.app-shell.riom-learning-platform {
  width: 100vw;
  height: 100dvh;
  overflow: hidden;
  position: relative;
  display: grid;
  grid-template-rows: var(--header-height) minmax(0, 1fr) var(--quick-actions-height);
  padding: 12px;
  gap: 12px;
}

.riom-app-header,
.riom-sidebar,
.learning-workspace,
.ai-workspace,
.quick-actions {
  min-width: 0;
  background: var(--surface);
  backdrop-filter: blur(18px);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-sm);
  border-radius: var(--radius-lg);
}

.riom-app-header {
  position: relative;
  z-index: 100;
  height: var(--header-height);
  min-height: var(--header-height);
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}

.riom-app-header__left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.riom-app-header__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-heading);
}

.riom-app-header__brand img {
  height: 24px;
}

.riom-app-header__center {
  font-size: var(--text-base);
  color: var(--text);
  font-weight: 500;
  flex: 1;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  padding: 0 16px;
}

.riom-app-header__right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.app-main {
  min-height: 0;
  display: flex;
  position: relative;
}

.main-workspace-container {
  display: grid;
  grid-template-columns: minmax(0, 1.8fr) minmax(340px, 1fr);
  gap: var(--main-gap);
  width: 100%;
  height: 100%;
}

.course-navigation-drawer {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 360px;
  max-width: min(390px, 94vw);
  height: 100%;
  max-height: 100%;
  transform: translateX(-110%);
  transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 110;
  background: var(--surface, #ffffff);
  border: 1px solid var(--line, rgba(23, 38, 70, 0.12));
  box-shadow: 0 16px 48px rgba(15, 31, 55, 0.18);
  border-radius: var(--radius-lg, 16px);
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  box-sizing: border-box;
}

.course-navigation-drawer[aria-hidden="false"] {
  transform: translateX(0);
}

.course-navigation-drawer__top {
  padding: 14px 16px 10px;
  border-bottom: 1px solid var(--line, rgba(23, 38, 70, 0.08));
  display: grid;
  gap: 10px;
  background: var(--surface, #ffffff);
}

.course-navigation-drawer__section-group {
  display: grid;
  gap: 4px;
}

.course-navigation-drawer__title-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2px;
}

.course-navigation-drawer__title-bar h2 {
  font-size: 1rem;
  font-weight: 800;
  margin: 0;
  color: var(--primary-strong, #081f45);
}

.course-navigation-drawer__title-bar .icon-button {
  background: transparent;
  border: none;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--text-muted, #72809a);
  cursor: pointer;
  padding: 0 4px;
  border-radius: 6px;
}

.course-navigation-drawer__title-bar .icon-button:hover {
  color: var(--primary-strong, #081f45);
  background: var(--surface-soft, #f1f5f9);
}

/* Focus Mode Header & Layout */
.course-navigation-drawer__focus-header {
  display: none;
  padding: 12px 16px 10px;
  border-bottom: 1px solid var(--line, rgba(23, 38, 70, 0.08));
  gap: 8px;
  background: var(--surface, #ffffff);
}

.course-navigation-drawer__focus-header[hidden] {
  display: none !important;
}

.course-navigation-drawer__focus-topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.course-navigation-drawer__back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: none;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary, #0b2c5d);
  cursor: pointer;
  padding: 6px 10px;
  border-radius: var(--radius-sm, 8px);
  transition: background 0.15s ease, color 0.15s ease;
}

.course-navigation-drawer__back-btn:hover {
  background: var(--surface-soft, #f1f5f9);
  color: var(--primary-strong, #081f45);
}

.course-navigation-drawer__focus-info {
  display: grid;
  gap: 2px;
}

.course-navigation-drawer__focus-course-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.course-navigation-drawer__focus-course-title {
  font-size: 0.95rem;
  font-weight: 800;
  color: var(--primary-strong, #081f45);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.course-navigation-drawer__content-area {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  min-height: 0;
  overflow: hidden;
  background: var(--surface-soft, #f8fafc);
}

.course-navigation-drawer__content-area.is-collapsed {
  grid-template-rows: auto;
  min-height: auto;
}

.course-navigation-drawer__content-panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.course-navigation-drawer__content-panel[hidden] {
  display: none !important;
}

/* Full Area Focus Mode */
.course-navigation-drawer.course-navigation-drawer--focus-mode {
  display: flex !important;
  flex-direction: column !important;
  height: 100% !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__top {
  display: none !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__focus-header {
  flex: 0 0 auto !important;
  display: grid !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode #riomDrawerContentTriggerWrap,
.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__section-header--blocks {
  display: none !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__content-area {
  flex: 1 1 0% !important;
  min-height: 0 !important;
  display: flex !important;
  flex-direction: column !important;
  overflow: hidden !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__content-panel {
  flex: 1 1 0% !important;
  min-height: 0 !important;
  display: flex !important;
  flex-direction: column !important;
  overflow: hidden !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__blocks {
  flex: 1 1 0% !important;
  min-height: 0 !important;
  overflow-y: auto !important;
  overscroll-behavior: contain !important;
}

.course-navigation-drawer.course-navigation-drawer--focus-mode .course-navigation-drawer__footer {
  flex: 0 0 auto !important;
  margin-top: auto !important;
}

.course-navigation-drawer__accordion-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: transparent;
  border: none;
  padding: 8px 16px;
  cursor: pointer;
  min-height: 44px;
  text-align: left;
  transition: background 0.15s ease;
  user-select: none;
}

.course-navigation-drawer__accordion-trigger:hover {
  background: rgba(23, 38, 70, 0.04);
}

.course-navigation-drawer__accordion-label {
  display: flex;
  align-items: center;
  gap: 8px;
}

.course-navigation-drawer__accordion-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted, #72809a);
  transition: transform 0.2s ease;
}

.course-navigation-drawer__accordion-trigger[aria-expanded="false"] .course-navigation-drawer__accordion-icon {
  transform: rotate(0deg);
}

.course-navigation-drawer__accordion-trigger[aria-expanded="true"] .course-navigation-drawer__accordion-icon {
  transform: rotate(90deg);
}

.course-navigation-drawer__blocks {
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 6px 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  scrollbar-gutter: stable;
}

.course-navigation-drawer__footer {
  padding: 12px 16px;
  border-top: 1px solid var(--line, rgba(23, 38, 70, 0.08));
  background: var(--surface, #ffffff);
  z-index: 2;
  display: flex;
  align-items: center;
}

@media (max-width: 768px) {
  .course-navigation-drawer {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: min(360px, 88vw);
    height: 100%;
    max-height: 100dvh;
    border-radius: 0 18px 18px 0;
    z-index: 1100;
  }

  .course-navigation-drawer__footer {
    padding-bottom: max(16px, env(safe-area-inset-bottom, 16px));
  }
}

.drawer-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.4);
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
  border-radius: var(--radius-lg);
}

.drawer-backdrop[aria-hidden="false"] {
  opacity: 1;
  pointer-events: auto;
}

.learning-workspace,
.ai-workspace {
  min-height: 0;
  height: 100%;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.ai-workspace {
  container-type: inline-size;
  container-name: assistant;
}

.learning-workspace__shell,
.ai-workspace__shell {
  min-height: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.learning-workspace__shell {
  padding: var(--learning-workspace-pad-desktop, 24px 28px);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-section-gap, 20px);
}

.learning-workspace__content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-section-gap, 20px);
}

.ai-workspace__shell {
  padding: 0;
}

.ai-workspace__header {
  padding: 12px 18px 8px;
  border-bottom: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.ai-workspace__titles {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.assistant-nav-tabs {
  display: flex;
  align-items: center;
  flex-wrap: nowrap;
  overflow-x: auto;
  gap: 6px;
  padding: 8px 18px 10px;
  border-bottom: 1px solid var(--line);
  background: var(--surface);
  scrollbar-width: none;
}

.assistant-nav-tabs::-webkit-scrollbar {
  display: none;
}

.ai-workspace__navigation {
  display: flex;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
  gap: 8px;
  padding: 16px 28px 18px;
}

#promptTabs:empty {
  display: none !important;
  margin: 0 !important;
  padding: 0 !important;
}

.ai-workspace__content-area {
  display: flex;
  flex-direction: column;
  flex: 1 1 auto;
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
  padding: var(--resource-panel-pad-desktop, 24px 28px);
  gap: var(--spacing-tabs-content, 20px);
}

.assistant-nav-divider {
  width: 40px;
  height: 1px;
  background: var(--line);
  border: none;
  margin: 0;
}

.ai-workspace__insights {
  display: flex;
  flex-direction: column;
}

.quick-actions {
  height: var(--quick-actions-height);
  min-height: var(--quick-actions-height);
  display: grid;
  grid-template-columns: auto auto minmax(220px, 1fr);
  align-items: center;
  gap: 10px;
  padding: 0 12px;
  overflow: hidden;
}

.learning-workspace__body {
  min-height: 0;
  overflow: auto;
  scrollbar-gutter: stable;
  padding-right: 4px;
  flex: 1;
}

/* Base states for mobile/drawer elements */
.riom-assistant-menu-sheet {
  display: none;
}