1rem 1.5rem;
    font-size: 1rem;
}

.btn.btn-topic:hover:not(:disabled) {
    background: var(--secondary-color);
    color: #000000;
    transform: translateX(5px);
    box-shadow: none;
}

.btn.btn-topic.locked {
    border-color: #444;
    color: #666;
    opacity: 0.8;
}

.btn.btn-topic.locked:hover {
    background: var(--surface-color);
    transform: none;
    color: #666;
}

.btn.btn-topic.completed {
    border-color: var(--completed-color);
    background: rgba(76, 175, 80, 0.1);
    color: var(--completed-color);
}

.btn.btn-topic.completed:hover:not(:disabled) {
    background: rgba(76, 175, 80, 0.2);
    transform: none;
    color: var(--completed-color);
}

.topic-navigation {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
}

/* Teacher Unlock Form */
.unlock-form-container {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.unlock-form-container input[type="password"] {
    width: 100%;
    padding: 0.5rem 0.75rem;
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: calc(var(--border-radius) / 2);
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 0.9rem;
}

.unlock-form-container input[type="password"]::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
}

.unlock-form-container .btn-unlock {
    width: 100%;
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    background: var(--surface-color);
    border: 1px solid var(--secondary-color);
    color: var(--secondary-color);
}

.unlock-form-container .btn-unlock:hover:not(:disabled) {
    background: var(--secondary-color);
    color: #000000;
}

.unlock-error-message {
    font-size: 0.8rem;
    color: var(--fail-color);
    text-align: center;
    margin-top: 0.25rem;
}

/* Disclaimer Modal */
.disclaimer-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2000;
  backdrop-filter: blur(5px);
  animation: fadeIn 0.3s ease-out;
}

.disclaimer-modal {
  background-color: var(--surface-color);
  padding: 2.5rem;
  border-radius: var(--border-radius);
  width: 90%;
  max-width: 500px;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--primary-color);
}

.disclaimer-modal h3 {
  font-size: 1.6rem;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.disclaimer-modal p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.disclaimer-modal ul {
  list-style-position: inside;
  padding-left: 0.5rem;
  margin-bottom: 1.5rem;
}

.disclaimer-modal ul li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.disclaimer-actions {
  display: flex;
  justify-content: flex-end;
  gap: 1rem;
  margin-top: 2rem;
}

/* Video Disclaimer Section */
.video-disclaimer-section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  text-align: center;
}

.video-disclaimer-section h4 {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.required-star {
  color: var(--fail-color);
  margin-right: 0.25rem;
}

.video-disclaimer-section p {
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.video-container {
  position: relative;
  overflow: hidden;
  width: 80%; /* Make video container smaller */
  padding-top: 45%; /* Adjust padding to maintain 16:9 ratio (80% * 56.25%) */
  border-radius: var(--border-radius);
  background-color: #000;
  margin: 0 auto 1.5rem auto; /* Center the container and add bottom margin */
  box-shadow: var(--shadow);
}

.video-container iframe,
.video-container video {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 100%;
  border: none;
}

.video-disclaimer-section .btn-secondary:disabled {
  background: var(--completed-color);
  border-color: var(--completed-color);
  color: #000000;
  opacity: 1;
  transform: none;
  box-shadow: none;
  cursor: default;
}

.disabled-message {
  margin-top: 0.75rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-style: italic;
}

/* Realtime Clock */
.realtime-clock {
  margin-bottom: 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  width: 100%;
}

.realtime-clock p {
  font-size: 1rem;
  color: var(--text-secondary);
  font-weight: 500;
  letter-spacing: 0.5px;
  margin: 0;
}

/* Main Footer on Welcome Page */
.main-footer {
    width: 100%;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    text-align: center;
}

.main-footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.matatag-logo {
    height: 2em;
    margin: 0 0.5ch;
    vertical-align: middle;
    background-color: #fafafa;
    border-radius: 4px;
    padding: 2px;
}

.cooperation-logo {
    height: 2.5em;
    margin-left: 0.75ch;
    vertical-align: middle;
}

.main-footer a {
  color: var(--secondary-color);
  text-decoration: none;
  word-break: break-all;
}

.main-footer a:hover {
  text-decoration: underline;
}


/* Responsive Design */
@media (max-width: 992px) {
  .welcome-section {
    flex-direction: column;
    padding: 2rem;
  }
  .welcome-content, .welcome-image-container {
    max-width: 100%;
    text-align: center;
  }
  .welcome-content h2, .welcome-content .subtitle {
    text-align: center;
  }
  .welcome-image-container {
    margin-bottom: 2rem;
  }
}

@media (max-width: 768px) {
  #root {
    padding: 1rem;
  }
  
  header {
    gap: 1rem;
    align-items: center;
  }

  .course-detail-view {
    padding: 1.5rem;
  }

  .course-detail-header h2 {
    font-size: 1.8rem;
  }

  .course-discussion-content h4 {
    font-size: 1.3rem;
  }

  .welcome-image-container {
    width: 80%;
    max-width: 300px;
    margin-bottom: 1rem;
  }

  .video-container {
    width: 100%;
    padding-top: 56.25%;
  }

}

/* PDF Generation Styles */
.course-detail-content.pdf-render-mode {
  background: white !important;
  padding: 1rem;
}
.course-detail-content.pdf-render-mode,
.course-detail-content.pdf-render-mode * {
  background-color: white !important;
  color: black !important;
  text-shadow: none !important;
  box-shadow: none !important;
}
.course-detail-content.pdf-render-mode h2, 
.course-detail-content.pdf-render-mode h3, 
.course-detail-content.pdf-render-mode h4, 
.course-detail-content.pdf-render-mode h5 {
  color: black !important;
}
.course-detail-content.pdf-render-mode a {
  color: #0000ee !important; /* Standard link blue */
  text-decoration: underline !important;
}
.course-detail-content.pdf-render-mode a:after {
    content: " (" attr(href) ")";
    font-size: 9pt;
    font-weight: normal;
}
.course-detail-content.pdf-render-mode .styled-table,
.course-detail-content.pdf-render-mode .example-box {
  border: 1px solid #ccc !important;
}

/* Loading Overlay for PDF Generation */
.pdf-loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  color: white;
  flex-direction: column;
  gap: 1rem;
  font-size: 1.2rem;
  backdrop-filter: blur(5px);
}

.spinner {
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top: 4px solid #fff;
  width: 40px;
  height: 40px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

@media print {
  /* Hide UI, only show content for printing. Fallback for browsers without direct download. */
  body * { visibility: hidden; }
  .course-detail-view, .course-detail-view * { visibility: visible; }
  .course-detail-view { position: absolute; left: 0; top: 0; width: 100%; }
  .course-detail-footer, .course-detail-header .btn { display: none !important; }
}