:root {
  color-scheme: light;
  --canvas: #ffffff;
  --surface: #ffffff;
  --support: #fafafa;
  --control: #f4f4f4;
  --hover: #eeeeee;
  --active: #e5e5e5;
  --selected: #ececec;
  --text: #202020;
  --muted: #666666;
  --focus: #202020;
  --danger: #a12b23;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  --radius: 6px;
  --target: 44px;
  --toolbar-height: 64px;
  --content-width: 1440px;
  --library-width: 360px;
  --layer-sticky: 2;
  --layer-skip: 10;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html,
body,
#root {
  min-width: 320px;
  min-height: 100%;
  margin: 0;
}

body {
  background: var(--canvas);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
}

#root {
  display: flex;
  height: 100dvh;
  flex-direction: column;
}

button,
input {
  font: inherit;
}

button,
[role="option"],
a[href] {
  cursor: pointer;
}

button:disabled,
[data-disabled] {
  cursor: not-allowed;
}

h1,
h2,
h3,
h4,
p {
  margin: 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  inset-block-start: var(--space-2);
  inset-inline-start: var(--space-2);
  z-index: var(--layer-skip);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius);
  background: var(--text);
  color: var(--surface);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: none;
}

.toolbar {
  display: flex;
  width: 100%;
  max-width: var(--content-width);
  min-height: var(--toolbar-height);
  flex: none;
  align-items: center;
  justify-content: flex-start;
  gap: var(--space-4);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

.wordmark {
  font-size: 14px;
  font-weight: 650;
  letter-spacing: -0.01em;
}

.quiet-button,
.clear-search,
.course-trigger,
.lesson-trigger,
.load-preview {
  border: 0;
  border-radius: var(--radius);
  background: transparent;
  color: var(--text);
}

.quiet-button {
  min-height: var(--target);
  padding-inline: var(--space-3);
  color: var(--muted);
}

.quiet-button[data-hovered],
.clear-search[data-hovered],
.course-trigger[data-hovered],
.lesson-trigger[data-hovered],
.load-preview[data-hovered] {
  background: var(--hover);
  color: var(--text);
}

.quiet-button[data-pressed],
.clear-search[data-pressed],
.course-trigger[data-pressed],
.lesson-trigger[data-pressed],
.load-preview[data-pressed] {
  background: var(--active);
}

.quiet-button[data-disabled] {
  color: var(--muted);
  opacity: 0.55;
}

.quiet-button[data-focus-visible],
.clear-search[data-focus-visible],
.course-trigger[data-focus-visible],
.lesson-trigger[data-focus-visible],
.load-preview[data-focus-visible],
.resource-item[data-focus-visible],
.source-link[data-focus-visible],
.search-field .react-aria-Input[data-focus-visible] {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.system-status {
  width: 100%;
  max-width: var(--content-width);
  flex: none;
  margin-inline: auto;
  padding: 0 var(--space-6) var(--space-3);
  color: var(--muted);
  font-size: 12px;
}

.system-status:empty {
  display: none;
}

.workspace {
  display: grid;
  width: 100%;
  max-width: var(--content-width);
  min-height: 0;
  flex: 1;
  grid-template-columns: minmax(280px, var(--library-width)) minmax(0, 1fr);
  gap: var(--space-16);
  margin-inline: auto;
  padding: 0 var(--space-6) var(--space-6);
  overflow: hidden;
}

.library,
.viewer {
  min-width: 0;
  min-height: 0;
  overflow: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
}

.search-wrap {
  position: sticky;
  inset-block-start: 0;
  z-index: var(--layer-sticky);
  padding-block: var(--space-2) var(--space-4);
  background: var(--surface);
}

.search-field {
  position: relative;
}

.search-field .react-aria-Input {
  width: 100%;
  min-height: var(--target);
  padding: 0 var(--space-12) 0 var(--space-3);
  border: 0;
  border-radius: var(--radius);
  background: var(--control);
  color: var(--text);
  outline: none;
}

.search-field .react-aria-Input[data-hovered] {
  background: var(--hover);
}

.search-field .react-aria-Input::placeholder {
  color: var(--muted);
  opacity: 1;
}

.clear-search {
  position: absolute;
  inset-block: var(--space-1);
  inset-inline-end: var(--space-1);
  width: 36px;
  padding: 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1;
}

.search-field[data-empty] .clear-search {
  visibility: hidden;
}

.course-tree {
  padding-block-end: var(--space-8);
}

.disclosure-heading {
  font: inherit;
}

.course-trigger,
.lesson-trigger {
  display: grid;
  width: 100%;
  min-height: var(--target);
  grid-template-columns: 14px minmax(0, 1fr);
  gap: var(--space-2);
  align-items: center;
  padding: var(--space-2);
  text-align: start;
}

.course-trigger {
  font-weight: 650;
}

.lesson-trigger {
  min-height: 40px;
  font-weight: 500;
}

.course-trigger > span:last-child,
.lesson-trigger > span:last-child {
  min-width: 0;
  overflow-wrap: anywhere;
}

.chevron {
  display: inline-grid;
  width: 14px;
  place-items: center;
  color: var(--muted);
  font-size: 18px;
  line-height: 1;
  transform: rotate(0deg);
  transform-origin: center;
}

.course-disclosure[data-expanded] > .disclosure-heading .chevron,
.lesson-disclosure[data-expanded] > .disclosure-heading .chevron {
  transform: rotate(90deg);
}

.course-disclosure + .course-disclosure {
  margin-block-start: var(--space-1);
}

.course-panel {
  padding-inline-start: var(--space-3);
}

.lesson-panel {
  padding-inline-start: var(--space-3);
}

.source-group {
  padding: var(--space-1) 0 var(--space-2) var(--space-2);
}

.source-group + .source-group {
  margin-block-start: var(--space-2);
}

.source-name,
.resource-kind {
  padding: var(--space-2) var(--space-2) var(--space-1);
  color: var(--muted);
  font-size: 12px;
  font-weight: 600;
  line-height: 1.35;
}

.resource-kind {
  font-weight: 400;
}

.resource-group + .resource-group {
  margin-block-start: var(--space-1);
}

.resource-list {
  padding: 0;
  outline: none;
}

.resource-item {
  display: flex;
  min-height: 40px;
  align-items: center;
  padding: var(--space-2);
  border-radius: var(--radius);
  color: var(--text);
  line-height: 1.35;
  overflow-wrap: anywhere;
  outline: none;
}

.resource-item[data-hovered] {
  background: var(--hover);
}

.resource-item[data-pressed] {
  background: var(--active);
}

.resource-item[data-selected] {
  background: var(--selected);
  font-weight: 600;
}

.resource-item[data-focus-visible] {
  outline-offset: -2px;
}

.quiet-state,
.preview-empty {
  padding: var(--space-3) var(--space-2);
  color: var(--muted);
}

.viewer {
  padding-block: var(--space-2) var(--space-8);
  scroll-margin-block-start: var(--space-4);
}

.preview-content {
  width: 100%;
  max-width: 960px;
}

.preview-stage {
  position: relative;
  display: grid;
  width: 100%;
  place-items: center;
  overflow: hidden;
  background: var(--support);
}

.preview-stage-video,
.preview-stage-external,
.preview-stage-message {
  aspect-ratio: 16 / 9;
}

.preview-stage-document {
  height: calc(100dvh - var(--toolbar-height) - var(--space-8));
  min-height: 520px;
}

.preview-stage video,
.preview-stage iframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
}

.load-preview {
  min-height: var(--target);
  padding-inline: var(--space-4);
  background: var(--control);
}

.media-message {
  padding: var(--space-6);
  color: var(--muted);
  text-align: center;
}

.media-status {
  position: absolute;
  inset-inline: var(--space-3);
  inset-block-end: var(--space-3);
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

.source-link {
  display: inline-flex;
  min-height: var(--target);
  align-items: center;
  margin-block-start: var(--space-2);
  padding-inline: var(--space-1);
  color: var(--muted);
  font-size: 12px;
  text-decoration: none;
}

.source-link[data-hovered] {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.route-error {
  display: flex;
  min-height: 240px;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  color: var(--muted);
}

@media (max-width: 1040px) {
  :root {
    --library-width: 320px;
  }

  .workspace {
    gap: var(--space-8);
  }
}

@media (max-width: 760px) {
  :root {
    --toolbar-height: 56px;
  }

  html,
  body,
  #root {
    height: auto;
  }

  #root {
    min-height: 100dvh;
  }

  .toolbar {
    padding-inline: var(--space-4);
  }

  .system-status {
    padding-inline: var(--space-4);
  }

  .workspace {
    display: block;
    flex: none;
    padding: 0 var(--space-4) var(--space-12);
    overflow: visible;
  }

  .library,
  .viewer {
    overflow: visible;
    scrollbar-gutter: auto;
  }

  .library {
    max-height: 52dvh;
    overflow: auto;
    overscroll-behavior: contain;
  }

  .viewer {
    padding-block-start: var(--space-6);
  }

  .preview-stage-document {
    height: 70dvh;
    min-height: 440px;
  }

  .course-panel,
  .lesson-panel,
  .source-group {
    padding-inline-start: var(--space-2);
  }
}

@media (prefers-reduced-motion: reduce) {
  .chevron {
    transition: none;
  }
}

@media (forced-colors: active) {
  .resource-item[data-selected] {
    outline: 2px solid Highlight;
    outline-offset: -2px;
  }
}