* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
  background-color: #f4f6f8;
  color: #333;
}

.lms-container {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* Sidebar Styles */
.sidebar {
  width: 400px;
  background-color: #ffffff;
  border-right: 1px solid #e1e4e8;
  display: flex;
  flex-direction: column;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid #e1e4e8;
  background-color: #0284c7;
  color: #ffffff;
}

.modules-list {
  flex: 1;
  overflow-y: auto;
}

.module-group {
  border-bottom: 1px solid #f0f0f0;
}

.module-title {
  padding: 14px 20px;
  background-color: #f8fafc;
  font-weight: 600;
  font-size: 0.95rem;
  color: #1e293b;
  cursor: pointer;
  
}

/* Chevron Arrow Indicator */
.module-title::after {
  /* content: '▲'; */
  display: inline-block;
  font-size: 0.75rem;
  color: #64748b;
  transition: transform 0.2s ease;
  padding-left: 10px;
}

/* Rotates the arrow when module is collapsed */
.module-group.collapsed .module-title::after {
  transform: rotate(180deg);
  padding-right: 10px;
}

/* Dropdown Content */
.topics-container {
  display: block;
}

.module-group.collapsed .topics-container {
  display: none;
}

.topic-item {
  padding: 12px 20px 12px 32px;
  font-size: 0.9rem;
  color: #475569;
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
}

.topic-item:hover {
  background-color: #f1f5f9;
  color: #0f172a;
}

.topic-item.active {
  background-color: #e2e8f0;
  color: #0284c7;
  font-weight: 600;
  border-left: 4px solid #0284c7;
}

/* Main Content Styles */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  padding: 24px;
}

.video-container {
  position: relative;
  width: 100%;
  padding-top: 56.25%; /* 16:9 Aspect Ratio */
  background-color: #000;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.lesson-details {
  margin-top: 24px;
  background: #ffffff;
  padding: 24px;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

.lesson-details h1 {
  font-size: 1.5rem;
  margin-bottom: 12px;
  color: #0f172a;
}

.lesson-details p {
  line-height: 1.6;
  color: #475569;
}


/* Modal Backdrop */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.6);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal.hidden {
  display: none;
}

/* Modal Box */
.modal-content {
  background: #ffffff;
  padding: 24px 32px;
  border-radius: 8px;
  width: 100%;
  max-width: 400px;
  position: relative;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.close-btn {
  position: absolute;
  top: 12px;
  right: 16px;
  font-size: 24px;
  cursor: pointer;
  color: #666;
}

.modal-content form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 16px;
}

.modal-content input {
  padding: 10px 12px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

.btn-primary {
  background-color: #0073aa;
  color: #fff;
  border: none;
  padding: 12px;
  border-radius: 4px;
  cursor: pointer;
  font-weight: bold;
}

.coupon-box {
  display: flex;
  gap: 8px;
  margin: 12px 0;
}

.coupon-box input {
  flex: 1;
}

.auth-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  border-bottom: 1px solid #eee;
}

.tab-btn {
  background: none;
  border: none;
  padding: 8px 16px;
  font-weight: bold;
  cursor: pointer;
  color: #666;
}

.tab-btn.active {
  color: #0073aa;
  border-bottom: 2px solid #0073aa;
}

#auth-message {
  margin-top: 10px;
  font-size: 14px;
}

/* Responsive collapse for small screens */
@media (max-width: 768px) {
  .lms-container {
    flex-direction: column;
    height: auto;
  }
  .sidebar {
    width: 100%;
    height: 300px;
  }
}