/* ============================================
   Pen Cloud Academy — Lesson Page Styles
   Video player, sidebar, tabs, discussions
   ============================================ */

.lesson-layout {
  display: grid;
  grid-template-columns: 1fr 360px;
  min-height: calc(100vh - var(--header-height));
}

.lesson-main {
  padding: 24px 32px 48px;
  overflow-y: auto;
}

.lesson-sidebar-panel {
  background: var(--color-white);
  border-left: 1px solid rgba(0, 0, 0, 0.06);
  overflow-y: auto;
  position: sticky;
  top: 0;
  height: calc(100vh - var(--header-height));
}

/* Video player */
.video-container {
  position: relative;
  width: 100%;
  padding-bottom: 56.25%; /* 16:9 */
  background: var(--color-dark);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  margin-bottom: 24px;
}

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

.video-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--color-gray-300);
  gap: 12px;
}

.lesson-header {
  margin-bottom: 32px;
}

.lesson-header h1 {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.lesson-header-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--color-gray-500);
}

.lesson-description {
  color: var(--color-gray-700);
  line-height: 1.7;
  margin-bottom: 32px;
}

/* Lesson tabs */
.lesson-tabs {
  display: flex;
  gap: 4px;
  border-bottom: 2px solid var(--color-gray-100);
  margin-bottom: 24px;
  overflow-x: auto;
}

.lesson-tab {
  padding: 12px 20px;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--color-gray-500);
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.lesson-tab:hover {
  color: var(--color-dark);
}

.lesson-tab.active {
  color: var(--color-orange);
  border-bottom-color: var(--color-orange);
}

.lesson-tab-content {
  display: none;
}

.lesson-tab-content.active {
  display: block;
  animation: fadeIn var(--transition-base) ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Resources section */
.resources-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Assignment section */
.assignment-card {
  background: var(--color-cream);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 16px;
}

.assignment-card h4 {
  margin-bottom: 8px;
}

.assignment-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.875rem;
  color: var(--color-gray-500);
  margin-bottom: 16px;
}

.assignment-instructions {
  color: var(--color-gray-700);
  margin-bottom: 20px;
  line-height: 1.7;
}

.assignment-upload {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px;
}

.file-upload-area {
  flex: 1;
  min-width: 200px;
  padding: 24px;
  border: 2px dashed var(--color-gray-300);
  border-radius: var(--radius-md);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.file-upload-area:hover {
  border-color: var(--color-orange);
  background: rgba(254, 85, 36, 0.04);
}

.file-upload-area.dragover {
  border-color: var(--color-orange);
  background: rgba(254, 85, 36, 0.08);
}

.file-upload-area input {
  display: none;
}

.file-upload-icon {
  font-size: 2rem;
  margin-bottom: 8px;
  color: var(--color-gray-500);
}

.submission-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  background: var(--color-white);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
}

.submission-status.submitted {
  color: var(--color-success);
}

.submission-status.pending {
  color: var(--color-warning);
}

/* Notes section */
.notes-section {
  position: relative;
}

.notes-textarea {
  width: 100%;
  min-height: 200px;
  padding: 16px;
  border: 2px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  background: var(--color-white);
  resize: vertical;
  line-height: 1.7;
  transition: border-color var(--transition-fast);
}

.notes-textarea:focus {
  outline: none;
  border-color: var(--color-orange);
}

.notes-save-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  margin-top: 8px;
}

.notes-save-indicator.saving {
  color: var(--color-orange);
}

.notes-save-indicator.saved {
  color: var(--color-success);
}

/* Questions / Discussion */
.questions-section {
  margin-top: 8px;
}

.question-form {
  background: var(--color-white);
  border: 2px solid var(--color-gray-100);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 24px;
}

.question-form textarea {
  width: 100%;
  min-height: 100px;
  padding: 12px 16px;
  border: 2px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  resize: vertical;
  margin-bottom: 12px;
  transition: border-color var(--transition-fast);
}

.question-form textarea:focus {
  outline: none;
  border-color: var(--color-orange);
}

.questions-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.question-item {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: 20px 24px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-fast);
}

.question-item:hover {
  box-shadow: var(--shadow-md);
}

.question-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.question-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-orange);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8125rem;
  flex-shrink: 0;
}

.question-author {
  flex: 1;
}

.question-author h5 {
  font-size: 0.9375rem;
  font-weight: 600;
}

.question-author time {
  font-size: 0.8125rem;
  color: var(--color-gray-500);
}

.question-text {
  color: var(--color-gray-700);
  line-height: 1.7;
  padding-left: 48px;
}

/* Lesson sidebar */
.sidebar-lesson-header {
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--color-gray-100);
}

.sidebar-lesson-header h3 {
  font-size: 0.9375rem;
  margin-bottom: 12px;
}

.sidebar-progress {
  margin-bottom: 4px;
}

.sidebar-progress-text {
  display: flex;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  margin-bottom: 6px;
}

.sidebar-module-list {
  padding: 8px 0;
}

.sidebar-module {
  border-bottom: 1px solid var(--color-gray-100);
}

.sidebar-module-title {
  padding: 12px 20px;
  font-size: 0.8125rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-gray-500);
}

.sidebar-lesson-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  font-size: 0.875rem;
  color: var(--color-gray-700);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.sidebar-lesson-link:hover {
  background: var(--color-cream);
  color: var(--color-dark);
}

.sidebar-lesson-link.active {
  background: rgba(254, 85, 36, 0.1);
  color: var(--color-orange);
  font-weight: 600;
  border-right: 3px solid var(--color-orange);
}

.sidebar-lesson-link.locked {
  opacity: 0.5;
  cursor: not-allowed;
}

.sidebar-lesson-link .lesson-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-gray-300);
  flex-shrink: 0;
}

.sidebar-lesson-link.completed .lesson-dot {
  background: var(--color-success);
}

.sidebar-lesson-link.active .lesson-dot {
  background: var(--color-orange);
}

/* Lesson top bar */
.lesson-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: var(--color-white);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  position: sticky;
  top: 0;
  z-index: 50;
}

.lesson-topbar-back {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
  color: var(--color-gray-700);
  transition: color var(--transition-fast);
}

.lesson-topbar-back:hover {
  color: var(--color-orange);
}

.lesson-nav-buttons {
  display: flex;
  gap: 8px;
}

/* Mark complete button */
.mark-complete-btn {
  margin-top: 16px;
}

.mark-complete-btn.completed {
  background: var(--color-success);
  box-shadow: 0 4px 14px rgba(34, 197, 94, 0.35);
}

/* Responsive */
@media (max-width: 1100px) {
  .lesson-layout {
    grid-template-columns: 1fr;
  }

  .lesson-sidebar-panel {
    position: fixed;
    right: 0;
    top: 0;
    bottom: 0;
    width: 320px;
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: 300;
    height: 100vh;
    box-shadow: var(--shadow-xl);
  }

  .lesson-sidebar-panel.open {
    transform: translateX(0);
  }

  .lesson-sidebar-toggle {
    display: flex !important;
  }
}

@media (max-width: 768px) {
  .lesson-main {
    padding: 16px;
  }

  .lesson-tabs {
    gap: 0;
  }

  .lesson-tab {
    padding: 10px 14px;
    font-size: 0.875rem;
  }

  .question-text {
    padding-left: 0;
    margin-top: 8px;
  }
}

.lesson-sidebar-toggle {
  display: none;
  align-items: center;
  gap: 8px;
}

/* --- Academy Lesson Refresh --- */
body {
  background: #f6f8fb;
}

.lesson-topbar {
  min-height: 64px;
  padding: 12px 28px;
  background: #ffffff;
  border-bottom: 1px solid #dbe4ed;
}

.lesson-topbar-back {
  color: #334e5f;
  font-size: 0.9rem;
  font-weight: 800;
}

.lesson-topbar-back:hover {
  color: #ff5c35;
}

.lesson-nav-buttons {
  align-items: center;
}

.lesson-layout {
  grid-template-columns: minmax(0, 1fr) 380px;
  min-height: calc(100vh - 64px);
  background: #f6f8fb;
}

.lesson-main {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 34px 40px 56px;
}

.lesson-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px;
  margin-bottom: 22px;
}

.lesson-kicker {
  display: inline-flex;
  margin-bottom: 10px;
  color: #516b7c;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.lesson-header h1 {
  max-width: 760px;
  color: #1f2d35;
  font-size: clamp(1.8rem, 3vw, 2.8rem);
  letter-spacing: 0;
}

.lesson-header-meta {
  gap: 10px;
  margin-top: 12px;
}

.lesson-header-meta span {
  padding: 7px 10px;
  background: #ffffff;
  border: 1px solid #dbe4ed;
  border-radius: 999px;
  color: #334e5f;
  font-size: 0.8rem;
  font-weight: 800;
}

.mark-complete-btn {
  margin-top: 0;
  flex-shrink: 0;
}

.mark-complete-btn.completed {
  background: #1f9d72;
  box-shadow: none;
}

.video-container {
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 92, 53, 0.12), transparent 38%),
    #1f2d35;
  box-shadow: 0 18px 48px rgba(31, 45, 53, 0.16);
  margin-bottom: 24px;
}

.video-placeholder {
  color: #dbe4ed;
}

.video-placeholder p {
  color: #ffffff;
}

.video-placeholder-icon {
  width: 76px;
  height: 76px;
  margin: 0 auto 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid rgba(255, 255, 255, 0.18);
  border-radius: 50%;
  color: #ffffff;
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.lesson-description {
  max-width: 820px;
  margin-bottom: 28px;
  color: #425466;
  font-size: 1rem;
}

.lesson-tabs {
  width: 100%;
  gap: 6px;
  padding: 6px;
  margin: 30px 0 22px;
  background: #eaf2f7;
  border: 0;
  border-radius: 8px;
}

.lesson-tab {
  flex: 1;
  min-width: max-content;
  padding: 11px 16px;
  border: 0;
  border-radius: 7px;
  color: #334e5f;
}

.lesson-tab.active {
  background: #ffffff;
  color: #1f2d35;
  border-bottom-color: transparent;
  box-shadow: 0 8px 18px rgba(31, 45, 53, 0.08);
}

.lesson-tab-content {
  background: #ffffff;
  border: 1px solid #dbe4ed;
  border-radius: 8px;
  padding: 22px;
}

.lesson-sidebar-panel {
  background: #ffffff;
  border-left: 1px solid #dbe4ed;
  height: calc(100vh - 64px);
}

.sidebar-lesson-header {
  padding: 24px;
  border-bottom: 1px solid #dbe4ed;
}

.sidebar-lesson-header h3 {
  margin-top: 6px;
  margin-bottom: 16px;
  color: #1f2d35;
  font-size: 1.05rem;
}

.sidebar-progress-text {
  color: #516b7c;
  font-weight: 800;
}

.sidebar-module-list {
  padding: 0;
}

.sidebar-module {
  border-bottom: 1px solid #dbe4ed;
}

.sidebar-module-title {
  display: grid;
  gap: 3px;
  padding: 18px 24px 12px;
  color: #516b7c;
  letter-spacing: 0;
  text-transform: none;
}

.sidebar-module-title span {
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.sidebar-module-title strong {
  color: #1f2d35;
  font-size: 0.92rem;
  line-height: 1.3;
}

.sidebar-module-title small {
  color: #516b7c;
  font-size: 0.78rem;
  font-weight: 700;
}

.sidebar-lesson-link {
  display: grid;
  grid-template-columns: 28px 1fr;
  align-items: start;
  gap: 10px;
  padding: 11px 24px;
  color: #334e5f;
}

.sidebar-lesson-link:hover {
  background: #f7fafc;
}

.sidebar-lesson-link.active {
  background: #fff4ef;
  color: #c93f18;
  border-right: 4px solid #ff5c35;
}

.sidebar-lesson-link.locked {
  opacity: 1;
  color: #78909f;
}

.sidebar-lesson-link .lesson-dot {
  width: 28px;
  height: 28px;
  border: 1px solid #c9d6df;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  color: #334e5f;
  font-size: 0.68rem;
  font-weight: 900;
}

.sidebar-lesson-link.completed .lesson-dot {
  background: #1f9d72;
  border-color: #1f9d72;
  color: #ffffff;
}

.sidebar-lesson-link.active .lesson-dot {
  background: #ff5c35;
  border-color: #ff5c35;
  color: #ffffff;
}

.sidebar-lesson-copy {
  display: grid;
  gap: 3px;
  min-width: 0;
}

.sidebar-lesson-copy strong {
  color: inherit;
  font-size: 0.86rem;
  line-height: 1.35;
}

.sidebar-lesson-copy small {
  color: #516b7c;
  font-size: 0.75rem;
  font-weight: 700;
}

.resource-card,
.assignment-card,
.question-form,
.question-item {
  border: 1px solid #dbe4ed;
  border-radius: 8px;
  background: #ffffff;
  box-shadow: none;
}

.resource-card {
  padding: 16px;
}

.resource-icon,
.empty-state-icon {
  background: #eaf2f7;
  color: #334e5f;
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.assignment-card {
  background: #f9fbfd;
}

.file-upload-area {
  background: #ffffff;
  border-color: #c9d6df;
  border-radius: 8px;
}

.file-upload-icon {
  color: #334e5f;
  font-size: 0.8rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.notes-textarea,
.question-form textarea {
  border-color: #c9d6df;
  border-radius: 8px;
}

.notes-textarea:focus,
.question-form textarea:focus {
  border-color: #ff5c35;
  box-shadow: 0 0 0 3px rgba(255, 92, 53, 0.12);
}

@media (max-width: 1100px) {
  .lesson-layout {
    grid-template-columns: 1fr;
  }

  .lesson-sidebar-panel {
    top: 0;
    height: 100vh;
  }
}

@media (max-width: 768px) {
  .lesson-topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 12px 16px;
  }

  .lesson-nav-buttons {
    width: 100%;
    overflow-x: auto;
  }

  .lesson-main {
    padding: 24px 16px 40px;
  }

  .lesson-header {
    flex-direction: column;
  }

  .mark-complete-btn {
    width: 100%;
  }

  .lesson-tab {
    flex: 0 0 auto;
  }

  .lesson-tab-content {
    padding: 16px;
  }
}